have they found anything?

[amb]

I doubt very much that there may be hundreds or thousands Intelligent ETs in our galaxy.
If that is so, I ask like Fermi did. Where are they? Why aren't they here. Not one single one has so far been detected unless you believe the UFO garbage that still a fair few people seem to believe.

My stand is that because of the sheer number of stars out there, there is bound to be other intelligent lifeforms of some kind out there, but nowhere as many as people think.
I will stick my neck out and say that perhaps there may be up to 1000 at most. Living in the 10% of the habital zone of a spiral galaxy like our own. That's in the whole cosmos as far as we can detect it.
Don't forget, I'm talking about intelligent life like homo sapiens, not anything higher than primates.

[JoeTheJuggler]

I doubt very much that there may be hundreds or thousands Intelligent ETs in our galaxy.
But, don't you agree that there may be?

If not, then you're really arguing that we are unique and not that we may be unique.

This is a point I've been harping on for a while. We really don't know. I agree that we may be unique, but we also may be one of several or even one of many. If you deny the latter two positions, you're arguing that we ARE unique.

If that is so, I ask like Fermi did. Where are they? Why aren't they here. Not one single one has so far been detected unless you believe the UFO garbage that still a fair few people seem to believe.
Asked and answered. I even numbered my points, any one of which defeat this lame-ass argument. Don't bring it up unless you can address the objections I've already raised.

By the way, according to this lame-ass argument, we don't exist because we aren't everywhere in the galaxy ourselves. In fact, we're not detectable by our own technology outside of our own solar system. Yes--the "Why aren't they here?" approach is a pretty poor argument, because we do in fact exist even though we occupy only an infinitesimally small part of the galaxy.


My stand is that because of the sheer number of stars out there, there is bound to be other intelligent lifeforms of some kind out there, but nowhere as many as people think.
But what if people think (as the majority do), "We don't know"? How you can you say there are fewer than that?

I will stick my neck out and say that perhaps there may be up to 1000 at most. Living in the 10% of the habital zone of a spiral galaxy like our own. That's in the whole cosmos as far as we can detect it.
Don't forget, I'm talking about intelligent life like homo sapiens, not anything higher than primates.
Again, you're using "may be" as a hedge. If you can't admit there may also be a great many more, then I think the "may be" is just there to make your argument easier to defend.

By the way, the idea that only 10% of a galaxy like our own is habitable is unfounded speculation. It too has already been answered.

[amb]

But, don't you agree that there may be?

If not, then you're really arguing that we are unique and not that we may be unique.

This is a point I've been harping on for a while. We really don't know. I agree that we may be unique, but we also may be one of several or even one of many. If you deny the latter two positions, you're arguing that we ARE unique.
I would be a fool to argue against that. I could be completely out of sync with common wisdom. There may well be trillions of intelligent lifeforms in the whole cosmos. Like you say, we just don't know and unfortunately will never know in our lifetimes anyway.
But, and that's a big but. We still have no idea how or where the first cell managed to assemble itself. Better still, where did all the molecules that make up a cell start to replicate themselves? Yes I know biologists have a very good idea, but not a certain theory. Some say the elements were carried to Earth in comets ect. But if life didn't originate on Earth, all they're doing is shifting the origins elsewhere.
It must be admited that the very origin of life is like throwing a set of sixes in dice a thousand times straight.

[LarianLeQuella]

It must be admited that the very origin of life is like throwing a set of sixes in dice a thousand times straight.


Why must it be admitted to be such a longshot if we don't actually know for sure? I don't get it. If anything, the chemical processes seem actually downright simple and very natural. It's the latter steps that brought the universe humans that have a lot more uncertianty due to our single datapoint.

Depending on your age, we may actually know a lot more depending on the findings of Kepler.

[JoeTheJuggler]

We still have no idea how or where the first cell managed to assemble itself.
That's not true.

I offered a couple of links earlier that show we have fairly good ideas about how cells first came about. As I pointed out, natural selection kicks in about as soon as you've got a self-replicating molecule. From there on, any change that is advantageous (to reproduction) will be "selected". Variants with changes that are disadvantageous won't reproduce as successfully and disadvantageous changes will tend to disappear.

Evolution by natural selection. It really does explain how you get from a self-replicating molecule to complex organisms (including humans).

[JoeTheJuggler]

I would be a fool to argue against that. I could be completely out of sync with common wisdom. There may well be trillions of intelligent lifeforms in the whole cosmos. Like you say, we just don't know and unfortunately will never know in our lifetimes anyway.
We may never know, but then again we might find out. That's also part of what not knowing means.

Yes I know biologists have a very good idea, but not a certain theory.
No special theory is necessary. Chemistry already explains how you can get self-replicating molecules. The process has been done in the lab. From there on, natural selection explains it.

Some say the elements were carried to Earth in comets ect. But if life didn't originate on Earth, all they're doing is shifting the origins elsewhere.
Yes--so this notion of life being seeded from elsewhere is not necessary (it lacks parsimony) and it fails to address the question you asked--wrt abiogenesis. So the fact that some minority of biologists think it's likely is irrelevant.

It must be admited that the very origin of life is like throwing a set of sixes in dice a thousand times straight.
Nope--not at all. Chemistry happens all the time. That's all that was required to get a self-replicating molecule. As previously shown, from there on, life adapts to fit the conditions and not the other way around.

If you google the words spontaneous assembly protein (or polypeptide), you'll see paper after paper detailing these processes.

[amb]

It really is a fascinating subject isn't it? There is little doubt that the discovery of a single extraterrestial microbe, if it could be shown to have evolved independently of life on Earth, would drastically alter our world view and change our society as profoundly as the Copernican and Darwinian revolutions. It could truly be described as the greatest scientific discovery of all time. The effects on mankind would be awesome.
It would answer the greatest of questions. Has life spread from a single source or arisen in several places independently? An improbable accident or an inevitable result of the laws of biology and physics?

[JoeTheJuggler]

It really is a fascinating subject isn't it? There is little doubt that the discovery of a single extraterrestial microbe, if it could be shown to have evolved independently of life on Earth, would drastically alter our world view and change our society as profoundly as the Copernican and Darwinian revolutions. It could truly be described as the greatest scientific discovery of all time. The effects on mankind would be awesome.
It would answer the greatest of questions. Has life spread from a single source or arisen in several places independently? An improbable accident or an inevitable result of the laws of biology and physics?

I think it's a fascinating subject, and I'm thrilled to live at a time when some of these questions can be answered, BUT, I don't think finding an alien microbe would revolutionize science. In fact, I think it fits in with the conventional view.

I also don't think the question of whether abiogenesis happened in one place and spread or happened in more than one place is the "greatest of questions". (I can think of a few that would top that!)

I completely disagree that life as the result of "an improbable accident" or "the inevitable result of the laws of biology and physics" is a legitimate question. Neither one is a testable question. Science doesn't deal in things like the intention of the universe--which is really what you're implying.

Stuff happens in nature, and we can discern rules that describe these events. To call something "an improbable accident" or "inevitable" suggests something beyond science.

Have you heard of the Texas Sharpshooter Fallacy? You shoot a small bullet from a long range into the side of a barn. Then you locate the hole the bullet made and draw a tiny circle around it. Then you ask what are the odds against that bullet landing right inside that circle. Was the bullet hitting exactly that spot "an improbably accident" or was it "inevitable"? I think it's neither, and those questions are silly.

[amb]

Yes I agree with you to a certain extent.
But do you believe that if the tape of the history of the universe is re-played from the B/B to today, things would be exactly as they are now? What if there was a slight weakening or strengthening of gravity? My point been, all the parameters for the evolution of the universe and eventualy us are seemingly part of this universe in a possible multi-verse of which we are one out of perhaps billions of other universes.
Occam's Razor makes this theory very possible in explaining our origins.
We may be living in the only habitual universe out of billions.

[JoeTheJuggler]

Yes I agree with you to a certain extent.
But do you believe that if the tape of the history of the universe is re-played from the B/B to today, things would be exactly as they are now?
No, but that's just like saying if the sharpshooter took a second shot, he's extremely unlikely to hit the same bullet hole. Do you see the problem with that way of thinking?


What if there was a slight weakening or strengthening of gravity? My point been, all the parameters for the evolution of the universe and eventualy us are seemingly part of this universe in a possible multi-verse of which we are one out of perhaps billions of other universes.
Occam's Razor makes this theory very possible in explaining our origins.
We may be living in the only habitual universe out of billions.
This is the fine-tuning argument, and it really makes no sense at all.

It pretty much just says that if things were different they wouldn't be the same. Our universe seems to be fine-tuned to chemistry and life as we know it. But it's actually the other way around. (You seem to be stuck on this backward way of thinking that leads you to believe that a rare set of coincidences is necessary for things to happen.)

Even if any of the multiverse speculations (which have exactly zero empirical evidence to support them) are true, a universe with different constants than ours would be an unimaginably different universe than ours. While we couldn't exist in one of them, it doesn't mean that they need be uninhabitable.

BTW, hypothetical multiverse very clearly does violate Occam's razor. Occam's razor specifically states that you should not create unnecessary entities to explain something. The multiverse stuff is exactly that--unnecessary entities. It's fine for working on mathematical models, or speculation or sci-fi, but it really has nothing to do with the empirical world.

But if you are going to play around with that notion, there's surely no reason to say that ours is the only inhabitable one. We can't possibly have enough information to reach that conclusion.

[LarianLeQuella]

We may be living in the only habitual universe out of billions.

As Joe said, this is the finetuning argument. Although, one of the funny things that happens with a lot of people who make this argument is that they change one variable independent of the others. It has been shown that if the variables are changed along with each other, you can get an infite number of different configurations that would also "theroretically" support complex chemistry, and then the whole debate starts over.

I do need to dissagree with Joe on the multi-verse not being an extension of Occams razor though. While it may seem more complex from an intuitive point of view, mathematically it may be simpler. Sort of how anti-particles were discovered/therorized as a result of Dirac's equation. It may seem complex, but in the end it may indeed be the simplest answer from a cosmological sense. The universe is under no obligation to follow our conventions you know. :)

[JoeTheJuggler]

I do need to dissagree with Joe on the multi-verse not being an extension of Occams razor though. While it may seem more complex from an intuitive point of view, mathematically it may be simpler. Sort of how anti-particles were discovered/therorized as a result of Dirac's equation. It may seem complex, but in the end it may indeed be the simplest answer from a cosmological sense.
It is, nonetheless, the creation of new entities for which there is absolutely zero empirical evidence. That it satisfies some mathematical model is hardly evidence of the existence of the extra entities. (Mathematical models are themselves more like hypotheses. If there is no evidence to support them, there's no reason to think they're true.) And there's certainly no reason to assume other universes exist and then make arguments about the likelihood that of us being in the universe we're in.

The universe is under no obligation to follow our conventions you know. :)
I'm not sure what you mean here. The convention I'm referring to (Occam's razor) is about the way we come up with hypotheses. Otherwise, I'm pointing out that basing an argument (like the fine tuning argument) on the existence of entities for which there is no empirical evidence, is just silly.

The multiverse hypothesis might someday be testable, but--at least as far as I know--it is not right now.

But this topic probably should be on its own thread.

[amb]

The mystery of life's origin remains. I understand that if the conditions are right, life will somehow find a way to start evolving. But we still have no idea how the first molecules or elements came together to produce the first DNA, or the first RNA.
I read in my local newspaper that some scientists have stated that the production of living lifeforms in a laboratory is only around 5-10 years away, which will prove useless to this discussion as it is already existing life that is doing the experiments.
The greatest discovery in my humble opinion will be the discovery of how exactly did life originate. I know I sound like a ID believer. Nothing is further from the truth. I'm a militant atheist. A member of Atheist_Australia.

[JoeTheJuggler]

But we still have no idea how the first molecules or elements came together to produce the first DNA, or the first RNA.
That's not true.

We have some very good ideas of how that process works. I linked to some pretty good sources (see above) explaining some of these ideas --spontaneous amino acid and protein formation, etc.

And again, once you get a self-replicating molecule, natural selection can go to work.

It is not a mystery. We have a very good idea of how it probably happened.

The greatest discovery in my humble opinion will be the discovery of how exactly did life originate.
Short of time travel, I don't think that will ever exist as certain knowledge. We've already got a lot of evidence that supports the ideas I've outlined.

You know there are people who claim that fossil fuels, petroleum in particular, aren't actually formed by fossil processes? Their argument is similar to the one you're making--since we can't know exactly what happened, their abiotic theory of the origin of petroleum is equally valid. Of course, that's nonsense. We don't have to know something exactly or for certain in order to be reasonably confident by the bulk of the evidence that we are probably right, and that other ideas (that have little to no evidence) aren't equally valid.

[LarianLeQuella]

Before I derail, AMB, have you seen the articles on the fols making artificial life? I think those are helping us with a lot of insight into the how of the first RNA and DNA.

I'm not sure what you mean here.

Sorry, it made perfect sense in my brain when I typed it. Before Dirac wrote his equations, coming up with the notion of Anti-matter was probably outlandish and downright in te realm of fantasy. Now we accept anti-matter pretty much out of hand. I'm not saying that our current mathematics and understanding are at that level, and as you said, it is way beyond any testable hypotheses. However, anti-matter would seem as a bad a violation of Occam's prior to Dirac as multiverses are to us now. Maybe I'm not explaining my train of thought very well. It just seems that Occam's razor philosophy is being violated because we're ignorant? How's that?

And you are right, that is probably somethig for another thread... although... What about intelligences in those universes? If they are there, does the absense of any sort of inter-univers travellers indicates that such a possibility is rought out (infinite universes, infinite time?), or is this universe somehow unique? Oh, great, now we have a unique planet in a unique universe? WTF? :p (Personally, I'd say that our best understanding would indicate the former, not the latter by the way, but that's like a Homo habilis contemplating the LHC I suppose.)

[JoeTheJuggler]

I agree with your overall point about the fine-tuning argument. Basically, who says the constants of our universe are the only ones that can possibly sustain life?

Leaving the question of a multiverse for a moment, you get the same notion with amd's question that is basically, "If you ran the Big Bang over again, what are the odds against getting this exact universe?" The only thing special about our universe (in that sense) is that it's the one that happened. Just like the only thing special about the place the bullet hit is because we drew a circle around it after the fact.

[amb]

That's not true.

We have some very good ideas of how that process works. I linked to some pretty good sources (see above) explaining some of these ideas --spontaneous amino acid and protein formation, etc.

And again, once you get a self-replicating molecule, natural selection can go to work.

It is not a mystery. We have a very good idea of how it probably happened.


Short of time travel, I don't think that will ever exist as certain knowledge. We've already got a lot of evidence that supports the ideas I've outlined.

You know there are people who claim that fossil fuels, petroleum in particular, aren't actually formed by fossil processes? Their argument is similar to the one you're making--since we can't know exactly what happened, their abiotic theory of the origin of petroleum is equally valid. Of course, that's nonsense. We don't have to know something exactly or for certain in order to be reasonably confident by the bulk of the evidence that we are probably right, and that other ideas (that have little to no evidence) aren't equally valid.

I have read somewhere that fossil fuels are produced by the same processes that formed our planet over 4 billion years ago, not fossils at all.
And the scientist who came up with that idea [Andrew Gold ?] has never been wrong in all his research throughout his life.

[JoeTheJuggler]

I have read somewhere that fossil fuels are produced by the same processes that formed our planet over 4 billion years ago, not fossils at all.
And the scientist who came up with that idea [Andrew Gold ?] has never been wrong in all his research throughout his life.

Did you perhaps miss my point?

[amb]

You point been that until a theory is peer reviewed and proven beyond any doubt, we are all whisteling in the dark. or better still, winking at a pretty woman in the dark. You know what you're doing, but no one else does.

[LarianLeQuella]

Theories NEVER get proven beyond a doubt though. In order for it to be a valid theory, it has to be falsifiable. :) I like your analogy, but it's more out of a basis of ignorance as opposed to proven and peer reviewed. That said:

- We only have one data point, and even our understanding of that datapoint is incomplete.
- We ARE constantly surprised by how life DOES thrive in areas we would have ruled out life just a few dacades ago (boiling vents, radioactive mines, toxic pools, etc.).
- We have only searched an infitesemally teeny, tiny part of our galazy for planets.
-- Even with our methodology of only really being able to find big ones that are close to their stars, by golly we've found quite a few!
- Nearly everywhere we look, we see a lot of building blocks to make the stuff of life as we know it.
- We are just not starting to understand and figure out some of the starting processes
-- We DO understand evolution quite well though.

Given this incomplete list, I totally agree that we really don't know one way or another. However, given the stuff we DO know, the scales are tilting towards there being more out there, rather than less. Should we find evidence of life (past or even present) on Mars, Europa, or anywhere else in our own solar system, then the scales would tilt toward even more (especially if Martian or Europan life is totally independent of our own abiogenesis). Now, I will admit that I have a personal preference toward a universe and galaxy teeming with life, and even intelligent life, but I will settle for "We don't know" at this point. Just saying intelligent life then devolves into a debate of what it means to be intelligent, and even the very nature of life.

Kepler may help us with finding out more about the likelyhood of planets that match our ONE datapoint, but we are rather hamstrung by our lack of data at this point, so if nothing else, it behooves us to search for as much data as we can in all the nooks and crannies.

[JoeTheJuggler]

You point been that until a theory is peer reviewed and proven beyond any doubt, we are all whisteling in the dark. or better still, winking at a pretty woman in the dark. You know what you're doing, but no one else does.
You did miss my point, then.

You said
The greatest discovery in my humble opinion will be the discovery of how exactly did life originate.

My response was basically to say that we already know that to some degree of confidence and with some level of detail, and that short of time-travel we probably won't get much more certain than we are now.

[JoeTheJuggler]

- We ARE constantly surprised by how life DOES thrive in areas we would have ruled out life just a few dacades ago (boiling vents, radioactive mines, toxic pools, etc.).
Speaking of this, there was a story in the CNN headlines (http://www.cnn.com/2009/TECH/science/03/17/india.bacteria/index.html) just today:
Indian scientists have discovered three new species of bacteria in Earth's upper stratosphere that are resistant to ultraviolet radiation, researchers said.

Gee, who would have thought life could evolve to be resistant to UV radiation? Oh wait, I speculated that that might be possible on this very thread some pages ago in answer to the Rare Earth argument that there's too much UV for life to exist nearer the galactic center.


Kepler may help us with finding out more about the likelyhood of planets that match our ONE datapoint, but we are rather hamstrung by our lack of data at this point, so if nothing else, it behooves us to search for as much data as we can in all the nooks and crannies.
Amen.

[LarianLeQuella]

Amen.

Ramen! :D

[JoeTheJuggler]

We still have no idea how or where the first cell managed to assemble itself. Better still, where did all the molecules that make up a cell start to replicate themselves? Yes I know biologists have a very good idea, but not a certain theory.

The mystery of life's origin remains.

Here's a very accessible explanation of why you're wrong in these assertions:

U6QYDdgP9

[amb]

You did miss my point, then.

You said


My response was basically to say that we already know that to some degree of confidence and with some level of detail, and that short of time-travel we probably won't get much more certain than we are now.
I believe that in the not to distant future scientists will explain exactly how it happened. How exactly all the elements started to replicate.
Here's a very accessible explanation of why you're wrong in these assertions:

U6QYDdgP9
The video for some reason would not play on my screen.

[JoeTheJuggler]

I believe that in the not to distant future scientists will explain exactly how it happened. How exactly all the elements started to replicate.
Or in the recent past. (BTW, I don't think you meant "the elements".)

The video for some reason would not play on my screen.

Sorry--I must've messed up the link. I thought I tested it. Too late to edit it now.

Here it is:

U6QYDdgP9eg

[amb]

Great video. But as you know, I'm not argueing about the origins of life. I'm arguing about intelligent human life. That video explains the enormous amount of time it takes for life to evolve into Earthlike life. The fact still remains that 95% of stars are less massive than our sun. The reminder are to massive and will burn themselves out billions of years before any planet orbiting them can produce any advanced life. In fact, Earth life could only ever live on the tiniest fraction of the planets in the universe. Not only are Earthlike planets likely to be very rare; so are sunlike stars.
I will repeat that the cosmos is more than likely teeming with very primitive life, but intelligent life is very rare.
Also, not all galaxies have properties that are conductive to Earthlike life. Globular clusters, small galaxies, and elliptical galaxies are metal poor. Not every galaxy in the universe may have planets and other conditions necessary for life.[ as we know it]
The large moon hypothesis has as yet not been disproved as a requisite to stabilise the Eaths orbit and tilt to give us the seasons.
If all this was created by a god, which I completely reject, then perhaps people like physicist Paul Davies who collected a Templeton Prize may be correct in that the cosmos is designed for life, and knew we were coming.

[JoeTheJuggler]

Great video. But as you know, I'm not argueing about the origins of life.
Except that you said the following:

The mystery of life's origin remains. I understand that if the conditions are right, life will somehow find a way to start evolving. But we still have no idea how the first molecules or elements came together to produce the first DNA, or the first RNA.

It would answer the greatest of questions. Has life spread from a single source or arisen in several places independently? An improbable accident or an inevitable result of the laws of biology and physics?

I believe that in the not to distant future scientists will explain exactly how it happened. How exactly all the elements started to replicate.

I'm arguing about intelligent human life.
You get from the simplest cells to human life by evolution. Also no mystery. Evolution tells us that life will end up adapted to the environment, not the other way around.



That video explains the enormous amount of time it takes for life to evolve into Earthlike life.
I suggest you watch it again. It said time is one of the things that there is plenty of. So when you've got chemistry happening, and lots of time for it to happen in, you can easily get one of these self-copying molecules. (ETA: See below--enormous amount of time as compared to the length of time, for example, the Urey-Miller experiment ran.)

