Re: poly: polymath digest for 09 Dec 97

From: Hal Finney <>
Date: Thu Dec 11 1997 - 09:11:02 PST

David Brin, <>, writes:
> Frank Tipler's 'infinite subjective time' at the Omega Point depends on
> there being a totally unified context withing the collapsing fireball. In
> the Universe's final weeks, there will be so much usable free energy +
> available states that calculation (modelling) can take off exponentially,
> allowing an unrestrained expansion of subjectivity... effective
> immortality.

Weeks, days, hours, minute, seconds, milliseconds, nanoseconds... it goes
on forever.

> The fact that all of this is taking place in the final weeks of the Big
> Crunch is something Tipler shrugs aside, since those weeks have no meaning
> if there is no external context in which they will be measured. The Omega
> Point is effectively immortal from its own point of view, and that
> suffices.
> Now some of us lack Tipler's braininess, perhaps, but those 'few weeks'
> still linger at the back of my mind. Won't some sub units of the OP want
> to peer at that old 'objective' universe? If they do, does THAT provide a
> context? Won't some irritating jerb keep interrupting everybody else's
> infinite holodeck fantasies with sneering remarks about how there's only
> nineteen days to go now... Then he pops back in a billion subjective years
> later and says there's just eighteen... and so on. So much for
> immortality.

Immortality means living forever, which is somewhat ambiguous. "Forever"
depends on how you measure time. I could come up with a time scale which
makes the next one second last forever; contrariwise, even in an infinite,
steady state universe there could be a time scale defined which allowed
only a finite number of seconds to elapse before the end.

That's why I prefer to focus on the question of whether an infinite
amount of computing can be done. This is an objective matter and does
not rely on anyone's choice of time scale. Given that it is possible,
then if someone defines a time scale which provides only a finite span
of time during which that infinity of calculations occur, that doesn't
change the reality of the ongoing calculations. It may be that this
time scale is useful under some circumstances but not others, just as
we use different time scales to plan tomorrow's appointments than to
discuss evolutionary biology.

> Ironically, Lee Smolin -- the OTHER guy to present a theologically
> important cosmological idea lately, threatens Tipler's blithe scenario with
> utter demolition. If Smolin is right, that our Universe is just one of the
> latest in an ecosystem of trillions of universes, each giving birth to new
> ones that slowly evolve toward reproductive fitness ... then there is a
> plethora of external context! From all these other points of view, our
> last three weeks will be our last three weeks, then period. Kaput! Make
> way for the new! We may have an 'infinite' subjective spree during those
> three weeks... but when they are over, our OP god gets smushed.

An article about Smolin's views can be found at: That's a
pretty interesting site, BTW, with debates among people who are strong
"polymaths" in their own right.

I don't see too much connection between Smolin's theory and Tipler's.
Tipler considers the implications of daughter universes which bud off
from our own via black holes or inflation in appendix H, pp 452-456
in the hardcover. He concludes that the Bekenstein Bound limits the
amount of information which can be transferred to a child universe so
that this does not provide a mechanism for infinite computing (that is,
you can compute forever, but you can't accumulate infinite state).
The math is over my head so I don't know how good his argument is,
but he does consider it.

> In a more mundane matter -- we go attend the Postman premiere tomorrow
> night. Early word is that it's a good flick. I can tell you already that
> it's a huge improvement over the horrible early scripts. And Costner's
> camera eye is excellent. As for the rest.... Here's hoping.

I hope it is good. I know many people are looking forward to seeing
the movie. Did you get to meet Kevin Costner?

Received on Thu Dec 11 17:23:17 1997

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