Probability of Universe Being Here

[T'ai Chi]

Does anybody have any estimates or methods of calculating the probability of the universe even being here?

[triadboy]

Originally posted by T'ai Chi
Does anybody have any estimates or methods of calculating the probability of the universe even being here?

I've heard the probability is very good

[jayrev]

Originally posted by T'ai Chi
Does anybody have any estimates or methods of calculating the probability of the universe even being here?

Very near 1, I would say.

[Kullervo]

as opposed to being somewhere else?

[geni]

As it is a past event the probabilty is by definition 1.

[ceo_esq]

Do you mean (1) how likely is it that the universe as we know it really exists, or (2) how likely is it that the universe as we know it would arise randomly?

If the latter, the Princeton physicist Freeman Dyson addressed the subject in his book Disturbing the Universe, although I don't recall if he ventured any figures or not. I believe Thomas Bopp (of Comet Hale-Bopp fame) has also written on the topic - but again, I don't recall seeing any mathematical estimate.

[Diogenes]

The ' 1 ' answer seems logical..


The only thing you could compare it to, would be instances where the Universe is not here. Are you aware of such instances?

[Dancing David]

This sounds like the contingent history of the universe, if you tweak the major forces a little, the universe would still function, but if you tweak them a lot then the universe doesn't happen. If you like inflation theory, there could be universe bubbles that don't do much, and then there are those like ours where all this stuff happens.

I think a better question is which forces can be tweaked how much before things stop working?

Great question!

[Paul C. Anagnostopoulos]

Even if we could make any sense out of calculating the probability that the universe exists, don't we first have to ask if there is a reason it exists? If there is no reason, then the probability is surely meaningless.

~~ Paul

[T'ai Chi]

I guess I meant the probability of a universe absolutely identical to ours arising.

[Igopogo]

Hey, you think too much.

This reminds me a bit of Rene Descartes 'Discourses on Method'. We all know his famous thought experiment where he he wanted to assertain that which he could be the most sure of. He came up with the oft quoted "I think therefore I am." Brilliant concept - good food for thought - However, he loses me on his next biggest (and rarely quoted) certainty: that he has a soul. (IMHO his logic is noticeably faulty, I would trust my eyes before trusting it - squinty & out of focus they may be). I have a hard time tricking myself into thinking things that are inconsistant with every single experience I've ever had and have no reason to doubt. Philosophy - nice place to visit, but I wouldn't want to live there.

(edited to add - didn't get to see above post - that negates mine here)

[Martin]

Originally posted by T'ai Chi
I guess I meant the probability of a universe absolutely identical to ours arising. Give me a few more Universes to compare with it and I'll get back to you.

[Yahweh]

Originally posted by T'ai Chi
I guess I meant the probability of a universe absolutely identical to ours arising.

Given an infinite amount of space (a universe with no bounds), where an infinite amount of energy/matter exists, the probability of a universe or local system identical to ours is hypothetically very possible (and strictly speaking, the scenerio would be "actual" in a literal sense).

Note: We dont live in a universe without bounds (as predicted by the Big Bang model). There is a finite amount of energy (but a lot of it) in the universe.

[T'ai Chi]

Originally posted by Martin
Give me a few more Universes to compare with it and I'll get back to you.

Well, according to some cosmologists, you already have those Universes.

But anyway.., I don't think you need to actually have another universe in order to calculate the probability of one occuring, just like you don't need to physically have a, say, deck in your hand to calculate the probability of drawing a queen.

In any case, it seems like there should be some way to calculate some probability, especially if it is all material that behaves according to mostly known physical laws.

[geni]

Assuming I understand your question it boils down to two things:

1 how many universes are there?

2 how many different universes could there be?

Divide 1 by 2 and you have your answer.

[c4ts]

Originally posted by geni

Divide 1 by 2 and you have your answer.

There are only .5 universes!

[shemp]

The universe is not here. It's actually right behind you, turn around and look!

[BillHoyt]

Originally posted by T'ai Chi
I guess I meant the probability of a universe absolutely identical to ours arising.

That's not the same question you started with. With your first question, you violated the most basic definition of probability. It is defined as a prediction of the future based on past events. Your question was meaningless. Now your second question is also meaningless, given that we don't know if any other universes have arisen. Once again, you violated the most basic definition of probability.

[Jon_in_london]

Originally posted by shemp
The universe is not here. It's actually right behind you, turn around and look!

Arrrghh!!! whats that doing there!!!

[T'ai Chi]

I said this:


Does anybody have any estimates or methods of calculating the probability of the universe even being here?


and later I said something like this:


What is the probability of a universe identical to ours actually arising?


then Bill said this:


That's not the same question you started with. With your first question, you violated the most basic definition of probability. It is defined as a prediction of the future based on past events. Your question was meaningless. Now your second question is also meaningless, given that we don't know if any other universes have arisen. Once again, you violated the most basic definition of probability.

