Dammit! I don’t think I finished my thought there! What I meant to say is that the above conclusion–that your hand is common–would be just as absurd as concluding that you hadn’t been dealt the hand at all.

Several trillion is several orders of magnitude above 635 billion, but I think the point is still valid whether we’re talking 1/635*10^9, 1/10^12, or 1/2 (“I had a fifty percent chance of getting this result, therefore I’m not sure if I did or didn’t!”).

The problem isn’t with the trillion, it’s with the 1/100th of a percent or even 1/1000th of a percent or 50%; we don’t know if the chance of an intelligent civilization evolving and inventing radio is literally one-in-a-trillion or one-in-three, except to say that if it’s one-in-three it seems very quiet out there. One-in-a-trillion seems hard to believe, but there’s no objective reason for that, merely that it intuitively seems long-odds–what Dr. Shostak basically called “miraculous”–to think they’re that low.

There’s a great John Allen Paulos quote–I wish I could find the exact line right now–about how the odds of getting dealt any specific Bridge hand, a combination of 13 specific-but-randomly-dealt cards, is one in 635 billion; and yet it would be absurd for somebody to pick up a hand of cards, look at it, compute the math and decide that he couldn’t possibly have been dealt that hand or that the hand must have been choice-picked for him. One might extend that to say that with 635 billion possibilities out there, hands just like that one must be common and this hand can’t possibly be unique because it’s so unlikely to be dealt a unique hand. If we’re alone in the universe, it’s not a miracle, and if we’re not alone, it’s not an expected outcome of the size of the galaxy or number of galaxies out there. The probability or improbability of an event that’s already occurred is basically meaningless.

I hope we’re not alone. Meanwhile, what’s your favorite resolution for the Fermi Paradox?

Are they out there? Definitely. But can we afford to meet?

Again, I don’t think you’re considering just how BIG a trillion is. I also see a lot of “may” in your argument and of course if you stack the negative assumptions high enough then yes, being alone is a case that can be made. As you say later, we don’t have much data, but it’s unlikely that all of the assumptions line up on the extreme negative side (and the opposite is true of course).

Re the Copernican principle – it’s very unlikely we’re in the middle. It’s FAR more likely we’re at the very early edge of civilizations. Again, if we look at a technological civilization as having a 50 or 100,000 year lifespan, we’re 5-10% of the way in. If such civilizations last much longer were a very very small way into the lifespan of the typical civilization.

Likewise, Xopher, it’s unlikely there’s much life at the core of the galaxy due to the environment there. Might someone drop by? perhaps. After all, we send people into remote forests and find Neolithic tribes… Again, if a civilization is hundreds of thousands of years old, it’s FAR more advanced than we. Even if no technique for things like FTL is ever found and our basic understanding of physical laws is correct, that’s a very very long time.

The problem is that while the Copernican Principle is a useful way of giving ourselves a kick in the pants and enforcing modesty, it also has no objective basis. That is, we should continue to remind ourselves we probably aren’t special, in spite of the fact that we are (as far as we know) unique and therefore very special.

It’s often taken for granted in conversations about extraterrestrial life that there must be civilizations more advanced than we are because there are planets and stars that have had more time to produce such civilizations and we are, per the CP, probably not special. Only, see, there’s not actually anything to back up that assumption. Someone has to be first and most advanced, and until we meet somebody else, it appears that we are, however improbable that may seem.