" [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"."