Re: doomsday argument

From: Jacques Mallah <>
Date: Sun, 16 Sep 2001 18:31:12 -0400

    I will eventually get around to answering some of the other recent posts
on this list, none of which contain any really new or interesting ideas BTW.
  Recently, of course, I have been more concerned with the destruction
caused in NYC by the advocates of suicide and believers in immortality.
(I'm currently in North Dakota, but have lived in NYC most of my life. I
did not know anyone who was in the WTC.)

>From: "Saibal Mitra" <>
>Bruno wrote:
> > Charles wrote:
> > >(BTW, would I be right in thinking that, applying the SSA to a person
>who "finds himself" to be 1 year old, the chances that he'll live to be 80
>is 1/80?)

    That's basically right in a special case: If a genius baby is abandoned
on a deserted island, and figures out how to feed himself, use Bayesian
reasoning, find shelter, and other such basics, then indeed (since he has no
other information) his best estimate of what his lifespan will be is indeed
about his current age. There is no way he could do better at that point,
especially not by refusing to make any guess!
    Of course, if he found additional information, like seeing a bunch of
natives of various sizes and noting that the small ones slowly got bigger,
then he would be able to revise his prior and would come up with a better
estimate for his expected lifespan.

> > This argument (against Leslie Bayesian Doomsday argument) has been

    It's by no means an argument against the Doomsday argument! It's
complete baloney to call it that. I guess it's like saying the Chinese room
is an argument against computationalism - in both cases, people just take a
particular example - a perfectly normal example in which the idea under
attack works fine, say "aint that cwazy", and think they have said something
interesting. They haven't.

> > I think it is a good point against too quick use of Bayes in infinite or
>continuous context.

    For shame, Bruno. Not only is it a total non-point, it has nothing to
do with whether the case is infinite or continuous.

>An interesting article by Ken Olum can be obtained from:

    I read the abstract. It's just the same stupid stuff we've seen before.
  (Yawn.) And he's obviously no friend of the MWI. It says "Treating
possible and actual observers alike also allows sensible anthropic
predictions from quantum cosmology, which would otherwise depend on one's
interpretation of quantum mechanics." In other words, he's trying to
prevent the fact that the MWI is observationally supported by anthropic
considerations from counting as evidence for the MWI.
    "Possible observers" can't use Bayesian reasoning unless they also
happen to be actual. Hence the paper is 100% wrong. QED.

                         - - - - - - -
               Jacques Mallah (
         Physicist / Many Worlder / Devil's Advocate
"I know what no one else knows" - 'Runaway Train', Soul Asylum
         My URL:

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Received on Sun Sep 16 2001 - 15:32:09 PDT

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