Re: poly: Is our lightcone is uninhabited except for us?

From: Damien R. Sullivan <>
Date: Mon Dec 15 1997 - 14:26:59 PST

On Dec 15, 3:08pm, "Perry E. Metzger" wrote:

> The colonization thread has reminded me of an old argument I've
> made. I suspect that there are no other intelligent lifeforms
> substantially more advanced than us visible in our light cone, because
> if there were, they would have already built Von Neuman machines that
> would have arrived and taken over our solar system.
I've argued something similar. I can see intelligent beings still
guarding the occasional preserve while they gobble up the rest of the
universe, though, so what I usually argue is that the presence of
visible stars weighs against aliens. We might be left alone, but lots
of energy seems to be wasted elsewhere. The universe just doesn't look

> Although it might seem odd that we would be the only intelligence in
> our light cone, it shouldn't be overly bizarre, as if Von Neuman

Not so odd. Theories of life's origin on Earth generally assume a
single ancestor cell. Any lifeform that finds itself at large spreads
rapidly. All of the recent calculations support what should be
the default assumption: one occupying species, which then specializes.

-xx- ROU Bibliovore X-)

To Aphrodite sworn was I,
But how could I a god deny?
Received on Mon Dec 15 22:19:05 1997

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