X-Message-Number: 13675 From: "John Clark" <> Subject: Minds, Machines, and the Multiverse Date: Wed, 3 May 2000 12:28:35 -0400 I found an interesting quotation from a new book on quantum computers called "Minds, Machines, and the Multiverse" By Julian Brown, if comes from a chapter on the work of Ed Fredkin, one of the leaders of the "physics is computation" school: " [Fredkin] estimated the total amount of computation going on in the universe, producing, ironically, a figure that seems puzzlingly low. He calls this the problem of the missing workload. Essentially what he has done is calculate how large a cellular automation would need to be to simulate the entire universe in all its details. The answer, he argues, is that the CA that operated at the tiniest quantum scales known as the Plank length and Plank time would only need to be not much larger than a bigish star to faithfully simulate the entire macroscopic evolution of our universe from the Big Bang to the present in about 4 hours. The difference in space time volume between the universe and such a system is a factor of 10^63. This figure is Fredkin's "missing workload", which he contrasts with two other great mysteries of the cosmos: the missing neutrinos from the sun (a factor of around 3) and the missing mass of the heavens (perhaps a factor of 50). So what explanation does he have for the missing workload? "Either something else is going on in the universe that we don't know about" he says, "or God was incompetent on a scale that boggles the mind"." John K Clark Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=13675