The fact still remains that 95% of stars are less massive than our sun. The reminder are to massive and will burn themselves out billions of years before any planet orbiting them can produce any advanced life. In fact, Earth life could only ever live on the tiniest fraction of the planets in the universe. Not only are Earthlike planets likely to be very rare; so are sunlike stars.
There are still billions of stars like our own. Even so, you're confusing probably tens of billions of years with millions or hundreds of millions of years. When the video talked about a long time for chemistry to come up with a self-replicating molecule, that "long time" means compared to the time we run lab experiments.


I will repeat that the cosmos is more than likely teeming with very primitive life, but intelligent life is very rare.
Yes, I know your position. Too bad you have nothing to support it.


Also, not all galaxies have properties that are conductive to Earthlike life. Globular clusters, small galaxies, and elliptical galaxies are metal poor. Not every galaxy in the universe may have planets and other conditions necessary for life.[ as we know it]
All of these have been asked and answered. There is sufficient heavier elements pretty much everywhere in our galaxy.


The large moon hypothesis has as yet not been disproved as a requisite to stabilise the Eaths orbit and tilt to give us the seasons.
But you're the one making the claim. It's not up to me to "disprove" your speculation, though I've shown already that I can speculate the opposite case. Seasons, for example, are certainly not necessary for complex life. (I once read a sci-fi story where interstellar explorers had landed on a lush planet and were testing, measuring and sampling life, when a month or so later, everything withered and died. They assumed that they'd introduced a horrible pathogen despite their precautions. Turns out, the planet was the Earth, and all that happened was winter.)

As for "stablizing" the orbit--I asked you earlier if you think it's impossible to have a stable orbit without a large moon. Do Venus and Mars have unstable orbits?


If all this was created by a god, which I completely reject, then perhaps people like physicist Paul Davies who collected a Templeton Prize may be correct in that the cosmos is designed for life, and knew we were coming.
Yes, I've already noted that the approach you're taking (the Fine-Tuning argument, the backward approach that conditions must be fitted to life, rather than the other way around) is consistent with Creationism more than it is with science.

[LarianLeQuella]

I'm arguing about intelligent human life.

(Emphasis mine) Well, THERE'S the problem! :p
I would argue that human's aren't that intelligent to start with, so we have a bit of a paradox to deal with!

Okay, my lame attempts at humour aside, let's address this line though. Why is a humanlike intelligence the only measure of intelligence? Sure, it's the only datapoint we are aware of, which I contend has limited us in our ability to conceive of any other types. We are arguing out of ignorance.

I can agree that the rare earth/large moon hypotheses does apply for ONE instance. OURS. That's it! You cannot reliably argue that it applies to any other potential intelligent life since we just don't have any data either way. The rare earth/large moon is true for us because we're here though, not the other way around as far as we can reliably determine.

[amb]

L L Q is right. We only have one example at present and all our discussions are based on this premise. And life on this one example has been proven to exist in the most inhospitable places on Earth, like deep sea vents where the temperatures is thousands of degrees fahrenheit and a complete lack of sunlight or oxygen.
And under the ice of Antarctica. So primitive life is more than likely teeming in the universe.
That Earth life has developed to homo sapiens stage only where conditions are suitable and the migrated to more extreme locations like the Arctic Circle and Sahara regions only once it became well established. These are the conditions necessary for Earth like life. In our solar system, Earth is the only place where this became possible.
Other solar systems would need the same, or as close as possible conditions to develop intelligence.

[JoeTheJuggler]

L L Q is right. We only have one example at present and all our discussions are based on this premise. And life on this one example has been proven to exist in the most inhospitable places on Earth, like deep sea vents where the temperatures is thousands of degrees fahrenheit and a complete lack of sunlight or oxygen.
And under the ice of Antarctica. So primitive life is more than likely teeming in the universe.
You are making conclusions far beyond the dataset. You have no idea what life is like elsewhere in the universe.

That Earth life has developed to homo sapiens stage only where conditions are suitable and the migrated to more extreme locations like the Arctic Circle and Sahara regions only once it became well established. These are the conditions necessary for Earth like life. In our solar system, Earth is the only place where this became possible.
Other solar systems would need the same, or as close as possible conditions to develop intelligence.
That's fine, if you're talking about homo sapiens evolving elsewhere in the galaxy. But SETI is the search for ANY extra-terrestrial intelligence.

Again, you're still thinking of the relationship between complex life and conditions in a backward way (the same way Creationist do when they make the Fine-Tuning argument). Life adapts to conditions, not vice-versa.

[LarianLeQuella]

Other solar systems would need the same, or as close as possible conditions to develop intelligence.

Because of how varied and surprising life is HERE, I fundamentally disagree with that statement. To go from simple life steps to some sort of intelligence is an unknown process except for what we have here. We as human beings are even MORE hampred by our one data point. I have no idea what other solar systems would need to come up wth an alien intelligence. That is the point I am trying to make (and I think Joe is too). We just don't have the data, what so ever. I think that the universe wil surprise us, like it has on our humble rock. ;)

[amb]

Seti is the search for intelligent life elsewhere in the cosmos. Whatever the imagined possibilities, the strong conclusion is that we can only live on this blue speck in a vast universe. perhaps many similar blue specks exist throughout the universe, but homo sapiens is unlikely to ever find them. In that regard I agree with physicist Paul Davies.
Our species is probably marooned in space, on spaceship Earth, and likely to become extinct long before the sun burns its last hydrogen atom. Or long before we ever can make contact with another intelligent species, whether Earth Like or not.
So far our most powerful instruments have only ever seen chaos in the universe. That there must be tiny specks of Oder and complexity out there is not deniable as we live in such a place and there has to be places in all this chaos where life has evolved even beyond our wildest dreams. But all this is not a given. My often repeated argument that out of the billion or so lifeforms that have ever lived on this planet, only one has built a technology that enables even this discussion.

[JoeTheJuggler]

Seti is the search for intelligent life elsewhere in the cosmos. Whatever the imagined possibilities, the strong conclusion is that we can only live on this blue speck in a vast universe.
This doesn't make sense. The fact that most of the universe (including the near vacuum of space) is hostile to human inhabitation, is NOT a conclusion of the SETI program.


So far our most powerful instruments have only ever seen chaos in the universe.
That's also a false statement (even assuming "chaos" is being misused here to mean "nothing like an Earth-like planet"). We have detected hundreds of extrasolar planets, some of them in the "superEarth" mass range. However, the area where it's possible (so far) for us to detect those planets is a teeny tiny part of our galaxy.

Otherwise, we have detected various levels of organization of matter (as small as planets and as large as the frothy bubble structure at the largest scale--that is, above the level of super cluster of galaxies).

That there must be tiny specks of Oder and complexity out there is not deniable as we live in such a place and there has to be places in all this chaos where life has evolved even beyond our wildest dreams. But all this is not a given. My often repeated argument that out of the billion or so lifeforms that have ever lived on this planet, only one has built a technology that enables even this discussion.
Aside from the fact that you're misusing the terms "Order" (capitalized for no reason) "complexity" and "chaos". . .

so what? We know the mental capacities that allow this (or any other discussion) exists on a continuum among life forms on Earth. We know that those traits are all well explained by the theory of evolution.

Even so, you're making conclusions far beyond the dataset if you use that to make assertions about the rest of the universe.

And finally, even if you want to engage in speculation (by filling in values in the Drake Equation, for example), changing an approach to technological intelligence on Earth being 1:1 (that is 1 per planet) to 1: billions (1 per all the species on Earth), doesn't help your argument at all. I've already pointed this out.

[amb]

This answer was voted the best on a site called Ask. To the question; is there life in the cosmos.

well
lets see
lets say we have 100,000,000,000 stars in our galaxy (an aprox made by NASA)

and there are about 100,000,000,000 galaxies out there with as many stars as us. ( a low guess on my part )

so that gives us
10 000 000 000 000 000 000 000
stars out there

since we have not found life on any other planet yet.
we don't have an accurate guess at the probability for life on a planet.

we seem to be 1 in 10 000 000 000 000 000 000 000
thats way less than 1 percent. its trilllions of times smaller than 1 % its 0.0 000 000 000 000 000 000 001

(I) think we have at least a .00001 chance of life out there.
that gives us 100 000 000 000 000 000 chances of life out there in those stars

@ 1% we have
100 000 000 000 000 000 000 chances of

yes. I don't know if I buy the drake equation either.
but I know mine is just as bad

[Lonewulf]

How many other planets do we know of, and how many have we deeply probed for life?

[JoeTheJuggler]

since we have not found life on any other planet yet.
we don't have an accurate guess at the probability for life on a planet.

I agree completely with this.

Any other conclusion is just speculation. Not that there's anything wrong with speculation, but as Carl Sagan said in the quote I offered earlier, "Really, it's okay to reserve judgement until the evidence is in."

I reject anyone's assertion that they have a good idea of the incidence of ET intelligence in the universe (or galaxy).

ETA:
For example, this bit:
we seem to be 1 in 10 000 000 000 000 000 000 000
thats way less than 1 percent. its trilllions of times smaller than 1 % its 0.0 000 000 000 000 000 000 001

. . is just a number pulled out thin air and means nothing. (As Lonewulf points out, we haven't discovered and determined as lifeless anywhere near that many planets.)

[JoeTheJuggler]

How many other planets do we know of, and how many have we deeply probed for life?
A couple hundred (and growing quickly) and zero, respectively.

That "couple hundred" comes from a tiny sphere in our immediate vicinity--a teensy part of our galaxy.

[JoeTheJuggler]

This was from much earlier in the thread, but perhaps it's time to review this and see which, if any, of these points you're prepared to reject yet.


Here is my list of why I believe we may be unique in this galaxy at least.
1. Right distance from our sun.
2. Right planetary mass.
3. Plate tectonics.
4. Right mass of our star.
5. Jupiter-like neighbor.
6. Oceans, [ not to much. Not to little.]
6. Stable planetary orbits. [ Giant planets do not create orbital chaos.]
7. A Mars. [Small neighbor as possible life source to seed an Earth like planet, if needed.]
8. And last but by no means least. A large Moon. [At a very right distance to stabilize the Earths tilt.]
9. Seasons not too severe.
10. Our atmosphere.
11. Right position in galaxy. [ not in center, edge or halo.]
12. The exact amount of carbon. [ Enough for life. Not enough for runaway greenhouse as Venus has]
13. Evolution of oxygen. [Invention of photosynthesis. Not too much or too little. Evolves at the right time.]
14. Wild cards. [Snowball Earth. Cambrian explosion. Inertial interchange event.]
Among many other reasons. We still don't know exactly where life began. Was the Earth seeded by asteroids or meteorites? Did it start here in a million coincidences with inorganic elements somehow becoming organic and then evolution taking over to produce what now exists on Earth?
When I was a kid, I always believed that if life [ especially intelligent life] was abundant in the universe, then there was a god. If not, we are an accident or a freak of the laws of physics.

1 and 2 are generally OK, though we don't know for sure that Earth-like planets are the only places complex life might arise. (As I mentioned, there are large satellites of gas giants; the twilight zones of planets around red dwarfs, or stuff we haven't thought of.)

3. How are plate tectonics a requirement? Also, do you have any idea of how common tectonic activity is on other planets? (From what we've seen in our own solar system, it seems to be relatively commonplace.)

4. As noted, that's a great big maybe, but I'm fine with focusing our search on stars like Sol. There are billions of these in our galaxy alone.

5. I've addressed this bit of speculation already. It could well be that lack of a Jupiter-like neighbor could result in MORE chances of evolving intelligence. Besides that, do you have any notion that gas giants are scarce? (In fact, the evidence points to the opposite conclusion.)

6. The presence of liquid water is pretty much included in assumptions 1 and 2.

Other 6. What? Gas giants don't have stable orbits? What does that even mean?

7. There's no evidence that terrestrial life started on Mars. It's an unparsimonious theory on abiogenesis.

8 (last but not least except for the others). Another bit of nonsense. You assert that a stable orbit isn't possible without a large moon. Why?

9. Why? A planet with no seasons (no axial tilt) might be more amenable to life, but a planet with a more severe axial tilt isn't necessarily anathema to life.

10. The atmosphere on the Earth has changed over time. Our present atmosphere is largely the result of life, not a prerequisite to life.

11. There's no evidence that life couldn't not exist nearer the galactic center (life can evolve in the presence of UV radiation) or nearer the galactic edge. Even so, there's an awful lot of territory in between.

12. Carbon is abundant in the galaxy. We know this for sure.

13. The element oxygen was forged in stars. I take it, you're talking about the presence of O2 gas in the atmosphere. I already addressed this in number 10. At any rate, O2 in the atmosphere was not an "invention". It was the result of the evolution of photosynthesis. With this gas in our atmosphere, some organisms evolved that make use of it (and more or less convert O2 to CO2 in the atmosphere). Again, life evolves to fit the conditions rather than vice-versa. On a planet without abundant atmospheric O2, you wouldn't see organisms adapted to abundant O2.

14. What do you mean by these things? The Cambrian Explosion is pretty well understood.

And what are the "many other reasons"? If these are the cream of the crop, I doubt these many others will be more persuasive.

The last bit sounds a lot like creationism or a supernatural explanation of some kind. You're basically saying, that you once thought the presence of life implies the existence of a god. Then you say, "If not, we are an accident or a freak of the laws of physics." I have no idea what you mean by this. Is there any event that is not an "accident" (if it's not the result of a deity)? In other words, if the option is "accident" or "by intention", then everything is "accidental", isn't it?

And what do you mean by "freak of the laws of phsyics"? You mean that if life were abundant, it would imply that natural law has somehow been violated? Why?

[Crowlogic]

In spite of being an avid follower of most things science I have over time developed the position that whether intelligent life exist elsewhere in the Galaxy...So what!

Why so what? There's no denying that it would be exciting, monumental and benificial to our species if there is technology sharing. However even if we were to meet 1000 or 10,000 civilizations of intelligent beings the ultimate answers to existence such as where did the universe come, where is it going and where do we go after death woud remain unanswered and un answerable. I sincerely believe that those answers are as elusive to any other mortal sentient beings as the are to us. So at the end of the day meeting other cosmos dwelling civilizatons will amount to some neat new parlour tricks to buzz on about but I've the feeling that them's out there are as cluless as we down here as to what the bottom line to existence isreally about, or even if its about anything at all.

[Lonewulf]

You can't think of any other benefits besides that? Really?

[amb]

I'm very suspicious of statements such as the cosmos is teeming with intelligent life of some kind. That to me describes a cosmos that's designed to produce intelligence wherever conditions suit. In other words, god did it. That is the argument put forth by physicist Paul Davies in his book_The Goldilocks Enigma.
In other words the universe has been designed life friendly. All the evidence we have so far discounts that theory. The universe looks just like it should been born in a chaotic Big Bang.

It seems as if we are the result of an accident of no consequence in the scheme of things.

[JoeTheJuggler]

I'm very suspicious of statements such as the cosmos is teeming with intelligent life of some kind. That to me describes a cosmos that's designed to produce intelligence wherever conditions suit. In other words, god did it.

I would reject anyone's claims that the universe is teeming with life also. (The first point I made in this thread, though, is that words like "rare" and "common" or "teeming" are very relatively, and I'd prefer that people define what they mean anyway.)

However, I don't think it automatically points to "goddidit". In fact, I think the lesson we've learned in the past that there is nothing special about humans or their place in the universe at least points to the default position that since there are so many stars, and there's nothing magical about us, then the same materials and physical laws that resulted in life on Earth probably has resulted in life elsewhere.

And I'm not just making this up. The "goddidit" approach once led to the hypotheses that the Earth was the center of the universe, that Europe was the the center of the Earth (culturally, etc.), that the age and size of the universe was in proportion to human existence, and so on.

It did not lead to speculation of ET intelligence. That came out of the realization that there's nothing special about humans or the Earth's place in the galaxy, or our galaxy in the universe. The laws of nature (physics, chemistry, and biology) certainly don't operate in a different way elsewhere.

I think your associating SETI with theism is wrong.

In other words the universe has been designed life friendly. All the evidence we have so far discounts that theory. The universe looks just like it should been born in a chaotic Big Bang.

It seems as if we are the result of an accident of no consequence in the scheme of things.
Yes. And I also think it's absurd to suggest that such an "accident" (see above about my problem with that word) only happened once in the galaxy is preposterous.

To me, that line of thinking implies that we are special (as in the result of a Creator or designer)--that we are unique. There is no evidence to support that conclusion.

It seems like your approach now is that either there is a lot of life (or "complex" life) in the galaxy, and that implies a deity, or we are unique. I think that's flawed reasoning. For us to be unique would be the more exceptional theory (one that seems to require a deity).

[JoeTheJuggler]

In spite of being an avid follower of most things science I have over time developed the position that whether intelligent life exist elsewhere in the Galaxy...So what!

Why so what? There's no denying that it would be exciting, monumental and benificial to our species if there is technology sharing. However even if we were to meet 1000 or 10,000 civilizations of intelligent beings the ultimate answers to existence such as where did the universe come, where is it going and where do we go after death woud remain unanswered and un answerable. I sincerely believe that those answers are as elusive to any other mortal sentient beings as the are to us.

Well. . . you admit the benefits and advances in knowledge would be "monumental".

The fact that you can still dream up supernatural silliness does nothing to decrease the value of such knowledge.

When you ask "where do we go after death?" what exactly do you mean by "we"? The stuff that we know comprises a person ceases to exist after death. It's sort of like asking, "Where does your lap go when you stand up?" Without a body, "we" have no language, no memory, no sensory inputs, no motor outputs, no gender, no name, no spatial location, etc. So if you can't say what the "we" is that you're talking about, the question is meaningless.

Sort of like, "What color is height?"

The fact that no one will ever be able to answer that question does nothing to detract from advances in knowledge that science leads to.

[Crowlogic]

Well. . . you admit the benefits and advances in knowledge would be "monumental".

The fact that you can still dream up supernatural silliness does nothing to decrease the value of such knowledge.

When you ask "where do we go after death?" what exactly do you mean by "we"? The stuff that we know comprises a person ceases to exist after death. It's sort of like asking, "Where does your lap go when you stand up?" Without a body, "we" have no language, no memory, no sensory inputs, no motor outputs, no gender, no name, no spatial location, etc. So if you can't say what the "we" is that you're talking about, the question is meaningless.

Sort of like, "What color is height?"

The fact that no one will ever be able to answer that question does nothing to detract from advances in knowledge that science leads to.

Supernatural silliness? "We" as in human beings in general. Not to be confused with human beings on this forum BTW. Don't confuse me with being in the supernatural camp either. I'm not but I am aware of the core quesitons that drive so much of human thought and action. Us meeting them, wow lots of neat show and tell but core questions unanswerable, so what else is new? See?

We don't need intelligent life from out there, we are the intelligent life from out there. Sooner or later we'll become our own aliens.

[amb]

I don't agree. The limit light speed places on us is impossible to overcome. Even a voyage to our nearest neighbor Alpha Centaurus would take hundreds of years at even a quarter the speed of light. If a colony of earthlings is ever sent to another star system, their descendants if they ever wished to return to Earth would more than likely find a long dead planet. The speed of light and our puny lifetimes places impossible limits on our exploration of the cosmos to overcome.

[JoeTheJuggler]

Supernatural silliness?
Yes, as in the question you asked, "Where do we go after death?"

"We" as in human beings in general.


Human beings have DNA (and gender, etc.). Since you're talking about after death, you're talking about something else. It's up to you to say what that something else is.

ETA: Unless you want a trite answer to your question, like "in the ground" or "burned up and pulverized then placed in an urn on a shelf" or some such.

I can give you a list of characteristics that that something else does not have (thing wholly dependent on various aspects of the body). See above.

Don't confuse me with being in the supernatural camp either. I'm not but I am aware of the core quesitons that drive so much of human thought and action.
How can you construe the question "Where do we go after death?" not to be a supernatural question?

Us meeting them, wow lots of neat show and tell but core questions unanswerable, so what else is new? See?
Yeah--"core" questions like, "What color is height?" I do see.

We don't need intelligent life from out there, we are the intelligent life from out there.

No, we certainly don't need intelligent life from out there. (However, we are not "from out there"--that is, we are terrestrial, not extra-terrestrial.)

I have a driving curiosity, and I do want to know as much as we can know about the universe. I'd say that's a want rather than a need.

Sooner or later we'll become our own aliens.
What does that mean? We're going to spread out across the cosmos and then forget that we did and descendants of humans will encounter each other as strangers? (Or maybe you're using the term "alien" to mean "savior" or some such?)

[JoeTheJuggler]

I don't agree. The limit light speed places on us is impossible to overcome. Even a voyage to our nearest neighbor Alpha Centaurus would take hundreds of years at even a quarter the speed of light. If a colony of earthlings is ever sent to another star system, their descendants if they ever wished to return to Earth would more than likely find a long dead planet. The speed of light and our puny lifetimes places impossible limits on our exploration of the cosmos to overcome.

I agree that the vast stretches of space make interstellar travel either a pipedream or a one-way proposition. However, we can still explore much of the cosmos with telemetry (telescopes of various types) and probes.

I also don't see that even if other intelligent life forms were relatively commonplace in our galaxy there would ever be any galactic civilization. Even communication at light speed over vast distances isn't feasible.

[rwp]

The speed of light limitation also limits the speed of our communication. Imagine that we discover intelligent life in a solar system 10 light-years away. It would take 10 years for each message to reach its destination.

[LarianLeQuella]

Imagine the patience we might learn though? ;)

[arthwollipot]

I can imagine that there may be techniques that can be used to travel/communicate vast distances in reasonable time without breaking the light speed limit (wormholes, etc), but we certainly don't know of any methods with our current understanding of physics.

There's a book by Michio Kaku called, I think, Physics of the Impossible in which (according to reviews I've read) he breaks various science-fiction concepts down into three categories: Stuff that is theoretically completely possible but we don't have the technology yet, stuff that is impossible as far as we know but new science may make it possible, and stuff that is absolutely, completely and utterly impossible.

