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Why Haven't Aliens Contacted Us Yet? (Fermi Paradox)



Fermi's Paradox (named after an Italian physicians) is that if an interstella civilisation existed they would already be here.
Even if this civilization was only a few hundred thousand years older than us, this would give them ample time to colonize the entire galaxy through use of sub-light Von Neuman machines.
And even if we were in some sort of nature preserve/quarantine, the physical evidence of a galaxy-wide civilization would be impossible to miss - em transmissions, stella engineering, Dyson Spheres.
So either we are alone, or all spacefaring civilizations become extinct before than can get very far.
Its a depressing conclusion, so I hope somebody can shoot a few holes in it.
Maybe we are in a reservation. I cam imagine that one day we reach the outer edges of the solar system, and get through some force field. Only to find there are spaceships everywhere, and more aliens that you can shake a tentacle at. But they have been hidden from us.
If what we see in deep space is only what was there 2 million or so years ago and not what is actually there now, then the possible inhabitants of said place can only see what was here on earth in the same period using their telescopes/space craft etc.

So they maybe only see dinosaurs or creatures crawling out of the mud. They are probably not interested in any of this.
Blueswidow said:
So they maybe only see dinosaurs or creatures crawling out of the mud. They are probably not interested in any of this.

But any self-respecting galaxy colonizers would see a planet full of rare and useful resources, so we would have been stripmined by a hoard of Von Neuman machines.
As to Xanatic point, that presumes that any galatic civilization would be benevolent, but wouldn't it be more logical that they would be like us: agressive, selfish, curious and sometimes violent.
All in all maybe its a good thing we've never met (formally anyway) ETI's. Can anyone think of a contact in earth's history between a technologically advanced civilization and a more primitive one, that didn't result in the more primitive one getting screwed over ?
On the whole, I've always found Fermi's argument troubling, but it's not necessarily ironclad. There are some hidden assumptions being made. First is the assumption that we'd necessarily recognize signs of the activities of a technology significantly more advanced than our own. Would their technologies necessarily put out that much EM? A really good technology isn't going to leak waste energy, and there are probably more efficient ways to communicate than we've yet dreamt of. An interesting analogy is that of natives on an island, listening for distant talking drums, completely unaware of the radio and television traffic all around them.
So far as Dyson spheres, the only way you'd know they were there is by the background heat they'd give off. Perhaps we don't see them because some way has been discovered to make use of the waste heat? Maybe they're using ringworlds, or have engineered themselves to live in vacuum and freefall?
Stellar engineering becomes useful only on a very long time scale, or for military operations. I'd suggest that rather than 'normalizing' stars, it would probably be more efficient to genetically engineer life to adapt to the existing star, rather than re-engineer a star to fit an arbitrary standard. So far as military use, an unusual abundance of supernovae might be a sign that something's going on. On the other hand, weapons that extreme would likely be employed only in a civil war. Two civilizations meeting are likely to be at such different levels of instrumentality that less dramatic measures would be used. There's not much point in blowing up a whole planetary system if you don't have to.
In the end, though, a lot of the uncertainty comes from trying to guess what would look like a good course of action to aliens. I'm still trying to wrap my brain around the fact that the entire Japanese government were convinced that a sneak attack on the United States would be a good idea.
People seem so wrapped up in sci-fi that they never entertain the possibility that we might be the most advanced civilisation in the universe. Depressing thought, eh?
Yeah, but when have humans ever been THAT special?

No, I think we might be the rather drab inhabitants of a rather drab world. Yes, the rest of the universe may see us as the insurance salesmen of the cosmos. :)

Personally I think Fermi's Paradox doesn't hold up for a variety of reasons.

1) It assumes that Von Neuman machines are a) safe and b) not an idea unique to earth.

I mean would YOU be willing to turn hoardes of self-replicating machines loose on the cosmos? Think of the damage they could do! Also, we may be the only ones to come up with this idea. Seriously. The Incas built amazing temples and cities, yet lacked the wheel. The concept may be only human.

2) It assumes that EM radiation is the way to go for transmitting information.

If current experiments with quantum computing and Bose-Einstein particles pan out, in 50 years the main method of communication over long distances may not be radio waves, but some form of "quantum radio". Which wouldbe undetectable to any outside source.

3) It assumes Dyson spheres. I mean that would be a BITCH to build! A massive 2 AU wide sphere? Good luck!
Good thread - nice to get on to something fairly Fortean after all the energy being expended on other, rather trivial, threads...(!)

