Why is there SETI?

Sometimes I can't hear radio because of so much static. Do you really think we would be able to hear an ET? :bugeye:

 

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Though as very rare as it may be, it's highly probable that ETI 'might' have existed in the universe in one form or the other, millions or even billions of years ago. Even a more realistic view is to assume that even if ETI existed before in our universe or even in our own galaxy, it may 'not' exist today. Over time, over eons of time, ETI may have just vanished due to a host of reasons. Maybe just like the example or theory how dinosaurs died out here on planet earth. Who knows for sure. Sorry Carl, but the simple fact remains, if our own galaxy was 'teeming' with ETI and they have or had radio technology, we probably should have found it by now. Contrary to popular belief, we currently have the science to find it.

Okeydoke

 

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We have the science to find only civilizations that use radio waves. This is backward technology. I'm not surprised we cannot find any.

Not only that... if we want an accurate sign, we might as well have the radio telescopes orbiting around the planet, or even beyond that...


I know it's like finding a particular grain of salt in the middle of the ocean, but the ocean is big enough.

 

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And as that timeline points out, once technology is discovery, the process of evolution speeds up dramatically. Our minds are evolving faster then our bodies. This is one of the reasons why we have so many problems, such as rape, for instance.

 

No time to respond now. I may open a new thread to expand on my central contention, namely that we may be being far too optimistic about the prospects of intelligent life elsewhere.

 

Silly question: Does anyone right here and now try to beam a message to Mars and see if they get a response?

 

It's a fantastic ideal that we all have, thinking that intelligent life exists elsewhere in the universe. Hopefully, ETI would exist closby in our own galaxy, close enough to communicate with it. But the reality is, if there were intelligent life forms that inhabited planets around stars that were within a distance 5,000 light years and it had the radio transmitting technology to send out narrow band radio waves over 5,000 years ago, then we should be hearing something now. We currently have the technology and radio signal science to recieve it. It's probably safe to say that there is 'probably' not any ETI (if there is any ETI at all) living within a star system at that distance that has or had the level of technology that we currently enjoy. It's doubtful that we'll ever communicate directly with ETI even if ETI 'does' exist within 5,000 light years, unless ETI has something better and is willing to share it.

Okeydoke

 

Due to the nature of the subject matter, and nothing else at all, we "just know" how likely any of us are to ever contact extra-terrestrials.

I suspect that if some radio amateurs want to CQ Mars, they will get results with antennas that are like the Earth-Moon-Earth communications antennas, which use the moon as a passive reflector. This technology is about 47 years mature, and EME communications are much more demanding than are communications between Earth and Mars.

 

Okeydoke: I think you have a bit to learn about SETI if you think "the reality is" and "the simple fact remains"... In fact it's not simple at all.

As you put it, if the galaxy is 'teaming' with life AND actively use radio to communicate with life elsewhere it's still unlikely that SETI with todays technology would contact any of it. Even if the galaxy is teaming with ETI the distances are still huge.

'Project Phoenix' by SETI used a very powerful radio telescope for only 3 weeks out of the year and could only search one star at a time. Even if the star it was searching had ETI, that ETI would have to be pointing it's radio signals at Earth at the right moment for us to recieve the signal correct me if I'm wrong. And you mention about 5,000 light years, SETI weren't even searching that far, from what I read it only ever had stellar reconnaissance of 1,000 stars. 1,000 stars in a galaxy of 100/400 billion stars is the equivelant of trying to catch a great white shark with a drawing pin.

Your post to me suggested that you thought SETI were doing a good enough job to detect ETI therefor we should draw the conclusion that ETI isn't out there. That couldn't be further from the truth in my opinion as I believe SETI is nowhere near the level of flexability required for such a task. That doesn't mean I don't think it's worthwhile, it's rather cheap and can only get better from this day forward, and maybe one day in the distant... distant future they just might succeed... Although I highgly doubt that if they succeed, that it will be with radio technology.

Of course the construction of the Allen Telescope Array does improve things for the time being... slightly.

 

Sorry Charlie, but you'll have to do better than that. The Arecibo radio telescope has the potential of recieving narrowband radio signals up to several thousand light years away from our solar system. That's a fact you'll have enjoy. Arecibo has already explored the areas around certain stars (perhaps 150 stars) that have been chosen as 'likely' sources for SETI research and/or areas of radio signal noise that make them suspicious stellar candidates to check out. To date, none of these stars within a distance of 5,000 light years and some even much closer than that (perhaps within 200 light years) have yielded anything more than perhaps 'wishful' thinking on part of SETI scientists.

Okeydoke

 

"Phoenix doesn't scan the whole sky. Rather, it scrutinizes the vicinities of nearby, sun-like stars. Such stars are most likely to host long-lived planets capable of supporting life. We naturally include stars that are known to have planets. There are about one thousand stars targeted for observation by Project Phoenix. All are within 200 light-years distance."

I actually share some of your doubts of ETI in the galaxy, but I can not comprehend that you would use SETI as proof of that, especially the above paragraph which shows SETI have barely even scratched the surface.

I will let you carry on in naive bliss.

 

Details. How powerful does the signal have to be in order to be detected at 5000 light years?

