Why is there SETI?

I find that a ridiculous thing to say with regards to seeking contact with intelligence.

Our big blue planet exists for any powerful alien telescope to see. We're on the edge of being able to see planets the size of Earth around other stars with presant day human telescope technology, there's no telling what views other potential intelligence would have of our world. If they seen our water & oxygen rich cool planet, then it's more likely we'll be hijacked by simply just existing rather than because we somehow alert potential hijackers.

 

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What did you not like about the movie? Did you read the book? It was 1000x better.

I agree the book was better, as is usually the case.

My favorite director is Kubrick and I tend to compare most movies to his. Of course, as soon as I heard Jodie Foster was the star, I began kicking and screaming. It's some of worst acting I've ever seen from James Woods, as well. He could have saved the movie for me, but didn't.

 

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The thing is, if humans were capable of putting a HUGE object into space that would alert any alien astronomers that there is intelligent life here, would we do it? Lets say it would be cheap and not so hard to do, would we do it?

I doubt it would be cheap, I remember looking at the numbers 4-5 years back, in which putting payloads into LEO with the shuttle cost about $51,000 per kilo. We need to seriously get that cost down, but unfortunately, solid rocket boosters are the cheapest way so far, and are in effect the only available technology.

 

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In seeking the existance of SETI, the word 'contact' really doesn't work well. It's very doubtful that we'll ever make contact with another so-called intelligent lifeform beyond our solar system. To contact someone or something, you first have to exchange information or communication. As many have pointed out in this and other threads, the distances are far to great to even begin to consider any form of communication with an ET. If they're out there and if we ever do pick up a radio signal from ET and they are 20,000 light years away or so in the other part of the galaxy, are you going to send them an email via a radio telescope at: ETreticulae@hotmail.com and just hang out at your computer for the next 40,000 years and wait for their reply? That's a very boring and not very productive idea. If ET was out there and he had the 'curiosity' to look for us backed up with his advanced technology, chances are we should have picked up a real signal from ET by now.

Okeydoke

 

There's a lot of assumptions though isn't there. For example most of us expect ETI to have all their eggs in one basket like we do on Earth and not have expanded to other planets. And as Fermi said (I think), if they have started colonizing new planets it should be reasonable to think if they carried on, momentum would gather and they could perhaps be widespread through parts of the galaxy.

The question is though, how easy is it to survive long enough to reach a stage were a species can make a new planet it's home? And how many achieve this? It would be surprising if we found out it wasn't a case of sending a signal 20,000 light years accross the galaxy, but instead 200 or so light years. There could, afterall, be something interesting behing the UFO phenomenon...

Another assumption made by SETI is that aliens would (like us) send radiowaves in straight lines accross the galaxy at the speed of light. I think it's rather naive to think this way as a higher intelligence might have found a better way. SETI I think assumes ETI will be pretty much like us.

 

So far we 'haven't' found a better way to communicate across the cosmos and we may 'never' find a better way, except using narrow band radio signals for communication at the speed of light. If you haven't considered the possibility yet, then consider this. We here on the planet earth may also be the 'highest' so-called intelligence in our galaxy. After that, all other considerations are 'Null & Void'.

Okeydoke

 

If it is an advanced civilization, it could well use entangled particles in communication between planets inhabited by them, because then they could create particles and send one of the pair to a known location (why not a few tonnes?).
So it might well be possible that such an advanced civilization no longer uses radio or any other light speed method for communication.

But they could use it for radio astronomy though.

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If ET lived in our galaxy within a radius of 5,000 light years and had the ability to do radio astronomy and transmit/recieve narrow band radio signals at several thousand light years distance, then we would be able to detect them with our radio telescopes here on planet earth. So far this hasn't been the case and it's doubtful it ever will be.

Okeydoke

 

Even if a relatively close star was transmitting such signals, would it actually be a simple task for us to detect them or would that even still be a long shot?

 

Narrow band radio signals if transmitted by a strong ET (if he's out there) transmitter, should be strong enough to be recieved by powerful receiving antennas here on earth like the big radio telescope in Arecibo, say out to several thousand light years distance (say 5,000 light years for starters). Broad band signals such as transmitted by TV & etc. are lucky if they make it out of the solar system even on a good day and it's a good chance they wouldn't anyway. So if ET is out there and he's got a powerful enough transmitter/reciever, then he could send us a narrow band radio message at about 5,000 light years distance. For right now, with our present radio signal transmitting/recieving technology, forget about distances greater than that. It ain't going to happen.

Okeydoke

 

This site gives an idea of SETI's ability to detect signals.

http://www.satsig.net/seticalc.htm

For an example, the air search radar on the SA-10 Grumble surface to air missile system (NATO designate Flap Lid) is a pretty "outspoken" resident here on Earth. It operates in the I-band (about 420 Mhz), with a peak power output of, maybe, 75,000 watts. Figure a transmitter diameter of about 3 meters. Type those variables in, and you get a SETI detection range of: jack squat. The thing would practically have to be sitting right on top of earth to see it.

Now, for larger systems (such as the USA's air traffic control radar network) - any know how to calculate detection range of a group of transmitting stations?

Assuming communication is both possible and desired by both parties, then a meaningful conversation would take thousands of years. Which begs the question: So what? The potential life-span of our species in this galaxy is measured in millions, or billions, of years.

This implies that their motive for talking or not talking to us is contingent upon our wishes. I don't think that is likely. If, on the other hand, we assume that they are there, know of us, but don't want to talk to us, then a fairly obvious motive to explain their behavior: there is no reason to do so.

The question here not one of science - it's one of power politics. How far away are we from them? How long will it take for us to detect them? To arrive at their location? What are we? What motivates us? How smart are we? How fast will we advance technologically?

