Wow signal and SETI?

[Mr Manifesto]

I found this article via idleworm.com, but you may as well look at the original source- save a click or two.

The Mysteries of the Wow Wave
(http://www.spacedaily.com/news/seti-03d.html)

Anyone heard of this? Has any alternative explanation been given that might not have been pursued by this article? Somehow the 72 second business makes me think 'malfunction' (maybe it read a star too high or something?) but I know nuthink 'bout stargazin' and stuff, so any ideas/help would be appreciated.

[Iconoclast]

From the cited article
The Wow signal's unusual nomenclature connotes both the surprise of the discovery and its sox-knocking strength 60 Janskys in a 10 Khz channel...
60 Janskys in a 10 KHz channel!!! WOW!

And... whaddahell's a Jansky?

Sort of reminds me of this (http://www.geocities.com/Area51/Stargate/8653/121gigaw.wav).

[espritch]

From the link:
So was the Wow signal our first detection of extraterrestrials?

It might have been, but no scientist would make such a claim. Scientific experiment is inherently, and rightly, skeptical. This isn't just a sour attitude; it's the only way to avoid routinely fooling yourself.

That pretty well sums it up. I don't know if they detected something unusual from space or just interference from Earth or a technical glitch. But unless the signal can be found again, it really doesn't matter since no useful conclusions can be drawn from the information available.

[Diamond]

I remember reading that the "WOW" signal came from the locale of a very small number of quite unremarkable stars. Its never been repeated, so it will be filed under "WTF".

Edit: I found the link: http://news.bbc.co.uk/1/hi/sci/tech/1122413.stm

Which is a shame. If wishes meant anything in the Universe, then I wish it was a signal of alien life....

[T'ai Chi]

Has SETI passed any "sniff tests" ?

[Ratman_tf]

Originally posted by T'ai Chi
Has SETI passed any "sniff tests" ?

SETI hasn't made any claims. They just listen and hope. ;)

[T'ai Chi]

Originally posted by Ratman_tf

SETI hasn't made any claims. They just listen and hope. ;)

It is not pseudoscience, just parts that are probably bad science.

What about it is falsifiable? They could always say 'oh, we haven't found anything yet.. but we just need to search more.. and search with higher powered instruments' etc. ad infinitum.

Oh, and in no other field could there be something as speculative as the drake equation.

[Yahweh]

:wow2: :wow2: :wow2: :wow2: :wow2: :wow2: :wow2: :wow2: :wow2: :wow2:

[Ratman_tf]

Originally posted by T'ai Chi


It is not pseudoscience, just parts that are probably bad science.


Anything specific?

What about it is falsifiable? They could always say 'oh, we haven't found anything yet.. but we just need to search more.. and search with higher powered instruments' etc. ad infinitum.


Perhaps so. Since SETI is privatley funded, and makes no claims, I don't see a problem with them looking to their heart's content. I personally support the search for ET, but I aknowledge that some others don't.

Oh, and in no other field could there be something as speculative as the drake equation.

I think I agree with you there. Everything in the subject of ET life is pretty damn speculative.

[espritch]

Oh, and in no other field could there be something as speculative as the drake equation.

The Drake equation looks like a real equation so a lot of people take it to actually mean something (a lot of UFO believers like to trot it out to "prove" their assumptions). The problem of course is that almost none of the parameters involved can really be acurately determined at this point, so any conclusion drawn from it is pure speculation - equation or no equation.

[zer0vector]

Originally posted by Iconoclast

60 Janskys in a 10 KHz channel!!! WOW!

And... whaddahell's a Jansky?


A Jansky is 10^-23 ergs s^-1 cm^-2 Hz^-1 steradian^-1. In case that is a bit obtuse, it's a unit of flux density, basically describing the amount of energy coming from a source, kind of like the magnitude of a star.

60 Jy is pretty high, especially in such a small bandwidth. The brightest sources in the radio sky around 1000 Jy, and there are only a handful of those (Cygnus A, Sag A). At the 60 Jy level there are probably only 100 or so.

