SETI Is 50 Years Old; No Sign of ET 454
EagleHasLanded writes "The Search for Extraterrestrial Intelligence is 50 years old next month, and still no sign of intelligent alien life. Paul Davies of the Beyond Center (also Chairman of the SETI Post-Detection Taskgroup) says it's time to re-think and expand the search for ET."
Patience! (Score:5, Insightful)
Re:Patience! (Score:4, Interesting)
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But maybe lemmings have invented religion and that's why they kill themselves.
Snopes [snopes.com] to the rescue!
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Whales are not as intelligent as you may have been led to believe, in fact quite the opposite...ask any marine biologist.
Re:Patience! (Score:5, Informative)
Re:Patience! (Score:5, Funny)
Don't you mean "[cetacean needed]"?
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"Whales are not as intelligent as you may have been led to believe, in fact quite the opposite...ask any marine biologist."
Japanese marine biologists?
They think they are more tasty than intelligent.
Re:Patience! (Score:5, Interesting)
I recently heard an interesting theory about pachyderm intelligence. They're the largest survivors of the early phase of the Holocene extinction event [wikipedia.org]. Before this event, there were impressive megafauna on every major land mass outside Antarctica. There are various theories as to what happened to this megacritters, the most popular being that they their long reproduction cycles made it impossible for them to keep up with hunting by humans..
So why did elephants survive when their cousins the woolly mammoths and various superbirds (I particularly like giant grazing ducks [wikipedia.org]) did not? The theory is that elephants co-evolved with humans. As our ancestors got smarter and better at hunting, elephants got smarter and better and not being hunted. It wasn't until humans left Africa and started hunting megafauna that had no experience with them that the extinctions began. All these other animals simply didn't have time to evolve the way elephants did.
Which is too bad, really. Think of all the friends we could have had. Once they forgave us for eating them, of course.
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Why don't start trying to find signs of intelligent life on Earth? Intelligence don't have to mean technology, and some species right here (dolphins? whales?) could be as intelligent or more than us, but while we see intelligence as use of tools we will keep ignoring them.
We are already doing that though. The way I see it, we all have an "itch that we scratch". I'm into computers and my wife on the other hand is into anthropology/history.
As a species, I think we're doing pretty good. We have researchers in all sorts of fields. It's true that I don't care so much about the past, and as far as my wife is concerned, HTML5 doesn't mean anything.
But collectively we're actively seeking knowledge and forms of intelligence to enhance our lives, be it our ancestors, map/reduce, or do
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Re:Patience! (Score:5, Funny)
Of course dolphins are more intelligent than us: we've achieved so much (wars, the wheel, and so on), while all the dolphins have done is muck about in the water having a good time.
Re:Our eight tentacled friends. (Score:5, Funny)
Have you even seen what octopuses have done to Japanese schoolgirls?
Yeah. 'Nuff said.
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Well, I'm trying to find signs of intelligent life on the Earth, and I haven't been very successful either.
Fermi Paradox anyone?? (Score:2, Insightful)
http://en.wikipedia.org/wiki/Fermi_paradox [wikipedia.org]
Re:Fermi Paradox anyone?? (Score:5, Interesting)
The Fermi Paradox is woefully shortsighted. How long did it take modern human to actually explore other continents and find out that other intelligent human life was inhabiting a large patch of land on the same planet? Decades? Centuries? Whatever the plural of millennium is? It took ages for humans to even begin to explore our own planet. Every single day we find new species, new small islands, new pockets of underwater ocean life.
If we can't even complete a species list on our own planet how can you expect us to even begin to understand how to contact (theoretical) alien life that exists far outside of our immediate grasp? For all we know a planet just like our earth, or earth in its infancy, or like our earth but at its end cycle, may exist somewhere out there. We have no way of being able to immediately confirm that though. And we might not ever.