I haven't been able to find a copy of the book in the local bookstores, but I'm pretty sure he puts travel between stars in reasonable time in the second category.

[amb]

Wormholes are just that, a hole a worm has chewed it's way through. Fiction at it's best.
It would need a black hole, now everyone knows what happens if anything approaches a black hole. You come out of it looking like a spaghetti if you're lucky.
The dream of reaching the speed of light is just that. An impossible dream. There's not enough energy in the whole universe to propel a ship to the SOL.
Not to mention that anything that reaches that impossible dream would become infinite.

[JoeTheJuggler]

Wormholes are just that, a hole a worm has chewed it's [sic] way through. Fiction at it's [sic] best.
It would need a black hole, now everyone knows what happens if anything approaches a black hole. You come out of it looking like a spaghetti if you're lucky.
The dream of reaching the speed of light is just that. An impossible dream. There's not enough energy in the whole universe to propel a ship to the SOL.
Not to mention that anything that reaches that impossible dream would become infinite.

Yet you don't mind the fact that the argument based on the Fermi Paradox rests on the assumption of technology that doesn't exist today.

In fact, it not only assumes technology that is beyond us is possible, it says that if it's possible, then the presence of alien ET intelligent civilizations guarantee that it would be done (and that it would have been done millions of years ago).

[amb]

We are still evolving into who knows what. Who's to say if we survive the next 2-3 million years what our bodies may be like, or even look like. We could well evolve into the very thought we seem to be shackled with, namely the gods themselves. We could theoretically exist without a body. But the laws of physics seem to fixed. Einstein taught us that nothing can travel faster than the speed of light. Even if in the distant future that law can be broken, A round trip to the edge of the galaxy would still take thousands of years.
Fermi's Paradox deals with millions of years. If life originated on a first generation star system's planet, say 4 billion years after the B/B, they would in fact be more than 9 billion years ahead of us. Who was it that said. ''Such a species would be indistinguishable to a god.'' Or they would appear [I]magical to us.

[JoeTheJuggler]

We are still evolving into who knows what. Who's to say if we survive the next 2-3 million years what our bodies may be like, or even look like. We could well evolve into the very thought we seem to be shackled with, namely the gods themselves. We could theoretically exist without a body.

What? You don't seem to understand the very basic workings of evolution. And how do you think we could theoretically exist without bodies? What is the "we" to which you refer if it is something other than our bodies (and all the emergent properties thereof)?

Fermi's Paradox deals with millions of years. If life originated on a first generation star system's planet, say 4 billion years after the B/B, they would in fact be more than 9 billion years ahead of us. Who was it that said. ''Such a species would be indistinguishable to a god.'' Or they would appear [I]magical to us.
I think you're referring to Arthur C. Clarke's statement that "Any sufficiently advanced technology is indistinguishable from magic." I personally don't accept that. (If, for example, I saw someone from an advanced civilization do something like levitate or dematerialize, I would not for even an instant think it was the result of magic.)

As for Fermi's Paradox, I've shown already that the absence of probes from other civilizations in no way proves that other civilizations do not exist. By that standard, we ourselves would no exist since we have not sent out self-replicating probes that are now ubiquitous throughout the galaxy. Yet we exist.

[arthwollipot]

Wormholes are just that, a hole a worm has chewed it's way through. Fiction at it's best.No, they're actually very well-described in the literature, it's just that we haven't found any yet, and we don't actually know whether they exist or not. They're in the same state that black holes were in the 1950s - theoretically predicted, but never actually observed.

[amb]

At the minute wormholes are science fiction. Black holes are different. Some astrobiologist claim there's one in the center of each galaxy. At least one is suspected to exist in the center of ours.
This is an extract of Paul Davies book, Are We Alone. I quote: Carl Sagan has written; ''The available evidence strongly suggests that the origin of life should occur given the initial conditions and a billion years of evolutionary time. The origin of life on suitable planets seems built into the chemistry of the universe.'' This is a common view among scientists concerned with Seti. End quote. In short what is implied is that given the right conditions like the right temperature, the right soup of chemicals, a stable energy source, ect, ect. Life will develop. I agree with all that. What I'm disputing is intelligence. That is an entirely different kettle of fish. Looking at the only example we have, intelligence seems to have occurred entirely by accident.

[Lonewulf]

Right. That was after we looked for evidence of black holes and found it. Before that, they were purely theoretical.

[JoeTheJuggler]

Black holes are different. Some astrobiologist claim there's one in the center of each galaxy.
I think you mean astrophysicists.

I agree with all that. What I'm disputing is intelligence. That is an entirely different kettle of fish. Looking at the only example we have, intelligence seems to have occurred entirely by accident.

Again, if intelligence occurred by accident, then everything that happens happens by accident. You seem to have this false dichotomy in mind where things are either done by a God/Creator/Intelligent Designer/Fine Tuner or they happen by accident.

If that's true, the workings of chemistry is just as much an "accident" as the workings of evolution by natural selection.

[Lonewulf]

I think you mean astrophysicists

MAN, do I feel stupid for not catching that earlier...

[arthwollipot]

At the minute wormholes are science fiction. Black holes are different. Some astrobiologist claim there's one in the center of each galaxy. At least one is suspected to exist in the center of ours.Allow me to correct you.

At the moment wormholes are theoretical. Black holes are different. Astrophycists predict that there's one in the center of each galaxy. One has been observed in the centre of ours.

[amb]

I think you mean astrophysicists.



Again, if intelligence occurred by accident, then everything that happens happens by accident. You seem to have this false dichotomy in mind where things are either done by a God/Creator/Intelligent Designer/Fine Tuner or they happen by accident.

If that's true, the workings of chemistry is just as much an "accident" as the workings of evolution by natural selection.

Of course I meant Astrophysicist. Sorry about that. It's just an oversight. Clicking submit before I read the post. :o

Here is a question I would like you gentlemen to answer as honestly as possible.
If homo sapiens for whatever reason was to become extinct next week.
Do you honestly believe another species will automatically take it's place as the most intelligent species on the Earth??

[amb]

We must ask the question, how many of the features of Earth Life are due to chance, and how many to necessity? In particular, is intelligence a random accident, or the outcome of a ''trend''? Most biologists seem to regard it as an accident.

[JoeTheJuggler]

Here is a question I would like you gentlemen to answer as honestly as possible.
If homo sapiens for whatever reason was to become extinct next week.
Do you honestly believe another species will automatically take it's [sic] place as the most intelligent species on the Earth??

No. That's not the way evolution works. Nothing is "automatic".

However, it does not follow that you are therefore correct in your assertion that there is something special or unique about the Earth.

ETA: In another way, the answer to your question is yes: if the most intelligent species were wiped out, then whatever the second most intelligent species (arguably chimpanzees) would "automatically" become the most intelligent species on the Earth. I don't think that's what you meant (though that is what you asked). It is like asking, "If the tallest kid in the classroom left the room, would someone else automatically become the tallest kid in the classroom?"

[JoeTheJuggler]

We must ask the question, how many of the features of Earth Life are due to chance, and how many to necessity? In particular, is intelligence a random accident, or the outcome of a ''trend''? Most biologists seem to regard it as an accident.
False statement.

Again, you're using the language of the Creationists. Biologists do not speak in terms of intelligence as an "accident". Either nothing is an accident (because everything that happens obeys natural laws--the laws of chemistry and physics) or everything is an accident (because there is no Creator, Intelligent Designer or Fine-Tuner intending anything).

In evolution, variation happens randomly (within the laws, again--for example, point mutations can be said to be random, but polyploidy is not). However natural selection is NOT random. So when you consider something like "intelligence", you have to look at a million advantageous changes that were selected for over a long period of time. Humans are not, in this regard, unique except that we occur at one end of the continuum of intelligence.

You're speaking of "intelligence" the same way some Creationists have argued that the human eye is irreducibly complex. In fact, "intelligence" refers to a host of mental capacities that exists to a greater or lesser degree in many organisms. Every one of these traits that natural selection favored helped the organism to have better reproductive success. Intelligence (and structures like the human eye) did not pop into being out of nothingness with no antecedents and no selective advantage on the way to some pre-defined end result.

[JoeTheJuggler]

AMB, could you kindly respond to my post number 539 and the point I brought up below?

I have been answering your questions, yet, you keep ignoring these points.


As for Fermi's Paradox, I've shown already that the absence of probes from other civilizations in no way proves that other civilizations do not exist. By that standard, we ourselves would no exist since we have not sent out self-replicating probes that are now ubiquitous throughout the galaxy. Yet we exist.

A similar argument can be made for any argument that uses the SETI results to reach the conclusion that other ET intelligences don't exist. We ourselves have not been sending a continuous narrow beam radio signal out long enough to reach even nearby stars yet. (Our broadbeam radio signals would not be detectable outside our own solar system even with a radio telescope two orders of magnitude more sensitive than Arecibo.) So if no result from SETI means ETI's don't exist, then using the same logic would suggest that we ourselves don't exist.

[arthwollipot]

Personally I think that intelligence is such a good survival trait it would be favoured by natural selection wherever it appeared. So yes, I do believe that if there is life outside of our solar system, and I think it's extremely likely that there is, then I think that it is almost inevitable that some of them would be intelligent.

And if human beings were to magically disappear from this planet, then another species would eventually gain our level of intelligence.

My opinion only.

[LarianLeQuella]

Here is a question I would like you gentlemen to answer as honestly as possible.
If homo sapiens for whatever reason was to become extinct next week.
Do you honestly believe another species will automatically take it's place as the most intelligent species on the Earth??

Assuming you mean "would another species on our planet evolve to our level of intelligence AND civlization", I'd have to go with, "Hard to tell."

Depending on what species ends up filling out place(s) in nature, and which ones manage to develop any sort of civilization, perhaps all the artifacts we left behind would serve as some sort of warning. They may employ their intelligence in a totally different way. It's such a speculative answer that it's probably best left to science fiction story tellers moreso than a conversation regarding extra terrestrial intelligence. I mean, would we consider them intelligent even if they eschewed technology for philosophy? Much like the problem we run into in trying to identify and categorize ET intelligence, we'd have the same problem with any that replaced us.

But, since intelligence is a beneficial survival trait, eventually something would probably come about.

Sort of along the lines of my position from the start. We just can't relaibly tell with the datapoints we have.

[JoeTheJuggler]

I don't think intelligent (like ours--a pretty extreme version) is one of those basic things that's adaptive in a great many niches (like say--eyesight of one form or another). I think it evolved in most primates as an adaptation for living in increasingly complex social groups.

It could well be now that primates are around, the only thing that can compete with them are other animals living in very complex social groups. I don't know.

Some structures (like the eye, or the sabertooth in big predators) evolved again and again. Other traits maybe aren't so generally adaptive.

About all we can say to AMD's question is, "We don't know."

However, that's not the same as making a claim that you know it won't happen again.

[amb]

AMB, could you kindly respond to my post number 539 and the point I brought up below?

I have been answering your questions, yet, you keep ignoring these points.



A similar argument can be made for any argument that uses the SETI results to reach the conclusion that other ET intelligences don't exist. We ourselves have not been sending a continuous narrow beam radio signal out long enough to reach even nearby stars yet. (Our broadbeam radio signals would not be detectable outside our own solar system even with a radio telescope two orders of magnitude more sensitive than Arecibo.) So if no result from SETI means ETI's don't exist, then using the same logic would suggest that we ourselves don't exist.

How can you compare our puny efforts by the Seti results? If civilizations exist out there, they could be billions of years ahead of us. Surely they would be as curious as we are and would have searched the cosmos for other civilizations by now. Hence Fermi's Paradox. Could it be that low level life is teeming all over the universe, but that human like intelligence is a once in a trillion chance of happening twice?

[amb]

Personally I think that intelligence is such a good survival trait it would be favoured by natural selection wherever it appeared. So yes, I do believe that if there is life outside of our solar system, and I think it's extremely likely that there is, then I think that it is almost inevitable that some of them would be intelligent.

And if human beings were to magically disappear from this planet, then another species would eventually gain our level of intelligence.

My opinion only.

Then why hasn't it done so already? Our nearest family member, the chimps have been here longer than us, yet they haven't advanced one percent from their original state. No Wolli. If the human species were to suddenly become extinct, nothing would change. All the species that rely on us would also become extinct. And the chimps would continue as they have always done.
The The Planet Of The Apes was just a movie, a good one at that, but only science fiction.

[amb]

False statement.

Again, you're using the language of the Creationists. Biologists do not speak in terms of intelligence as an "accident". Either nothing is an accident (because everything that happens obeys natural laws--the laws of chemistry and physics) or everything is an accident (because there is no Creator, Intelligent Designer or Fine-Tuner intending anything).

In evolution, variation happens randomly (within the laws, again--for example, point mutations can be said to be random, but polyploidy is not). However natural selection is NOT random. So when you consider something like "intelligence", you have to look at a million advantageous changes that were selected for over a long period of time. Humans are not, in this regard, unique except that we occur at one end of the continuum of intelligence.

You're speaking of "intelligence" the same way some Creationists have argued that the human eye is irreducibly complex. In fact, "intelligence" refers to a host of mental capacities that exists to a greater or lesser degree in many organisms. Every one of these traits that natural selection favored helped the organism to have better reproductive success. Intelligence (and structures like the human eye) did not pop into being out of nothingness with no antecedents and no selective advantage on the way to some pre-defined end result.

Please don't even think of me and creationist in the same breath.
I repeat here that most biologists worth their salt regard that the course of evolution does not follow any law-like trend but is purely random. This 'blind watchmaker' thesis is defended robustly by Richard Dawkins, Stephen Jay Gould and many others. If these esteemed gentlemen are correct, then a feature of life such as intelligence is purely chance phenomenon, exceedingly unlikely to arise elsewhere independently.

[JoeTheJuggler]

How can you compare our puny efforts by the Seti results? If civilizations exist out there, they could be billions of years ahead of us. Surely they would be as curious as we are and would have searched the cosmos for other civilizations by now. Hence Fermi's Paradox.
The problem is that your argument based on Fermi's Paradox says that they MUST BE way ahead of us, not "could be". In fact, as I've shown, by your reasoning, we ourselves don't exist since we haven't sent out probes that are now ubiquitous in the galaxy.

There could be thousands of civilizations at roughly the same level as our own, and there would be no sign of them available to us right now. They wouldn't be detectable. Similarly, we would be undetectable to them. They could be sitting there considering XGherYl!#or's Paradox and insisting that Earthlings don't exist because if they did, we'd be way in advance of their own civilization and our self-replicating probes would already be ubiquitous.

Could it be that low level life is teeming all over the universe, but that human like intelligence is a once in a trillion chance of happening twice?
I've already answered that. Yes, it could be. Is there any reason to think that it is so? No. (By the way, once in a trillion whats? Species? Planets? Biospheres?)

[JoeTheJuggler]

Please don't even think of me and creationist in the same breath.

I call 'em as I see 'em. You keep referring to things as "accident".

For example:
In particular, is intelligence a random accident, or the outcome of a ''trend''? Most biologists seem to regard it as an accident.

I keep pointing out to you that the only way "accident" is meaningful is as opposed to "on purpose" or "by intention", which certainly smacks of theism.

If you don't mean something like that, then it is meaningless, as I've shown. Either everything is accidental or nothing is accidental.

[JoeTheJuggler]

Then why hasn't it done so already?

First, only one species can be "the most intelligent" species. This points out that intelligence exists as a continuum and not a hard-line between animals with it and those without it. Chimpanzees are intelligent animals. If we discovered a species at their level of intelligence on another planet, I would certainly consider that to be "ET intelligence"--and news of a planet with organisms that complex would be truly amazing!

Second, our fabulous success might mean that we have out-competed our nearest relatives. It could be that ecologically, "There can be only one." (To borrow from The Highlander.)

Third, there is evidence that in the past our family tree was somewhat bushier. Even in relatively recent times, we know that Neanderthals and Modern Humans both existed at the same time. The fact that chimpanzees aren't our peer doesn't mean that there haven't existed at one time or another other animals that were even closer.

[LarianLeQuella]

AMB, exactly how long have humans been around? It's a comparative eyeblink. I think there have been a few lucky breacks in our technology (not our intelligence) that may have leapfrogged us compared to what I would GUESS is a typical developmental track. That said, we have absolutely no frikkin idea at all about how things normally go. We have one example, and one example only. All our views are biased by our own history. AMB, your viewes in particular do seem to indicate an incredibly human/earth centric point of view. Step back from what we do know and realize how much we really don't know.

[arthwollipot]

Then why hasn't it done so already? Our nearest family member, the chimps have been here longer than us, yet they haven't advanced one percent from their original state.No, they haven't They've been here exactly as long as us. Humans and chimps are descended from the same common ancestor, which was neither a human nor a chimp.

No Wolli. If the human species were to suddenly become extinct, nothing would change. All the species that rely on us would also become extinct. And the chimps would continue as they have always done.So something would therefore prevent chimps from developing increased intelligence through evolution. It'd have to. We know that intelligence is an evolutionary trait. We can see it in varying levels in the animal kingdom with us at one end of the spectrum and nematodes at the other. Intelligence undoubtedly evolves.

Why haven't chimps evolved that level of intelligence yet? Presumably, they never got the mutation that we did that vastly accelerated our development. Have you seen how quickly in geological time our hominid ancestors' brain cases grew?

Humanity has been here for an eyeblink in evolutionary time. Perhaps the chimps just haven't had the time. Perhaps we're somehow preventing them through competition. The animal rights movement and the study of nonhuman intelligence have been around for a tiny fraction of humanity's eyeblink - how do you think we treated chimps before about the middle of the 20th century?

The The Planet Of The Apes was just a movie, a good one at that, but only science fiction.I don't think it was even a particularly good movie, but YMMV.

[amb]

Intelligence in any species is for the survival of that species. Mankind seems to have an overkill of the trait. We don't need to be so smart for survival purposes. An ant that possesses a brain the size of a half grain of sand seems to survive just fine with what it's got.
A microbe hasn't even that. It's taken homo sapiens, more than 4 billion years to reach the stage of intelligence we now enjoy. How many planets out there have the luxury of such a huge time span? Larian is correct, we only have this one example. But this example has taken a hell of a long time to develop. A third of the time the universe has existed, almost. Perhaps animal life is widespread in the cosmos, but has it our capacity of brain power? Until we know otherwise, we have to assume we could well be alone, at least in this galaxy.

[JoeTheJuggler]

Intelligence in any species is for the survival of that species. Mankind seems to have an overkill of the trait. We don't need to be so smart for survival purposes. An ant that possesses a brain the size of a half grain of sand seems to survive just fine with what it's got.
Are you saying there's something special or magical about any organism that's not like an ant?


It's taken homo sapiens, more than 4 billion years to reach the stage of intelligence we now enjoy.
Homo sapiens hasn't existed for that long. Also, you seem to think of intelligence as a pre-determine goal. It's already been pointed out to you that intelligence exists on a continuum in many organisms.

How many planets out there have the luxury of such a huge time span?
Do you mean, how many planets in the galaxy (or universe) have been around for 4 billion years? I suspect the number is very very high. You made this "time" argument before, and I still don't understand it. You seem to think more time has elapsed here than elsewhere in the galaxy or universe.


Larian is correct, we only have this one example. But this example has taken a hell of a long time to develop. A third of the time the universe has existed, almost.
And again, no more time has passed here than anywhere else in the universe. This argument makes no sense. It also seems to argue the exact opposite of your argument that we are unique based on Fermi's Paradox. In that one, you say that if intelligence exists, it must have existed already for a long time and filled the galaxy with probes.

Perhaps animal life is widespread in the cosmos, but has it our capacity of brain power?
Unknown.

Until we know otherwise, we have to assume we could well be alone, at least in this galaxy.
No, we don't have to make any such assumption. Why do you think we do?

It seems to me that assuming knowledge we don't have quashes curiosity and the drive to learn more.

[JoeTheJuggler]

Why haven't chimps evolved that level of intelligence yet? Presumably, they never got the mutation that we did that vastly accelerated our development. Have you seen how quickly in geological time our hominid ancestors' brain cases grew?

Also it could be one of the two reasons (in the series of 3--the first one addressing what AMB asked rather than what he meant to ask) I listed earlier.

It could be that the reason a chimpanzee with that extra little change was wiped out due to our huge success. (When our ancestors got that last increase in brain size, there wasn't an already-established competitor in place.)

And it could be that something that evolved from our common ancestor with chimpanzees already did in fact reach intelligence levels similar to humans. (After all, a chimpanzee that evolved human-like intelligence would no longer be a chimpanzee, would it?) There is evidence that our ancestors may have coexisted with other hominid species that are now extinct.

[JoeTheJuggler]

By the way, saying "it took 4 billion years to evolve human intelligence" makes as much sense as saying it took 4 billion years to evolve a certain type of virus or parasitic worm.

[LarianLeQuella]

Also, saying it took 4 billion years to get humans would imply some sort of linear progression. Evolution does NOT have any particular goal in mind to follow any sort of linear path. There are fits and starts, dead ends and mistakes that are made along the way. The most linear path to us probably only started 30 million years ago.

[arthwollipot]

Intelligence in any species is for the survival of that species. Mankind seems to have an overkill of the trait. We don't need to be so smart for survival purposes.Personally I think our intelligence is the result of a self-reinforcing feedback loop.

Have you read The Blind Watchmaker? That's the one where Dawkins goes on about arms races and positive feedback loops, I think.

[amb]

Also, saying it took 4 billion years to get humans would imply some sort of linear progression. Evolution does NOT have any particular goal in mind to follow any sort of linear path. There are fits and starts, dead ends and mistakes that are made along the way. The most linear path to us probably only started 30 million years ago.

But that's my argument. Our intelligence could well be a random accident of evolution.
If the Earth's history was replayed from day one. What are the chances we would exist exactly as we are? None is my argument.

