[tom (OP)]

Why SETI program is unsuccessful?
My answer is simple: it would be successful lets say 10 million years ago, or over lets say 10 000 years, but I'm sure nobody will listen to radio signals from space in year 12 000. We are simply lost in time. What is your opinion?

[Donnah]

Perhaps we are looking for the wrong kind of signal.

[Pappy]

Perhaps nobody/nothing is transmitting.

[chris]

I think the argument goes that if there are planets at varying stages of evolution and at varying distances from earth, at any given time we should be able to pick up signals from those that are near and invented radio recently, and those that are farther off but invented radio a while back and hence their signals are only just arriving.

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx

[Ylide]

Or, more importantly, if there is a sufficiently advanced civilization out there, maybe they have moved beyond using electromagnetic energy to communicate.  

Quantum physicists have been theorizing the ability to use separated atomic subparticles as a communications device.  (This is my rough understanding of how it works...I'm a chemist, not a physicist, so feel free to correct me if I'm mistaken.)

Atomic subparticles have a property called spin.  Two particles of the same type that make up larger atomic particles (protons, neutrons, electrons) will have spins of equal magnitude but opposite "direction."  If the spin of one subparticle is changed, the other changes to maintain its opposite character.  Supposedly, when these pairs are separated, they keep this characteristic, regardless of the distance separating them.  If there are two spin states, 0 and 1, and you are capable of detecting changes in spin state, you can transmit binary data across any distance at whatever rate your detection device can detect the spin state change.

I probably just made every physicist that reads this forum cringe, but that's my understanding of it.  

Back to my original point, if they're using something of this nature, there would be no signal to detect.  (Unless we're detecting something they used thousands of years prior to their current technology level that took time to reach us)



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[chris]

But Cannabinoid, some of our nearest neighbours in space are millions of light years away, and there are billions of them.

Now assume that somewhere out there are other intelligent life forms that, like us, deiscovered radio waves before they discovered fancier means of communication.

Give the magnitude of the universe, it is not too impossible to imagine that there might be planet bearing intelligent life a sufficiently great distance from earth, and with sufficiently advanced inhabitants, that they were emitting radio waves a few million years ago - after all the universe is about 10 billion years old, and life on earth is about 3.9 billion years old so there is plenty of slack in the system for other intelligent life forms to spring up way ahead of us and potentially be several billion years ahead of us.

For example, say for simplicity that our intelligent neighbours are a million light years away, and are a million or so years ahead of us in terms of their development (a drop in the ocean on a cosmic time scale) then their radio transmissions (travelling at the speed of light) will tkae a million years to get here - and hence although they are now using far more advanced forms of communication, the hallmark of their earlier work is still spreading out around the universe, as is ours, and we should be able to detect it.

What really worries me is that someone, somewhere, in the universe has already seen the kind of crap we broadcast (like friends and other **** like that) and is making a very every effort to avoid us to avoid social contamination !

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx

[Quantumcat]

Wait one question, how old will our sun be before it gets old and explodes and kills us all?

Am I dead? Am I alive? I'm both!

[Ians Daddy]

I think spending millions of dollars on trying to contact something in space is rediculous. Dolphins are very inteligent creatures. However, it does us no good to spend any money to put TVs and radios into the ocean in hopes that they might communicate with us on our level. They are completely different and have their own language. I feel that if there isn't anything out there, it would be like burying radios all over the place at the cost of billions of dollars in hopes that the earthworms might pop up and say hello. To me, it's a waste of money. Furthermore, I agree with Chris. If they are out there listening, they sure as hell don't want anything to do with us. We ride the short bus of the universe. If they are advanced enough to get here, they would only come here to make pets out of us.

[tweener]

I think I have to agree with IansDaddy about any "civilization" capable of getting here probably just wanting to make pets of us.  Or maybe they would just want to study primitive life forms.  Or maybe they won't even recognize us as life forms.

As for the age of the sun before it explodes, I believe the best theories now are that the sun is about half way through it's life at 4.5 Billion years.  So, figure another 4 Billion years or so.  Probably enough time to enjoy your trip to France!



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No words of wisdom here.

[Pappy]

Ians Daddy, Tweener got it right! Besides, The Twilight Zone never lies. The episode: "To Serve Man" says it all......."IT'S A COOK BOOK"

[chris]

There are 2 points I'd like to add to this debate.

Firstly, don't be mislead into thinking that the SETI project is expensive. As science goes it's a very cheap project; in fact it's so cheap, in the grand scheme of things, that it's a project that we cannot afford to neglect because the potential ramifications of a positive result from SETI would be so huge.

The second was to agree with Tweener's statistics. I quote from Prof. Sir Martin Rees's book (he's the astronomer royal at Cambridge University) :

"less than half the sun's central hydrogen has so far been used up, even though it is already 4.5 billion years old. It will keep shining for a further 5 billion years. It will then swell up to become a "red giant", large and bright enough to engulf the inner planets and to vapourise all life on Earth. During this red giant phase, lasting some 500 million yers, hydrogen will continue to burn in a shell around the helium core. Next the sun will undergo a more rapid convilsion, triggered by the onset of helium fusion in its core. The action will blow off some outer layers - about a quarter of the sun's mass altogether.The residue will become a white dwarf - a dense stellar cinder no larger than Earth - which will shine with a bluish glow, no brighter than today's full moon, on whatever remains of the solar system."