Carl Sagan even wrote that we should be open to the idea that an intelligent life form could have visited earth in the past.
url:http://en.wikipedia.org/wiki/Ancient_astronauts#Scientific_consideration
Re:Fermi Paradox anyone?? (Score:5, Interesting)
You miss the point of the Fermi Paradox entirely. Given that humans have only been in existence on earth for 200K Years, why is it that no aliens have colonised Earth *before* we got here? It would take only one expansionist alien culture to exist in the billions of years the galaxy has existed before us and the Earth and the entire galaxy would have been well and truely colonized already.
I mean some relatively straight-forward extrapolations of humans shows *us* colonizing the galaxy in a few million years.
Basically the Fermi paradox says, they are *no* other intelligent civilizations in the galaxy otherwise we would have had dramatic evidence on Earth.
Still I see no particular harm in continuing to look. If something were found it would be a monumental breakthrough.
Re:Fermi Paradox anyone?? (Score:4, Insightful)
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I don't see why not.
If it has taken us this long to develop to the stage we are currently at, it is reasonable to assume that under similar conditions, life (similar to ours) on other plants would occur in roughly the same timeframe.
I'm not convinced that Occams Razor is applicable when talking about intelligent life and the ability to travel the stars.
If the simplest solution is usually the most likely, then the whole fact that we've only achieved space travel in the last 50 years out of 4.5 billion years
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If it has taken us this long to develop to the stage we are currently at, it is reasonable to assume that under similar conditions, life (similar to ours) on other plants would occur in roughly the same timeframe.
But 1% less time, not an unreasonable amount of error, would put them 100 million years before now (using a guess for the current age of the galaxy). Even if we go with just the age of the earth as the major factor, that error is 45 million years. That's a long time in which stuff can happen (for comparison, modern humanity has only really been going for half a percent of that). Given all that, and the immense size of the galaxy, where is everyone? That's the core of the Fermi Paradox.
There's huge unknowns
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Re:Fermi Paradox anyone?? (Score:5, Interesting)
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No, your math is fine.
If it hadn't been for asteroidal impacts wiping out the dinosaurs, some avian/lizard like creatures from Earth could have colonised this galaxy by now.
The fact that the galaxy hasn't been colonised by some earlier evolved species from another star, has only three (that I know of) explanations.
1) The good neighbour hypothesis. The galaxy is colonised, but they are advanced enough to be beyond our perception threshold, and they leave young species like ours alone.
2) The hostile neighbour
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It seems like there can't have been that many generations of suns before the formation of our planet.
The sun is a third generation star:
The sun is a relatively young star, a member of a generation of stars known as Population I stars. An older generation of stars is called Population II. There may have existed an earlier generation, called Population III. However, no members of this generation are known. The remainder of this section refers to three generations of stars.
The three generations differ in their content of chemical elements heavier than helium. First-generation stars have the lowest percentage of these elements, and second-generation stars have a higher percentage. The sun and other third-generation stars have the highest percentage of elements heavier than helium.
The percentages differ in this way because first- and second-generation stars that "died" passed along their heavier elements. Many of these stars produced successively heavier elements by means of fusion in and near their cores. The heaviest elements were created when the most massive stars exploded as supernovae. Supernovae enrich the clouds of gas and dust from which other stars form. Other sources of enrichment are planetary nebulae, the cast-off outer layers of less massive stars.
NASA Sun Worldbook [nasa.gov]
Re:Fermi Paradox anyone?? (Score:5, Insightful)
You miss the point of the Fermi Paradox entirely. Given that humans have only been in existence on earth for 200K Years, why is it that no aliens have colonised Earth *before* we got here? It would take only one expansionist alien culture to exist in the billions of years the galaxy has existed before us and the Earth and the entire galaxy would have been well and truely colonized already.
I mean some relatively straight-forward extrapolations of humans shows *us* colonizing the galaxy in a few million years.
Basically the Fermi paradox says, they are *no* other intelligent civilizations in the galaxy otherwise we would have had dramatic evidence on Earth.
Still I see no particular harm in continuing to look. If something were found it would be a monumental breakthrough.
