Re: Cosmology and Boltzmann brains

From: Brent Meeker <>
Date: Tue, 17 Jun 2008 21:24:21 -0700

Russell Standish wrote:
> On Sun, Jun 15, 2008 at 01:40:09AM -0700, Greg Egan wrote:
>>> But we do this all the time. Why is it we reject crackpot claims that
>>> the world will end on such and such a date for instance?
>> We reject those claims because they flow from theories that we reason
>> should have led to observable consequences in the past (e.g. theories
>> of interventionist deities). So what we have are prior probabilities
>> that strongly disfavour those crackpot theories -- and given equal
>> crackpot ratings, their predictions about the future are irrelevant.
>> If crackpot A tells me that the world will end in 2012, and crackpot B
>> tells me that the world will end in 20,012, then all else being equal
>> I will (in 2008) give them both *equal* low credence.
> I was actually thinking more of theories like "the law of gravity will
> be suspended on the 25th of July, 2012, but otherwise everything else
> is the same". Obviously it makes the same retrodictions as our usual
> scientific theories (doing so by definition). The reason it is
> rejected is because of the arbitrary nature of the date makes it a
> more complex theory (in the Occam's razor sense).

And it is not POVI.

Brent Meeker

You received this message because you are subscribed to the Google Groups "Everything List" group.
To post to this group, send email to
To unsubscribe from this group, send email to
For more options, visit this group at
Received on Wed Jun 18 2008 - 00:24:35 PDT

This archive was generated by hypermail 2.3.0 : Fri Feb 16 2018 - 13:20:14 PST