[Iconoclast]

Originally posted by zer0vector
A Jansky is 10^-23 ergs s^-1 cm^-2 Hz^-1 steradian^-1. In case that is a bit obtuse, it's a unit of flux density, basically describing the amount of energy coming from a source, kind of like the magnitude of a star.
Thanks ZV!

[tracer]

Wait a minute ... why are both square centimeters and steradians on the bottom of the fraction (in that definition of a Jansky)?

[zer0vector]

Originally posted by tracer
Wait a minute ... why are both square centimeters and steradians on the bottom of the fraction (in that definition of a Jansky)?

The square centimeters takes into account the r^-2 behavior of any radiation field. Basically the power through a spherical surface of radius r drops off as inverse of the square of r. This can then be related to the effective area of your detector, which determines how much of thie power you can collect.

The steradians deals with the case where you have an extended source in the sky. Since no source is perfectly pointlike, it's angular size must be taken into account.

[tracer]

Oh ... so the "per square centimeter" part deals with the size of your collector, and the "per steradian" part deals with the size of your source. Gotcha. (Hmmm ... the stellar magnitude system doesn't take the angular size of the source into account. Is there an equivalent Jansky-like unit that doesn't have steradians in the denominator?)

BTW ... isn't Hz^-1 another way of saying "seconds"? ;)

[zer0vector]

Originally posted by tracer
Oh ... so the "per square centimeter" part deals with the size of your collector, and the "per steradian" part deals with the size of your source. Gotcha. (Hmmm ... the stellar magnitude system doesn't take the angular size of the source into account. Is there an equivalent Jansky-like unit that doesn't have steradians in the denominator?)

BTW ... isn't Hz^-1 another way of saying "seconds"? ;)

You're right, magnitudes don't deal with any structure of the source, but the Jansky was defined in radio astronomy, where just about everything is extended. Stars are pretty much invisible in the radio, so what you do get is mostly ionized gas, high velocity gasses, or ions moving in magnetic fields. As such, I'm not sure if there is a single unit defined as being Jy * steradian.

Yes, technically Hz^-1 is a second, but it makes more sense to say it that way since it relates directly to the frequency bandwidth of your system.

[Undesired Walrus]

Single greatest image ever, in my opinion.

http://patriot.net/~jlazio/images/WOW.gif

Why isn't there more press on the Wow signal these days? As I thought they established it was hard for that signal to come from a supernova or something similar.

[Beerina]

It is not pseudoscience, just parts that are probably bad science.

What about it is falsifiable? They could always say 'oh, we haven't found anything yet.. but we just need to search more.. and search with higher powered instruments' etc. ad infinitum.

It no more needs to be falsifiable than does an archaelogical expidition or an expedition a hundred and fifty years ago to some island in the Pacific nobody's ever been to, just looking for stuff. Animals. Traces of people. Whatever.

It's the find-and-categorize wing of science.

And in any case, the more they don't find, as the years stretch into decades, and then into centuries, that, too, is an interesting development.

It might be more fruitful to search for signs of life, intelligent or otherwise, i.e. chemical signatures of living cells or whatever, though how that would be done at interstellar distances this side of using the sun as a gravitational lense, I don't know.

Oh, and in no other field could there be something as speculative as the drake equation.

The Drake equation was intended as something to think about, not as an actual calculating device.

It will only be mildly accurate probably after thoroughly examining (as in going there) at least a decent sized chunk of our own galaxy.*









* Or finally talking to someone who has. :)

[Diagoras]

Oh, and in no other field could there be something as speculative as the drake equation.
In what other field is there less evidence to go on? The Drake equation is just a conceptual tool to grasp a rough idea of the scale of probabilities we're dealing with. When you really don't know hardly anything about the existence of life elsewhere in the universe, all you can do is speculate and look. And that's what they're doing. What's your objection?

Even if we don't find anything, that tells us something. It tells us we're special. And in my book, that's something worth knowing.

[T'ai Chi]

Even if we don't find anything, that tells us something. It tells us we're special. And in my book, that's something worth knowing.

