Ok, after watching yet another documentary featuring the work of SETI, I have decided to ask the question that has plagued me for quite a while now...
SETI - Search for Extraterrestrial Intelligence
I know that SETI searches for transmission from other civilizations by searching the skies for signs of unusual electromagnetic radiation.
I also know that they make the necessary assumption that electromagnetic radiation would be a medium of communication for advanced extraterrestrial life.
But why on earth would they make that assumption?
If you make the assumption that extraterrestrial life exists, and that they could be far more advanced than us, why would you assume that they would use such a primitive communication tool as "electromagnetic radiation"?
-That is the equivalent of Native Americans searching the skies for advanced life by actively searching for unusual smoke signals...
Using radio signals on earth to communicate is quite efficient, because the distances are so very small and the signal reaches its destination almost immediately. But if you are an advanced, Galaxy-crossing race, using radio signals to communicate would be very inefficient. If you wanted to send a message to your friend on a very nearby Solar System, it could take 4years to reach him... ? I refuse to think of advanced Life as having a delay in their communication time.
Quantum-physics tells us that particles across the Universe can communicate instantly. A form of communication based on that principle would be way more efficient, but I doubt you would detect it via electromagnetic radiation.
Technology today would be unfathomable for humans only a mere 1000 years ago. Just as a Technology (and the means to detect it) a 1000 years from now would be unfathomable to us today.
So my question is, why search for electromagnetic radiation if it is very unlikely that an advanced civilization would use it? -Is it just me, or am I missing something?
(I'm not sure if I'm in the correct forum, I could not find a SETI forum. If there is a more appropriate forum for this topic, please advise me where I could post it.)
Many people are doing optical SETI where they are searching for fast-pulsed lasers. The narrow beam and high directionality of lasers make them a good choice for interstellar communication. Here is an interesting article about my former Physics teacher discussing optical SETI:
Radio frequencies in the MHz and GHz range have better propagation characteristics than visible light has. For example: you can't see the stars on a cloudy night but your radio, GPS, and satellite TV work just fine. So there are some advantages to using radio frequencies as an interstellar communications channel.
You mentioned quantum entanglement which seems like a great long distance communications concept but we're not even sure if it's possible. I've read the articles about some short distance quantum entanglement experiments but I'm skeptical. We also don't know if this sort of communication is instantaneous or if it's limited by the speed of light. I'd bet on the later. Same thing goes for the speed of gravitational waves. We just don't know but I'd bet on the speed of light.
You're absolutely correct that we can't fathom the technology or science discoveries that will be made in the next 1000 years. Extraterrestrials may in fact be communicating across the cosmos using some sort of particle we don't know about. There isn't much we can do about that except wait for someone to discover it.
The philosophy of SETI is to make the best use of the technology we have today. When new Physics discoveries are made they will be incorporated into the search. The same goes for new computational discoveries. When Frank Drake did the first search 50+ years ago the FFT hadn't been discovered yet and that algorithm has been a revolution. Who knows what the future has in store? We have to search with what we've got and do the occasional upgrade when we can. The alternative is to do nothing and wait, forever.
I also don't agree with the optical approach, because that form of communication is also limited by the speed of light.
I seriously doubt advanced civilizations would use a form of communication or travel that is limited by the speed of light. -It would take a 150 000 years to reach the other side of the Milky way?
SETI is searching for advanced civilization based on signals from our own civilization, or maybe a little bit more advanced, but still based on our current understanding of physics.
Geoff Marcy says aliens could use lasers to communicate, but if you would send a message to a spaceship that is only as far as the sun from us, it would take 8min for the spaceship to receive the signal, and the spaceship would have to be standing in the exact same spot to where the signal was sent? You only have to think logically to know that this is a very primitive way to communicate.
I think the only signs of advanced life SETI could detect, would be from a civilization with more or less our own Technology, because that's what they're searching for.
If we would find a way to communicate or travel that's faster than the speed of light, we would stop using our current ways, and all traces of it would fall away, and you would not be able to detect it.
I am sure Aliens exist, but I am also sure most of them are way more advanced than us, and would not base their Technology on our primitive understanding of physics.
My point is, don't search for advanced life based on our current understanding of the universe.
I understand exactly what you are saying, but if these races are that much in advance of us, then we will never catch them up, so at what time, and what level do we say "We now know enough to detect alien transmissions"; I think that the philosophy you are preaching would suggest never.
Our technology may be primitive and rather slow; but according to our current understanding there is no evidence of faster than light communication or travel, so I think to suggest that we shouldn't expend any effort trying to detect ET just in case he has managed to violate physics as we understand it seems more of a long shot than assuming that our current theories might possibly be right. Detecting aliens by looking for radio or light signals might only have an infinitesmal chance of success, but it is still infinitely greater than not looking at all.
I still have yet to be convinced that any race will evolve any further than the point at which they have complete control of their environment; although it is evident that the way we are poisoning our planet, we have yet to reach that point, it it clear that we are not too far from it. Your original premise that ET will be very much more advanced than us, is as far as I am concerned 'yet to be proved'.
Am I wrong?
Speculation abounds about advanced ET communication abilities, that we are focusing on the wrong frequencies, that these ETs wouldn't use the radio waves cause their too darn smart, blah, blah, blah.
I think/hope that any other advanced technological civilization would have gone through the same stages of communications in somewhat the same way we did.
Steps like the telegraph, radio, television, communications satellites, microwave based communications and on and on into the future.
So given the distances to exoplanets, it seems like a good possibility to me that we may very well be able to pick up there 'earlier' communications that are just arriving/about to arrive here on Earth.
Even if they've already advanced to communications way beyond our current capabilities/understanding, or blown themselves up 100+ light years ago, the signals they originally produced are still limited to the speed of light and therefore well within the reach of our current technology.
