From: Robert J. Bradbury (bradbury@www.aeiveos.com)
Date: Thu Sep 30 1999 - 12:44:39 MDT
On Tue, 28 Sep 1999 Spudboy100@aol.com wrote:
> Is there anything going on with Tipler's Final Anthropic Principle, lately?
> I have read the critique by Nick Bostrom and Dr. Cirkovic, and am aware of
> the data being worked on regarding an accelerated expanding universe. But
> has any work been done, since Tipler's book "Physics of Immortality"? Have
> there been any others with there own versions of it?
>
I've got most of Tipler's earlier articles and the responses to them online.
I haven't read PoI yet, just glanced at parts of it. It seems however to
be pretty irrelevant unless something happens to close the universe.
We seem to be more in a Dyson universe (ever expanding), than a closed
(Tiplerian) one. I can't justify spending the time to read a book
about the end to a universe that probably doesn't exist that was
written, perhaps in part, promoting Tipler's "Christian" perspective.
[Someone should correct that if its a mis-impression on my part.]
There is an interesting argument in this week's Nature that that
argues the geometry of the universe may be flat. I get a
little warped when I try to read this stuff since my mind doesn't
do geometry of universes very well.
I'm surprised that nobody went forward with my suggestion that the
"purpose" of the universe is to convert all of the H & He into
higher forms of elements and leave behind the ultimate "crystalline
entity". Particularly of interest would be whether we could structure
such an entity that would prevent long term proton decay (~10^37 years).
I've got the paper Anders' suggested "A dying universe: the long-term
fate and evolution of astrophysical objects", F. C. Adams & G. Laughlin
from Reviews of Modern Physics, Vol. 69(2):337-372, April 1997. It
carries on to some degree from where Dyson & Tipler have left off.
There are some things in it I don't like (such as discussions regarding
magical "Dark Matter") and it is missing the critical discussion of
what are the limits to astroengineering!!! An interesting question
becomes whether or not in a universe populated by intelligence we
can transform it from a Dysonian/open state to a stable or
Tiplerian/closed state? You might not be able to do it with the
"space" of the universe, but it seems that you could do it with
the "matter" (i.e. pack all the matter into the smallest possible
space short of that that produces a black hole).
There is some cool stuff, like star formation from colliding brown
dwarfs and the formation and decay of positronium (the final stuff
of the Dark Era...)
The summary of the evolution of the universe is as follows:
The Radiation dominated Era: 10^0 - 10^4 years
The Stelliferous Era: 10^6 - 10^14 years
The Degenerate Era: 10^15 - 10^37 years
The Black-Hole Era: 10^38 - 10^100 years
The Dark Era: > 10^100
The only thing that keeps me going is that in the Dark Era, energy
is going to be in such short supply, that we will be able to go
millions of years between the regrowths of the ugly heads of
guns/no-guns or libertarian/government-nazi debates.
Actually, in thinking about this, I think there are a several
people on the list who are potential candidates for being
joined together as siamese twins. They could then debate
head-to-head so to speak at Extro 5... :-;?
Robert
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