Even more importantly, why does everyone think Fermi's paradox is well posed?
There's also a really simple explanation: The astronomical distances separating Earth from other stars require astronomical amounts of energy and/or astronomical amounts of time cross. Maybe accessing this amount of energy and time is just too improbable for any civilization. We could play some games with the Drake equation and "prove" this, but we'd be extrapolating into bullshit-land. Of course, that is where the current Drake equation parameters are anyway.
But even if this barrier could be crossed, consider advanced aliens that develop the means access such a large amount of energy and to travel such great distances. Let's say that life is so common that they are able to come across millions of other life forms. Chances are, those life forms will be much more primitive than they are. After you have "discovered" a few million primitive life forms are you really going to visit them all? Or would you rather use your time more efficiently, and ignore the life forms that are much less primitive that you and only visit the ones that are near or above your level of sophistication? When was the last time you talked to the ants in your backyard on the way to hang out with your girlfriend?
I am guessing that even advanced aliens don't have infinite time and energy at their tentacle tips. They're not going to waste their time with us. We can barely get to low earth orbit on a good day.
Re:Fermi Paradox anyone?? (Score:4, Interesting)
or perhaps; they are intelligent, out there, have sufficient grasp of the huge distances/difficulties involved and decided not to waste their energies on 'travel' to focus on their own planets and civilizations...
Fermi Paradox: SOLVED - They Are Here Now! (Score:4, Interesting)
A friend of mine who is much smarter than me (I know, I know, that doesn't mean much) INSISTS that they are here now. However since he works at a very high level in a field which requires him to tell the state department 3 months in advance before he is allowed to leave the country, I pay attention to what he says in technical matters at least.
Like the dog in "Men In Black" said: "Silly Humans, why do you always think something powerful has to be big?" (or something like that, no thanks to you Mr. Google!); perhaps Aliens or rather their NANO sized machine emissaries reached Earth a long long time ago (in keeping with the Fermi Paradox) and have basically infested the entire solar system, waiting...
Now as we start dabbling with nano-technologies and begin to have the capability of actually seeing them with our new atomic-force microscopes, they have to make a decision. Do they allow themselves to be discovered? I assume they could either do this passively like letting us see some of their machinery scuttle about amongst the atoms or they might as well come out and say "We're Here!". (Kinda like "Horton hears a Who")
Or, will they 1) leave the planet and keep withdrawing just beyond the range of our increasingly sophisticated probes? 2) maybe they will actively try to remain hidden, should be easy (for awhile) to cause subtle "problems" in our equipment from finding them. Experiments will mysteriously (or not depending on how clever they are) not work and our own attempts to create nano-machines will forever be thwarted.
Or maybe they'll decide, time's up, this species is not worth keeping; let's clean the planet and start over with another (bears?).
One way or another maybe we'll find out soon!
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Suppose you could make a human the size of a mouse, and that that human was just as human as the humans around now, and comparably able in every way except size. Then instead of billions of them, you might be able to have trillions or even quadrillions of them infesting the earth for the same resources. For a short time ( because of exponential growth in population, if everyone were shrunk to the size of mice, then the world would again be an open and plentiful land short only of people, and hence the val
Re:Fermi Paradox anyone?? (Score:4, Insightful)
Technically, due to the whole speed of light thingy, often we are looking for signs that intelligent life existed thousands or hundreds of thousands of years ago. Civilisations could have blinked out of existance long before our capacities to collect their signals were up to speed. Or they exist right now, but their signals won't arrive for another century or so.
Actually, we only need to look at our own example of how well we've been advertising our existence. The switch to digital and satellite broadcasting has severely cut down on the number of signals we've been sending into the void. Things like Arecibo are mere blips, in the hopes that the other radio antenna is listening at that moment and not sweeping a different sector. By the time they look at our solar system again our signals may not be discernable against the background noise of our sun.