Yes, "prediction of the future based on past events", ok, and my second question is equivalent to asking What is the probability of a universe identical to ours arising again?, if you like.

Didn't Penrose come up with some probability? -Or was it some probability for life arising?

[BillHoyt]

Originally posted by T'ai Chi
Yes, "prediction of the future based on past events", ok, and my second question is equivalent to asking What is the probability of a universe identical to ours arising again?, if you like.
We have one instance of a universe, and no knowledge of any prior rolls of the universe die. We have no basis on which to state a probability for another universe event.

Didn't Penrose come up with some probability? -Or was it some probability for life arising?
Neither. Penrose calculated a probability for a universe to contain our particular set of physical constants. The IDers have attempted to commandeer this calculation as proof of an anthropic principle. But the Penrose calculation is not a calculation for a universe arising (it was effectively a conditional probability; given the existence of a universe, what is the probability it contains x,y,z physical constants). Neither is it a calculation for life arising, because we have no knowledge of how many different sets of physical constants could give rise to life.

[Ladewig]

You have to be careful when using probability this way. If I asked what is the probability that I was born, I could answer it this way. If people on average over the past couple of hundred years had a 10% of dying before having children, I can then multiply that out to show that by the time I get to my great, great, great grandparents, 62 people were involved. Therefore, .90 raised to the 62nd power is 0.00146. The chances of me being born are less than 1/5 of one percent. How wonderfully rare I am.

But like the universe question, this question ignores that the event has already happened.

It is true that if any one of a wide variety of physical constants had a slightly different value then a stable universe would not be possible, but the problem arises when trying to assign probabilities to each variable. How does one calculate what the probability that a electron has a mass of exactly 9.10_x_10^-31 kg? That's the value it has now. It is meaning less to ask what the probability is that it might have a value of 9 x 10^-41 or 9 x 10^-21 instead.

[evildave]

Of course, you all disregard time.

Given that the matter in this space will eventually perish, either collapsing into a singularity or dissipating as radio waves, what is the likelihood of matter existing in something like space-time?

Given an infinite quantity of "something", a particular instance of "something" existing "somewhere", "sooner or later" approaches 1.

Especially when "something" is as poorly defined as a "universe". After all, would a similar univere suffice? How about a very different one? A universe in which some form of life comes into being, or ANY form of life comes into being, or in which any sort of being to notice its passing never exists?

Even that nothing between stars and galaxies is something. If radio waves and gravity and other signals propagate through it, it is a media of some sort. We don't even know exactly what that media is in the universe we're familiar with.

Even with an infinite supply of "nothing", is it truly going to be a uniform "nothing"? Who's going to do the quality control on all of that "nothing", if there's "nothing" to do it? If that nothing can be non-uniform, it can hold state of some sort, and there you have "something" again. And if a universe is "something", you'll always have one, even if it's pretty much "nothing".

Now how's that for silly logic?

[gnome]

I think the problem concept here is "Identical"...

If you mean identical in every way, down to the atoms and sub-atomic particles, and quarks, and so forth, I would say "infinitesimal".

If you mean identical in a practical sense, as in having certain physical constants, life such as ours, and so forth... I think that's a very different question.

Yet another question, in another sense you could be asking, how likely is it that a universe as /interesting/ as hours would come about, though not necessarily the same... just interesting enough that residents of that universe might ask the same question.

[Dorian Gray]

Some believe that there are an infinite number of universes. In that case, there would be an infinite number exactly like this one.

[c4ts]

Originally posted by Jon_in_london


Arrrghh!!! whats that doing there!!!

Preparing to stab you in the back.

[Ratman_tf]

Originally posted by Dorian Gray
Some believe that there are an infinite number of universes. In that case, there would be an infinite number exactly like this one.

And an infinite number of universes whose existense somehow negates the existence of other universes.

[jj]

Originally posted by T'ai Chi
Does anybody have any estimates or methods of calculating the probability of the universe even being here?

Since we've observed it, the probability is '1.0'.

What did you intend to ask?

[Ladewig]

Yes, "prediction of the future based on past events", ok, and my second question is equivalent to asking What is the probability of a universe identical to ours arising again?, if you like.

Didn't Penrose come up with some probability? -Or was it some probability for life arising?

If you are looking fro the probability that there is intelligent life elsewhere in the galaxy, you can use the first five variables in the Drake Equation. (http://www.pbs.org/lifebeyondearth/listening/drake.html)

[gnome]

Originally posted by Dorian Gray
Some believe that there are an infinite number of universes. In that case, there would be an infinite number exactly like this one.

Nope... if repetition was present, all the ones that repeat to infinity could be different from ours. Like, let's say there's only 5 possible states for a universe... (to reduce it to a convenient absurdity)... let's say ours is 1... the infinite collection of universes could be 1, 2, 2, 3, 4, 4, 4, 4, 4, 3, 3, 2, 2, 2, 2, 5, 5, 5... and so forth. There's no guarantee that "1" will ever turn up again...

