X-Message-Number: 18450 Date: Thu, 31 Jan 2002 14:42:17 +0100 From: Henri Kluytmans <> Subject: simulation, can 813 coupled qubits simulate the universe Yvan Bozzonetti wrote : >To simulate the Universe (ten billion light years in radius for ten billion >years) you need 10^244 Planck's cubes ( One Planck's unit for each dimension >in space and time). This could be run by a quantum computer with a 813 bits >word in a single computation cycle, something as a billionth of a second. Ehhh ??? A quantum computer of 813 coupled qubits can only store a superposition of all 2^813 possible combinations of 813 normal bits. And it can perform operations on all those 2^813 combinations in only one single operational step. But it can not store or operate on 10^244 (~= 2^813) bits! The possible combinations of that number of bits are 2^(10^244) !!! Furthermore, does a Planck cube contain only 1 bit of information ? >This illustrates the potential power of quantum computers and the >effect of state superposition in quantum mechanics. Sorry, but this seems to be a huge misconception about the potential power of quantum computers. Grtz, >Hkl Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=18450