And yes, maybe Professor Sagan was right, but on the time scale that Lovecraft used: our planet may have been visited by intelligent life, but it could have been during one of the great die-outs, and they moved on with little more than a note to check again in a few millenia, and forgot about this rock.
Re:Fermi Paradox anyone?? (Score:4, Insightful)
If there's intelligent life out there, they'll have to be within 150 light years from us for them to find us, and the reverse would be true as well. Plus, any civilizations that use technology not based on radio will be invisible to us.
They are there invisibly (Score:5, Insightful)
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This is a classic variation of the old standard "I'm stupid, laugh" gag.
You might think you are making fun of the silly new age nonsense, but you aren't doing a very good job of it.
Re:They are there invisibly (Score:4, Funny)
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There's nothing subjective about pretending that the Maya calendar ends in 2012, it is pure stupidity.
You might as well imagine that our calendar predicts the end of the world in 9999.
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That little blip of 100 years of analog full-blast will not been seen by anyone else either.
Every time a SETI article comes up somebody posts this problem about detecting radio leakage and then somebody else has to post that SETI isn't looking for accidental leakage - they admit that they're only looking for intentional beacons.
I guess it's my turn.
After 50 years? (Score:3, Insightful)
Re:After 50 years? (Score:5, Insightful)
People need to study orders of magnitude [youtube.com] before they get on SETI's case about not finding anything exciting.
Better not: they'd know that SETI is useless and a waste of money.
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Better not: they'd know that SETI is useless and a waste of money.
Can you justify that statement?
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Can you justify that it isn't?
It's more fun than the lottery. Your turn.
Re:After 50 years? (Score:4, Funny)
It costs more than a dollar.
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Discovery of extra-solar life would be exciting and novel, but as far as the fate of Humanity is concerned it wouldn't be terribly useful
It would be far more useful than any religion or political ideology has ever been in demonstrating the futility of internecine war and in encouraging the development of high technology.
Re:After 50 years? (Score:4, Insightful)
Why couldn't an advanced civilization try to ping us every 1000 years or so and see if anyone responds? It's not like it has to be stray TV signals. To me it seems a reasonable thing to do if we start discovering Earth-like exoplanets, sure we'll try more often at first but it's not like we're going to ask "Has intelligent life evolved now?" every five minutes. Narrow beam, high power, simple signal, the kind that should be easy for SETI to detect if there's a big enough antenna pointing in the right direction at the right time. But if they're run by people like you, I suppose nobody will be there to listen...
Obligatory Bill Hicks... (Score:2)
Of course (Score:5, Funny)
Looks like ET's spam filter is working just fine ;)
I think expectations are too high... (Score:5, Insightful)
I see lots of posts that seem to miss the point. The mere _finding_ of an ET would be _dramatic_ for our civilization. Think of all the things that would change (not all religious).
If we can ever _prove_ we're not alone out here, I honestly believe it could sway the attitudes and priorities of many governments. I mean, honestly, if we know there is another alien life out there, that we could potentially communicate with, how many stupid squabbles would end?
Right now, we only worry about ourselves because, well, that's all there is to worry about. The prospect of learning from another civilization, or even just being afraid and try to "defend" ourselves from them (sad, but you never know what spin governments would put on a finding like that) could be utterly revolutionary.
Then again, so many people would dis-believe due to religious and/or conspiratorial reasons would probably be mind boggling.
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Just out of curiosity, which religions are incompatible with the existence of extraterrestrial life? To my knowledge, such an issue is not addressed by most religions, and is compatible with most beliefs. Scientology expressly revolves around the concept of aliens, but Scientology is a tax dodge, not a religion.
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Ultimately none of course. If religions would be disbanded because they are incompatible with science or simple truths, we would have rather less religions (if not none).
Religions die out if people start to believe in other religions, by force or not.
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Dislaimer: I am not a Roman Catholic but a Reformed Christian. However I broadly agree with this conclusion.
Re:I think expectations are too high... (Score:5, Insightful)
even just being afraid and try to "defend" ourselves from them (sad, but you never know what spin governments would put on a finding like that)
Government spin? That's the primary purpose for which we should be looking.