[JoeTheJuggler]

But that's my argument. Our intelligence could well be a random accident of evolution.
Is there any organism whose evolution is not a "random accident"? Can you at least say what you mean by "accident" since you deny it has any theological underpinnings?

Nothing in evolution is "intentional" or "on purpose".


If the Earth's history was replayed from day one. What are the chances we would exist exactly as we are? None is my argument.
And that has nothing to do with the question of whether or not intelligence is common or rare. That's the problem with the backwards thinking of the Rare Earth Theory.

It's exactly like the Texas Sharpshooter fallacy. Fire an unaimed bullet into the side of a barn and then draw a tiny circle around that bullet hole and ask "What are the chances of hitting exactly that spot?"

[LarianLeQuella]

But that's my argument. Our intelligence could well be a random accident of evolution.
If the Earth's history was replayed from day one. What are the chances we would exist exactly as we are? None is my argument.


And your argument is flawed as has been pointed out numerous times. FURTHERMORE, there are probably an uncountable number of "solutions" to "intelligence". Given your gambit; sure, Homo Sapiens wouldn't be here, but given what we do know, something else would probably be here.

[amb]

Something else? What exactly? An intelligent dolphin capable of building a satellite?
Perhaps a chimp building a skyscraper?
My thoughts are thus: We are a complete random event that is only repeated once every trillion or so times. That does not rule out that there are other Earths out there somewhere. But I think they're very rare.
If on the other hand intelligence is widely spread throughout the cosmos, then the theist/ deists may well be right.

[LarianLeQuella]

You are thinking too lineraly.... Why does it have to be a chimp or dolphin? Those are things that we have NOW. If you restarted the earth from abiogenesis and let it go, for all we know it could be a 4 legged 4 armed reptilian creature occuping the highest order. Or maybe some form of life we have no frame of reference to at all. I don't think there is anything special at all about intelligence, it's just a human centric notion that needs a "great demotion" as Sagan would say.

Why would a large number of intelligences make theists right? I suppose if they all had some similar mythologies as ours, perhaps, but if anything it would weaken their stance, especially if their mythologies bore zero resemblance too ours. Or better yet, they have outgrown mythologies?

So what do you have to back up your thought that "We are a complete random event that is only repeated once every trillion or so times." I think that's what Joe and I have been hammering you on. BACK IT UP! PROVIDE EVIDENCE. The BEST we can say is we have no frikkin idea, but the current evidence would indicate that there is nothing special about us really.

[amb]

Some theist sometimes use the argument that the laws of physics are responsible for intelligence existing in the cosmos, and then explain that these laws have been there since before the B/B. In other words they, after many words they inevitabily place their god in the gap just before the B/B as been the source of these laws.
A cop out of natural processes that instead rule out any god.
If the laws of physics are the same everywhere, and the evidence shows that they are, then it will be natural that wherever conditions suit, life will evolve.
But are these laws also responsible for consciousness? That is where the random accident of consciousness or intelligence may be extremely rare.
How can anyone back that up with evidence? No one can until we discover other intelligence that has evolved completely separate from homo sapiens.

[JoeTheJuggler]

This is the reason I keep saying you think like a creationist:

But are these laws also responsible for consciousness? That is where the random accident of consciousness or intelligence may be extremely rare.


Of course the laws of nature are also responsible for consciousness. If not, then consciousness is the result of the supernatural.

Please answer this: if you're not talking about an "accident" in terms of theism ("accidental" as opposed to "on purpose" or "by intention" or "by design")--what do you mean by "accident"? Is there any non-theistic approach where just some events are accidents and others are not?

All events obey the laws of nature. The laws of nature are the same everywhere. (That is, either everything is an accident or nothing is an accident.) There is nothing special or unique about the location of the Earth.

[LarianLeQuella]

Some theist sometimes use the argument that the laws of physics are responsible for intelligence existing in the cosmos, and then explain that these laws have been there since before the B/B. In other words they, after many words they inevitabily place their god in the gap just before the B/B as been the source of these laws.
A cop out of natural processes that instead rule out any god.
If the laws of physics are the same everywhere, and the evidence shows that they are, then it will be natural that wherever conditions suit, life will evolve.
But are these laws also responsible for consciousness? That is where the random accident of consciousness or intelligence may be extremely rare.
How can anyone back that up with evidence? No one can until we discover other intelligence that has evolved completely separate from homo sapiens.


Sounds like the strong anthropic argument (assuming I have my terminology correct). Again, it's BACKWARDS reasoning: Because we're here, then this place is perfectly suited to us. There is no accident what-so-ever involved. It's all a natural process that we did quite well in. Again, since we have no idea beyond our ONE datapoint, we cannot say for sure one way or another if this process has repeated lots of times or not out there, but given what we know of evolution the NATURAL PROCESS would indicate that it's absolutely within the natural order of things.

As for the natural laws being the same, not sure really where you are going with that per se. Are you talking about the possibility that pockets within our universe may have different physical laws?

As far as I am aware, it is generally accepted that everywhere within this universe has the same laws. Multiverses and ponderings on that level are a different story. Although, given an infinite multiverse, then statistically speaking, this universe must exist without the need for any supernatural balancing act. Also, keep in mind that if ALL the laws are on a sliding scale, this universe isn't as fine tuned as people think. The fine tuining of natural laws is another "irriducible complexity" nonsense argument. I have a copy of a paper on my blog about that, but sadly cannot access my blog from this computer in Qatar.

[amb]

Doesn't it strike you as strange why we of all the billions of life forms that have ever lived on this planet are the only ones who have ever evolved consciousness?
All other lifeforms have only the intelligence to be able to survive. Why has homo sapiens such an overkill of brain power if it's just to enable us to survive? Could it not just be an accident of evolution that may have only have happened in the cosmos once or at best, a dozen or so times? A universe teeming with intelligent life would have made at least one other be discovered by now. Also a universe teeming with intelligent life seems to me as a fine tuned conclusion to the question of how. As Fred Hoyle once stated: '' The universe looks like a put- up job.'' [Or words to that effect]

[JoeTheJuggler]

Doesn't it strike you as strange why we of all the billions of life forms that have ever lived on this planet are the only ones who have ever evolved consciousness?
The assumption you make in this question is not true. Why do think humans are the only organisms on Earth to have evolved consciousness?


All other lifeforms have only the intelligence to be able to survive.
Not true. Chimpanzees have the ability to learn human languages.

Why has homo sapiens such an overkill of brain power if it's just to enable us to survive?
Who says it's overkill? Humans adapted to live in complex social groups. Stuff like language, face recognition, the ability to infer agency, etc. is hugely adaptive to animals living in such a group. The pay off is that we have radiated to cover most of the Earth. Chimpanzees are on the verge of extinction.

Could it not just be an accident of evolution that may have only have happened in the cosmos once or at best, a dozen or so times?
What do you mean by "accident"? You keep using this word as if it had some meaning--as if something things that occurred were accidental but others were not (intentional?)

A universe teeming with intelligent life would have made at least one other be discovered by now.
Nope. Even we would be undetectable to ourselves beyond our solar system. This argument has been shown over and over to be deeply flawed. Why do you keep asserting it?

[LarianLeQuella]

Joe pretty much nailed it. AGAIN you are thinking too human-centric. Just because many "animals" don't do things we do, doesn't discount them from being intelligent or having conciousness. Also, we may have wiped out other species that may have had a chance. Finally, how long have we been around? In the scheme of things, it's just a virtual eyeblink. We may have, through our own evolution/actions, prevented other species from taking up niches that would have led them to intelligence.

So no, it's not at all strange, and stop being such a human-chavenist! :p

[amb]

OK. You guys are more than probably right, and I'm wrong. But we cannot ignore the fact that most biologists think our origins are a complete accident of evolution at work. If the recording of Earth history was replayed, not even the Earth itself could be assured. Also, using Drakes equation, there is either billions of Earths out there, or there could possibly be just one. Until we discover life of some sort that has evolved completely separate from the Earth, we stand at the start of this thread. Completely Ignorant. Even if we find microbial life on Mars, and it has completely different DNA to Earth-life, then that will be proof that life is widespread in the cosmos and intelligence must exist on perhaps millions of other galaxies.

[JoeTheJuggler]

OK. You guys are more than probably right, and I'm wrong. But we cannot ignore the fact that most biologists think our origins are a complete accident of evolution at work.

I've never heard a biologist use the word "accident" in the context of evolution. (And yes, I'm around biologists pretty often.) I've told you the problem I have with that word, but you keep ignoring me.

In what way is ANYTHING in evolution either an accident or not an accident?

If everything that happens in evolution is an accident, does the word have any meaning when you talk about human origins or intelligence in particular? (I think it does not.)



If the recording of Earth history was replayed, not even the Earth itself could be assured.
What recording of Earth history? How could "Earth history" be replayed but without the Earth? (Perhaps you mean if our solar system formed again, there's no guarantee that we'd have the planets we now have.)

So?


Also, using Drakes equation, there is either billions of Earths out there, or there could possibly be just one. Until we discover life of some sort that has evolved completely separate from the Earth, we stand at the start of this thread. Completely Ignorant.
I agree that we don't know, but that doesn't mean we're completely ignorant. We know a lot about chemistry and physics. We know that what happened here could happen elsewhere (that is, the same laws apply everywhere and the materials needed for life are among the most abundant in the universe).

We also know that historically, any time we thought there was something special or unique about us, we were wrong.

Even if we find microbial life on Mars, and it has completely different DNA to Earth-life, then that will be proof that life is widespread in the cosmos and intelligence must exist on perhaps millions of other galaxies.
How will it "prove" that? You're again making general conclusions waaaaay beyond the data. If we find life on Mars that's not related to Earth, we'll know that abiogenesis happened at least twice. That's not a big shock, though. I've shown you that chemistry adequately explains how you can go from non-living molecules to very simple living things. Once you've got a self-replicating thing (a molecule perhaps in a membrane), natural selection goes to work.

[LarianLeQuella]

OK. You guys are more than probably right, and I'm wrong. But we cannot ignore the fact that most biologists think our origins are a complete accident of evolution at work.

I think you may be confusing "We don't know the details" with the word accident. Most biologists I speak to never use the word accident when refering to abiogenesis, and most certianly never use it regarding evolution.

If the recording of Earth history was replayed, not even the Earth itself could be assured.

Irrelevant and also disingenious. Again, there is the natural chaos of complex systems to deal with, so obviosuly things won't turn out the same, and that's not the point. It DID happen though, so now we're here contemplating it.

Also, using Drakes equation, there is either billions of Earths out there, or there could possibly be just one. Until we discover life of some sort that has evolved completely separate from the Earth, we stand at the start of this thread. Completely Ignorant.

I personally think a lot of people put too much stock in the validity of the Drake equation, when it's really just a bunch of suppositions strung together, made with no concrete data. I agree, we are completely ignorant of the facts, however, we are pretty clever on many of the processes involved (evolution/chemistry), and getting smarter on some of the other processes (planetary formation).

EDIT TO ADD: And why is Completely Ignorant such a horrid thing? Isn't that where we go and look to see if we can find answers?

Even if we find microbial life on Mars, and it has completely different DNA to Earth-life, then that will be proof that life is widespread in the cosmos and intelligence must exist on perhaps millions of other galaxies.

It would still only be a small set of datapoints, although it would lend more support to abundance of abiogenesis. We are at the very dawn of this field of science. It's like expecting the alchemists of yore to know of organic chemistry. We haven't been at this very long, and really don't have the data. I suppose this is really a philisophical discussion where we support our stances with what we do know of science. :D

[JoeTheJuggler]

Also, using Drakes equation, there is either billions of Earths out there, or there could possibly be just one.
The Drake Equation says no such thing. It simply says that the number of planets that can sustain life is a factor in calculating how many intelligent civilizations there are.

You've presented a false dichotomy. There's nothing that says there must either be billions of Earth-like planets (depending on how you define it), or just one. There could be 2 or 3 or 4. Or there could be 12, or there could be 500. Or there could be 100 trillion. (You beginning to get the point?)

[arthwollipot]

What recording of Earth history? How could "Earth history" be replayed but without the Earth? (Perhaps you mean if our solar system formed again, there's no guarantee that we'd have the planets we now have.)I think amb is reiterating an argument from Stephen Jay Gould, who said that if time were somehow "rewound" back to life's origin, and allowed to play itself out again, it would be extremely unlikely that we would get the same mix and distribution that we have today. It's about divergence from initial conditions.

Gould, as far as I know, did not postulate that if life replayed like this, intelligence would probably not appear.

[MG1962]

I think amb is reiterating an argument from Stephen Jay Gould, who said that if time were somehow "rewound" back to life's origin, and allowed to play itself out again, it would be extremely unlikely that we would get the same mix and distribution that we have today. It's about divergence from initial conditions.

Gould, as far as I know, did not postulate that if life replayed like this, intelligence would probably not appear.

In his book "A Wonderful Lfe" He does sort of imply it though. His basic arguement is that life seems pre-disposed to certain body forms and function. He saw the Cambian Explosion as a sort of chemistry set gone mad, with some rather bizzare creations appearing.

From this he identified something like 8 basic characteristics that seem to hold right through the history of evolution, and intelligence does not seem to be one of them.

For one small branch of hominoids to develope intelligence as an adaptive suvival process, seems quiet extraodinary and point to some event rather unique in their developement. He considered this (unknown) event to be so rare, there was no promise, replaying the story of life on the planet would yield the same result

[arthwollipot]

I'll have to re-read it.

[amb]

I think amb is reiterating an argument from Stephen Jay Gould, who said that if time were somehow "rewound" back to life's origin, and allowed to play itself out again, it would be extremely unlikely that we would get the same mix and distribution that we have today. It's about divergence from initial conditions.

Gould, as far as I know, did not postulate that if life replayed like this, intelligence would probably not appear.

Physicist Paul Davies also stated the same thing with a slightly different viewpoint. Davies claims that either we are an improbable quirk of the laws of nature, or there are trillions of Earths and intelligences out there at one time or another in the history of the universe.
Both agree that consciousness is not a given while life of the animal kind and lower may well be widespread and the norm.
Carbon, the essential ingredient of life was not produced until at least the end of the first or second generation of stars lifetimes. Our sun is only around 4-5 billion years old having been formed from the wreckage of these first stars.
a whopping 9-10 billion years since the B/B. Assuming that the first and second generation of stars had a lifespan of say, 2-3 billion years, it doesn't give all that much time for consciousness to evolve does it? The carbon has to be created in the core of these first stars, then they need to go supernova and spew the carbon into empty space taking billions of years before it is finally used to make our bodies, or the DNA that produced our bodies

[JoeTheJuggler]

Davies claims that either we are an improbable quirk of the laws of nature, or there are trillions of Earths and intelligences out there at one time or another in the history of the universe.
Everything in nature is an improbable quirk of the laws of nature. If you re-ran evolution on Earth, is there any evidence that ants would evolve again?
There are some 11,800 species of ants, yet they too can be seen as "an improbably quirk of nature" if you talk about re-running the history of life on Earth.

At any rate, the observations that we wouldn't evolve twice is completely beside the point. In SETI, we're not looking for extra terrestrial homo sapiens.

[JoeTheJuggler]

For one small branch of hominoids to develope intelligence as an adaptive suvival process, seems quiet extraodinary and point to some event rather unique in their developement. He considered this (unknown) event to be so rare, there was no promise, replaying the story of life on the planet would yield the same result
If that's an accurate description of what he said, I'd have to disagree.

First, "one small branch of hominoids" aren't the only organisms on Earth to have developed intelligence. As mentioned repeatedly, intelligence exists on a broad continuum. If we're going to speculate on how things might be different, it could be that the first advanced technological civilization to arise puts a damper on others. (See above, my "There can be only one" speculation.)

Second, those of us arguing against amb's Rare Earth position aren't saying intelligence is inevitable. That would be like us making the claim that on every planet that can support life, there is an intelligent civilization. I for one have said repeatedly that we don't know is the best answer we can give to the question of ET intelligence. However, there's no reason to think it can't happen elsewhere. The materials for life are abundant in the universe, the laws of physics (and therefore chemistry) are the same throughout the universe, and the amount of time that has passed since the Big Bang is the same throughout the universe. (amb has argued on a couple of occasions that there hasn't been enough time for intelligence to arise elsewhere in the galaxy except on the Earth.)

I think I may have mentioned the mirror test for self awareness on this thread before. If not, it's described here (http://en.wikipedia.org/wiki/Mirror_test). Here are the animals that have passed this test (from the same Wiki article):
Animals that have passed the mirror test are all of the great apes (bonobos, chimpanzees, orangutans, gorillas, humans), bottlenose dolphins, Orcas, elephants, and European Magpies.

[amb]

I think I may have mentioned the mirror test for self awareness on this thread before. If not, it's described here. Here are the animals that have passed this test (from the same Wiki article):

That has absolutely nothing to do with homo sapiens level of self consciousness which is far beyond a level required for it's survival as is in the animal kingdom.
I take great credence on people like Gould who are geniuses compared to my feeble mind.
I repeat for the umpteenth time, conciousness is NOT a given in the scheme of things. But lower lifeforms may be so.

[JoeTheJuggler]

That has absolutely nothing to do with homo sapiens level of self consciousness which is far beyond a level required for it's [sic] survival as is in the animal kingdom.
So? I thought your Rare Earth theory said that microbial life was common, but not intelligence. And part of this is your continued assertion that humans are unique in the history of the Earth.
I take great credence on people like Gould who are geniuses compared to my feeble mind.
I like Gould as well, though I utterly reject his notion of NOMA.

I repeat for the umpteenth time, conciousness is NOT a given in the scheme of things. But lower lifeforms may be so.
Yes, and you're arguing against a straw man, as has been pointed out to you umpteen times.

For me to refute the assertion that humans are unique in the galaxy*, I don't have to prove that consciousness is "a given".

Also, as I've said repeatedly, nothing is "a given". Not ants, or even any given microbe.

*I know whenever I say that you maintain that you're only saying that humans may be unique. I told you that I'm happy to cede that we may be unique (though there's no evidence one way or the other), but if you're not willing to admit that there may be dozens or hundreds or even thousands of ET intelligent civilizations in our galaxy, then your position is in fact that humans are unique. As far as I know, no one is arguing that there must be dozens or hundreds or thousands of ET intelligences in the galaxy.

[amb]

Have you answered my question of why only homo sapiens out of the billions of lifeforms that have ever lived on this planet has evolved consciousness?

[JoeTheJuggler]

Have you answered my question of why only homo sapiens out of the billions of lifeforms that have ever lived on this planet has evolved consciousness?

Yes I did. It's a false statement. Homo sapiens is not the only species on the Earth to have evolved consciousness.

[JoeTheJuggler]

Re: the mirror test of self-awareness:
That has absolutely nothing to do with homo sapiens level of self consciousness which is far beyond a level required for it's survival as is in the animal kingdom.
Self-awareness is a subset of consciousness. That several non-human species have been proven to have self-awareness refutes your statement that Homo sapiens is the only species on Earth to have developed consciousness.

[LarianLeQuella]

I think AMB suffers from the misconception that just because we managed to build something in a relative eyeblink, that makes us special. He's a human chauvinist! :p (Just taking the piss outta ya mate!)

[JoeTheJuggler]

Self-awareness is a subset of consciousness.

I don't know if I worded that quite right. What I mean is, that all animals that are self-aware are conscious, but not all animals that are conscious are self-aware. Self-awareness or consciousness of self is just one possible application of consciousness.

[amb]

The mirror test proves nothing. I have done this test with my two dogs. All they see is other dogs, not themselves. They lack the self awareness to be able to see themselves.
Same tests done with primates has produced the same result.
Sometimes mirrors are placed in a parrots cage to keep the bird quite. The reflection It sees are other birds in the cage with it. Nowhere is there proof that the lower animals show they posses consciousness.

[arthwollipot]

"Lower" animals...? :rolleyes:

Chimps pass the mirror test. If they see a chalk mark on the nose of the chimp in the mirror, they will wipe their own nose to get rid of it.

Humans are not the only animals to recognise themselves in a mirror. I believe that dolphins do too.

Anyway, the mirror test is merely one arbitrary milestone on the scale of consciousness. Is your dog happy to see you when you come home from work? Is that an emotion your dog is feeling? Can non-humans ("lower" animals) even feel emotion?

[JoeTheJuggler]

The mirror test proves nothing. I have done this test with my two dogs. All they see is other dogs, not themselves. They lack the self awareness to be able to see themselves.
You obviously didn't look at the Wiki link I provided. Dogs, cats, and so on fail the mirror test. Only the great apes, some cetaceans, elephants and one bird species pass the mirror test.

My point is that self-awareness is just one type of consciousness. General "consciousness" is far more widespread in the animal kingdom.

Dogs, for example, have nociceptors (neural receptors for pain). Their behavior demonstrates that they are aware of painful stimuli--that they feel and are conscious of painful stimuli.

This refutes your contention that humans are the only "conscious" animal to have evolved on Earth.

I think maybe you're trying to substitute "consciousness" for "intelligence"?

Nowhere is there proof that the lower animals show they posses consciousness.
You're wrong. Here's a simple thought experiment: compare neutering a dog without anaesthesia compared to doing it with anaesthesia. What would you say is the difference?

Even putting all this talk of "consciousness" aside, and going back to the question of intelligent civilizations with at least radio technology: observing that we are the only species on Earth to have gotten that far still does nothing to support your argument that we are unique in the galaxy. (And again, don't pretend you're only claim we "may be" unique--not unless you're willing to admit the we also "may be" one of thousands of such intelligences in the galaxy.)

We've gone over this before too. If you're not going to say that the Earth is 1 for 1, but instead say humans are 1 in the number of species that have evolved on the Earth, then you're just changing the ratio you're looking at from the number of intelligent civilizations per planet to the number per total number of species in the galaxy.

[JoeTheJuggler]

Humans are not the only animals to recognise themselves in a mirror. I believe that dolphins do too.

