Aliens need a lot motime to find us

On Jan 22, 2007, at 18:48 UTC, Jake wrote:

> Alone??? No way...

Way! Either that, or we're in a nature preserve (i.e., the ETs know
darn well we're here and are choosing to conceal themselves from us).
Those are the only two plausible possibilities.

> Even if you subtract all the solar systems in our
> galaxy with stars not conducive to life, and subtract the ones too
> close to the center to allow for life, you still end up with a huge
> amount of possibilities..

Right. Probably a billion or more.

> If you consider that it's taken us a few
> million years to evolve to the point of even looking outside our own
> solar system for other life.. The chances of us finding other beings
> with advanced enough technology for us to be able to detect them from
> this distance is very slim.. Not to mention where to look?

>From what distance? If they wanted to talk to us, the distance would
be "zero" and the place to look would be "right here," because they'd
be here already. In fact, they'd have been here millions (probably
hundreds of millions, if not billions) of years ago.

Look, the universe is more than 12 billion years old; the odds that two
civilizations are going to arise in the same galaxy within a few
hundred million years of each other are extremely slim. (Technically,
what's ridiculously slim is the chance that the *first* two
civilizations to arise will be within a few 100MY of each other... for
civilizations in the middle of the bell curve, it's a different story.)
Someplace is going to be first, just by luck, and it's going to be
first by hundreds of millions of years -- which, remember, is not very
long on a geological timescale. But it's long enough to colonize the
whole galaxy, once you've got interstellar travel.

So, either (a) we're the first, and we'll be colonizing the whole
galaxy within a few hundred million years, and as we do, we won't
encounter any other civilizations; or (b) we're not the first, and the
galaxy has been thoroughly settled for billions of years, and ET is
hiding right outside the nature preserve they've designated for us.

> The vastness of just our galaxy alone is daunting..

It's vast, but not too vast to colonize. Now, the whole universe is
another story... there may well be advanced civilizations in other
galaxies, that we haven't found out about yet (and maybe never will).

> The proverbial "Needle in a haystack" is minuscule compared to this..

It would be, except that we're not looking for a needle. It's more
like, looking for life in a pond. You don't have to look far, because
if there's life in it at all, it's *teeming* with life. You can pretty
much sample any drop of it, chosen at random, and if you find no
microorganisms at all, then the whole pond is sterile. So too with the
galaxy. Once the first civilization develops interstellar travel, the
whole galaxy will be teeming with life in fairly short order.

> But that has nothing to do with the overwhelming possibility of them
> being there... Somewhere..

I'd like to think so too, but we can't let our wishes cloud our
thinking. The universe doesn't always turn out the way we'd like.
Maybe we are in a nature preserve, but if so, it's unlikely we'll find
out about it until our keepers are good and ready to introduce
themselves. Till then, we should proceed on the assumption that we're
all there is, and if anybody's going to bring life to the galaxy, it's
up to us.

Best,
- Joe

Joe Strout -- joe@...