Re: Is 'time' time or is it not.

On Sun, 28 Aug 2005 07:25:09 +0000, RHNL wrote:

> Simply put: Is 'time' a constant or a variable?
>
> If it is a 'constant' why is it applied differently
> in QM and GR?
>
> If it is a 'variable', why do we call it 'time'?

"Constant" and "variable" tend to describe how one
is using a quantity in a calculation. Time can be viewed
as a parameter which is used the same way in GR as
in QM. In GR one parameterizes physics on charts or
coordinate regions using 4 somewhat arbitrarily chosen
real parameters, one of which locally acts like time
(which one depending on the metric). In QM, which
is usually applied in very small regions of space,
states and operators are parameterized in time. In
QFT this is even more evident in the Heisenberg picture
in which field operators are supplied as operator valued
distributions on a manifold (like in GR).

.