From the Wiki article (http://en.wikipedia.org/wiki/Mirror_test):

Animals that have passed the mirror test are all of the great apes (bonobos, chimpanzees, orangutans, gorillas, humans), bottlenose dolphins, Orcas, elephants, and European Magpies.[3]

Humans, by the way, fail the test up until about 18 months of age. Dogs fail the test.

[arthwollipot]

Thanks Joe for the cite that I was too lazy to find...

[JoeTheJuggler]

This is also a pretty good book (http://www.press.uchicago.edu/Misc/Chicago/308650.html) (which I have on my shelf here at home). It's a bit dated by now. This kind of research moves along pretty fast. There's also the Cheney and Seyfarth work with vervet monkeys. This is another book on my shelf (http://dannyreviews.com/h/How_Monkeys_See_the_World.html).

[Radrook]

I find the genetic engineering explanation more compelling.

[JoeTheJuggler]

I find the genetic engineering explanation more compelling.

The "genetic engineering explanation" of what?

[LarianLeQuella]

??? http://en.wikipedia.org/wiki/The_Chase_(TNG_episode)

[amb]

I have never claimed we are alone. I have always claimed we may be alone. For all we know the galaxy could literally be overrun with intelligent conscious beings. But by observing this one example we have here, it's quite possible that a planet such as the Earth, with all that's in it's favour for the evolution of animal lifeforms is not a common event in the galaxy. Not Forgetting the intelligence that homo sapiens has acquired, purely by chance for a moment, it's either extremely rare, or intelligence is a product of the laws of physics which in that case are built in as Paul Davies claims, an act of a designer. Another physicist whose name escapes me now once stated: The universe seems to have known we were coming.

[Lonewulf]

Another physicist whose name escapes me now once stated: The universe seems to have known we were coming.

I'm not impressed, as that sounds rather silly.

Of course Earth has all that we need. We wouldn't have evolved here if it didn't. If Earth lacked a resource or two, it's highly plausible that life would have simply adapted, and looked entirely differently than what it does. They'd also probably think that the "universe seems to have known they were coming", and wouldn't question those changing resources.

[JoeTheJuggler]

I have never claimed we are alone. I have always claimed we may be alone.

Then you DO agree that we may be one of dozens, hundreds or even thousands of intelligent civilizations in the galaxy? (I've only been asking you to agree to this for weeks if not months now, and prior to this post, you haven't indicated agreement to that.)

[JoeTheJuggler]

Not Forgetting the intelligence that homo sapiens has acquired, purely by chance for a moment, it's either extremely rare, or intelligence is a product of the laws of physics which in that case are built in as Paul Davies claims, an act of a designer.

Again, your thinking is all backwards and leans toward a perspective that is common among creationists.

All traits arose "purely by chance" AND ALSO as "a product of the laws of physics". There's no either/or about it. Everything in the natural world (that is to say, everything) obeys the laws of physics.

No Designer or Deity is necessary.

Another physicist whose name escapes me now once stated: The universe seems to have known we were coming.
Utter Creationist nonsense!

We know exactly what a universe tailored to humans would be like: it's the one believed by most people to be the case until science proved otherwise. It's a universe whose scale in time and space is proportional to human existence. That is, it's only a few thousand years old (created about the time human history started) and not very big at all. The Earth is at the center of that universe. The amount of stuff in that universe isn't much more than the eye can see. (And those things that look like tiny dots in the night sky are in fact just tiny dots.)

We now know that the Earth is not the center of the universe. Our solar system doesn't even occupy a special place in our galaxy. Our galaxy occupies no special place in the local group, etc. The age of the universe is nearly 14 billion years. The amount of stuff and distances are staggering.

You keep forgetting that life evolves adapted to conditions. Conditions are not created to fit life.

ETA:
This bit:
the intelligence that homo sapiens has acquired
makes no sense whatsoever. Homo sapiens did not acquire intelligence. There is no such thing as pre-intelligence homo sapiens. Rather "intelligence" is a term used to describe a grouping of traits that homo sapiens has. While it seems like a minor point, I think it once again shows that your approach to evolution is very similar to that of the Creationists.

You seem to think there's a magic point where humans were invested with intelligence (or consciousness) and that those things never existed in other organisms before in any form at all. You seem to think there's a sharp demarcation that separates humans from all other organisms on the planet. You seem to deny (or at least ignore) the fact that intelligence --or at least the traits that comprise it-- exists on a continuum among organisms on Earth.

With that Creationist approach, you also continually set up the dichotomy whereby intelligence is either the result of a Designer or it is "an accident". By accident, you seem to mean something that doesn't normally obey the laws of physics. (Again--there's no way around this--you are advocating a supernatural origin of intelligence. If not, then saying intelligence is an "accident" is no more meaningful than saying that ants or anything else evolved as an "accident".)

You use the same approach wrt the universe. You've used a version of the Fine Tuning argument with its backward approach to things. (The Texas Sharpshooter approach.)

[amb]

You keep forgetting that life evolves adapted to conditions. Conditions are not created to fit life

Think man will ever adapt to the conditions on Mars, Venus, Europa?
Of course life adapts to the conditions, but the conditions also need to be as they are here on Earth to a certain degree. It was the very first life that appeared on this planet that made more complex life possible billions of years later. If not for algae, there would probably be no oxygen, no complex life.
The origin of life itself is not accounted for by evolution alone. Some pre- biological process such as self-organization must have been involved, and later evolution took over.
There is a current gap in scientific knowledge, [for the present time] but plausible natural mechanism, sufficient to keep god out of any hypothesis.

[JoeTheJuggler]

Think man will ever adapt to the conditions on Mars, Venus, Europa?
Again, that's not how evolution works. Man didn't evolve on Mars, Venus or Europa.

Of course life adapts to the conditions, but the conditions also need to be as they are here on Earth to a certain degree.
Says who?


It was the very first life that appeared on this planet that made more complex life possible billions of years later. If not for algae, there would probably be no oxygen, no complex life.
I thought your thesis was that simple life is commonplace and complex life depends on conditions being identical to the Earth in every imaginable way. Now you're contradicting yourself. (You even admit that "conditions" like the oxygen in our atmosphere is the result of life and not a prerequisite.)

The origin of life itself is not accounted for by evolution alone. Some pre- biological process such as self-organization must have been involved, and later evolution took over.
There is a current gap in scientific knowledge, [for the present time] but plausible natural mechanism, sufficient to keep god out of any hypothesis.
We've gone over this before. Do you remember watching this video?

U6QYDdgP9eg
Hint: you did watch it. Your response was to say: "Great video. But as you know, I'm not argueing [sic] about the origins of life." Here it is 100 posts later, and you're back to claiming that abiogenesis is some big mystery that science can't explain. (As if, even if it were true, our ignorance somehow adds even a shred of evidence to support the Rare Earth thesis.)

Did you ever read the links I posted prior to that about spontaneously forming proteins? It explains it quite well. There is no huge gap in our knowledge wrt abiogenesis. There's no great mystery. Chemistry explains it quite well.

Look, you're offering nothing new but only jumping around. You're only repeating arguments that have been thoroughly refuted. You're contradicting yourself. And you're not responding to my questions. (Like how can human intelligence be an "accident" but not every trait of every organism?)

[LarianLeQuella]

but the conditions also need to be as they are here on Earth to a certain degree.


Really? Says who? Our one datapoint? And exactly what sort of conditions? Underwater volcanic vents? Radioactive mines? Arid mountain tops?

[arthwollipot]

Think man will ever adapt to the conditions on Mars, Venus, Europa?Given enough time, yes. Assuming that we had a way to survive there in the first place, then over many thousands of generations, humanity would adapt to whatever conditions it found itself in.

Of course, by then they probably wouln't be called "human".

[amb]

Number of alien worlds quantified

Breach of rule 4 removed. If you want to discuss an article, a link and short quote should be sufficient.

[JoeTheJuggler]

Number of alien worlds quantified

Quoted breach of rule 4 removed.

You really should use quote tags when you're quoting a block of text. You should also provide a reference and link to the source. It looks like you quoted a news story here. However, it looks like you're taking credit for writing it. And I think the man's name is the alt text for a photo that appeared in the newstory.

At any rate, this story is about what I've been saying from the beginning. I think even if there are many intelligent civilizations in the galaxy, it's unlikely we'll ever contact another one just because things are so spread out in time and space. (Really that's exactly what my first several posts on this thread said. You can go back and read them.)

[JoeTheJuggler]

I think maybe this is the article (http://news.bbc.co.uk/2/hi/science/nature/7870562.stm) that amb plagiarized (presented as his own words).

I'm also pretty sure it's the same group that has done modeling of the question of ETs that I referred to (with proper quote tags and a link to the article in question) back in post number 456 (http://forums.randi.org/showthread.php?postid=4462496#post4462496).

It would really save a lot of time, amb, if you simply read my posts with care.

[Radrook]

There are just too many transitional-stage unanswered questions for one to take evolution seriously as the mechanism producing life on this or any other planet.

[JoeTheJuggler]

There are just too many transitional-stage unanswered questions for one to take evolution seriously as the mechanism producing life on this or any other planet.
More creationist nonsense.

ETA: Even AIG lists this one as one of the "arguments to be avoided (http://www.answersingenesis.org/get-answers/topic/arguments-we-dont-use)".

[JoeTheJuggler]

There was a cool story in the news today (http://www.cnn.com/2009/TECH/science/04/16/microbes.antarctic.discovery/index.html) about subglacial microbes with a novel approach to living without oxygen:
At chilling temperatures, with no oxygen or sunlight, these newly found microbes have survived for the past 1.5 million years using an "iron-breathing" technique, which may show how life could exist on other planets.

I think it was Larian who said earlier that we must not wear blinders as to what conditions might sustain life. We keep getting surprised by terrestrial life in strange conditions. We shouldn't rule out ANY possibilities for ET life.

[amb]

I think maybe this is the article (http://news.bbc.co.uk/2/hi/science/nature/7870562.stm) that amb plagiarized (presented as his own words).

I'm also pretty sure it's the same group that has done modeling of the question of ETs that I referred to (with proper quote tags and a link to the article in question) back in post number 456 (http://forums.randi.org/showthread.php?postid=4462496#post4462496).

It would really save a lot of time, amb, if you simply read my posts with care.

I apologize for that. It's always a lack of time on my part. Rush, rush. I should have previewed it before posting, or at least read the post after posting which I didn't do as I switched off immediately after that post.
I thought the source would have been shown as well. It didn't.

[amb]

Next time I will post a link.

[amb]

There are just too many transitional-stage unanswered questions for one to take evolution seriously as the mechanism producing life on this or any other planet.

You must be joking! Evolution is not in question and is a fact. The very origins of self replicating molecules are the only remaining questions to be answered, and sooner or later it will. The means of how it happened, was it on Earth or somewhere else and brought here by an asteroid, comet or whatever that scientist still dispute.
What is in dispute here is the likely/unlikely ''Rare Earth'' hypothesis.
Life is more than likely teeming in the universe. But perhaps for various reasons, intelligence isn't.
If conditions suit, life will somehow evolve everywhere on an Earth like planet, and perhaps non-Earth Like as well as claimed by some biologists.
But there are a few who claim that we may be unique, an accident that only occured once, or at best, a few dozen times throughout the cosmos.

[LarianLeQuella]

There was a cool story in the news today (http://www.cnn.com/2009/TECH/science/04/16/microbes.antarctic.discovery/index.html) about subglacial microbes with a novel approach to living without oxygen:


I think it was Larian who said earlier that we must not wear blinders as to what conditions might sustain life. We keep getting surprised by terrestrial life in strange conditions. We shouldn't rule out ANY possibilities for ET life.

Don't forget microbes that seem quite content in sulfuric acid. :p

I would love to see another "great demotion" for our place in the universe once Webb has a chance to look around a bit more and hopefully finds some candidates. Remember, we couldn't even detect our own civilization from the nearest star with the technology we have. We currently have a selection bias to NOT find anything, even if it's teeming out there at our level of development. And to make things more difficult for anyone to find US, is that we are leaking less and less extranious radio noise because of focused transmission technology and fiber optics. Someone may conclude that we wiped ourselves out instead of became more efficient with our communications technology! Woudn't that be funny!

[amb]

Please have a look at this. A bit longish, but well worth it if you all have not yet seen it.
It is exactly what I've been trying to put across, but by a giant of one of today's scientists.

http://www.youtube.com/watch?v=Un1,ZW29GTw

It's not working. It is a lecture by Richard Dawkins addressing a hall seemingly full of theists.
Sorry guys, Ive spent half an hour trying to get it back to no avail.

[JoeTheJuggler]

Please have a look at this. A bit longish, but well worth it if you all have not yet seen it.
It is exactly what I've been trying to put across, but by a giant of one of today's scientists.

http://www.youtube.com/watch?v=Un1,ZW29GTw

It's not working. It is a lecture by Richard Dawkins addressing a hall seemingly full of theists.
Sorry guys, Ive spent half an hour trying to get it back to no avail.

You correctly pointed out to Radrock that the question of ET intelligence is not a question of theism, so I'm not sure if this video would've helped your case anyway. You really have been using the language of creationists in making your case. That's why I think it's you that have been muddying the waters and bringing in that point of view even as you reject it. (The false dichotomy that either intelligence like ours is designed and commonplace in the universe or "accidental" and extremely rare is what I'm talking about. It raises the creationist point of view. It's just bad arguing, but it really does depend on the creationist perspective.)

[LarianLeQuella]

Hey, an interesting article: http://www.sciam.com/article.cfm?id=what-makes-us-human&sc=DD_20090420

Haven't got through the article yet (I just received it in email) so let's see where that takes this discussion.

[amb]

The video I was trying to show was of Dawkins discussing more or less what I have been saying here for months. And that is that the stupendous likelihood of life originating are trillions to one. But because we are here discussing it shows that it has happened, at least once. Also, that the universe is probably teeming with microbial life. But because we at this juncture of time, just aren't sure. Anything is possible in an almost infinate cosmos.
Also, that there may well be a god out there, but this god has evolved from a simple life form to the complexity of whatever it is today.
A civilization that has managed to survive for billions of years would in our eyes be God himself and more.
Then he speaks of the Fermi Paradox. If it was so, why isn't this god/civilization here, now. Surely they would have the curiosity bug to explore the universe for other signs of life. Unless the light speed problem is unsolvable even by a god like civilization they most certainly would have discovered our little planet by now.

[JoeTheJuggler]

Unless the light speed problem is unsolvable even by a god like civilization they most certainly would have discovered our little planet by now.
And with that you can prove that it's not likely that a god-like civilization has existed for a long time in our galaxy. However, as I've already shown, a civilization just like our own would be undetectable by us even just beyond our own solar system.

So all of this says absolutely NOTHING about the existence of ET intelligent civilizations in our galaxy. It only says something about god-like intelligent civilizations (which might be an impossible fantasy).

[JoeTheJuggler]

duplicate post

[amb]

" All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by appearance of probability.''

____David Hume

[amb]

http://www.youtube.com/watch?v=kNu8F01BD9k

Still trying to get that link to that lecture of a few days ago.

This is not that link, but interesting nevertheless.

[JoeTheJuggler]

" All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by appearance of probability.''

____David Hume

I'm skeptical of the claim that there is something unique about the Earth in the galaxy. From what we know, the laws of physics, chemistry and biology are the same everywhere. The same amount of time has passed everywhere.

You should read the Creationist book, The Privileged Planet, and see how similar its way of thinking is to the Rare Earth way of thinking.

[LarianLeQuella]

" All that belongs to human understanding, in this deep ignorance and obscurity, is to be skeptical, or at least cautious; and not to admit of any hypothesis, whatsoever; much less, of any which is supported by appearance of probability.''

____David Hume


You realize that this exact quote can be used AGAINST your position that the earth is somehow unique or rare? :p

[amb]

I have as yet not received a satisfactory answer of why, out of the billions of lifeforms that have ever lived on this planet, [ dinosaurs lived here for around 20 million years] only homo sapiens managed to develop such an intelligence to ask these questions.
I'm far from saying that it's certain we are alone in this almost infinite universe.
I still state that most probably, the cosmos is teeming with microbial life. Perhaps even some kind of animal life. But so far there is not a shred of evidence for any highly intelligent beings such as ourselves.

[amb]

http://www.youtube.com/watch?v=Uu1iZW29GTw


Found it! [I hope]

[JoeTheJuggler]

I have as yet not received a satisfactory answer of why, out of the billions of lifeforms that have ever lived on this planet, [ dinosaurs lived here for around 20 million years] only homo sapiens managed to develop such an intelligence to ask these questions.

Natural selection. Also, humans are not the only species to attain intelligence or consciousness as you seem to think. It exists as a continuum among many animals. As I mentioned earlier, you're basically asking why is there only one animal that has the highest level of this collection of traits. That's because only one can be the highest level. It's just like asking why is there only one tallest animal ever to have lived.


I still state that most probably, the cosmos is teeming with microbial life. Perhaps even some kind of animal life. But so far there is not a shred of evidence for any highly intelligent beings such as ourselves.
There's also not a shred of evidence that the cosmos is teeming with microbial life. You apparently admit to that possibility because you think chemistry and physics works the same elsewhere as it does here. Yet you seem to accord "intelligence" some sort of magical origin not explainable by natural selection and the laws of physics.

I'm far from saying that it's certain we are alone in this almost infinite universe.
No you're not very far from saying that. Since you're still unwilling to admit that it's entirely possible that there are many intelligent civilizations in the galaxy, you are still arguing that we are unique in the galaxy (and not merely that we may be unique--a position that I don't think anyone disagrees with).

[LarianLeQuella]

And to throw more gas on the fire, who says you even need a planet at all: http://www.sciam.com/blog/60-second-science/post.cfm?id=complex-organic-molecules-detected-2009-04-22&sc=DD_20090423 :p

[JoeTheJuggler]

I just read about a book called Life Everywhere by David Darling (http://books.google.com/books?id=Xx5Lidc_8ssC&dq=%22Life+Everywhere%22+David+Darling&printsec=frontcover&source=bl&ots=ud4xPyF5XT&sig=dGe2iKc_IpOOnSS1SQtEDchyMtc&hl=en&ei=UTLxSaqsGZTAM-vmxKoP&sa=X&oi=book_result&ct=result&resnum=1#PPR7,M1). I've only read about the book (in Victor Stenger's God: The Failed Hypothesis), but it supposedly gives a point by point refutation of each of the so-called "requirements" for life in Rare Earth.

I'll add this book to my list, but I may not get to it very soon.

[amb]

I've read the book by Stenger, and he discusses both scenarios. But the main theme of that book is the failure of science to prove God. There is not a single clue in all the universe to prove that there is a god. All the evidence available instead proves there is no God.

[JoeTheJuggler]

I've read the book by Stenger, and he discusses both scenarios. But the main theme of that book is the failure of science to prove God. There is not a single clue in all the universe to prove that there is a god. All the evidence available instead proves there is no God.
And this has nothing to do with my post. Have you read Darling's book?

[amb]

I just ordered it through Amazon. I see Ward has a book out a well which sounds good seeing he is co-author of ''Rare Earth,'' titled ''Life As We Not Know it.''
I wish I had the time and money. I would order a dozen such books on that page.

It really is a fascinating subject with a hundred differing views.
The book ''Rare Earth'' has not really been criticized as much as I expected by orthodox astrobiologists. Is it because it's possible?
Looking forward to reading Darling's book. I should get it within a week.

[JoeTheJuggler]

Just looking at the bit of the Darling book that's available on-line, I think there's just the one chapter that addresses Rare Earth. Without going into the details, I think he's saying about the same thing I am. In this game of speculation, there's probably as much (or more) evidence to speculate that when the "conditions" on the Earth were destabilized or less friendly to existing life forms, that's when you got bigger and faster changes through evolution.

It sounds a lot like punctuated equilibrium.

Where the Rare Earth theory says that in order to get higher forms of life you need to have an exact copy of the Earth as it is now. Darling says, I think, that since life responded well to pretty big changes over the history of the Earth, it could thrive in a lot more diverse environments elsewhere too.

[amb]

Life thrives in impossible places right here on Earth. Microbes inside a volcano, life at the vents at the bottom of the seas where temperature is many thousands degrees F. Tube Worms have been discovered there. There is no oxygen or even sunlight in such places, yet there is life. That bodes well for finding primitive forms of life elsewhere in the the solar system. Microbial life has been found in the frozen wastes of Antarctica miles beneath the surface.
Who knows, there may be bacteria living on our moon deep under the surface away from the damaging ultra violet light and radiation which destroys cells.
A planet with no ozone layer to protect surface life from radiation from it's parent star can only have life deep underground. It would need to be technologically millions of years ahead of us to build any kind of civilization in such conditions, which brings me back to; If they're so far advanced and live within say 100-200 light years distance, surely they would be here by now. Or at least have left some clue of their existence.
Fermi's Paradox is stuck in my very thick skull it appears.

[JoeTheJuggler]

A planet with no ozone layer to protect surface life from radiation from it's [sic]parent star can only have life deep underground.
You don't know that. What is this statement based on? Earlier in this thread, I showed you evidence of animals that adapt to radiation and basically produce their own shields in their anatomy.

It would need to be technologically millions of years ahead of us to build any kind of civilization in such conditions,
Why? This makes no sense at all. There is nothing that requires another technological civilization be at any particular stage with regard to ourselves.

In fact, we don't actually know if "technology millions of years ahead of us" is even possible. It could be that we're close to the end of technological advancement that is possible. It could also be that civilizations tend to wipe themselves out at a certain level of technological development. We simply don't know. Therefore, we shouldn't assume technology that's substantially beyond ours (near lightspeed transportation, time travel, etc.)

which brings me back to; If they're so far advanced and live within say 100-200 light years distance, surely they would be here by now. Or at least have left some clue of their existence.
Fermi's Paradox is stuck in my very thick skull it appears.
Yes, and I've rebuked your Fermi's Paradox argument numerous times on this thread. The last two times I did so, I numbered the points and requested that you please not bring this failed argument up again without responding to each of my numbered points.
http://forums.randi.org/showthread.php?postid=4412527#post4412527

[LarianLeQuella]

If they're so far advanced and live within say 100-200 light years distance, surely they would be here by now. Or at least have left some clue of their existence.