Even if communication is limited to e/m waves, lasers would be almost undetectable by anyone apart from the intended recipients.

And most long distance comms would have to be very narrow beam, meaning that chance interceptions (bearing in mind that relative movements of planets, habs, ships, etc, means that the transmission will have to be continually re-aimed) would only capture short fragments of 'message', and these fragments would be too short to be recognized as deliberate messages in most cases.

The original SETI argument relied far too much on the idea of broadcast radio, which in deep space is impractical.
Schmell said:
Yeah, but when have humans ever been THAT special?

No, I think we might be the rather drab inhabitants of a rather drab world. Yes, the rest of the universe may see us as the insurance salesmen of the cosmos.

That's precisely my point. We're always very keen to do ourselves down. We always seem to think "there must be someone better than us out there, I mean look at us!"
It reminds me of someone arguing "there must be a God, and an afterlife, because, well, look at us! This can't be it!"
Dark Detective said:
People seem so wrapped up in sci-fi that they never entertain the possibility that we might be the most advanced civilisation in the universe. Depressing thought, eh?

Why is it drepressing DD
It means that there are new worlds to conquer
I mean explore, of course

Niles "...Tis not too late to seek a newer world..." Calder
Fermi's Paradox has so many holes its untrue.

1) It assumes that ETI would be technological, look at the distribution of technology on the earth... Not everybody can build a radio.

2) It assumes the EM spectrum is used for broadcasting (not a bad assumption at face value). Also that technological races have to have communications of some sort, to go for true pulp sci-fi telepaths don't use radios lensman. However we don't know what else is out there. Also we don't know how far away this civilization would be, perhaps their signals have long since been drowned out by other signals from stars, quasars etc...Or they've discovered a way of infering a shear signal onto background microwave radiation, allowing them to communicate FTL. Unless we knew what we were looking for and where to look we could not intercept that signal.

3) It assumes we could recognize such emissions if we saw them. This is an ETI we're talking about, how would we recognize EM broadcast Pheromone transmissions? How would we recognize mathematics based on a non-linear number system, or something uninvisioned on earth.

We tend to think in terms of sound and vision, imagine a race for whom these were entirely new concepts, thought patterns would be radically different, communication of any sort might be utterly impossible between our peoples unless we could find some common ground. Even mathematics is based on our perceptions of the universe around us. It is not a truely universal language, we can just hope that it is pretty broad.

4) Its assumes that ETI would want to contact us (not sure I would). With time our own systems will probably become lossless as we don't want to waste resources broadcasting to the universe in general.

5) It automatically assumes Von Daniken and his cohorts are wrong. I certainly wouldn't discount some alien race having visited the earth a long time ago. Pick up a few choice specimens and then on to the next locale. If they wiped the dinosaurs out we'd never know now, what evidence would survive 65 million years- which lets face it is a long time for a mountain to last let alone a species or civilization.

And that's without getting into the idea that a race would expand spherically throughout the universe (we percieve it as the best way of expanding a higher order intelligence may disagree as the expansion front must become thinner until possibly the expansion front is so weakened that it can't manage to secure a resource to replicte the von neuman machines). Even on earth few animals expand in a circular manner from an initial point. Look how much trouble we've had tracking mans own history, people tend to jump from location to location almost at random, you might spot a trend over a thousand years, but on a yearly basis its pure mayhem.

Or that we could be isolated from the rest of the Galaxy by higher technology races deliberately. - interstellar conspiracy theories anyone.

Its also assuming that one of the many mystery objects that astronomers have looked at a come up with some startling theories regarding (quasars, pulsars et al), aren't infact observences of huge generational ships travelling through (or away from) the galaxy. Remember there is no real evidence either way, nobody has been to have a look, we just have speculation based on size and power of emissions. -Although I wouldn't want my old physics professors to hear me saying that ;)

The only way we can ever really know the answers is if we manage to get out there and have a look. Unfortunately unless science can crack wormhole/warp/bloater drive or some other FTL theory we'll be guessing a long time.
Yeah, new worlds where you don't have to worry about disturbing the natives. Prime directive and such.

But why would a civilisation want to build the Von Neumann machines? What is the point of sending robots into the universe? If it won't be able to send any information back anyway, no reaosn to pollute the universe with them. If I can't go there, I don't want to send robots.
ithaqua said:
Fermi's Paradox has so many holes its untrue.