Well that can never happen, because one can always say 'the universe is infinite/very large, and even though we didn't find anything at time t, we could have found something at time t+1. Or heck, the aliens may be in another universe all together! So let's keep looking.'

[T'ai Chi]

It no more needs to be falsifiable than does an archaelogical expidition or an expedition a hundred and fifty years ago to some island in the Pacific nobody's ever been to, just looking for stuff. Animals. Traces of people. Whatever.


Yeah but in those cases 'finding land' or whatever is unarguable. But how do you know when a signal from aliens is 'good'? (of course, this all assumes that aliens exist, they have technology, they are interested in communicating, and presumably they communicate in math or some other language humans can detect/understand). Even a repeating signal doesn't rule out some non-life space-phenomenon.

So how do you detect design?
(smirk)


The Drake equation was intended as something to think about, not as an actual calculating device.


Well anything can be 'something to think about'. I've seen Sagan and others actually use the Drake Equation. What is it an equation of exactly? Well, it kind of shows what happens when you multiply a bunch of assumptions as far as I can tell. Can any tight bounds be established on any of them?

[Diagoras]

Well that can never happen, because one can always say 'the universe is infinite/very large, and even though we didn't find anything at time t, we could have found something at time t+1. Or heck, the aliens may be in another universe all together! So let's keep looking.'
And your problem with that is...what? Yeah, we may never exhaust every possibility of looking anywhere, but if we search the skies and we find no signal for a really really long time after a really really extensive search, that still tells us something. It tells us we're special. Maybe not unique, but at least exceedingly rare. That's all I meant. I'm not claiming that there is ever going to come definitive proof that we are the only intelligent life in the universe, and I'm not claiming that there is going to be any definitive disproof either. But what's wrong with looking to get some preliminary ideas on how common intelligent life is out there? Some of us would like to know if there's some kind of detectable intelligent life out there in the galaxy, and would also like to know if our galaxy is devoid of such signals. There's only one way to find out.

[Gr8wight]

Same old Justin. What part of, "SETI doesn't make any claims," did you not understand?

[Diagoras]

Well anything can be 'something to think about'. I've seen Sagan and others actually use the Drake Equation. What is it an equation of exactly? Well, it kind of shows what happens when you multiply a bunch of assumptions as far as I can tell. Can any tight bounds be established on any of them?
It's a mathematical relationship between a set of different probabilities. Sagan was well aware that he was operating on a set of assumptions (although not all are assumptions; I think we have a good handle on how many stars there are in the universe, for example). Sagan never pins down an exact number and says "Here, this is how likely finding intelligent life is."

However poor our estimates may be given our limited knowledge at this point, and however limited in usefulness the Drake equation is because of that, you can't deny that the various probabilities in that equation, whatever their numbers be, would yield the probability of finding intelligent life in the universe when multiplied together.

[ponderingturtle]

Well that can never happen, because one can always say 'the universe is infinite/very large, and even though we didn't find anything at time t, we could have found something at time t+1. Or heck, the aliens may be in another universe all together! So let's keep looking.'

And do you have a practical point? Determining how common techonogical civilizations might be in this area is not a pointless endevour.

[Hamradioguy]

For a fascinating look at the Ohio State Big Ear radiotelescope that detected the WOW signal get a copy of "Big Ear" by John Kraus. My copy was written in 1976, so no mention of that mysterious signal, but lots of neat non-technical reading on radioastronomy, and some interesting speculation on extraterrestrials. (Dr. Kraus wrote THE college textbook on antenna theory-for those who like lots of math, and was the chap who invented the helical antenna.)

[CFLarsen]

Yeah but in those cases 'finding land' or whatever is unarguable. But how do you know when a signal from aliens is 'good'? (of course, this all assumes that aliens exist, they have technology, they are interested in communicating, and presumably they communicate in math or some other language humans can detect/understand). Even a repeating signal doesn't rule out some non-life space-phenomenon.

So how do you detect design?
(smirk)



Well anything can be 'something to think about'. I've seen Sagan and others actually use the Drake Equation. What is it an equation of exactly? Well, it kind of shows what happens when you multiply a bunch of assumptions as far as I can tell. Can any tight bounds be established on any of them?