Where does this idea of the peaceful alien come from? There has never been mutual cooperation between civilizations or species competing for the same resources. Among civilizations, it has always resulted in destruction or subjugation of the less technologically advanced civilization. We need to be keeping our ears open and our mouths shut.
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I'm sorry you feel everyone is out to get you/us, but are we searching just to conquer an ET? Or are we doing so just for the sake of doing it and for whatever benefits/truths can be made from such a discovery?
Maybe they want our resources, maybe we make good eats or maybe we make good batteries, I don't know. Could they want to find us just to kill us for one reason or another? Of course it is possible, but there is no reason to not look.
Re:I think expectations are too high... (Score:5, Insightful)
I think that if anything can show up here and say hi they probably don't need anything from us. Unless they come from Proxima Centauri they can probably find whatever they need much closer, and sending anything from here back wherever they came from is probably mind boggingly expensive in energy expenditures.
For instance take the lack of interest in mining asteroids or the moon. We probably could if we had a good reason to, but it's so expensive it's not worth it.
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Re:I think expectations are too high... (Score:4, Interesting)
I'm sure that's what the Spanish thought in 1492 too.
Are you kidding me? They were looking for a better trade route to India, to avoid sailing all around Africa.
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And I think that anything that does show up here would do so for a purpose, and most likely one that we really wouldn't like [wikipedia.org].
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The aliens aren't using radio... (Score:4, Funny)
They're using subspace communications, or ansible, or ultrawave.
or semaphore...
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They're using subspace communications, or ansible, or ultrawave.
or semaphore...
Not entirely sure why this was modded "Funny" - it's a very valid point. Just because electromagnetic radiation is the best tool we have for long-range communications does not mean that other, more advanced civilizations aren't using something that we don't even know how to detect (Gravity wave telegraphy? Quantum entanglement semaphores?).
Listening to the Heavens (Score:2)
Given that any intelligent god that wasn't born on earth would be (by definition) an extraterrestrial intelligence, do any religious people expect SETI to one day contact one of the gods or find evidence for their existence?
Differing levels of civilization (Score:3, Insightful)
With that in mind, how would a civilization sufficiently advanced to travel here from Alpha Centauri view our civilization?
"Mostly harmless."
"We'll give them a little longer. When they manage to visit the rest of the neighborhood - maybe when they're able to travel to another planet in their little solar system - we'll say hello. As long as we use short words and simple sentences, we might be able to help them understand speed-of-light travel."
"Okay. But if they start shooting those cute little firecrackers at us, I'm throwing a marble [read: black hole] into the middle of their little planet."
Why would an alien civilization make contact? (Score:3, Funny)
Our technology is too primitive, our cultures are backward. Our population is xenophobic and militaristic in varying degrees. One would have to be insane
to give cultures like that faster than light travel or even travel at near light speed. On its face it would seem we have nothing to offer these aliens, youd be wrong.
At first the idea of slaves but robots can do the job cheaper and faster.
Then the idea hit me...soldiers. If youre a wealthy interstellar civilization with enemies or just really bad pest pro
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Unfortunately, your post has a pitfall also covered in your post:
At first the idea of slaves but robots can do the job cheaper and faster.
Sufficiently advanced robots would make better soldiers than us.
Antenna not big enough? (Score:2)
Question, what kind of antenna would we need to build in order to detect a TV or FM radio transmitter on another planet with similar strength and radiation pattern as common commercial radio TV and Radio transmitters on this planet, if they were located on the other planet. What about other common transmissions of ours as well?
I think at some point that SETI assumed that a ET civilisation would eb generating a signal stronger than we normally produce in day to day activities and pointing it at this solar sy
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Depends entirely on how far away your planet is, of course. Read up on the inverse square law.
