Re: effective probability

From: <hal.domain.name.hidden>
Date: Sat, 30 Jan 1999 14:12:44 -0800

I thought that the explanation for why the doomsday argument fails in
the everything-exists case went like this:

Either we are in a world where the human race lives for a very long
time but we are very early in its history, or we are in a world where
it lives for a short time and we are at a typical point in its history
(or something in between).

The first case is unlikely because we should not be so early. But the
second case is unlikely because "we" (considered as randomly chosen
observers from among all possible worlds) should not have ended up in a
world with so few human observers. We would have been much more likely
to be in the world with many humans.

Either way we face an unlikely event, and from what I understand the
detailed analyses show that the unlikelihoods exactly balance. If all
worlds exist, we can't conclude anything about the duration of the human
race or our likely place in it, just from knowing our birth order.

Hal
Received on Sat Jan 30 1999 - 14:20:55 PST