1) It assumes that ETI would be technological, look at the distribution of technology on the earth... Not everybody can build a radio.
It doesn't assume that all sentient beings would be spacefarers. It only take one spacefaring civilization and a little bit of time to colonize the entire galaxy, so why hasn't it happened.
3rd generation stars, ie. stars stable enough to support planets have been around for millions of years, so there should have been at least one go-getting, colonizing, doesn't give a shit about the prime directive civilization out there.
All of which is based on the unverifiable assumption that a non-terrestrial intelligence would be something remotely indentifiable as such. We look for radio waves and spaceships - let's face it, these are cultural products of a slim sector of the last hundred years of our species. Infinitesimal, quite frankly. Would we even be able to percieve an alien intelligence?

Emeric Pressburger (if you don't know who he is, you damn well ought to) once described the experience of running a silent movie for a group of Hungarian shepherds, in the early years of the last century. They enjoyed the experience tremendously, until he asked them what they thought of the star. They were absolutley baffled by the question; they had not seen anything which they could identify as human, merely a collection of entertaining lights.

Actually, that last description - hang on a minute -
Fermi's Infirmity

When asked, "Where are they?" I'd have quipped, "Where are WE? If we knew that, we might know where they are."

In other words, they may well be here, who can say what form a truly ET life or sentience may take?

Oh, and another conundrum: Even if we proved to ourselves that UFOs are from outer space and ET is real, et cetera, what then? We'd still be flummoxed by their maneuvers and abilities, and kept at arm's length at their whim, right?

For peace of mind, it may be better for us to remain in doubt, rather than confirming our inarguable inferiority.
Whenever a prominent expert is reported as suggesting that there is nothing to a particular idea, most people nod, say "See? I told you", and never give it another thought, save to shake their heads at the misguided few who still consider it worthy of attention. Standard operational technique.
It seems there could be up to a billion Earth type planets in our Galaxy, if this is true, if only one percent of those worlds harbour sentient life forms, it begs the question, why no radio signals from any of them? Article.
Well P. it could be that we're the first civilisation to reach this stage of development without being wiped out by our own stupidity or the cruel vagrancies of the universe.

Alternativley we might be the only ones stupid enough to broadcast our existance to the galaxy at large... :)

Niles "catflap" Calder
just cos there is life on them doesnt mean there will be intelligent life, there may be lifeforms on those planets that we cant even comprehend because theres nothing like them on earth.
Also these other beings may not use radio waves for communication, they could be more advanced and use another method that we havent discovered or they could of got so pissed off at chris evans on the radio that they threw them all out.
Its possible
Originally posted by Niles Calder

Alternativley we might be the only ones stupid enough to broadcast our existance to the galaxy at large... :)

I have a pet theory, there is a very advanced civilisation out there that are shielding the Earth from all broadcasts from around the Galaxy until we mend our ways and become civilized enough to join the Glactic club.
Since we mostly listen on the background hiss of Hydrogen, and there being no guarantee that anyone would actually broadcast on this hiss, maybe were just not listening in the right places withthe right sensitivity. Also there are good reasons why we broadcast on the frequencies we do for our TV/Radio. They may hold true else where, so the grey version of 'I Love Lucy' may have been stomped on inthe UK by the re-run of 'The Good Life'.

The WOW sisgnal is the most likely SETI signal we've had, especially since it was similar to our, one off burst. Maybe theyre as dilligent as we are looking for others and that was the budget blown :)

I recall posting similar before, but......

Imagine an Amazonian tribe sending out smoke signals for all they're worth, and it's reported by us civilised types as 'sporadic jungle fires'....

And we're searching for ET on the radio frequencies....

And ET & co. arrive, and say 'didn't you get the message?'

So we explain SETI, and radio, etc. and they say 'Radio? Oh no, we gave that up years ago, how about.... whatever (next year's "big thing")

And we've set up all these 'lighthouses' - what, you thought quasars were a natural phenomenon? God, you're soooooo backward, mere savages.......

Maybe we're the most advanced civilisation yet in our part of the universe.

Maybe we're not civilised yet, and are still 'Amazonian savages'.

It ranks among the most enduring mysteries of the cosmos. Physicists call it the Fermi paradox after the Italian Nobel laureate Enrico Fermi, who, in 1950, pointed out the glaring conflict between predictions that life was elsewhere in the universe - and the conspicuous lack of aliens who have come to visit.

Now a Danish researcher believes he may have solved the paradox. Extra-terrestrials have yet to find us because they haven't had enough time to look.