Can you come up with a better way?

Other than point to your god, of course.

[T'ai Chi]

Sagan never pins down an exact number and says "Here, this is how likely finding intelligent life is."


True, he comes up with anywhere from 10 to millions, but everything is qualified incredibly.
(http://www.youtube.com/watch?v=0Ztl8CG3Sys)


, you can't deny that the various probabilities in that equation, whatever their numbers be, would yield the probability of finding intelligent life in the universe when multiplied together.

Let's assume that only Earth is it. Can you tell me what the other values are to make N = 1 ?

[Thomas]

Single greatest image ever, in my opinion.

http://patriot.net/~jlazio/images/WOW.gif

Why isn't there more press on the Wow signal these days? As I thought they established it was hard for that signal to come from a supernova or something similar.
Indeed, but the signal was never re-detected. From 1987 to 1999 Robert Gray searched for a recurrence of the signal using various telescopes, even more powerful than the Big Ear, and found none. Ehman who found the signal in the first place, stated that the lack of recurrence pointed towards an earth-based signal reflected by space debris. "U" is the highest intesity variation ever detected by the Big Ear telescope and a 72 second response should correspond to that of ET contact due to the earth rotation cycle, hence the WOW!.. However, at this point, it does seem that Ehman's interpretation is the most plausible.

Still, all hard to know.

[Diagoras]

Let's assume that only Earth is it. Can you tell me what the other values are to make N = 1 ?
If you sat down and looked up all the information we do know about these variables, I bet you could come up with lots of different combinations of values that come out with N = 1 within the error bars we have so far, or N = just about any other number. We just don't know enough about the actual values of so many of the variables, so there's lots of room to fudge the numbers to come out with whatever result you want if you make different assumptions. If you want to come up with a sequence of assumptions that end up with 1, you can do that, but I don't see the point so I won't.

The only assumption I'm comfortable making right now is that 1 ≤ N < some absurdly large number like 70 sextillion (the number of stars in the universe).

[T'ai Chi]

The only assumption I'm comfortable making right now is that 1 ≤ N < some absurdly large number like 70 sextillion (the number of stars in the universe).

Same here.

But we both could have done that without any 'equation'.

[Diagoras]

So I guess it doesn't matter to you what the various variables would be in determining what N is? And it doesn't matter that we have a good grasp of at least a couple of those variables, and we can potentially narrow down the error bars on others in the future?

[DRBUZZ0]

I doubt there will ever be any proof of what the "Wow" signal may have been - artificial, a freak natural event, a malfunction, an earth signal bouncing off a piece of space debris or whatever.

The problem is we will never know what the signal was. All we have is the printout that says a signal of a relaitvely high strength and narrow bandwidth was detected. There was no recording of the signal, modulated or demodulated. There wasn't even anything as rudimentary as an audio tape recorder. It's like saying that a sound was detected but you don't know if it was a person talking or a truck going by. The data is lost and never was logged.

It could have been anything. Too bad though. It would have settled a lot if there had been some sort of recording of the actual content.

[arthwollipot]

I have tremendous problems with the phrase "we will never know". It's possible that someday we will know what the Wow signal was. I happen to think that it's extremely unlikely, but I wouldn't use the phrase "we will never know".

[drzeus99]

I have tremendous problems with the phrase "we will never know". It's possible that someday we will know what the Wow signal was. I happen to think that it's extremely unlikely, but I wouldn't use the phrase "we will never know".

And how could this possibly happen? Humans will never be able to travel back in time to listen/measure it again. We only have numbers on a piece of paper. It's IMPOSSIBLE to know FOR SURE "exactly" what ocurred at that exact moment in past history. We might guess, or have an idea, but to know EXACTLY, I don't believe that's possible.

Now, if you are postulating that an advanced alien race MIGHT contact us and tell us that it was their uncloaked star we picked up, then yes, the chance are above ZERO that that may happen. The problem with that is that they could be lying. We'd NEVER for 100% for sure. It could wind up to be
99.99999999% based on a replication of that signal today, but it's still impossible to PROVE beyond ANY doubt that it explained a signal in the past.


