Re: Doomsday-like argument in cosmology

2002-08-18 Thread Hal Finney
I've read the paper more closely and I think I understand it somewhat better. The paradox in the paper is actually closely related to the comments with which I concluded my earlier message. What they are saying is that if we are part of a Poincare recurrence, it is overwhelmingly likely that

Re: Doomsday-like argument in cosmology

2002-08-18 Thread Tim May
On Saturday, August 17, 2002, at 11:37 PM, Hal Finney wrote: Now you might say, so what, the whole idea that we formed in this way was so absurd that no one would ever take it seriously anyway. But the authors of this paper seem to be saying that if you assume that there is a positive

Re: Doomsday-like argument in cosmology

2002-08-18 Thread Hal Finney
Tim May writes: OK, let us assume for the sake of argument that we should be overwhelmingly likely to be living in one of these time-reversed cycles (which I distinguish from bounces back to a Big Bang state, the more common view of cycles). By the same Bayesian reasoning, it is

Re: Doomsday-like argument in cosmology

2002-08-17 Thread Hal Finney
Dyson, L., Kleban, M. Susskind, L. Disturbing implications of a cosmological constant. Preprint http://xxx.lanl.gov/abs/hep-th/0208013, (2002). Most of this paper is way over my head. I need to read the ending much more carefully in order to understand its conclusions. But I wanted to

Re: Doomsday-like argument in cosmology

2002-08-17 Thread Brent Meeker
On 17-Aug-02, Hal Finney wrote: Dyson, L., Kleban, M. Susskind, L. Disturbing implications of a cosmological constant. Preprint http://xxx.lanl.gov/abs/hep-th/0208013, (2002). Most of this paper is way over my head. I need to read the ending much more carefully in order to understand its

Re: Doomsday-like argument in cosmology

2002-08-17 Thread Wei Dai
On Sat, Aug 17, 2002 at 04:55:59PM -0700, Brent Meeker wrote: I think what the paper says is that when matter/energy have thinned out enough so that we have essentially empty space again, a de Sitter universe, a vacuum fluctuation can start a new universe. You're not understanding the paper

Re: Doomsday-like argument in cosmology

2002-08-17 Thread Brent Meeker
On 17-Aug-02, Wei Dai wrote: On Sat, Aug 17, 2002 at 04:55:59PM -0700, Brent Meeker wrote: I think what the paper says is that when matter/energy have thinned out enough so that we have essentially empty space again, a de Sitter universe, a vacuum fluctuation can start a new universe.

Doomsday-like argument in cosmology

2002-08-15 Thread Wei Dai
- Forwarded message from Wei Dai [EMAIL PROTECTED] - Date: Thu, 15 Aug 2002 13:28:43 -0700 From: Wei Dai [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: Re: Nature Article On Thu, Aug 15, 2002 at 12:45:17AM -0400, [EMAIL PROTECTED] wrote: Dyson, L., Kleban, M. Susskind, L. Disturbing

Re: Doomsday-like argument in cosmology

2002-08-15 Thread Saibal Mitra
I think that the difference is that invoking the SIA does not affect the conclusion of the paper. Saibal Wei Dai wrote: On Thu, Aug 15, 2002 at 12:45:17AM -0400, [EMAIL PROTECTED] wrote: Dyson, L., Kleban, M. Susskind, L. Disturbing implications of a cosmological constant. Preprint

Re: Doomsday-like argument in cosmology

2002-08-15 Thread Wei Dai
On Thu, Aug 15, 2002 at 11:28:28PM +0200, Saibal Mitra wrote: I think that the difference is that invoking the SIA does not affect the conclusion of the paper. Why do you say that? I think SIA affects the conclusion of the paper the same way it affects the Doomsday argument. It's kind of

Re: Doomsday-like argument in cosmology

2002-08-15 Thread Saibal Mitra
PROTECTED] Aan: Saibal Mitra [EMAIL PROTECTED] CC: [EMAIL PROTECTED] Verzonden: donderdag 15 augustus 2002 23:46 Onderwerp: Re: Doomsday-like argument in cosmology On Thu, Aug 15, 2002 at 11:28:28PM +0200, Saibal Mitra wrote: I think that the difference is that invoking the SIA does not affect

Re: Doomsday-like argument in cosmology

2002-08-15 Thread Wei Dai
On Fri, Aug 16, 2002 at 12:26:10AM +0200, Saibal Mitra wrote: I haven't read the paper in detail, so I could be wrong. Consider the two alternatives: 1) true cosmological constant 2) no true cosmological constant We also assume SIA. Is it the case that there are much fewer observers in