Article continues Using a computer simulation of our own galaxy, the Milky Way, Rasmus Bjork, a physicist at the Niels Bohr institute in Copenhagen, proposed that a single civilisation might build eight intergalactic probes and launch them on missions to search for life. Once on their way each probe would send out eight more mini-probes, which would head for the nearest stars and look for habitable planets.

Mr Bjork confined the probes to search only solar systems in what is called the 'galactic habitable zone' of the Milky Way, where solar systems are close enough to the centre to have the right elements necessary to form rocky, life-sustaining planets, but are far enough out to avoid being struck by asteroids, seared by stars or frazzled by bursts of radiation.

He found that even if the alien ships could hurtle through space at a tenth of the speed of light, or 30,000km a second, - Nasa's current Cassini mission to Saturn is plodding along at 32km a second - it would take 10bn years, roughly half the age of the universe, to explore just 4% of the galaxy. His study is reported in New Scientist today.

Like humans, alien civilisations could shorten the time to find extra-terrestrials by picking up television and radio broadcasts that might leak from colonised planets. 'Even then, unless they can develop an exotic form of transport that gets them across the galaxy in two weeks it's still going to take millions of years to find us,' said Mr Bjork. 'There are so many stars in the galaxy that probably life could exist elsewhere, but will we ever get in contact with them? Not in our lifetime,' he added.

http://www.guardian.co.uk/space/article ... 05,00.html
Fermi's paradox makes one rather arrogant assumption - that we are just so doggone fascinating that intelligent creatures from across the cosmos should be beating a path to our door. Perhaps someone should consider that a truly advanced race might not find humans all that worthy of study or interaction.

Another thought - not that we aren't interesting but just too bloody dangerous to risk going near! Remember the flurry of sightings when we went nuclear.

Another point. What if they are here already but are studying us like insects, rather than take me to your leader style? When you study an animal in the wild, you do so as inconspicuously as possible because you don't want to interact with it, creating a relationship that spoils its natural way of life. To properly study it, you must remain 'invisible' (see article about this subject a few issues back, to know what I'm on about and also the experimenter effect, which any scientist tries to minimise, to get most unsullied data possible).

I don't see aliens as being like George Bush in Iraq but more like the united nations - ineffectual and uninvolved rather than stupid and overinvolved (tar baby effect). If they've got here, they are at least technically advanced and initially in small numbers as with any sensible scouting movement (Is it safe? Is it worth investing more effort in?).

Also as has been pointed out, what if they've been here secretly all along and working in the background to direct our evolution, like superior racial parents? Again why would they need or even want to make their presence obvious? Motive decides action/inaction and we can only second guess this because we are not them or in their minds, if this is the case: People who assign motives for them, then say why they therefore can't exist, based upon this belief, only betray their own limits on the subject, not their knowledge of the truth - though they'd have others believe it is the truth and not just a personal theory. True science is open minded because that is how you make discoveries - ignorance defends the faith and stops people looking.
Maybe they are picking up our television signals and are seeing Jade Goody on Big Brother, and thinking to themselves

"Hmmm, they haven't really come on much since those dinosaur things... let's not bother." :roll:
davidplankton said:
Maybe they are picking up our television signals and are seeing Jade Goody on Big Brother, and thinking to themselves

"Hmmm, they haven't really come on much since those dinosaur things... let's not bother." :roll:

Yeah, so they ignore us. Apart from the teenage Aliens who get up to their little tricks...
Bjork has assumed that only sixty-four probes will ever get built, an absurd assumption. Fermi realised that any civilisation that really wanted to explore would do so exponentially; that is, by building new probes in every suitable star system. Even if it takes thousands of years for each step, an exponentiating wave of exploration would cover the galaxy in ten million years, not ten billion.
Suppose a single probe did find us. How would we know - assuming that it didn't instantly announce its presence to us? It might be disguised as a chunk of rather ordinary looking space rock for all we know.

The problem with Fermi's paradox is that it was formulated at a time when we still assumed that any visiting aliens would map and explore the planet in low flying aircraft. Now that even we have spy satellites that can read number plates, that kind of thinking is quite obsolete.
If Fermi is right, and Bjork is wrong, the exploration of a galaxy takes millions of years. That makes it unlikely that we would witness the arrival of a single probe. If the probes have made it to our solar system, they most likely arrived several million years ago, and have been watching ever since; we would almost certainly not be able to detect them unless they wanted us to.
They almost certainly would not fly around above our cities with their lights on unless they wanted to be seen; and if they want to be seen, they must want to make contact.
Unless it's just DR and Quinch winding us up...