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Here's a calculator someone cooked up that might be able to answer the question.
http://www.satsig.net/seticalc.htm [satsig.net]
If you run with the default numbers (Aerocibo sized receiver+transmitter) the range is around 23 light years. The real numbers are going to be a bit different however, since our transmissions are usually not directional, but the transmit power is also higher.
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So how big of an antenna would it take for, lets say, a civilisation on a remote solar system planet to detect the day to day RF activity on this planet?
As I understand it, an impossibly large one. And it still wouldn't work. It just gets lost to the background noise of the universe at any real distance...
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> Of course if FTL is really impossible then the whole idea is pretty
> pointless, and remote civilizations will never contact each other.
You assume they are short lived and impatient.
earth like planets (Score:3, Interesting)
I'm too lazy to look up the links, or the names of the projects, but I understand within the next few years focus is being placed on locating earth like planets (close to our same size, orbiting a similar star at roughly the same distance we are ours, etc.). I just assumed when I read about this the first time that SETI would be very interested and excited to be given locations of planets that actually have a decent chance of supporting life (as we know it) rather than just randomly focusing on a particular area. This should be exciting times for SETI and their followers but I'm surprised there isn't any mention of it in the interview.
I hope SETI is going to be all over this as locations of earth like planets are announced and that that is what Paul Davies means by "time to re-think and expand the search for ET"!
The problem is time (Score:5, Informative)
The problem's basically one of time. Think about this: the first radio transmission on Earth was in 1866. That's 144 years ago. That means that any alien civilization more than 144 light-years away from Earth can't see us in the radio bands. They'd have to be inside the bubble formed by our first radio transmissions to even have a chance of spotting us using the methods SETI does. And that bubble isn't a sphere either, it'll eventually have an inside surface as well as an outer one. We're getting more and more efficient, wasting less and less power beaming radio waves off in all directions. Eventually we'll be broadcasting so little that we won't be detectable at any reasonable distance. Anybody inside that inner surface won't be able to see us either. That'll leave probably a 250-300 light-year thick zone moving steadily outwards that any race looking for us will have to be in to see us by looking for radio transmissions. They won't have to just be looking for us, they'll have to be looking for us during the 3-century period when they're in that zone. Look too early or too late and we're invisible to them.
And the same applies to us: we can look all we want, but if we're not in the radio-transmission zone for another species they'll be invisible to us.
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> ...the first radio transmission on Earth was in 1866...
I think you mean 1886 (and that transmission by Hertz was very low power and wideband).
Re:The problem is time (Score:4, Informative)
They'd have to be inside the bubble formed by our first radio transmissions to even have a chance of spotting us using the methods SETI does.
No, SETI is looking for intentional beacons, not accidental leakage.
In your terms, our SETI-style space-time bubble is a very very very thin shell from the one (or was it two?) times we actually beamed out a signal. Actually not a shell, because it was directional. Interestingly the small handful of candidate signals fit this pattern.
Personally, I think until we're unafraid enough to light up a real beacon, any more advanced society won't pay us any attention. We're panicky and prone to irrational behavior, which probably makes us uninteresting peers. It seems none of us will live long enough to see humanity get over itself, though perhaps we can push it a bit in that direction.
Sigh (Score:2)
At the most, a SETI search could have detected intelligent, broadcasting in cleartext life at a range of 50 light years. That's not terribly far. And halve that if we're sending out a message and waiting on a return.
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> At the most, a SETI search could have detected intelligent, broadcasting in
> cleartext life at a range of 50 light years.
How do you figure that?
is there space fade that is like rain fade? (Score:2)
is there space fade that is like rain fade? or other stuff that makes some stuff show up as something that is too broken up to be any thing that looks like something from ET.
Or are we just looking at the wrong band?
Imagine the arguments a discovery would create! (Score:3, Insightful)
A significant number of the population doesn't even believe we landed on the moon. Should SETI ever detect artificial radio transmissions then the arguing, debates, and conspiracy theories that would abound are unfathomable!
