Matt, I understand your explanation, but you haven't answered my main problem here: why to simulate the universe we only need physics, but not chemistry, biology, psychology, history, philosophy, ...? Why not to say "all human knowledge"?
Pei On Thu, Oct 30, 2008 at 1:51 PM, Matt Mahoney <[EMAIL PROTECTED]> wrote: > --- On Thu, 10/30/08, Pei Wang <[EMAIL PROTECTED]> wrote: >> [C]. "Because of B, the universe can be simulated in >> Turing Machine". >> >> This is where I start to feel uncomfortable. > > The theory cannot be tested directly because there is no such thing as a real > Turing machine. But we can show that the observable universe has finite > information content according to the known laws of physics and cosmology, > which assumes finite age, size, and mass. In particular, the Bekenstein bound > of the Hubble radius gives an exact number (2.91 x 10^122 bits). > > http://en.wikipedia.org/wiki/Bekenstein_bound > http://en.wikipedia.org/wiki/Age_of_the_universe > > This does not mean you could model the universe. It would be impossible to > build a memory this large. Any physically realizable computer would have to > be built inside our observable universe. But that is not a requirement for > Occam's Razor to hold. > > I realize we don't have a complete theory of physics. In particular, quantum > mechanics has not been unified with general relativity. I also realize that > even if we did have a complete theory, we couldn't prove it. > > -- Matt Mahoney, [EMAIL PROTECTED] > > > > > ------------------------------------------- > agi > Archives: https://www.listbox.com/member/archive/303/=now > RSS Feed: https://www.listbox.com/member/archive/rss/303/ > Modify Your Subscription: https://www.listbox.com/member/?&; > Powered by Listbox: http://www.listbox.com > ------------------------------------------- agi Archives: https://www.listbox.com/member/archive/303/=now RSS Feed: https://www.listbox.com/member/archive/rss/303/ Modify Your Subscription: https://www.listbox.com/member/?member_id=8660244&id_secret=117534816-b15a34 Powered by Listbox: http://www.listbox.com