But "ignore" us? Never. What if one of our hippie-driven space shaggin' wagons accidentally plows into their planet on a .95C joyride?

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We are not on the verge of "being able to see" other Earth-size planets in distant solar systems. We are getting to the point where the existence of such planets can be detected by the slight wobble they cause in their host stars.

There shouldn't be anything about Earth (or our solar system), in terms of resources ("water & oxygen"), that should appeal to any ET's out there. The only interesting thing here is US. And, I'd hazard a guess that the only reason we might be interesting is because, in a galactic heartbeat, we will spread out from this star into the galaxy.

I think it a reasonable assumption that a technically advanced, ancient species will have done precisely as you describe.

Yes, this assumption is pretty much a starting point for the Galactic Zoo hypothesis. If ET is ancient, he'd have had millions - or billions - of years to find us and get here. If he's here, he ain't talking. If he ain't talking, then his intentions are not what we'd call friendly. If he's not friendly, then as odd as it seems, he probably fears us.

SETI's assumptions are based upon what it's possible to do here on Earth to detect potential signals, not on what ET's most likely to have done when communicating out there.

There are three realistic possibilities:

1) ET isn't here.
2) ET isn't anywhere
3) ET isn't talking

I would not rate #2 as being the most likely.

 

I was thinking more of that they would have a good reason not to talk to us, at the moment anyway. Maybe they know (from experience?) that an intelligent civilisation who hasn't yet made contact needs plenty of time to get used to the idea.

Today we feel very lonely and isolated... if tommorrow we found out the true extent of the ETI out there and what they can do, what effect would it have on us in our world? It could be a dangerous jolt. Humans still rely on religion to try and answer the big questions and have only had science and technology for a short time.

They could just be protecting us by not letting us know?

 

4) ET isn't capable of talking (Dinosaur lips)

I would not rate #4 as being the most unlikely (at least in our galaxy).

 

Originally Posted by Ophiolite
In case you hadn't noticed we are in the middle of a global extinction event at the moment. Oh, you hadn't noticed.

With all due respect Kenny, **** humanity. I wasn't talking about humanity. I am fairly sure humanity will survive global warming, the destruction of the environment, genetic manipulation of the biosphere and any, and all 'horrors' we impose on the planet. That doesn't alter the fact that we are wiping out species at a terrifying rate, whic was my point in the earlier post.

 

We're so busy looking for intelligent life elsewhere, I'm not sure if there is really intelligent down here.

 

I am for SETI. I am interestd in the little green mens Technologies.

 

I think it might be something along the lines of 9/11 in terms of weight of impact. Huge for weeks, then gradually fading in importance. By week three or so, something else would be the leadoff story. Like 9/11, it would continue to be in the news for years afterwards in various guises.

I can’t see why a friendly, advanced civilization would bother to come all the way to Earth from parts unknown, for the reason of not to talking to us. Also, it would be risky to be friendly without first coming here to closely investigate us. By the same token, I can see why a hostile civilization would come here and not converse; there is nothing to talk about. Here’s how the conversation might go:

Human: “Hi. Give us your technology.”
ET: “Hi back. Not a chance. Don’t leave this system.”
Human: “No can do. Give us your technology.”
ET: “Don’t call back.”

A hostile motive could be inherent to the realities of logistics in the galaxy. Moving anywhere takes an incredible amount of time; the speed of light is an impermeable barrier that no technology can circumvent. This is in absolute contrast to the speed of our technical development here on Earth. We’ve gone from horse-powered plows to the Moon in a galactic nanosecond. Our scientific knowledge advances rapidly in all fields, and given the possibilities inherent in biological engineering, it’s not infeasible to a paranoid ET that the pace will pick up tremendously as we begin to modify the genome to sprout home-run-hitting babe-magnetic brainaics in unnumbered hordes. Churchill once wryly noted that a lie gets halfway around the world while truth is still putting his pants on. In a similar vein, ET wouldn’t even get 1/10th the way to Earth before we’ve matched his technology and are awaiting him on an equal military playing field (remember, at the energy levels we are talking of, all it takes to ruin your day is one single thing plowing into your planet at .99C).

I suspect the effect would be to lend weight to some sort of quasi-pacifistic, internationalist hippie-revisionist movement. Joan Biaz would make a comeback. Religion would just adapt to the change in stride over the course of decades. Countries – most particularly Western countries - might find it harder to reach a consensus on when/if to go to war without clearly being the wronged party. (Even when our interests demand it). Of equal concern, there would be a serious political battle to get to the bottom of whatever cover-up took place from the 1940’s onward. That debate could get really ugly.

I would. No. 2 requires us to be unique amongst 100 billion stars over the past 13.7 billion years. As a rule of thumb, any statistician assumes that a single data point is average, and not shifted, say, 10 standard deviations.

We do have to account for why we see nothing via SETI. But from what I understand of the topic, SETI isn’t able to detect normal, daily emissions that we can reasonably expect ET to be making.

 

If ETI were alive and well with the technology and willing to try and contact us, then they most likely would. Right now, this is probably not the case. I liken the odds of finding ETI the same as the 'Second Coming'.

 

Hmm.. Well I'm not so sure. Would you travel to Africa to see some ants on a tree?

If we are to believe that UFO's are alien visitations then yes, they have come to see ants, but not to speak with them.

 

ETI and the search for it means so far, using our most powerful radio telescopes scanning millions of channels and frequencies on a 24 hour basis for the last 20 years has failed to find a single 'confirmed' SETI contact event. What does that tell you? It tells me that even though ETI 'may' be out there, they're not advertising and it looks like they probably never will. You can keep hoping though.