Why do you keep coming back to this? :confused:

OUR civilization isn't even detectable out to the nearest star.
Why aren't WE out there yet then?
Who says that their technology is even remotely like ours?
Hell, who says their intelligence is even remotely like ours?

As Joe said, please address the numbered points if you are going to repeat the same question over and over again.

[JoeTheJuggler]

The logic that says, "I can prove by the lack of evidence that there are no intelligent civilizations that are millions of years in advance of our own in the galaxy" does not prove that there are no other intelligent civilizations besides ourselves in the galaxy. In fact, it doesn't rule out a galaxy full of intelligent civilizations at or near our own technological level.

I think the primary flaw in this argument (aside from assuming that any technology that is possible to attain will be attained, and that any technology that is attained will have been used millions of years ago) is that it moves the goalposts. We're not talking about arguments for or against the existence of super-advanced technological civilizations that have existed for millions of years. I would stick with what we know for sure is possible (ourselves) and ask what it would take to prove that civilizations just like our own do not exist in the galaxy.

We have nowhere near enough information to make any such conclusion.

[amb]

The logic that says, "I can prove by the lack of evidence that there are no intelligent civilizations that are millions of years in advance of our own in the galaxy" does not prove that there are no other intelligent civilizations besides ourselves in the galaxy. In fact, it doesn't rule out a galaxy full of intelligent civilizations at or near our own technological level.

I think the primary flaw in this argument (aside from assuming that any technology that is possible to attain will be attained, and that any technology that is attained will have been used millions of years ago) is that it moves the goalposts. We're not talking about arguments for or against the existence of super-advanced technological civilizations that have existed for millions of years. I would stick with what we know for sure is possible (ourselves) and ask what it would take to prove that civilizations just like our own do not exist in the galaxy.

We have nowhere near enough information to make any such conclusion.

In answer to Larian. We have had our present technology for a little over a hundred years, yet we have already sent probes that have left our solar system and are at present travelling into interstellar space. What will we do in say, a thousand years?
To Joe, I say this.
Have you actually sat down and looked at the dozens of coincidences that have made animal life possible on this planet?
Why do you think man finds it dificult to adapt to living in the Sahara Desert?

[JoeTheJuggler]

In answer to Larian. We have had our present technology for a little over a hundred years, yet we have already sent probes that have left our solar system and are at present travelling into interstellar space. What will we do in say, a thousand years?
But our probes are not ubiquitous in the galaxy. By your argument based on Fermi's Paradox, we don't exist right now.

I repeat: to make anything of the absence of ubiquitous probes from advanced intelligences wrt to the question of whether or not ET intelligences exist in the galaxy requires you to make a number of unreasonable assumptions. I've refuted them thoroughly already. Please drop this line of argument unless you are willing to respond to my numbered points that refute this approach.


To Joe, I say this.
Have you actually sat down and looked at the dozens of coincidences that have made animal life possible on this planet?
Why do you think man finds it dificult to adapt to living in the Sahara Desert?
You're stilling using a backward approach to evolution that smacks of Creationist arguments. There were absolutely NO "coincidences" that made animal life possible. Life adapted to the conditions, not the other way around.

I suggest you read up on evolutionary biology before you continue this approach.

[LarianLeQuella]

In answer to Larian. We have had our present technology for a little over a hundred years, yet we have already sent probes that have left our solar system and are at present travelling into interstellar space. What will we do in say, a thousand years?
Again, that's just humans. Stop being such a frikkin humanchauvenist. And those probes that have left our solar system, are any of them heading towards any particular star? How long will it take for those probes to reach said star? (HINT: Our species will most likely be extinct by then!) Do we have plans for any other probes that will leave the solar system? Again, we apparently don't exist still.


To Joe, I say this.
Have you actually sat down and looked at the dozens of coincidences that have made animal life possible on this planet?
Why do you think man finds it dificult to adapt to living in the Sahara Desert?

NAME a coincidence. Cite exactly what about it is a concidence. I contend that there is not a singe coincidence at all, and you are again being a fraking humanchauvinist.

[LarianLeQuella]

hehe found this: Human-chauvinism: http://www.simonyi.ox.ac.uk/dawkins/WorldOfDawkins-archive/Dawkins/Work/Reviews/1997-06fullhouse.shtml

[amb]

I could give you any number of coincidences from the book ''Rare Earth, but it appears you guys reject it out of hand anyway, so why bother.

''The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, [to which] our species could migrate.'' ---Carl Sagan, Pale Blue Dot.

[JoeTheJuggler]

I could give you any number of coincidences from the book ''Rare Earth, but it appears you guys reject it out of hand anyway, so why bother.

''The Earth is the only world known, so far, to harbor life. There is nowhere else, at least in the near future, [to which] our species could migrate.'' ---Carl Sagan, Pale Blue Dot.

The source doesn't matter. It's this backward way of looking at evolution that I reject.

Also, I should point out, we've gone over this before.

Do you remember the business about the Texas Sharpshooter fallacy? That's all you're doing.

Also, no one here is saying human life should be well adapted to other places in the galaxy. That makes no sense. Your Carl Sagan quote says nothing about your Rare Earth theory. You're just making a straw man argument. None of us said that homo sapiens is likely to have evolved in other places in the galaxy.

Here's the problem with the Rare Earth argument: you cite a number of things about the Earth and claim that absolutely every last one of them is a requirement for any type of complex or intelligent life. When queried, you point out that there might be a case for some of them being requirements for human life to have developed. Do you understand that "human life" is not the same thing as "any kind of complex or intelligent life"?

And that's leaving aside for a moment that you could as well argue that what led to the evolution of complex and intelligent life forms on Earth was not the fact that it is so stable, but rather instability in environments that kept shaking up ecology (punctuated equilibrium).

[JoeTheJuggler]

Example of a "coincidence": when a baby horse is born, his legs are exactly strong enough to stagger to his feet in order to nurse in 1 g of gravity. If the Earth were significantly larger or closer to the sun, or the sun was more massive, and our gravity was more than 1 g--even by a little bit, then the horse couldn't stand up and nurse and survive and pass on its genes.

Coincidence?

[LarianLeQuella]

I could give you any number of coincidences from the book ''Rare Earth, but it appears you guys reject it out of hand anyway, so why bother.



We DON'T reject them out of hand. They are POOR arguments... Your quote only means that it's the only planet we know of, and the only datapoint we have. If you only had a tomato from Kansas, would that somehow represent every fruit on the planet? Would Kansas soil be the ONLY conditions that even that tomato could grow in, never mind the numerous different biospheres throughout earth that have fruit?

Really, the conditions set forth in rare earth are only applicable to ONE datapoint. I suppose it's an accurate title as far as describing the specific planet that homo sapiens evolved on, but it has zero bearing on any other possible planet with intyelligent life.

[amb]

Isn't the argument about ''Earth Like'' lifeforms? I won't argue that there's not some planet out there with twice the size and gravity of Earth. That the intelligent inhabitants of this world weigh around two tons. In the infinity of space, most things are possible.
Other Earths are even possible, but rare in my humble opinion.

[JoeTheJuggler]

Isn't the argument about ''Earth Like'' lifeforms?
What argument? The question of the existence of ETI is NOT about the question of finding a near duplicate of the Earth and a near duplicate of humans.

You're backpedalling now. That's fine, but you should admit it. You've been saying all along that you don't think any kind of complex life other than the Earth is likely possible in the galaxy.

(And yes, I recognize you've used the softer language of "may be" and "likely", but when I ask if you'll also admit that there "may be" dozens or hundreds of intelligent civilizations in the galaxy, you won't say it. That's why I still say you're arguing the stronger position. If you rule out that possibility, then you are actually arguing that something is the case, not that something may be the case.)

[JoeTheJuggler]

I won't argue that there's not some planet out there with twice the size and gravity of Earth. That the intelligent inhabitants of this world weigh around two tons. In the infinity of space, most things are possible.


You have been arguing against exactly that. You've repeatedly stated the Rare Earth Theory positions which is that simple life may be common, but complex life and intelligence is vanishingly rare, and that we are probably the only intelligence in the galaxy, and maybe only one of a dozen in the entire universe. The Rare Earth Theory claims that virtually every detail about the Earth is an absolute essential requirement for complex life, and that finding another near duplicate of the Earth is the only way to find complex life. Since that would be be very rare, it would reduce the number of candidates for intelligent life down to just a few, and almost certainly eliminate the possibility of intelligent life elsewhere.

I can cite many times you have said that you think microbial life is common, but complex life is very rare and requires almost every little feature that the Earth (by "coincidence") has.

I'm glad you have changed your position and admit that a planet not exactly like the Earth could have an intelligent species not at all like humans on it.

[LarianLeQuella]

some planet out there with twice the size and gravity of Earth. That the intelligent inhabitants of this world weigh around two tons.

I for one welcome our two ton overlords!






Oh wait, those would be Americans from Mississippi, wouldn't they... :(


And no, the argument has been for ANY "intelligent" life out there. It could be a gian't crab looking thing, or some amorpheous group conciousness of geleatinous goop, or whatever the hell evolution comes up with on some distant panet. We don't know.

[amb]

:) You have been watching too many S/F shows.

[arthwollipot]

OUR civilization isn't even detectable out to the nearest star.We have been broadcasting radio signals for over fifty years. In theory, any civilisation within fifty light years could potentially have detected us.

[LarianLeQuella]

We have been broadcasting radio signals for over fifty years. In theory, any civilisation within fifty light years could potentially have detected us.


Potentially, but not reliably. That nasty inverse square law mucks it up. Even the Ariceibo can't detect us from Alpha Centauri.


As posted in #226 (http://forums.randi.org/showpost.php?p=4302936&postcount=226):

It is very unlikely that alien civilizations are going to pick up television transmissions according to the table from this site:
http://www.faqs.org/faqs/astronomy/faq/part6/section-12.html

see copy of table in this post:
http://forums.randi.org/showpost.php?p=3557598&postcount=82

Note the range for UHF television (2.5 AU) and the range for the UHF carrier (0.3 LY). Neither estimate is enough to make it out to the nearest star. They don't list a range for VHF television but FM radio is in the middle of the VHF television band and the estimated range for that is 5.4 AU. Again no where near enough to make it to the first star.

The optimistic ranges for detecting a nearby planet are based on either massively powerful transmitters or highly focused outputs from large transmitters.

The calculations that I made in a previous post suggested that one would need an Arecibo sized antennae with a 250,000 watt transmitter to be able to send a detectable signal to a planet as far away as 150 light years.

This is easily with the capability of earth's technology. The Arecibo antennae has only limited steering capability. I think it is mostly constrained by the direction it is pointing as it rotates with the earth so there are lots of potential targets it couldn't be aimed at. The 250,000 watts could be pulsed so that no where near 250,000 watt of continuous power would be required. But will the powers that be that control enough of earth's resources ever feel like funding a major effort to transmit to unknown alien civilizations?

Post where the calculation was discussed:
http://forums.randi.org/showpost.php?p=3565450&postcount=94

I think the most likely intentionally produced electro magnetic radiation produced on the earth today that could be detected by an alien civilization would be from radars. These are focused and some of them are very powerful. I notice that the table lists the range of a particular weather radar as .01 light years. That doesn't validate my guess because it lists the range of a UHF carrier as .3 light years but I suspect that other radars would do better. Military radars might do much better.

But even if the ranges of military radars are much greater than what is listed for the weather radar in the table, the ranges are still probably much too small to get much beyond the nearest stars.

In another post I linked to an article discussing the feasibility of a laser transmitter to reach stars. If the powers that be wanted to dedicate some resources to this idea the authors suggest that we might hit a 1000 light years with a currently feasible optical laser. I think that bumps the stars for which a signal might be detected from about a 1000 that lie within 100 light years to about a 100,000 that lie within a 1000 light years.

The article on the possibility of optical SETI:
http://seti.harvard.edu/oseti/tech.pdf

Why is it that things have to be repeated so often? :p

[arthwollipot]

Potentially, but not reliably. That nasty inverse square law mucks it up. Even the Ariceibo can't detect us from Alpha Centauri.Well, yes, I did say "potentially". And it depends on their detecting technology. They may have radio receivers more sensitive than Aricebo. :cool:

[amb]

Fermi's Paradox still holds true until otherwise proven.

[JoeTheJuggler]

Fermi's Paradox still holds true until otherwise proven.

Wrong.

If you refuse to reply to my numbered points:

http://forums.randi.org/showthread.php?postid=4412527#post4412527

then you should at least address the Wiki article that also gives a number of explanations for why they're not here:

http://en.wikipedia.org/wiki/Fermi_paradox#Explaining_the_paradox_theoretically

But at the very least, quit pretending that the argument that there are no other intelligent civilizations in our galaxy based on Fermi's Paradox is in any way a valid argument.

[JoeTheJuggler]

Ignore this one.

I got confused thinking I was seeing a new post that rehashed an old argument when in fact I was looking at a very old post.

[LarianLeQuella]

Well, yes, I did say "potentially". And it depends on their detecting technology. They may have radio receivers more sensitive than Aricebo. :cool:

:p All of a sudden I had an image of a giant asteroid (or small moon) carved out wiht a receiver on it, and I heard in my mind, "That's no moon!" I am such a geek!

AMB - You mean a horrible supposition, based on flawed understandings, is somehow even relevant to this discussion? Please explain...

[JoeTheJuggler]

Well, yes, I did say "potentially". And it depends on their detecting technology. They may have radio receivers more sensitive than Aricebo.

From the page linked earlier:
http://www.faqs.org/faqs/astronomy/faq/part6/section-12.html

For example, a TV picture having 5 MHz of bandwidth and 5
MWatts of power could not be detected beyond the solar system
even with a radio telescope with 100 times the sensitivity of the
305 meter diameter Arecibo telescope.

[arthwollipot]

Okay, okay. You got me. I concede.

[davefoc]

Well, yes, I did say "potentially". And it depends on their detecting technology. They may have radio receivers more sensitive than Aricebo. :cool:

I don't think this is likely.

I believe the limitation on detection range listed in the table I posted was based on the noise level at the particular frequency. In order to detect a signal its amplitude needs to be large enough to allow it to be detected out of the EM noise. At some point the sensitivity of a receiver ceases to be the limiting factor on the ability to detect a signal and the ambient noise at that frequency becomes the limiting factor.

It is possible to improve detection range by using a bigger antenna. This works because the greater directionality of the larger antenna improves the signal to noise ratio of the received EM radiation

[amb]

Wrong.

If you refuse to reply to my numbered points:

http://forums.randi.org/showthread.php?postid=4412527#post4412527

then you should at least address the Wiki article that also gives a number of explanations for why they're not here:

http://en.wikipedia.org/wiki/Fermi_paradox#Explaining_the_paradox_theoretically

But at the very least, quit pretending that the argument that there are no other intelligent civilizations in our galaxy based on Fermi's Paradox is in any way a valid argument.

It may be that technological extraterrestrial civilizations exist, but that human beings cannot communicate with them because of various constraints: problems of scale or of technology; because their nature is simply too alien for meaningful communication; or because human society refuses to admit to evidence of their presence. From the Wiki article
Doesn't this sound like a conspiracy of Governments to silence on the Ufology subject?

[JoeTheJuggler]

It may be that technological extraterrestrial civilizations exist, but that human beings cannot communicate with them because of various constraints: problems of scale or of technology; because their nature is simply too alien for meaningful communication; or because human society refuses to admit to evidence of their presence. From the Wiki article
Doesn't this sound like a conspiracy of Governments to silence on the Ufology subject?

The only thing that makes sense here is the part that I've highlighted, and that only if by "scale" you mean how far apart things are in the galaxy and universe.

But I'm glad to see you've abandoned that Rare Earth stuff.

[LarianLeQuella]

Joe,

I'd also plausibly consider the "simply too alien" bit as well, only because we really have no idea what so ever what, if any, type of intelligence is out there. Sure, we have dreamt up all sorts of strange aliens with our stories, but nature always seems to manage to surprise us.

On the scale, again, if they have been advanced for a long, long time, maybe we're nothing more than a curious homnid that really hasn't shown true intelligence. As it is, many animals on our planet display a great deal of intelligence attributes, but for the most part, to humans they are just animals. I can see where AMB could be thinking on that.

[JoeTheJuggler]

I'd also plausibly consider the "simply too alien" bit as well, only because we really have no idea what so ever what, if any, type of intelligence is out there.

That could be a reason why we end up unable to communicate with an ETI we come across in the future. But at this point, it's not a reason why we have no knowledge of them. In other words, the scale question: it could well be that there are about 100 ETI roughly equivalent in technological development with us scattered about the galaxy. Let's assume they've all had a similar history to ours--have had the ability to produce and receive radio waves for maybe 100 years or so. Chances are that they'll all be way too far apart for any two to make contact, at least for a very long time.

That's a very different sort of argument to the one that if we encounter an alien life form, its intelligence may be too alien for us ever to communicate.

[JoeTheJuggler]

amd, did you get the Darling book yet? I got mine yesterday and just read the chapter on the Rare Earth Theory today.

For the most part, it makes the exact same points we've brought up on this thread. You can't assume the Earth is so ideally suited to life that 1) complex barely arose here by the skin of its teeth, and 2) every last detail about the Earth and its history was essential for complex life to arise.

On the idea of punctuated equilibrium (interesting that no where in that chapter does Darling use that term, but that's clearly what he's talking about in terms of jump-starting or boosting evolution): he points out that the authors of R.E.T. want to have it both ways, sometimes pointing to episodes of instability as being necessary for the path that led to humans and sometimes that instability is anathema to the development of higher life forms.

The fact that life didn't become very complex on Earth for such a long time, might mean that the Earth is less than ideal. In R.E.T., though, you must assume that if anything were even a tiny bit different than the Earth--conditions and events--that complex life would be impossible. As I've said, this is unsupported speculation that could as easily go the other way--that is, that there could be conditions MORE amenable to complex life than the Earth.

As Darling says, the trend that started with the Copernican revolution will most likely continue, and we'll most likely find that there is nothing special or unique about the Earth. Without know anything else, I think it's safest to assume that we are an "average" planet that supports complex life. There's no reason to assume the Earth is the most ideal possible in the galaxy (or beyond!).

I was very surprised to see that my intuition about how all this sounded similar to Creationist talk has a very real source. Guillermo Gonzales, the astronomer that the authors of R.E.T. relied heavily on is, in fact, a Christian apologist. The very same arguments he uses in the context of Rare Earth are the ones he also uses to support the idea of a divine designer. From what I read, the authors were genuinely unaware of these other writings of Gonzales (even though, as he himself says, they weren't covert in the least). Just the language is what made me suspect something like this: fine-tuned, coincidence, accident, miraculous, etc.

[LarianLeQuella]

The fact that life didn't become very complex on Earth for such a long time, might mean that the Earth is less than ideal.

I love that train of thought! :D

[arthwollipot]

I don't think this is likely.Yes, I already conceded. :p

[amb]

amd, did you get the Darling book yet? I got mine yesterday and just read the chapter on the Rare Earth Theory today.

Not yet. I can't wait to read it. I should get it sometime this week or at the latest, next week.
I still believe that all of the dice falling into place as they did to produce an Earth are not as common as most people think. Not forgetting that without our moon and size of it also makes animal life possible here. I have never denied that microbial life is probably teeming out there. Even in our own solar system, I'm convinced that microbes will be discovered in the not to distant future, perhaps even deep underground on Mars. The question then will be asked. Are these microbes the same as on Earth? If they are, then there has in the distant past been a cross flow of these microbes from Mars to Earth or vice a versa. If entirely different it will open up a Pandora's Box of possibilities.

[JoeTheJuggler]

Not forgetting that without our moon and size of it also makes animal life possible here.
Unproven speculation. You can forget that.

The point of the moon argument is that it's required to make the Earth's axial precession go faster and stay out of phase with its slower orbital precession. Darling points out 1) large collisions that caused a large moon might be the rule rather than exception and 2) you can get faster precession with a lot of other scenarios rather than a large moon, and 3) even if you have the resonance of coinciding precessions, the extra tilt that would give and ensuing climatic changes are still gradual over millions of years and life on Earth has flourished under more severe traumas.

In fact, as noted above, a big part of refuting the R.E.T. is that trauma of one sort or another seems to have driven the biggest bursts of evolution. This cozy "just right" planet as a prerequisite to complex life isn't even supported in our sample size of one.

[amb]

If the Earth had no suffered a catastrophic collision with a comet 65 million years ago that wiped out around 70% of existing life, including the dinosaurs that inhabited this planet for around twenty million years, we would not now be here to even ponder these questions. And, by the way, why didn't a dinosaur evolve intelligence? surely they had enough time.
See what I'm getting at? We are here today due to a string of coincidences that perhaps don't happen too often in the universe. We live in a HZ of the galaxy that has only around 10% of the total stars.
Just as life can only persist on a planet at a specific distance from it's star, it seems like the star itself must orbit within a certain ring around the galatic core.
The outer edge of this ring is set by the minimum metallicity required to form rocky planets, the inner boundry by various hazards posed by the central realm of the galaxy, such as the greater danger of close shaves with other stars and nearby supernovae. Even a solar system futher out in the disc is not safe, as regular crossings of the spiral arms carry similar risks. The safest place for life is probably within a thin halo around the galaxy, not to close to the center, and not too far as the edge of the galaxy as that has not enoegh mettalicity to form rocky planets and therefore, us.

[JoeTheJuggler]

You're just repeating the same stuff you said pages and pages ago that's already been answered.

I've had enough. The conversation isn't going anywhere.

