Tuesday,
13 April 2004
No, Reallythe Problem of Time
Gordon Belot
University of Pittsburgh
12:05 pm, 5J52 Posvar Hall
Abstract:
The general covariance of general relativity is supposed to lead
to a problem of time for classical and quantum theories of gravity.
The problem is supposed to be that there is some sort of difficulty
in making out the sense in which there is change in generally covariant
theories. Many philosophers are skepticalsurely a solution
like an FRW solution represents the universe as expanding, and hence
as changing? Skeptics have wondered: whether there is a problem
of time; whether it is really a problem; what it has to do with
general covariance; what it has to do with change. Often all of
this is tied up with a feeling that the source of confusion must
lie in the 3+1 decompositions of spacetime from which presentations
of the problem of time typically depart. I will discuss formulations
of general relativity in which no 3+1 decomposition is madethe
space of state is a space of solutions, rather than a space of initial
data. In such a formulation it is easier to see what the problem
of time is, why it is a problem, what it has to do with change,
and what it has to do with general covariance.
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