This requires two suppositions for us to draw any conclusions:

First, ET must communicate with radio while blasting energy off in all directions (rather than efficiently and tightly focused upon the recipient star) for us to detect. If he does not, then we must just happen to fall in line with the originating and the receiving stars to intercept the message and a radio telescope here would have to just happen to be pointed in the right direction. Much like Swedish quadruplet cheerleading nymphomaniacs: Not likely.

Second, SETI assumes that radio is the most efficient form of communication between stars at great distances. Obviously it is not if ET is able to approach the speed of light. The disadvantage of radio is that it is not INTERACTIVE. The transmitter of a message cannot anticipate all of the needs or questions of the recipient - he can only guess at what they may be. If he guesses wrong, then for a star at a range of 5,000 light years, 15,000 years are wasted while whatever issue omitted was clarified.

What alternatives are there that don't reek of chic '60's science fiction schlock? Well, it's fairly obvious. If we are to assume ET is a clever sort, barred only by the speed of light itself, then ET can send a ship, an emissary, or some other form of messenger to the distant star requiring the information, and arrive there just a fraction later than light itself would have. And in contrast to a radio message, he's able to deliver much more information, to converse, to feedback, all to heart's content when he gets there (the trip was a mere matter of days or weeks to him).

For communication between far-flung stars, ET is far better making the journey himself (or sending his go-boy) at near-light speed than relying upon a radio signal.

 

Yea, but that's what SETI is relying on, Radio Signals and strong ones at that and hopefully ETI transmitts them at around 1420MHz range. Arecibo is the worlds largest and most powerful radio telescope in the world and has been for the past 42 years. If any radio telescope ever finds a strong ETI radio signal, it will probably be Arecibo that does it. Scratching the surface in the search for SETI? We've been scratching the surface for past 42 years (actually since 1932) and have found 'nothing' convincing to date. If ETI is out there, then he's not broadcasting his presence, at least not to us and not within 5,000 light years. And what's even more interesting is the fact that we've (Pheonix) found nothing within 200 light years either, after looking and listening in areas around stars where the probability of finding ETI should be/could be high. ET is just not phoning home these days, is he?

Okeydoke

 

The first observed neutron star caused hopes of ET contact to soar. Very steady pulsing radiation was detected. The signal pulsed 200-300 times per second, with no measurable variation in the rate.

At first nobody could imagine a natural sorurce of such radiation. It was assumed that we were detecting signals from an ET civilization. Many were very excited.

After only a day or so, some bright astrophysicist realized that a neutron star could pulse in that fashion. If the explanation had not come so soon, there would published accounts in newspapers and magazines like Discovery or Scientific American. I wonder what the reaction would have been if average citizens had seen early reports of the observation.

 

Jocelyn Bell discovered the first Pulsar in 1967 working as a graduate student with a 'rag-tag' radio telescope at Cambridge University. I even believe that she wished it to be a signal from ET. It was found to be a Pulsar, pulsating at a rapid rate, perplexing astronomers and scientists into thinking ET at long last finally sent us a message at.....Not to be, was it? So it's obvious there are lots of 'pretenders' out there in deep space, none of which so far (in the last 40 years) are convincing enough to fool us, at least for the present. Unless we recieve something that resembles the strong radio signal produced by the 'WOW' Signal (Circa: 1977 - Still not sure what that one was or is), then it's probably a 'pretender'. Until then, keep guessing.

Okeydoke

 

R U all dumb, dont U get it ? Dont U know what USA will do with all the technology ET will give us ? It will do a agrivated war on terrorism, instead of demilitarising the world. SO do U think ET will contact U with that sin comming on their hands. DO Think ETs are as primitive as U all r ? U morohons.

 

Hey dude, cut back on your daily dose of Viagra when you start to write your next thesis on ETI. O.K.? There is a whole lot people out here that just don't understand your pulsating brain waves.

Okeydoke

 

First take care of your planet, then go hunting ETs. Who wants to contact such primitive life forms as U. Anys ways life on Earth is a gonner. foolish humans.

 

Okeydoke, you are failing to post a significant argument. You are clinging to straws when you mention that SETI's lack of signals on a whole 1,000 stars is a significant discovery. Because "the simple fact is" as you are so keen to say, even if all of those 1,000 stars had ETI, it doesn't mean they are not there as the likelyhood of detecting such human technology on those stars is highly unlikely.

Your origional argument was perhaps a relevant one when you say perhaps our star could be rare... but your argument loses all credence when you say there is no ETI because SETI has not yet found it in our first few decades of technology.

The fact you don't even have a basic understanding on how SETI functions just tells me that you are keen to argue on what you "believe" which is easily witnessed on the religious section on this forum.

You think why I am arguing is that I want to believe in ET... but that's not the case... Because I'm willing to accept the fact the we could be the most advanced lifeforms in the galaxy...

 

What we need to start with is an extremely sensitive antenna that can receive from all directions, placed in a crater on the far side of the moon. There are millions of stars to scan, and if there are 10^8 transmitting in this galaxy, we are going to have to sort through a million stars in order to find one. When we find one, we can start quartering the sky to pin it down. Right now we don't have a chance in hell of finding a transmitting system by targeting one star at a time. We need to take in a million or more at a time. We also need to look at frequencies that either don't readily penetrate the Earth's ionosphere or are in widespread commercial use.