Friday, September 23, 2005

Where are the Aliens?

There are some who say that the universe can bring about life as a common event and that us and our life-serving environment here on Earth is nothing unique. If that's true, then we ought to expect life to develop everywhere and even intelligent life to at least be somewhat common and we ought to expect to see some signs of advanced technological species operating in our galaxy.

But where are they?!

Through calculating an exponential expansion from one star system to the next at a reasonable pace, it is not unreasonable to find that a single species could colonize the entire galaxy in as little time as ten million years. Through such activities we should expect to see obvious signs of artificial interaction with bodies in space. Mined stars, gathered nebulae, building huge constructs, all sorts of high engineering projects with the goal of using the natural resources for a species' own purposes. But we see none of that. The galaxy is virgin. We don't even hear any radio signals, despite SETI being active for decades already.

Surely the galaxy has been around for much longer than ten million years, so there should be little time constraint involved. Then where are the aliens?

This is what is known as the Fermi Paradox.

Some explanations for this apparent incongruity have been proposed. Perhaps the aliens are intentionally hiding themselves. Perhaps none survive to a point where they are capable of interstellar travel. Perhaps the aliens are simply not that aggressive and feel no urge to reach for the stars.

Or perhaps life is not so prevalent in the universe and we are indeed highly unique - and alone.

14 comments:

avian30 said...

One estimate of the number of galaxies in observable universe is 200 billion galaxies. Therefore, even if we never observe an extraterrestrial civilization because none exist in our galaxy or nearby galaxies, there still may be billions of civilizations in other galaxies farther away.

Orthoprax said...

Avian,

Yes, could be. But still, according to our regular assumptions about the universe, there ought to be more action going on that we can observe.

Alex said...

An atheist has to use calculations to figure out the likelihood of life on other planets. A God-believer is stuck with 50%. Either God wanted life out there, or He didn't.

alex said...

Your front page says "3 comments", but when I click on that hotlink, it says only "2 comments", with my comment missing. But when I click to add another comment, I see that my previous comment is there. Weird...

Ben Avuyah said...

I feel it too, I mean we were promised an exciting intergalactic existence by science fiction but reality is lagging hopelessly behind.

I think all of the equations may be a little off. Remember we are "in the hicks" of the milky way, no where near the galaxy center.

It's kinda like standing in a field in Iowa with no car, well to be to scale, make that no legs, and concluding that therefore no one else inhabits the planet.

Looking for radio waves makes presumptions about the bodily features and direction of technology of possible civilizations, that are not grounded in any observations (how could they be ?)

A better question may be, would we even recognize a very different life form if we came across it ?

Orthoprax said...

Alex,

"Your front page says "3 comments", but when I click on that hotlink, it says only "2 comments", with my comment missing...."

You're guess is as good as mine here. Blogger's comments program is kinda error prone.

Orthoprax said...

Ben,

"I think all of the equations may be a little off. Remember we are "in the hicks" of the milky way, no where near the galaxy center."

That's true - though I have also read that life is less likely to develop within the inner areas of the galaxy because of the higher incidence of violent episodes there. But that's also highly speculative.

"Looking for radio waves makes presumptions about the bodily features and direction of technology of possible civilizations, that are not grounded in any observations (how could they be ?)"

If a species is technologically inclined that means that they take advantage of and shape the environment to serve their purposes. The electromagentic spectrum is a natural resource that, one might think, such a species would eventually run across and see the use of it. And perhaps exploit it as we have.

"A better question may be, would we even recognize a very different life form if we came across it ?"

Yeah, it depends on how different, but we ought to be able to see at least the effects of an exploitative force in the galaxy.

Godol Hador said...

The aliens have had 15 billion frikkin years (well, maybe a bit less) to make some sign of their existence, yet there is nothing (maybe Har Sinai?). So my bet is there aren't any.

Orthoprax said...

GH,

Even so, the universe is a big place. It's hard to imagine the whole thing to be lifeless (except out little corner) especially as how we have explored such a minute fraction of it.

Alex said...

For anyone interested in the mathematical side of the question, google on "Drake Equation".

If you lean towards one side or the other, keep in mind that it's not really the probabilities that are tilting you, it is what you WANT to be true that is tilting you.

Orthoprax said...

Alex,

Sure, I know the drake equation. But it's just an equation with variables. The variables are the issue, of course.

Schmarty Pants said...

Consider this. Think of how far we have come technologically in 100 years, literally from horse-drawn carts to stealth jets and space shuttles. Now imagine, assuming we don't blow ourselves up when oil runs out in the next 5-10 years (I digress) and actually survive another 1000 years. How incredibly advanced could we be?

Therefore, your question is interesting but fatally flawed. All the other civilizations would need, is to be 1000 years older than ours to be incredibly more advanced. Now, take all possible civilizations and assume 50% are more advanced by anywhere from 1000 to 100000 years ahead of us. It's pretty clear that they are not going to be detected if they don't want to be!

We can observe monkeys from U-2 planes or satellites- do you think they have any chance of figuring it out?

I think that point should be abundantly clear, so what else can we take from it. Most important, you can assume that a civilization with one million years on us is capable of visiting us and not being detected whatsoever. Therefore, why assume we are not being visited or studied like monkeys?

Another point- perhaps other civilization exist but on a vastly smaller scale, thus being even harder to detect.

Also, SETI is more an academic exercise than a real hope of discovery.

Orthoprax said...

schmarty,

I mentioned your first proposed possibility when I said "Some explanations for this apparent incongruity have been proposed. Perhaps the aliens are intentionally hiding themselves." But we really have nothing except for speculation for why that would be. And if they are engaging in huge engineering projects, we should see evidence of this in the galaxy.

Also, about your second possibility, if other forms of intelligent life are anything like us, they'd likely have to be somewhat to scale. There are regular size limitations for intelligence. You need an organ large enough and complex enough to make intelligence possible and then you need an organism large enough to positively manipulate its environment.

It's not theoretically impossible to have civilizations on vastly different scales of size, but there is likely a limit and likely a bell curve.

Like or not, the fact that the galaxy appears virgin is a conundrum for fans of science fiction.

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