Probably already missed their version of I Love Lucy, darn
(repost from talk.setilive.org by me)
It took thousands of millions of years for a communicative civilization to evolve on Earth. If it takes a similarly long time for communicative civilizations to evolve on other planets, then it is unlikely that we would be out of technological sync with them, in the manner that you describe, by only a few hundred years.
An immensely powerful transmitter would be required for a SETILive participant to detect in a waterfall image generated from ATA data a non-targeted signal (eavesdrop) from the Kepler Field. Much more powerful than I think most people participating in the SETILive project realize. We are not likely to be targeted, which would improve the situation somewhat, because our radiosphere (revealing that we are here) has only made ~ 1/10 the journey there.
I plan to make a SETILive chat post on this topic with calculations.
I'd very much like to see those calculations.
What prompted me to ask the "I Love Lucy" question was a couple of articles I read debating the possibilities.
It seems that 'debate' is what fuels the fires of progress in the scientific community, and there is plenty to debate after reading these articles.
Here are the links that fueled my interest in the whole "Is ET watching 'I Love Lucy' right now".
BTW, thanks for posting your answer over on SETILive! I appreciate the time you took to put it together. It was technical for the techies, and simple at the end for... well, the rest of us.
Welcome to SetiQuest. Your enthusiasm is appreciated.
Please be aware that afeder is not a representative of setiQuest or the Seti Institute.
The current observing system is designed to detect a beacon targeted at Earth from
an advanced Civilization. At present we can not detect leakage from the Alien TV shows.
The SetiLive program selects frequency bands so full of signals that the current
system has difficulty processing them.
Thanks for your interest,
Software Engineer at the SETT Institute
I think you're throwing poision tipped darts at the wrong target. I am a level "-1" SETIzen scientist when it comes to the technology, but a level "4" SETIzen scientist when it comes to really wanting to help in any small way I can in the search for ET. THAT, is why I signed up, for the first time I could help in the search, no prior experience required.
I realize now that many setiQuest members had a 'whole nother idea' about what 'doors' SETILive would unlock for the much more technical savy members of setiQuest.
Being a "moderator" over there on the 'dark side' doesn't mean I am oblivious to other channels of information. I spend part of every day I can learning on the setiQuest site, reading the blogs/forums on a regular basis and visiting the ever expanding sites I find relating to our quest for ET.
I have been able to produce my first image and plot following the guidelines at http://setiquest.org/wiki/index.php/Windows_setiQuest_Data_tutorial (on a Win7 machine no less) thanks to the software and instructions on the setiQuest site. Big thanks to those who took the time to produce a Windows version!
So, no technical arguments from me, but I do feel it is my right to use the setiQuest forum to ask questions/leave comments and expect a certain amount of civility in the responses.
afeder, I am interested to know more about the inverse-square law as it applies to our quest for ET that you mentioned.
"Due to the inverse-square law, radio leakage from a civilization similar to ours would be severely diminished in power by the time it reaches Earth."
So, what I get out of your 'lesson' is that by the time a signal 100 light years away reaches us it will be 10,000 times weaker than the original signal (is that right?), so nothing except DSP technology (I have no idea what that is, but I'm going to look it up) can detect an ET signal buried within.
Does that mean that "I Love Lucy", ET style, could be picked up with DSP technology? I don't know, I'm just asking the question.
I hope everyone over here at setiQuest doesn't have the same opinion when a comment/question comes in from a member of SETILive who hasn't passed through setiQuest first. I sense your pain/frustrations in all things SETI, but I have learned that the 'wheels of SETI Science' turn at a much slower rate than we would like. Time will tell.
I'm not sure 'meg' would appreciate a similar response sent to her from a comment she might make over at SETILive to a valid question/commment. Right?
thanks for joining the setiQuest community. it's good to know that you are able to make progress via the tutorials. at the SETI Institute we are a small group, and unable to consistently provide the scrutiny required to insure that all participants exhibit best behaviors.
if i understand your query, you were interested to know how likely it is that setiQuest data would contain signals that are no stronger than our TV leakage. the answer is not likely. the 42-element array has the collecting area equivalent to a 34 m single dish. the effective radiated power that gets broadcast by our TV stations is less than ~ 1 MW. with receiving equipment comparable to the ATA, these signals aren't detectable at the distance of the nearest star. while radio and TV are our most numerous leakage signals, they are not our strongest. that distinction belongs to the planetary radar associated with the large radio telescope in Arecibo, Puerto Rico with an effective radiated power of 2x10^13 W. IF you happened to be in the beam of that transmitter, it's signal could be detected half way to the center of the galaxy. ionospheric radars are more plentiful and have powers in between. so the question of leakage isn't completeley cut and dried. as we build out the ATA with more antennas, it will get more sensitive. and if an ET transmitter 'leaks' a lot more power than our own in the 21st century (e.g. a radar shield against incoming asteroids) than they will be detectable at greater distances. bottom line is that the easiest signal for us to detect is one that somebody else has gone to the trouble of deliberately transmitting to attract our attention.
you might wish to take a look at SETILive.org, where citizen scientists are trying to help us see if there could be an ET signal embedded in and obscured by our own communciation signals at frequency bands allocated to terrestrial communcications. this works on live data from the ATA and we're trying to iron out the bugs of closing the feedback loop quickly enough (~90sec) to be able to follow up on interesting candidate signals in near-real-time. the tutorials there are quite helpful and there is more moderation of the community discussion, so it exhibits less abrasive behavior.
Thanks to all for clearing up (literally) my 'I Love Lucy' question!
I am a strong supporter of all things SETI, and what I can't do with my wallet, I will continue to do with my time.
Special thanks to janebird, jrseti, and of course to jctarter (what an honor)!