Arken

I also should add at this point that despite my pessimism, I am a huge supporter of continuing SETI work. To paraphrase Carl Sagan "Even if we determine that there are no other civilizations we should keep looking, because we might be wrong."

markfiend

I'm not a detractor! All the Fermi question means to me is this:
"Given our hypothesis that life should be fairly common in the universe, it's a little strange that we can't see any evidence for it"

And the only evidence for life elsewhere we're likely to see any time soon (unless we find anything in Europa's ocean) is signals (or an invasion LOL) from intelligent life.

I concur.

Arken

And while finding life on Europa would be quite an achievement, there would be no way to prove that it was not 'seeded' via a meteor from Earth (or vice-versa), a situation almost totally unlikely if it were discovered on an extrasolar planet.

cheetah

A new perspective came to me as I read, a couple weeks ago, about the "oldest planet" discovered in a binary system (can't remember name right now). Anyway, that planet is a gas giant, but they believe that, based no the history of that solar system, an earthlike planet was possible, many billions of years ago, as, inside the path of the gas giant, the habitable zone could have had a planet that supported life. Any evidence thereof would have been destroyed when the one star went supernova, but it at least looks to satisfy many of the criteria Arken listed. We may never know, but it brings about the perspective (finally back to my point here!) that life may have existed and been snuffed out elsewhere already. Certainly, I agree with the estimations that with the number of stars in the universe, it is incredibly likely that there is other life right now, I also think that the expanded odds when one considers the number of stars over the last 14 billion years makes it a virtual certainty!

markfiend

A small understatement methinks

Well, if hypothetical Europan life used something other than DNA/RNA for its genetic material, or something other than the proteins we know (made of the 22 "biological" amino acids) as enzyme-analogs, etc. etc. I for one would be preared to accept that it had a separate beginning from Earth-life.

You'd still get people claiming it's just evidence for "panspermia" I'd guess.

Rhaedas

Someone here had suggested reading up on the Rare Earth Hypothesis, proposed by Peter Ward and Donald Brownlee in their book Rare Earth.

Essentially their thoughts are that life in bacteria form may be abundant, given that we are finding more and more examples of extreme forms of life, from volcanic vents to far beneath the surface inside rocks. Life such as this may form quite soon after a planet cools and solidifies. Mars, Europa, and other places may have alien microbes under the surface or ice.

More complex life may be much rarer, dependant on how important earth-like characteristics are to their formation. Things like being in a habitable zone long enough, having a star that "behaves", how critical a large moon may be, the need for plate techtonics to recirculate elements, and more...the more you add, the less likely plant and animal life as we know it can exist elsewhere. It's a good read, even if their ideas are speculation at this point just as much as the Drake equation is. It's made me rethink my assumptions about large lifeforms elsewhere.

I can't remember who, but I read once that until we do find other life, complex or otherwise, it's best to act as if there is no other life, and we are indeed alone, and try our best to preserve the only self-awareness we know of in the universe.

Godless Dave

Fermi's "paradox" is no paradox at all. Think about how far transmissions from other civilizations would take to get here. We've only been broadcasting radio signals for about a hundred years. It'll take another 90 thousand years for those signals to get to the other side of our galaxy. And that's just one little galaxy.

Gawdawful

That sounds a great deal like Pascal's Wager, "be religious, just in case you're wrong." So what if we're wrong about aliens? I think the chance that some advanced aliens in another galaxy aren't going to suddenly show up and whack us with their Romulan Distrupter Beam weapons because we didn't return their call is virtually zero. Why waste the time and expense?

But, then, I might be wrong. In that case, I'd better get to work on that backyard nuclear fallout shelter; even though I probably don't think I'll need it, I might be wrong (actually the odds are much, much higher for this event to occur).

......... etcetera, etcetera, etcetera....

Unless.... this SETI thing is just to prove 99.9% of earth's religions are bunk, then by all means have at it; anything for that cause. I'm pulling for NASA, et al finding evidence of life on Mars or Europa because that would be a step in that direction; no more Geocentrism. However, the pessimist in me says the religious will just modify their religion to fit the facts or just plain deny the facts like they already do. Facts and reason don't seem to be working all that well.

Warren in OK

Arken

Well, I might get some flack for this, but when applied to things other than religion, I don't think Pascal's Wager is always a bad thing. For example, if I'm in the woods and I get bitten by a raccoon, I'm going to get rabies shots because even though I don't have proof that I have rabies, I'd rather get the shots than take that chance.

Majestyk

I don't think that Pascal's Wager applies. The premise of the wager is to believe a concept to be true without any evidence to support it. Whereas, the search for extraterrestrial intelligence does not make the claim that such intelligence actually exists but rather the probability of it is evidenced by, our own existence. The search is an attempt at confirmation. Pascal's Wager demands acceptance without confirmation.