[amb]

I'm afraid Joe that we will not live long enough to get a definite answer on this most intriguing of subjects.

[LarianLeQuella]

http://xkcd.com/638/ :p

[amb]

Jeezus H Christ. This thread is still alive? Has anything changed?

[LarianLeQuella]

Depends, have you abandoned the "Rare Earth" nonsense as a prerquisite for an advanced civilization? (Sorry, haven't been keeping track.) :p

[davefoc]

This is one of those rare threads that goes on and on without an obviously crazy person to drive it.

It is also a thread that despite a whole lot of effort by the people involved I never exactly understood exactly what the issues of contention were.

Everybody seems to agree that given the vast number of stars in a galaxy and the vast number of galaxies that some form of sentient life probably exists outside the earth.

Everybody seems to agree that as of yet there is no probative evidence for a visit to Earth by sentient beings from outside the Earth.

It seems that nobody could disagree with amb's overview of the reasons why sentient life hasn't been detected on the Earth:

It may be that technological extraterrestrial civilizations exist, but that human beings cannot communicate with them because of various constraints: problems of scale or of technology; because their nature is simply too alien for meaningful communication; or because human society refuses to admit to evidence of their presence.

I think everybody would agree that Fermi's paradox, that while interesting, does not provide a definitive answer as to whether there is sentient life that is within range of contact from the earth.

So what is the issue that people disagree about? Is it that some people think that sentient life in the galaxy is rare and some other people think it is very rare? Is it that some people think the chances of contact with alien sentient life on earth is low and some people think it's somewhat more likely than that?

My gut feel about the situation is that human beings will never detect another civilization with sentient life. This is based on my view that sentient life is rare and that there are far too few places where sentient life seems possible within a range where communication is possible to provide much of a chance of contact. Is this the notion that some people are disagreeing with?

If one is looking for an argument from authority that I am wrong one needs to look no further than Mr. Drake himself who seems to have gotten more enthused of late about the possibility of contact. My own horribly amateurish take on Mr. Drake's thoughts on this is that he underestimates the importance of data that has been found since he first published his equation that suggests that sentient life is even less likely than he originally estimated and that he exaggerates the possibility of sentient life on non-earth like planets that have been detected since he published his equation originally.

[JoeTheJuggler]

This is one of those rare threads that goes on and on without an obviously crazy person to drive it.
I wouldn't say amb is "obviously crazy" but he definitely goes against almost every one of your "everybody" statements:

Everybody seems to agree that given the vast number of stars in a galaxy and the vast number of galaxies that some form of sentient life probably exists outside the earth.
Amb has followed the Rare Earther line and said that it is almost certain that we are alone in the galaxy and there may only be a dozen or so ETIs in the entire universe.

Everybody seems to agree that as of yet there is no probative evidence for a visit to Earth by sentient beings from outside the Earth.
I agree. This wasn't a UFO thread.

It seems that nobody could disagree with amb's overview of the reasons why sentient life hasn't been detected on the Earth:
That wasn't amb's words. He was quoting (without tags or quotation marks) from a Wiki article. His comment on it was, "Doesn't this sound like a conspiracy of Governments to silence on the Ufology subject?" In other words, he was disagreeing with the quote you offered.

ETA: Amb was equating the Wiki quote you quoted with UFO CTers. He was dismissing refutations of the Fermi paradox by saying it's the same as people who think we're being visited by space aliens.



I think everybody would agree that Fermi's paradox, that while interesting, does not provide a definitive answer as to whether there is sentient life that is within range of contact from the earth.
Again, amb has steadfastly maintained that Fermi's paradox is strong proof that ET intelligence does not exist.

So what is the issue that people disagree about?
Mostly, amb espouses the quasi-religious arguments given in The Rare Earth hypothesis. While amb is not a creationist, the arguments he supports in the Rare Earth position are just as backward as the Fine Tuning arguments. The Rare Earth position states that every rare or unique feature about the Earth is prerequisite to complex life.

Is it that some people think that sentient life in the galaxy is rare and some other people think it is very rare? Is it that some people think the chances of contact with alien sentient life on earth is low and some people think it's somewhat more likely than that?
There's rare and then there's rare--a point I've made time and again. (If something happens in 1 per 1 million stars, then it still would happen some thousands of times in our galaxy alone.) I believe things in the universe (even within our galaxy) are so spread out in space and time that it's unlikely we'll ever encounter another radio-technology using civilization.

However, I don't think there's anything unique about the Earth. The same laws of physics and chemistry that apply here apply throughout the cosmos. The same amount of time that has elapsed here has elapsed elsewhere.

My gut feel about the situation is that human beings will never detect another civilization with sentient life. This is based on my view that sentient life is rare and that there are far too few places where sentient life seems possible within a range where communication is possible to provide much of a chance of contact. Is this the notion that some people are disagreeing with?
No. The point of disagreement is the Rare Earth business. Amb has also made the false dichotomy that either complex life must be ubiquitous, or it is virtually non-existent. IIRC, he also made the false dichotomy that either we are unique in the galaxy, or there must be a god, though I can't remember quite how that line of thinking went.

In fact, the limits of what SETI could detect and the limits of a self-replicating probe have been pointed out as a good reason not to extrapolate the non-existence of ETI based on a lack of results.

Someone even posted a graphic that showed the tiny sphere within the galaxy within which we have even been able to detect extra-solar planets at all. I pointed out that we know almost nothing about most of them. About all we can say about extra solar planets is that whenever we've used a technology to detect them with certain characteristics (size, alignment with us relative to their star, etc.), we have found them in abundance.

If one is looking for an argument from authority that I am wrong one needs to look no further than Mr. Drake himself who seems to have gotten more enthused of late about the possibility of contact. My own horribly amateurish take on Mr. Drake's thoughts on this is that he underestimates the importance of data that has been found since he first published his equation that suggests that sentient life is even less likely than he originally estimated and that he exaggerates the possibility of sentient life on non-earth like planets that have been detected since he published his equation originally.
A more or less recent Drake article was cited fairly early in this thread where he said what you've summarized. I believe he now thinks his famous equation would give an underestimate. From what I read, the main reason was that he left out the possibility of life in situations other than an Earth-like planet around a single main sequence star. One example I recall was the possibility of life arising in the twilight zone of a tidally locked planet the right distance from a red giant. Or possibly interstellar planets or some such.

At any rate, my position has always been that we don't know, but there's no reason to suspect there is anything unique about the Earth. The universe is really really really big, so it would surprise me if complex life forms didn't exist elsewhere. But we don't know. Not knowing is not the same thing as knowing it doesn't exist.

[davefoc]

Thanks for the response JTG. I was frankly a bit confused by exactly what amb meant in the post where he quoted Wikipedia. I thought this statement: Doesn't this sound like a conspiracy of Governments to silence on the Ufology subject was completely tongue in cheek. If this wasn't the case then I have really misunderstood some of amb's intent.

Based on your reference I read through the Wikipedia article on the Rare Earth Hypothesis. At least to my mind, the rare earth hypothesis does not seem to be principally a supernaturally influenced idea. That is not to say that amb's use of it wasn't.

[LarianLeQuella]

I don't think AMB sees the rare earth hypothesis as a supernaturally influenced. But rather a requirement for intelligent life to develop (i.e. a large moon, at the right distance, the right size, mamilian animal types, asteroid impacts, etc. etc. etc. describing OUR planet). While I and many others contend that with our ONE datapoint, we can't say. The sheer amount of space and incredibly rich possibilities of evolution suggest that earth is just one of a myriad of possibilities that can arrive at intelligent life. We know that the rare earth has a 100% probability of intelligent life, because we're here, but to make assertions beyond that is way too "human-centric" as I put it.

Clear as mud?

[amb]

It seems that this thread is been turned into a witch hunt for me. I will not go over what has been already discussed here in the past, as that would be a waste of time.
Anyway, my argument has always been that the cosmos is more than likely teeming with life. Microbial, not intelligence at our level or beyond. For the record, I'm a militant atheist.

[davefoc]

It seems that this thread is been turned into a witch hunt for me. I will not go over what has been already discussed here in the past, as that would be a waste of time.
Anyway, my argument has always been that the cosmos is more than likely teeming with life. Microbial, not intelligence at our level or beyond. For the record, I'm a militant atheist.

That was very much not my intent and my apologies if that has been the result. I just went back and reread a few of the last pages to see if I could understand this thread a tad better. I couldn't. It looks to me that AMB believes that sentient life is a very rare phenomena and others believe it is somewhat less rare. And everybody agrees that we don't know and probably won't ever know. Seems like a reasonable, well defined dispute that centers mostly on the process by which we combine a few facts and our biases to make judgments about the answers to questions for which the data is insufficient to allow us to determine a pure fact based answer. No harm. No foul.

But I also reread something that I wrote and was somewhat embarrassed to see that I had made a stupid arithmetic error:

In another post I linked to an article discussing the feasibility of a laser transmitter to reach stars. If the powers that be wanted to dedicate some resources to this idea the authors suggest that we might hit a 1000 light years with a currently feasible optical laser. I think that bumps the stars for which a signal might be detected from about a 1000 that lie within 100 light years to about a 100,000 that lie within a 1000 light years.If the range is increased by a factor of ten the volume contained within the range is increased by a factor of 1000 (103) so bumping the range by a factor of 10 should increase the number of stars from about a 1,000 to about a 1,000,000. Sorry for the mistake.

[JoeTheJuggler]

Based on your reference I read through the Wikipedia article on the Rare Earth Hypothesis. At least to my mind, the rare earth hypothesis does not seem to be principally a supernaturally influenced idea. That is not to say that amb's use of it wasn't.
Actually, I think amb's use of it is less religiously-motivated than the originator of the ideas in it.

The origin of most of the arguments used in Rare Earth was Guillermo Gonzales, professor of astronomy at the University of Washington. He is a public Creationist who admits that his theological views motivate his science. (I think Rare Earth authors Ward & Brownlee, like amb, were unaware that they were being fed a religiously-motivated argument. Gonzales correctly points out that his religious motivation is not a secret.)

The arguments themselves, as I mentioned, are often very much like the Fine Tuning argument. They take as many characteristics of the Earth (extremely large moon, proximity of a Mars-like planet and a Jupiter-like planet, etc.), take all of those characteristics as prerequisites for complex life, then ask, What are the odds of this exact constellation of characteristics happening elsewhere in the galaxy?

[JoeTheJuggler]

It seems that this thread is been turned into a witch hunt for me. I will not go over what has been already discussed here in the past, as that would be a waste of time.
Anyway, my argument has always been that the cosmos is more than likely teeming with life. Microbial, not intelligence at our level or beyond. For the record, I'm a militant atheist.

Of course your opinion on the presence of microbial life is not the topic of the thread or the point of contention.

You have been arguing in favor of the Rare Earth "hypothesis" that uses speculation to suggest that we are likely alone in the galaxy. You have used the Fermi Paradox and lack of a "hit" from SETI to support your contention that no ETI exists in our galaxy.

I accept that you are an atheist, but I think you have been using arguments that were originated for religious motivations.

[JoeTheJuggler]

That was very much not my intent and my apologies if that has been the result. I just went back and reread a few of the last pages to see if I could understand this thread a tad better. I couldn't. It looks to me that AMB believes that sentient life is a very rare phenomena and others believe it is somewhat less rare.
Again, there's rare and there's rare. AMB has said he thinks we are alone in the galaxy and that there are no more than a dozen such intelligences in the entire universe.

And everybody agrees that we don't know and probably won't ever know. Seems like a reasonable, well defined dispute that centers mostly on the process by which we combine a few facts and our biases to make judgments about the answers to questions for which the data is insufficient to allow us to determine a pure fact based answer. No harm. No foul.
AMB has argued that if ETI existed in our galaxy it must have existed for millions of years and evidence of it would be ubiquitous in the galaxy (basically an argument based on Fermi's Paradox). Since such evidence does not exist, there is no ETI. (I've pointed out repeatedly that that argument rules out our own existence since we are largely undetectable by our own technology beyond our own solar system.)

He has also argued, following the Rare Earthers, that a Mars-like planet is necessary for complex life (because, apparently, abiogenesis could have happened on Mars and then Mars meteorites seeded the Earth, but abiogenesis couldn't happen on an Earth-like planet where complex life might evolve).

He has also argued that a Jupiter-like planet is necessary to protect the Earth-like planet from collisions with asteroids or whatever. (I've pointed out that not only isn't it certain that Jupiter affords such protection, even if it did, one could speculate as well that complex life would arise earlier if you hit the ecological "reset" button more frequently.)

He has also argued that a large moon like ours is extremely rare (based on guesswork) and essential for complex life since it prevents Earth's rotational precession from resonating with orbital precession. (Again, no evidence that the gradual climate change such a resonance might cause would make complex life impossible--nor, for that matter, that it might not actually be more favorable to the evolution of complex life!)

[JoeTheJuggler]

The other very quasi-Creationist argument AMB has used is the notion that intelligence is an all-or-nothing thing, and that only one species on Earth has ever evolved intelligence.

He even argued that cetaceans arose much earlier than primates, but how come cetaceans never reached higher levels of intelligence? Of course, cetaceans and primates arose at roughly the same time--actually the order primata is probably a little bit older than cetacea.

[amb]

So you still believe that if all homo sapiens were to die out tomorrow, some other Earth species will develop our level of intelligence? Maybe an ant? Perhaps a Bonomo?

Darwinian evolution argues that far from intelligence been a given, it's entirely a random event as espoused by Richard Dawkins and Stephen Jay Gould. If this is correct, then a feature of life such as intelligence is purely a chance phenomenon, exceedingly unlikely to arise elsewhere independently.
That is not to say that animal life is only likely to have appeared on Earth. There may well be a few planets out there with such life. What I'm saying is intelligence at our level is exceedingly rare. A probability of 0.

Returning to Darwinian evolution. The concept of alien life is, therefore fundamentlly anti- Darwinian.

[JoeTheJuggler]

So you still believe that if all homo sapiens were to die out tomorrow, some other Earth species will develop our level of intelligence? Maybe an ant? Perhaps a Bonomo?
A bonobo?

At any rate, that's not the way evolution works. There's not a pre-set goal or end. However, since homo sapiens is not the only organism to have evolved intelligence, your position that we are the only intelligence ever to have evolved on Earth is simply factually wrong. As with many characters, intelligence exists on a continuum in a great many organisms. We are the most intelligent. If humans were to go extinct tomorrow, another organism would be the most intelligent.

Darwinian evolution argues that far from intelligence been a given, it's entirely a random event as espoused by Richard Dawkins and Stephen Jay Gould. If this is correct, then a feature of life such as intelligence is purely a chance phenomenon, exceedingly unlikely to arise elsewhere independently.
That is not to say that animal life is only likely to have appeared on Earth. There may well be a few planets out there with such life.



Have you read the Darling book? He makes a strong case that convergence is much more common than you seem to think. Convergent evolution is indeed part of conventional theory of evolution by natural selection. Certain characters and structures come up over and over.

Returning to Darwinian evolution. The concept of alien life is, therefore fundamentlly anti- Darwinian.
This is an example of the kind of statements you make that make me wonder whether or not you are really a creationist. If alien life is "fundamentally anti- Darwinian" what about life on Earth? Do different rules apply here? Are you not saying that humans couldn't possibly have evolved? It really sounds like a Creationist argument.

As an aside, I reject the terms "Darwinian" and "anti-Darwinian" because they are ambiguous and are frequently used by Creationists to mischaracterize concepts in biology. Even using the term as you do suggests that Darwin was some sort of infallible cult leader, rather than merely a scientist. At best (http://rationalwiki.com/wiki/Darwinism), it's an ambiguous term (http://www.skepticwiki.org/index.php/Darwinism).

What I'm saying is intelligence at our level is exceedingly rare. A probability of 0.
Davefoc, do you see what I mean now? He's using the term "rare" but is actually claiming to know that we are unique.

Or maybe amb doesn't understand what a probability of zero means.

[Puppycow]

IMO we could speculate forever and never get anywhere.
I suspect that the distance scales involved mean that we would not have detected alien life yet even if it was present on a planet around Alpha Centauri. Even Alpha Centauri is farther away than human imagination can comprehend.
Because we cannot even see earth-size planets. We can only detect Jupiter-size planets that orbit closer than Mercury by seeing a star wobble slightly. We cannot actually directly see the planets. So even if there was life like us on every other star system, we might be none the wiser.
Which is to say, let's keep developing telescopes that can see farther with better resolution.

[JoeTheJuggler]

IMO we could speculate forever and never get anywhere.
I suspect that the distance scales involved mean that we would not have detected alien life yet even if it was present on a planet around Alpha Centauri.
I agree.

We can only detect Jupiter-size planets that orbit closer than Mercury by seeing a star wobble slightly.
This is not true. We have already detected both gas giants and "Earth-like" planets in various orbits. List of extrasolar planets (http://en.wikipedia.org/wiki/List_of_extrasolar_planets).

ETA: Also a few extrasolar planets have been found by direct imaging (http://en.wikipedia.org/wiki/Methods_of_detecting_extrasolar_planets#Direct_ima ging).

The Kepler Mission (http://kepler.nasa.gov/) will probably detect dozens if not hundreds of Earth-like planets in the habitable zone. It's a time consuming process, though. (You basically have to "see" the planet transit the star more than once--so you have to look at these stars a long enough time to measure the changes. In Kepler's case, it's observing fluctuations in the brightness of the star due to the planet eclipsing the star relative to us rather than wobble.)

But your broader point is true. Even of the extra solar planets that we have detected, we know relatively little about them (see list linked above).

[amb]

All creatures great and small have a certain level of intelligence, enough for them to survive in a world where the fittest and most adaptable only have and will survive.
Only man has far exceeded an intelligence level required for survival. This has taken 4 billion years, half the lifetime of the sun's stable period. In around another billion years, the Earth will no longer be able to sustain life of any kind unless some animals evolve to be able to withstand enormous variation of temperature.
Someone mentioned Alpha Centauri, at around 5 light years away this star system which by the way is a binary system, therefore quite impossible for a life bearing planet to evolve because of the chaos of gravity between the two stars would make a orbiting planet uninhabitable even by the most primitive of lifeforms. But lets suppose that somehow intelligence developed there at around the same time as here. That gives five years for any radio signals to have arrived here. I'm all ears, yet I hear nothing.
The fact that our radio signals have been traveling into space since Marconi invented the radio transmitter, hundreds of light years, enough time for a nearby neighbor to learn of our existence. We wait with bated breath for a responce.

[Puppycow]

But how powerful a radio telescope would be necessary to pick up radio signals from earth at a distance of 4 or more light years assuming the transmitter and receiver are not pointed at each other?

[JoeTheJuggler]

But how powerful a radio telescope would be necessary to pick up radio signals from earth at a distance of 4 or more light years assuming the transmitter and receiver are not pointed at each other?

A telescope 100 times more sensitive than Arecibo would not be able to detect broadband signals beyond even our own solar system.

So a civilization just like our own could exist even around the nearest stars and, at this point, still be undetectable to us unless they directed a signal at us (and we were listening to that spot in the sky exactly when that signal arrived).

[JoeTheJuggler]

All creatures great and small have a certain level of intelligence, enough for them to survive in a world where the fittest and most adaptable only have and will survive.
Sorry, but plants which have no nervous systems do not have anything like "intelligence". Nor do amoebas, bacteria, fungi, etc.

Only man has far exceeded an intelligence level required for survival.
That's not true.

This has taken 4 billion years, half the lifetime of the sun's stable period.
That's also not true.


The fact that our radio signals have been traveling into space since Marconi invented the radio transmitter, hundreds of light years, enough time for a nearby neighbor to learn of our existence. We wait with bated breath for a responce.
See Puppycow's question and my answer. A civilization with technology equal to our own would not be watching I Love Lucy 50 light years away. This point was covered very early in this thread.

[amb]

We seem to be going over old posts. I have nothing to add to this thread, and it seems neither have you.
One idea I may have never put forward is that if there are intelligences out there like us or vastly more so, that makes physicist Professor Paul Davies correct in his theory that the universe is tuned for life, tuned for intelligence by a designer. Davies has won a Templeton prize for his ideas.
I reject that idea completely. We are here only by a giagantic fluke of the laws of nature.
I repeat for the hundreth time. If homo sapiens were to suddenly become extinct, there will never be a species like us again on this planet.
Pretending that the history of this planet was a twenty four hour clock, homo sapiens appeared at 11.58 PM.

[JoeTheJuggler]

One idea I may have never put forward is that if there are intelligences out there like us or vastly more so, that makes physicist Professor Paul Davies correct in his theory that the universe is tuned for life, tuned for intelligence by a designer.
No it does not.

Even if we learn someday that intelligence is relatively common in the universe, it does nothing to argue in favor of a tuner or a designer. Physics, chemistry and biology (evolution) is sufficient to account for it.

Your argument that either a theological argument is correct or there cannot be other intelligences in the universe is fallacious.

[arthwollipot]

Joe, did you miss the bit where amb said "I reject that idea completely"?

[JoeTheJuggler]

Joe, did you miss the bit where amb said "I reject that idea completely"?

Not at all. He set up a false dichotomy.

He says, if there were many intelligences in the universe it would indeed mean that there is a designer or whatever. (He did not reject that part.) He rejects that there is a designer. Therefore, he argues, there aren't many intelligences in the universe.

It's flawed reasoning based on the part I quoted, where amb says Davies would be correct if there were many intelligences in the universe.

As I countered, even if there were many intelligences in the universe, it would NOT argue in favor of a creator or designer at all.

Similarly, lack of belief in a designer (even proof of the non-existence of a designer) does not support the position that we are unique in the galaxy or that intelligence is relatively rare in the universe.

ETA: The idea that amb "rejects completely" is that the universe is tuned for life. One can hold the position that life is relatively common in the universe without accepting any notion of a tuner or designer.