Another way of looking at it.. if in the collection of universes one is found that is absolutely identical to our own--for all intents and purposes, isn't it the same one? If you traveled from one to the other, your counterpart should travel the other way, or else they become different. It would not be possible to observe the fact that you were actually in a different universe.

[Dorian Gray]

If the number or possible universes was 5, and the chance for any given universe was less than infinity, then I think the odds of another '1' type universe turning up again would be rather high.

So it really depends on what the chance is for each universe to turn up.

[gnome]

Originally posted by Dorian Gray
If the number or possible universes was 5, and the chance for any given universe was less than infinity, then I think the odds of another '1' type universe turning up again would be rather high.

So it really depends on what the chance is for each universe to turn up.

Oh, sure, it CAN repeat. It might even be probable--but without knowing the "randomizing" mechanism--the "reasons" as it were that one comes up instead of another, the probability is impossible to calculate.

What I am disputing here is that there is guaranteed to be a repeat of any given universe.

[Dorian Gray]

I would put the probability at a very high number.

[MRC_Hans]

Originally posted by Ladewig
You have to be careful when using probability this way. If I asked what is the probability that I was born, I could answer it this way. If people on average over the past couple of hundred years had a 10% of dying before having children, I can then multiply that out to show that by the time I get to my great, great, great grandparents, 62 people were involved. Therefore, .90 raised to the 62nd power is 0.00146. The chances of me being born are less than 1/5 of one percent. How wonderfully rare I am.

But like the universe question, this question ignores that the event has already happened.

*snip* I know you are joking, but you happen to demonstrate another oft-committed fallacy. I don't know what to call it, but basically you confuse cause and effect. You are calculating the probability that you are you, but that is moot, because you ARE you. The probability that the (approximate) number of people in your generation should have been born is very high.

The probability that your generation ended up composed of exactly the persons it ended up with is very low, because the number of possible combinations was astronomical, but one of them HAD to come out.

Edited to add:
On another BB, I have met the "20 sixes" fallacy. Basically someboy has claimed that something (probably abiogenesis ;)) is as unlikely as rolling a dice 20 times and getting 20 sixes. Apart from the fact that nobody can make such a calculation and get a useful result, the fallacy is again the after the fact or cause and effect fallacy: The assumption that we must have the result we had. In fact ANY roll of 20 dice is equally unlikely. Roll a dice 20 times and note the sequence you got. Before you started, the probability of getting just that sequence was (appr) 1 / 3.7E15 ! Yet you got it.

Hans

[gnome]

Originally posted by MRC_Hans
Edited to add:
On another BB, I have met the "20 sixes" fallacy. Basically someboy has claimed that something (probably abiogenesis ;)) is as unlikely as rolling a dice 20 times and getting 20 sixes. Apart from the fact that nobody can make such a calculation and get a useful result, the fallacy is again the after the fact or cause and effect fallacy: The assumption that we must have the result we had. In fact ANY roll of 20 dice is equally unlikely. Roll a dice 20 times and note the sequence you got. Before you started, the probability of getting just that sequence was (appr) 1 / 3.7E15 ! Yet you got it.

Hans

I run into this a lot... but the argument can even continue from there--noting that 20 sixes is a far more remarkable result than a random-looking sequence. But then you have to ask, how many "remarkable" or "interesting" results are there? One might similarly comment if they had received 20 fives. Or 20 alternating fives and sixes. Or "1, 2, 3, 1, 2, 3, 1, 2, 3..." and so forth. So even that would not be colossally improbable.

[c4ts]

Originally posted by jj


Since we've observed it, the probability is '1.0'.

What did you intend to ask?

Doesn't the probability for any observed sequence of events automatically become 1.0? Is the universe being here not an observed event?

[Silicon]

A similar numberical probability fallacy was given in evidence in The Blind Watchmaker.

A professor would routinely use the example of a car license plate he saw in the parking lot just before his lecture:

"On my way in here today, I saw a license plate with the number 1LWQ948. Imagine that! There are MILLIONS of combinations of license plates, so the odds of seeing that EXACT plate must have been a million to one!"

The joke being that of course the license plate had no significance. There was no particular reason to think there was anything magical about observing some random series of numbers and calculating the odds against observing exactly that series.

Now if he had predicted that series before hand, that would be something for the books, indeed! But to rationalize it after the fact, is sheer folly.

Similarly, I think just about every religious believer somewhere in his belief system are amazed that of all the worlds in the universe, THIS one is the one with intelligent human life. Lucky us, to be living on the one planet we know of that could support us!

Lucky us to be living in the one universe that we know of that can support life. Surely that must be proof of God!

(Of course, we're merely looking at the facts around us already, like the license plates of cars that are parked in our parking lots.)

[c4ts]

What are our chances of existing somewhere where it is impossible for us to exist?

Zero.