Brilliantly written isn't it ?

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx

[Donnah]

Pappy, I remember that episode.  Thought it was great.

I don't think we have to worry about the sun destroying our planet, we're doing a fine job of that ourselves.

There is no doubt in my mind that we are already being observed by "visitors".  If they wanted to do us harm they would have done so already, although it is possible that they have both good "people" and assholes in their midst, just like we do.  I suspect their motives are more benevolent; perhaps they are gently nudging us away from the self-destruct course we are on.  

I was part of SETI; who else has been involved?

[chris]

Many of the hospital computers had it running !

Do you think that other life forms will have a social conscience like we do ? Do they obey the prime directive ?!

NASA went to great care to ensure that there is no threat posed to other planets by landing probes on them in terms of contamination with earth-derived organic material including bacteria.

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx

[tweener]

I ran the screen saver for a while, but started having serious problems with the stability of my computer.  I don't think it was the SETI, but who knows - maybe I was getting too close and the aliens wanted to get me and my "super computer" out of the way. (my graphical winkie didn't work).

As for the real SETI search, I agree that it is incredibly cheap compared to almost any other significant space exploration.  As for the chances of success, they are low, but the potential impact is HUGE!

As for the signals to look for, who knows.  I know the SETI scientists have made several assumptions about what for and where to look, most of them probably good.  

Humans have only been transmitting radio waves for 70 years (in quantity) which is not even a drop in the bucket.  Even in that short time, we are moving away from "broadcast" transmission and more into fiber optic.  Free space transmission will never go away, and overall the "airwaves" are becoming more crowded, but a higher percentage of our traffic will never be detectable from space.

Also, as the radio environment becomes more crowded and noisy, the modulation used is becoming more sophisticated and in some cases harder to detect.  By doing this, the signals are actually more robust to a receiver that knows exactly what to look for.

I didn't mean to write a book, but this is a thread I know something about and I'm very interested.

John


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No words of wisdom here.

[UScaV]

So basically the SETI program is a low budget type of program that attempts to recieve messages from space?  And then attempt to send some back out?  I don't really know anything about it, I didn't mean anything bad by low budget.

[tweener]

That's it in a nutshell.  I don't know about the send some back out.  We're sending gigawatts of stuff out - anything intelligent would probably get lost in the re-runs.

SETI stands for "Search for Extra-Terrestrial Intelligence".  It takes relatively little money to set up a receiver and computers to process the "noise" coming in from the universe and look for something that correlates better than randomness.  Mostly it takes a lot of computing power which is why they developed a screen saver for the masses.  All those idle PCs can wade through the correlations and send back the results.

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No words of wisdom here.

[Pappy]

Donnah - it was a great episode. However, you seem convinced someone is "out there" and watching us. Can you provide any tangeble evidence?? I have no doubt (and, sorry to say, no evidence) that life exists throughout the universe. However, I think it's somewhat presumptuous to think they're interested in US. Besides, it they are watching, why don't they present themselves. I mean really, if you want to influence human behaviour a space ship (or communication) from another world/place would be VERY convincing (like the movie: "When the World Stood Still," or something to that effect).

[Donnah]

Pappy, I think that in the incomprehensible infinity of the universe it is absurdly arrogant to assume that we are the only intelligent life.  So if there is other intelligent life, it would be reasonable to expect a wide range of intelligence.  Chances are slim that we would be the most or the least developed species; we would most likely be set at a point within that range.  Therefore there would be both more and less advanced beings than ourselves.  The more advanced beings could easily monitor our planet; because we are special to them in some way, or just because they happened to find us.  Why don't they present themselves...are we sure they haven't?

[Pappy]

Donnah - I think we're in the same camp regarding the existence of life throughout the universe. However, we most assurandly differ in regards to an alien watching/observing our planet. Your argument seems based in "psuedoscience" rather than the scientific method. Given the fantastic distances between stars and galaxies, an alien life form capable of traveling those distance would be so advanced that we would nothing more than ants along the evolutionary scale. Does the entomologist care if he/she is observed by the ants being studied.........I think not! Really, the alien visitation argument appears based upon belief and desire rather than facts and data.

I am however, very much open to the possibility when presented with same tangible evidence.

Cheers

[NakedScientist]

Here is the link to an interview we did with Professor Sir Martin Rees (whose book is quoted above) for the Cambridge Science Festival 2003. He came along to discuss the prospects of finding life elsewhere in the universe. He's an excellent speaker, I can strongly commend giving it a listen :

Follow this link and click on Martin's name, or click 'interview' on the top right. You'll need media player to hear it.

http://www.thenakedscientists.com/html/shows/2003.03.19.htm

TNS