ETA: Amb is using the same backward approach as the Creationists, while rejecting the existence of a Creator. In fact, life adapts to conditions and not the other way around.

[JoeTheJuggler]

I repeat for the hundreth time. If homo sapiens were to suddenly become extinct, there will never be a species like us again on this planet.
Of course, this depends on what you mean by "like us". If you consider biology as a whole (especially with regard to the question of exobiology), one could argue that many of the organisms on Earth are "like us". If you're talking strictly about intelligence, again, there are other intelligent species that exist (or at least have existed) on Earth.

I agree with you the probability of finding a population of homo sapiens that evolved independently on some extrasolar planet is as close to zero as matters, but that's not the only alternative to saying humans are unique in the galaxy.

[amb]

Joe, you can't have it both ways. Either we are unique in the cosmos or we are not.
Life adapts to the prevailing conditions. So unless conditions are exactly as they are on Earth, a homo sapiens like creature cannot exist anywhere else. What are the chances that there are uncountable planets in the cosmos exactly like the Earth?
Even here we have places where life is untenable like the Sahara desert where the only creatures that can exist are scorpions and other crawling life forms. Very little chance there to develop any kind of intelligence higher than an ant.
That's the point I'm trying to make.
Even the Earth's life friendly conditions which have over it's history produced millions of life forms, and more than once, have only ever produced one species intelligent enough to place a satellite in orbit.
Because the Earth is teeming with animal life lower than man, there may possibly be other planets in the cosmos that have evolved life forms such as animals, perhaps even as high as a monkey's intelligence. But the huge fluke that caused homo sapiens brain to evolve consciousness and machine making skills, mathematics, geometry, science, and to reason are in my humble opinion extremely rare in the cosmos.

[JoeTheJuggler]

Joe, you can't have it both ways. Either we are unique in the cosmos or we are not.
What are you talking about now? I've never been arguing for "having it both ways". You're the one asserting that you know certainly that humans are unique in the galaxy.


So unless conditions are exactly as they are on Earth, a homo sapiens like creature cannot exist anywhere else. What are the chances that there are uncountable planets in the cosmos exactly like the Earth?
No one involved in SETI or anything like (nor I myself) has argued that we will find homo sapiens on another planet. So what exactly do you mean by "homo sapiens like"? You're trying to say it's something identical to homo sapiens. Again, that's a straw man position that no one in his right mind is arguing for.

So. . you want to back off of saying that "homo sapiens like" means "identical to homo sapiens" and address the actual topic which is ETI--that is extra terrestrial intelligence. That does NOT mean identical to homo sapiens.

Even here we have places where life is untenable like the Sahara desert where the only creatures that can exist are scorpions and other crawling life forms. Very little chance there to develop any kind of intelligence higher than an ant.
You want to bet on that? Your understanding of biology and evolution is seriously flawed.


Even the Earth's life friendly conditions which have over it's [sic] history produced millions of life forms, and more than once,
What organism has evolved more than once?

have only ever produced one species intelligent enough to place a satellite in orbit.
Because the Earth is teeming with animal life lower than man, there may possibly be other planets in the cosmos that have evolved life forms such as animals, perhaps even as high as a monkey's intelligence. But the huge fluke that caused homo sapiens brain to evolve consciousness and machine making skills, mathematics, geometry, science, and to reason are in my humble opinion extremely rare in the cosmos.
I've addressed all this. According to you "friendly conditions" drives evolution. I've pointed out that there's plenty of evidence that just the opposite is true. Punctuated equilibrium argues that once you have a good fit to a stable environment, you see little change. It's when the environments changes that you see more rapid changes in forms.

In fact, the Rare Earth argument wants to have it both ways. They sometimes say that "friendly conditions" are necessary, but other times admit that traumatic events sometimes drive evolution.

Further the Rare Earth argument assumes that the Earth is the epitome of "friendly conditions" and that therefore every last characteristic of the Earth is an absolute prerequisite to complex life.

[JoeTheJuggler]

A little bit on the Fauna of the Sahar (http://www.sahara-online.net/eng/Geography/FaunaFlora/tabid/718/Default.aspx)a:

Fauna

Animals have also created some strategies to preserve water and avoid hot weather: thick skin and underground life for scorpions and insects, recuperation of water steam in pulmonary air by condensing it in nostrils, production of drained faeces and concentrated urine for some birds, loss of sudoriferous glands, clear colored skin to reflect the sun, search for water and food at night, accumulation of water in internal pockets, large ears to regulate calorific waste ( fennecs, sand cats), short hairs for better thermolysis, increase of internal temperature to avoid perspiration…

The emblematic animals of the desert are addaxes, gazelles, doncas and fennecs.

Camels are the main animal of the desert. Without them, humans could not have lived in the Sahara. They have a great capacity to resist heat and thirst. Even above 50°, they can stay without drinking water for many days. Camels can carry about 250 kg of commodities between two distant places.

Note that evolution of the characters mentioned here would not have happened in a "friendly" environment.

You think all the animals mentioned here are less intelligent than an ant?

[amb]

OK! But could the Sahara in your opinion ever host an intelligent creature such as man?
What about the Antarctica? Think a homo s could ever evolve in such conditions?
Didn't we evolve in African savannas where the temperature was just right?

I understand you position in holding to the itelligence of many animals to prove that it could and probably has done so on a few planets in the cosmos as well. But the animals intellince is to assure their survival, that's all. An animal like an ape or whatever, will never evolve the intelligence to build a civilization as homo sapiens has. An animal will even in a billion years never build a rocket that can actually leave it's home planet.
We are a fluke that may never happen again. All the more reason to look after our environment and assure our survival on Earth, and perhaps one day to colonise other worlds.

[LarianLeQuella]

OK! But could the Sahara in your opinion ever host an intelligent creature such as man?

First of all, get off that bloody homocentric view. Drop the "such as man" thing at the end, because I would argue that we are only marginally intelligent. But given the right conditions, an intelligence could evolve on a resource poor environment FOR US, but it may be rich for THEM. The real answer is, we don't know, but it's not against the laws of the universe as far as I can tell.

What about the Antarctica? Think a homo s could ever evolve in such conditions?

Why are you stuck on homo! What about ursa? You are thinking too much as if we are the end all, be all of intelligence in evolution. Nature may have come to our end by accident; but if nature were anthropomorphic, it would be regretting ever allowing such a self centered organism as us to evolve!

Again, with the right opportunities, an intelligent organism could evolve in such a climate as well. We just don't know at this point.
Didn't we evolve in African savannas where the temperature was just right?
IRRELEVANT! We evolved there, true, and the temperature was just right FOR US. That doesn't mean that because the temperature was just right, that we evolved into an intelligent species.
You keep using that backwards logic over and over again AMB, and that's what (at least in my case) I keep arguing against. That and the fact that currently we only have ONE datapoint, which is not even enough to make a line to vaugely extrapolate with.

[JoeTheJuggler]

OK! But could the Sahara in your opinion ever host an intelligent creature such as man?
What about the Antarctica?
I'm not sure what you mean by "host" but I'm certain humans are living in the Sahara right this moment. There are probably some in the Antarctic too.

Think a homo s could ever evolve in such conditions?
I believe the consensus is that humans evolved in tropical savannas. So no, humans did not evolve in Antarctic conditions. So?

Do you know for certain that Arctic conditions are more prevalent in the rest of the galaxy than tropical savannas? Do you know that complex organisms can only evolve in tropical savannas (in fact, if that's what you think, you're definitely wrong)?

Didn't we evolve in African savannas where the temperature was just right?
Yes, but you're still thinking backwards (the same way the Creationists/I.D./Fine Tuning people do). Of course we evolved where conditions were just right for us to evolve. It's because we evolved to adapt to the environment, not the other way around.

But the animals intellince [sic] is to assure their survival, that's all. An animal like an ape or whatever, will never evolve the intelligence to build a civilization as homo sapiens has. An animal will even in a billion years never build a rocket that can actually leave it's [sic] home planet.
Your understanding of biology and evolution is seriously flawed. Saying that an organism "evolves to" do anything is a wrong way of thinking of it. Evolution doesn't have any goals or aims or pre-determined outcomes. Natural selection merely guarantees that individual variants more suited to the environment will reproduce more successfully than variants less suited, and therefore the offspring of the "fitter" individuals will be greater in number than those less fit (i.e. "fit" to the environment at the time).

And don't even get me started on issues like epigenetics or sexual selection. (Both of which belie your idea that characters not essential to survival will not arise.)

You are asserting knowledge that you don't have (and that is certainly wrong, since humans are animals that evolved that can build rockets).

We are a fluke that may never happen again.
But intelligence is not. (You are still arguing against a straw man position that the search for ETI expects to find homo sapiens "out there". That's not a position any reasonable person supports.)

Intelligence is a characteristic that has arisen in many species and has proven to have great value in adapting to many different environments. In fact, taking the example from the Earth, we have had the greatest radiation of all organisms other than archaebacteria (and perhaps some groups of insects), and this is almost certainly due to intelligence (or at least to intelligence as a trait adaptive to complex organisms living in complex social structures).

Remember, the search for ETI is the search for ETI, not the search for homo sapiens.

Your arguments still smack of religious arguments, where Mankind is different in kind (rather than merely degree) from other animals--the result of some special divine agency where we were created in the image of a deity and therefore absolutely unique (rather than merely being the organism at present with the highest degree of a certain trait).

If humans went extinct today, another species would immediately be the most intelligent species on the planet. (That is, intelligence as a trait will not have disappeared from the face of the Earth.) Evolutionary biology suggests that since the niche humans occupy has been so rich, that if it were vacated, another species might in fact fill that niche.

But there is no pre-set ecology, so know one knows whether or not another organism would reach our level of technology. You claim knowledge that it would not, but you have nothing to support your case (other than irrelevant and trivial observations that homo sapiens is unique in being homo sapiens and that no other organism is likely to evolve to become homo sapiens).

[JoeTheJuggler]

Have you got around to reading the Darling book yet, Amb?

There's a lot of evidence that it's trauma that fuels the engine of evolution rather than "friendly conditions".

I notice you're no longer mentioning the Rare Earth stuff. Do you acknowledge that all these conditions (a large moon, a Mars-like planet, a Jupiter-like planet, etc.) are requirements for complex life?

It could be that on less "friendly" planets, complex life evolves much faster. It could also be that Earth isn't among the most life friendly planets (that maybe it's below the mean in "friendliness"). The fact is, we don't know.

As I've mentioned, the arguments made in Rare Earth are mostly speculation, and I could at least as legitimately speculate the exact opposite wrt to many of the so-called prerequisites to complex life.

ETA: For example, it could be that the high rate of collisions in the early days of our Solar System are atypical. It could be that the asteroid belt is a very unusual feature that seriously retards the development of complex life.

[amb]

I think this whole thread is pure speculation. I agree with Paul Davies when he says that although SETI is worth the effort, it would be a miracle if it produced positive results.
If there is other intelligent life forms out there, don't count on it been in the numbers Drake quoted. Darwinian evolution requires a huge time span. I doubt there may be some planets where it could possibly arise faster than what it did here even without an asteroid belt which is a planet that failed to form.

[LarianLeQuella]

I think this whole thread is pure speculation. I agree with Paul Davies when he says that although SETI is worth the effort, it would be a miracle if it produced positive results.
I agree with you wholeheartedly there. No argument at all.
If there is other intelligent life forms out there, don't count on it been in the numbers Drake quoted. Darwinian evolution requires a huge time span. I doubt there may be some planets where it could possibly arise faster than what it did here even without an asteroid belt which is a planet that failed to form.
This is where you get off into unsupported speculation and misstatements.

[JoeTheJuggler]

I agree with you wholeheartedly there. No argument at all.
I agree, but less than wholeheartedly.

I would not use the word "miracle" which introduces the idea of the temporary suspension of natural laws as by divine intervention rather than merely something improbable. I'd use a term like "unlikely" or liken it to finding a needle in a really really really big haystack (a comparison I'm pretty sure I've made on this thread before).

Given enough chances, highly improbable events happen with some frequency. Given that there are nearly 7 billion people, something that happens to people once in a million days, happens roughly 700 times every day (or am I off by an order of magnitude?). So is a 1 in a million event "miraculous"? Is its occurrence "rare"? (See my on-going point that there's rare and then there's rare.)

[LarianLeQuella]

Sorry, I use the word miracle in a much different manner. But then I do DoD acquisitions programs, and part of nearly every development program involves at least seven conscutive miracles, and the invention of unobtanium. :p So I should probably edit his quote to say "extremely unlikely" and then I agree wholeheartedly.

[amb]

Extremely unlikely it is. For once I agree. Finding another Earthlike planet is like looking for a needle on the planet Jupiter.

[JoeTheJuggler]

Extremely unlikely it is. For once I agree. Finding another Earthlike planet is like looking for a needle on the planet Jupiter.

So I see you now agree with my first post on this thread from way back when.

http://forums.randi.org/showthread.php?postid=4279474#post4279474

Have you abandoned your claim that we are the only intelligence in the galaxy and likely only one of a dozen in the entire universe?

Again, there's rare and then there's rare.

[amb]

The more we discover with such instruments as the Hubble telescope, and the more planets are discovered, some astrobiologists are realising that Earth is indeed very rare.
Depending on what you mean by intelligence, I think that intelligence such as ours or higher
is extremely rare in the universe. Lower intelligence such as an ape or a dolphin, much more likely.

[LarianLeQuella]

The more we discover with such instruments as the Hubble telescope, and the more planets are discovered, some astrobiologists are realising that Earth is indeed very rare.


And what exactly are you basing that assertion on? We have looked at about 300 stars. Out of 200 to 400 billion (http://seds.org/Messier/more/mw.html) in the Galaxy and associated near clusters. So after a sample size of 0.000000000015% you are ready to make that assertion? Especially considering that we don't even have the ABILITY to detect anything like an earth planet.

That's like saying, "I have visually examined this pond water, and declare it void of life." But if you used a microscope, instead of your naked eye, you would have seen it swarming with life (and maybe avoided a case of giardia)... The Hubble isn't really a planet finder telescope, so using that as your instrument of choice shows your inneptitude at the task at hand...

And why do you think that intelligence "akin" to ours is so rare? because a planet "akin" to ours is rare? Who says it has to have a planet like ours to start with? The data is incomplete at this point (as in we have only one datapoint, ours).

And here we go around the merry-go-round again with AMB... :rolleyes:

[JoeTheJuggler]

The more we discover with such instruments as the Hubble telescope, and the more planets are discovered, some astrobiologists are realising that Earth is indeed very rare.
I disagree. So far, whenever we've had a technique to detect planets of given characteristics (mass, orbital geometry relative to its star and the Earth, etc.) we have found them in abundance. The Keppler mission is set to detect Earth-like planets in the habitable zone. According to your theory, Keppler won't find any (or many). Care to put a wager on it?


Depending on what you mean by intelligence, I think that intelligence such as ours or higher
is extremely rare in the universe. Lower intelligence such as an ape or a dolphin, much more likely.
Why do you think that? (I accept that you're an atheist, but you should recognize that such a statement smacks of religious ideas.)

Even just considering life on Earth, the difference in intelligence among chimpanzees, humans and dolphins is almost nothing. There's no biological magic that happened to make humans different in kind. And frankly, the search for extraterrestrial intelligence would consider finding chimpanzee-like or dolphin-like life on another planet to be extraterrestrial intelligence. It would be hugely exciting to make such a discover.

[amb]

Humans are vastly superior to any other animal on this planet. How can anyone postulate that the difference between chimpanzees, dolphins, etc is almost nothing?
Can any other animal on Earth have the hair on the back of the neck literally stand up at a Mozart symphony? Be in awe at an image of a galaxy from Hubble? Cry at a very sad part of an emotional movie or laugh at a comedy film.
No, we are unique on this planet as the only ones able to do all that and much more.
At the risk of repeating myself. If we were to die out tomorrow, there is no other species that can possibly take our place. Civilization would die.
The coincidence that produced us must of necessity be extremely rare.

[LarianLeQuella]

No, we are unique on this planet as the only ones able to do all that and much more.


Are you 100% sure about that (http://www.sciencecentric.com/news/article.php?q=08050734)? And were there not two or even three species co-eisting on this planet alone that had the capability at one time? Two just happened to go extinct leaving us. And again, we have ONE datapoint. To make authoritative statements like you do is rediculous.

And (to repeat Joe's question) how rare? Given that the Milky Way has up to 400 billion stars, would that still leave us alone in this galaxy? I think you are observing the universe using the wrong tools.

[JoeTheJuggler]

Humans are vastly superior to any other animal on this planet. How can anyone postulate that the difference between chimpanzees, dolphins, etc is almost nothing?

Because the difference is of degree and not kind--which is what I said.

To think otherwise is to consider humans to be some special act of creation or some such. In fact, we're just part of the biosphere of the planet.

Imagine rather than discussing the character of "intelligence" you were talking about the character of "height". One or another species of giraffe is currently the tallest animal on the Earth. (Though there were certainly taller animals that are now extinct.) Would you consider the giraffe to be unique? If the tallest giraffe species went extinct, would you say that the Earth no longer had any tall animals?

Height and intelligence are comparable characters in that they've both proven to provide great adaptive success to different species.

For about the third time now, have you read the Darling book? Do you understand the idea of convergence? How can you rule out that intelligence--even of the degree humans have--is something that hasn't/won't ever evolve in another species?

[JoeTheJuggler]

If we were to die out tomorrow, there is no other species that can possibly take our place.

This is a false statement.

We don't know whether another species would take over the niche left by us. (On the other hand, it would take a huge catastrophe to wipe out nearly 7 billion humans, so it's likely that whatever wipes us out would change the environment so as to wipe our niche out of the ecology, at least for a while.)

There is no reason whatsoever that it is impossible for the level of intelligence humans have to evolve in another species. The rules of biology (esp. natural selection), chemistry and physics apply the same for all species.

To argue otherwise is to say there is something supernatural about humans.

[amb]

No, not supernatural. A giant fluke.[ mutation] Like spinning two coins into the air and getting more than 100.000 tails in a row. What caused man to climb out of the tree and start walking upright, developing a level of intelligence never seen before. The very origin of life is still a mystery that may never be solved although I'm confident that progress will continue.
When I see a monkey start playing a complex instrument and belting out a tune, I'll believe that we have a species ready to take our role in developing a civilasation if we were to become extinct.
A planet of the apes, Earth will never be.

[LarianLeQuella]

A planet of the apes, Earth will never be.

Uh... dude... WE ARE apes. :p

[JoeTheJuggler]

No, not supernatural. A giant fluke.[ mutation] Like spinning two coins into the air and getting more than 100.000 tails in a row.
You're pulling numbers out of thin air, though.

How do you know it's not like tossing 100 tails in a row? If you toss a coin billions of times, getting a streak of a 100 is virtually inevitable.

As I said before, if you consider a 1 in a million event (one that occurs to a human only once in a million days--meaning most of us never experience such an event), given that there are 6.7 billion people, such an event happens thousands of times every single day!

The same laws of physics, chemistry and biology (especially natural selection) that operate on humans operate on all matter everywhere.

That's why your claim that humans are unique smacks of a religious claim based on the supernatural.

[JoeTheJuggler]

When I see a monkey start playing a complex instrument and belting out a tune, I'll believe that we have a species ready to take our role in developing a civilasation if we were to become extinct.
And this is exactly a Creationist technique. "If I can't witness a big change in a species, then it can't possibly happen."

(Again, I don't think chimpanzees are likely to be the successor to humans since there are billions of us and less than 200 thousand of them--that's some 4 orders of magnitude difference. Whatever wipes out humans is likely to wipe them out first, since they're already on the brink of extinction.)

[amb]

You're pulling numbers out of thin air, though.

How do you know it's not like tossing 100 tails in a row? If you toss a coin billions of times, getting a streak of a 100 is virtually inevitable.

As I said before, if you consider a 1 in a million event (one that occurs to a human only once in a million days--meaning most of us never experience such an event), given that there are 6.7 billion people, such an event happens thousands of times every single day!

The same laws of physics, chemistry and biology (especially natural selection) that operate on humans operate on all matter everywhere.

That's why your claim that humans are unique smacks of a religious claim based on the supernatural.

The coin has been flipped more than a billion times on Earth already.
It only came up tails enough times to produce us.
In answer to Larian, yes we are apes, but very smart apes.
If intelligence is inevitable in the scheme of things, why didn't an intelligent dinosaur appear, after all they lived here for millions of years.

[LarianLeQuella]

If intelligence is inevitable in the scheme of things, why didn't an intelligent dinosaur appear, after all they lived here for millions of years.


They were a dead end as far as intelligence of our magnitude is concerned, however they were very successful at breeding and surviving. Evolution is full of such dead ends. That said, there was a nasty asteroid that cut them short. Who knows what could have happened. The timescale isn't the factor, it's the niches. I would say that earth as a planet is a poor place for intelligence to develop, and you need a more dynamic and chaotic planet to force species to develop intelligence. ;)

[JoeTheJuggler]

The coin has been flipped more than a billion times on Earth already.

That's another Creationist argument--that evolution through natural selection is random. Selection is not a coin toss. Each species does not arise as an independent, random thing. See the 4th of the Five Major Misconceptions about Evolution (http://www.talkorigins.org/faqs/faq-misconceptions.html)on the TalkOrigins site.

And again, even on the Earth, humans are not the only species to have the trait of intelligence. Indeed, you can look through the layers of the brain and trace them back through our phylogeny.

In the context of SETI, we don't have enough information to calculate the probability of life on other planets. We also don't yet know how many planets there are (though what we've been learning lately indicates that planets are the rule and not the exception).

[JoeTheJuggler]

If intelligence is inevitable in the scheme of things, why didn't an intelligent dinosaur appear, after all they lived here for millions of years.

No one is arguing that intelligence is inevitable. I'm arguing against your assertion that another instance of very high intelligence is impossible.

At the same time, you should read what the Darling book says about convergence.