Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: tom on 16/10/2003 13:46:50
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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?
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Perhaps we are looking for the wrong kind of signal.
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Perhaps nobody/nothing is transmitting.
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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
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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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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
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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!
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.stupid-boy.com%2Fsmilies%2Fkao%2Fotn%2Fcat.gif&hash=e4b91a72c020cc1c5d28487fff5428f1)
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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.
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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.
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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"
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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
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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?
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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
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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.
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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.
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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.
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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).
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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?
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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
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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
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Maybe we can't find alien life because the universe is so tremendously huge that the probability of finding them is extremely small. Think of the entomologist trying to study ants, but there are only 10 colonies in all of the land surface of the earth. And because of the "speed of light" limitation (in the universe not the analogy), she cannot go faster than a slow walk. Odds are the entomologist will have a very very long search. Maybe longer than the life span of her "civilization".
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John
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We will never make contact with extra terrestrial life and we will never make journeys into deep space.
The simple answer follows:
E=MC squared. Where E is energy required, M is mass and C is the speed of light.
Now based upon this equation, the closer we get to the speed of light, the more energy is required. If we plot this equation on a graph, we find that when we get to the speed of light we require infinite energy and infinite mass.
Now as this is impossible we can summise that nothing can travel faster than the speed of light.
I do not know how far away the nearest inhabited planet is but I'm pretty sure that it is millions of light years away.
This means that at the speed of light it would take millions of years to get there.
Thus we can see that this would be impossible.
When I have told people this before I usually get the "Star Trek" response ie "It might be possible if we had the technology..." This isn't an issue of technology but the laws of physics.
Intergalactic travel is and always will be impossible but then I'm a Pharmacologist and not a physicist.
Live long and Love life
Kevin Fisher
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drkev -
There are some theories being bantered around that might allow for "faster than light" travel. I don't understand the details, but they involve tunneling through other spatial dimensions to come out in another area of our own four dimensional space. It's probably a long way off.
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John
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We did a piece about time travel and wormholes last year.
Here's the link. The audio is in the third block down, and the text transcript is at the bottom of the page under "full length text" - click top right.
http://www.thenakedscientists.com/html/shows/2002.05.26.htm
Chris
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This subject came up during dinner with some friends. I'm constantly amused at how vigorously people insist extraterrestrials are here now or have visited in the past based on a negative argument (prove they're NOT here!). I'm also amazed at the suggestion that our government is suppressing the evidence and has dead aliens, crashed space craft, etc. Wow, in this day and age of fast information, a free and vigorous press and an abundace of interested, probing individuals, no government agency is that secure and non-porous. It's funny how people are so quick to point out the stupidity and incompetance of our government, except when it comes to hiding the evidence of alien visitation. In that respect, they are flawless! In addition, is the USA the ONLY country visited, certainly not.....perhaps every country has been visited and EVERY government is successfully hiding the evidence....ABSURD!!
The reason no tangible evidence has been presented is because there is no tangible evidence to present!! Occam's Razor!
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Amoung many other very important factors I think that the most imporotant factor is that intelligent life is so rare that its two species living so close togther in interstellar space is next to zero. It's just too difficult to comminicate over those distances with any technologym, even ones that we haven't been exposed to at all.
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If someone is trying to publish the DNA sequence of Sasquatch (http://www.thenakedscientists.com/forum/index.php?topic=47000.0), we should next see a publication of the DNA of "Aliens", and alien-human hybrids, showing startling similarities to the researcher's own DNA.
The prerequisite for intelligent life is just life. And, unfortunately we don't know how common either one is, or whether it is possible for life to be something other than hydrogen/carbon/oxygen/water based.
"Nearby" is all relative, astronomically speaking. There about 260,000 stars within 250 light years of Earth. (http://www.atlasoftheuniverse.com/250lys.html)
The two-way communication delay would be quite extraordinary between systems 250 light years apart, but one could imagine sharing data streams over moderate astronomical distances, even if direct travel is not practical.
The question is whether "life" or "intelligent life" is more common than 1:260,000
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I sometimes wonder if the extra-terrestrials have a different conception of time to us so that instead of looking for signals in a 1 Hz bandwidth we should be looking at a 0.001 Hz bandwidth.
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The bandwidth of the signal would depend somewhat on one's ability to decode the signal. I'm not real familiar with computer communications, but it would not be too surprising to use multiple channels for parallel communication, using as tight of frequency separation as could be discerned. Perhaps adding a timer signal to correct for frequency shifts. To an outsider, such parallel data transfers might look like "noise".
Our radio signals, of course, incorporate both amplitude modulation (AM) and frequency modulation (FM).
If one wished to initiate "first contact" with an alien species, say 250 light years away, I would think one would choose a very simple signal until one could ascertain that both parties were listening, then choose a more complex pattern. Or, perhaps both transmit a simple AM signal, as much to get attention as anything else, as well as a much more complex data transfer signal. Could you embed the key for the complex signal in the simple AM signal?
Of course, if one was just intercepting communication such as we use to voyager, and various satellites and deep space probes, then that would depend on the technology at the time of manufacture.
Anyway, a "first contact" signal should also be transmitted continuously, or as continuous as possible, just to increase the possibility that someone is listening.
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Dolphins live in the sea, so that makes them non-terrestrial.
Why can't we learn to communicate with them, first?
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You know Evan. I think we do know how to communicate with other animals here. We just don't notice that we do. And sometimes we don't want to notice it either, consider how many cultures that treat animals as less than humans, then consider how we use them for our food industries. To do the same with humans would indeed be inhuman, but seems acceptable when it comes to other species.
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I think spending millions of dollars on trying to contact something in space is rediculous. .
It's hardly ridiculous since it would answer a question that we've all been asking since the man walked the Earth: Are we alone?
It would make an immense difference to everyone on the planet. Hardly a ridiculous effort.
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I do not think SETI ridiculous but rather futile if we did find evidence of intelligent life the distance would probably be so great that with the large time delay any conversation would be impossible
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Syhprum - I agree with Pete, it would be an incredibly important moment in world history, finally knowing we are not alone. I think it would alter the way we approach many things
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If we wished to establish communication with aliens, perhaps the best thing to do would be to broadcast a "here we are" signal.
The likelihood that a single burst sent towards a neighboring star would be picked up would be low.
Earth, of course, "leaks" some radio waves, but not at a power or design to attract attention of extraterrestrials. Perhaps communication satellite uplinks, but even those would tend to sweep around the sky on a 24 hour basis, and not give continuous coverage anywhere.
What we really would need is a powerful omnidirectional broadcast antenna sending out, a simple, but unmistakably artificial signal. Then on a different frequency, perhaps a weaker signal carrying a digital photo dictionary, uncompressed, of course, and other selected communication. Embed information to find the second signal in the first one. And, if a response is received, to expect to send directed communication on a 3rd frequency.
And the signal pair would have to be continuously maintained for thousands, or perhaps millions of years, while always scanning for a response.
If we are unable to, or unwilling to invest in initiating contact, why would one think that an alien race would be doing it?