We can't even agree that we landed on the moon. How are we going to convince the world when we discover an ET version of 'Star Trek'? ;)
They'll listen and and learn. (Score:2)
I think it much more likely that, after monitoring signals from Earth, they'll specifically decide to leave us alone to our own destruction. Yes, we have some very good qualities, but seriously, we're a short-sighted, narrow-minded, self-absorbed, fucked-up primitive species.
Obviously nothing there (Score:5, Funny)
In other news, the Untied Ants of the Cupboard have checked the entire kitchen for the most common types of pheromone trails for the last 50 seconds and found nothing. Clearly, reports of mutilation and abduction by "Humans" is just wild fantasy.
How Far Away Could We See Ourselves? (Score:3, Interesting)
The closest star, Alpha Centauri is about four light years. It is likely that the nearest technological civilization is quite a lot farther than that.
He said that we were counting on detectable civilizations being lot more advanced than us, and so radiating a lot more power than we do. But I'm not so sure that that would help - possibly when a society gets more advanced, they develop more efficient communications technology and so radiate even less. An example is our own technology in which we now use undersea optical fiber rather than beaming so much power out at satellites.,P>
Re:How Far Away Could We See Ourselves? (Score:4, Insightful)
In any case, we will more likely observe life on their planet via chemical analysis of their atmosphere long before they get a signal from us. Given the leaps and bounds that extrasolar planet discovery has happened in the last decade, I'm guessing that we will know a great deal about the possibility of Earth-like life being on any planet within a thousand light years of us before our radio signals travel a tenth of that distance. If we find a planet that displays the chemical make up of life there is a high chance someone will start beaming it with radio signals but we will probably have the ability to actively observe the life on that planet long before the signal ever gets to them.
So is SETI really going to prove anything we won't know much more about in the next couple of decades? Doubtful. But if we do detect signals from another planet using the SETI project it will probably mean that they know we're here and they're reaching out to us for better or for worse.
Encryption (Score:3, Interesting)
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Weak (Score:4, Insightful)
It seems to me we're unlikely to find aliens and they are unlikely to find us. The distances between us and possible life are extreme and there's a whole universe of stars, black holes, radiation clouds, and other forms of interference in the way.
Are you seriously counting on those old AM/FM radio transmissions making a direct line through space-time to a planet 140 billion light years away? Let's look at what can go wrong. Assume the Earth has a bunch of weak transmitters which occasionally fire information into space - this will already be a weak version of a weak signal since it's gone through our atmosphere, clouds, etc.
1. This signal is subject to inverse-square law. By the time it's left our own solar system the signal is infinitesimal.
2. The earth itself will obscure more than 50% of all the signals as it rotates.
3. Signals will be shot straight into our sun or pass close enough to either bend into it's gravity or have it's course dramatically altered.
4. There's billions of other suns which will do the same thing as it passes by.
5. Signals will slowly approach chaos, and be in-detectable from background radiation.
6. Their receivers will be expecting more powerful signals and our will pass "under the radar".
There's likely a million other ways for a signal which is designed to bounce off our atmosphere to become lost in space as it tries to make it from here...to there, whereever there is. Don't expect contact any time soon.
Comment removed (Score:3, Interesting)
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I seem to remember (Mr. Google wasn't much help) an Arthur C. Clarke story where a future world government, scarred by a devastating asteroid impact, detonates a very powerful (Gigaton?) nuclear explosive on the other side of earth's orbit (so that the sun blocks it). This is so that an extremely bright "pulse" is created that very briefly illuminates every single object in the Solar System (except the earth) which makes their detection easy by prepared astronomers.
A few decades later, a signal is detected
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> But when you think about it, detonating vast amounts of plutonium releases a
> tremendous amount of energy all over the EM spectrum. It also gives off a
> unique signature of the kind that doesn't, or could *never* happen naturally.
No, not really. The "bomb" is pretty feeble by cosmic standards.
Or aliens are already here, but we can't see them. (Score:3, Insightful)
Perhaps their technology is so advanced, they we can't see them. Perhaps they have figured out all the physics mysteries we haven't figured out yet, and those physics allow mechanisms for communication that we cannot comprehend yet. Perhaps aliens were here in the past and left.