Cheers,
DrZ

[Doc Daneeka]

And how could this possibly happen? Humans will never be able to travel back in time to listen/measure it again. We only have numbers on a piece of paper. It's IMPOSSIBLE to know FOR SURE "exactly" what ocurred at that exact moment in past history. We might guess, or have an idea, but to know EXACTLY, I don't believe that's possible.

Now, if you are postulating that an advanced alien race MIGHT contact us and tell us that it was their uncloaked star we picked up, then yes, the chance are above ZERO that that may happen. The problem with that is that they could be lying. We'd NEVER for 100% for sure. It could wind up to be
99.99999999% based on a replication of that signal today, but it's still impossible to PROVE beyond ANY doubt that it explained a signal in the past.


Cheers,
DrZ



Actually, Arthwollipot was quite right. It isn't at all likely that we'll find out what the WOW signal was, but we can't rule out that possibility. Perhaps, for example, it's some sort of naturally occurring thing that repeats on relatively long time scales. We might then work out the nature of the signal eventually, once we've seen it repeat a few times.

As to whether the signal was a genuine signal from an intelligent source, who knows? I doubt it. Whatever one might think on that subject, it appears to have no bearing on the question of whether we might eventually determine the source of that signal.

[DRBUZZ0]

Actually, Arthwollipot was quite right. It isn't at all likely that we'll find out what the WOW signal was, but we can't rule out that possibility. Perhaps, for example, it's some sort of naturally occurring thing that repeats on relatively long time scales. We might then work out the nature of the signal eventually, once we've seen it repeat a few times.



I still disagree with that. We may know what it might be. But there's no way we can know what it was conclusively because we don't have the signal in any way shape or form, but only a printout that says there was a signal. There's no recording of any kind.

It's like when Tesla said that he had heard signals from Mars. We now think that what he heard were earth whistlers. This would be at the frequency range he was listening to and would be consistant with what he reported.

But we cannot know for sure and never will. It was probably whistlers. It could have been feedback in the equipment. It could have been Tesla looking for publicity when he didn't hear it. It could have been a malfunctioning transmitter or noise from power transmission lines somewhere.

We cannot ever be sure because there's just a vague report that he heard something. No recording, no high resolution print of the signal patern, no image from an oscilloscope. Nothing.

That is all the way signal is, it gives no details of what may or may not have been modulated onto the signal.

[arthwollipot]

That's completely fair enough. Suppose I rephrase to say that "It's possible that someday we will have sufficient knowledge to have a good idea of what the wow signal was to a reasonable degree of confidence."

I usually don't bother equivocating on the verb "to know", because although it's very true that we can't ever know something with 100% certainty, and that all we can have is a reasonable degree of confidence in an explanation of a phenomenon, it's usually a pain in the backside to type it all out like that, so I use the shorthand.

We know that birds evolved from dinosaurs. We don't need to go back in time to see it happening. All I was trying to say is that one day it's possible that we might know what the wow signal was to the same degree of confidence that we know that birds evolved from dinosaurs.

[Doc Daneeka]

I still disagree with that. We may know what it might be. But there's no way we can know what it was conclusively because we don't have the signal in any way shape or form, but only a printout that says there was a signal. There's no recording of any kind.

That's quite right. I agree. However, should this signal turn out to be something that repeats every, say, 93 years, we can be pretty sure after a few centuries that the WOW signal was one of these events. Whatever they are. Imagine that eventually some clever astronomer figures out that it's a weird extragalactic thing that does that every once in a while. Surely we can conclude that we've probably worked out what the WOW signal was?

Am I saying this is likely? No. I'm just saying that it's possible. As far as knowing EXACTLY what it was with 100% certainty...well, that's not really possible in science anyway; of course we can't ever do that. My point was that it's entirely possible that we will eventually be pretty bloody certain as to the cause. Again, I don't consider it likely:)

[Doc Daneeka]

The WOW signal: the astronomer's version of the Bloop (http://en.wikipedia.org/wiki/Bloop). Sure, there's most likely nothing real there, but it makes for a great story.