There are so many possibilities...ruling out the existence of alien intelligent life because we only have searched for 50 years and found nothing it's shortsighted at best.
Re:Think of the dangers, though. (Score:5, Interesting)
SETI is a detector, not an emitter.
If you're worried about any possible aliens' intentions, then SETI is precisely the right approach. You'd want to know if something is coming our way, and get at least some idea of what it might be like.
It also seems unlikely we can affect our visibility much. On one hand, we're absolutely tiny compared to other things happening in the universe. Any amount of energy we could send into space for instance is a drop in the bucket compared to what the Sun outputs. Anything we emit is unlikely to be received unless somebody is already looking in our direction for some other, more visible reason. But, on the other hand, if somebody is really looking, and capable of getting here, they almost certainly can figure out there's something here, and there's no way we can become quiet enough to pretend there isn't.
At this point we can barely get off this rock. If anything shows up, they almost certainly vastly surpass us just from the fact that they can travel all the way here. So if there's anything to do about that the best plan would seem to be to try to figure out if anybody is coming, and if they are use that information to come up with a plan.
Re:Think of the dangers, though. (Score:4, Funny)
I just knew you would say that, you dick.
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Actually, that was a premise behind a ST:TNG episode, as well. The ancient race that seeded itself on Earth, Vulcan, Kronos (sp? or am I a pa'tak?), Romulus, and so on searched the whole galaxy and found no intelligent life. It was only the later evolved races (hu-mans, klingons, etc.) that could therefore discover each other and the biological connection they all shared.
Re:We are the only ones (Score:5, Funny)
No, actually, we're the Last Ones Standing.
See, humanity was the first race to develop time travel, in the late thirty-seventh century by your calendar, during the Third Great Intergalactic War. We knew that if we didn't act it was only a matter of time before one of the other races would develop or get ahold of the technology and use it against us. So we went ahead and sterilized the other races' homeworlds in the distant past, before they developed any significant technology. War over. We win.
Once the word of what we'd done started getting out to the civilians, there was hell to pay, of course. But as far as I'm concerned there's no question. I don't have to worry that my grandkids will be wiped out because a Xenthasi Accelerator generates a supernova and wipes out their home star system, or that some Rtulmrachan Overlord will drop a galaxy-sized black hole in their immediate neighborhood, or that the Uiola will tear down our whole local group and re-use the matter to build the Largest Entertainment Mall in the Universe. We won.
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Look how difficult it was to get here in the first place. We are the First Ones.
I realize Slashdot loves the ET thing, but who modding the parent as a troll? Really? For suggesting we're alone and tosssing in a sci-fi cliche?
Beyond that, I don't even think it's a ridiculous suggestion on the merits. Life itself seems to have risen quickly, but it did take life a long time for any intelligence to appear on Earth--billions of years with life, but no technology and no intelligence. That certainly suggests it's not inevitable. It might really be a one in a billion fluke--we don't know
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Nah, you're confusing SETI with marriage. A common mistake.
Obligatory XKCD... (Score:5, Funny)
The Search [xkcd.com]
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Life produces things that other things don't produce. Oxygen in an atmosphere for instance.
Animals don't produce oxygen. Atmospheric composition is also not a good indicator; we can have 100 million people living on the Moon, under the surface, but it has no atmosphere. This is particularly relevant to intelligent life, which can create its own biosphere where necessary.
If you want to start talking about the life we don't know about and thus can't detect, go ahead. It's going to be either a very short
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So on one hand you have a civilisation with scientists trying to find out about their world by smashing things and watching closely. They use their discoveries to invent lots of things: electricity, medicine, computers, space ships etc, and eventually colonise the galaxy and become the intelligent life that we're looking for.
On the other hand you have a civilisation that didn't experiment because they might break something. They never invented space-faring rockets because they were scared they would crash i