Re: Best Laws Know No Bounds
Danny Yee (danny@STAFF.CS.SU.OZ.AU)
Tue, 12 Sep 1995 11:39:00 +1000
Bob Graber writes:
> I cannot share M. Carson's impression that all laws have spatio-temporal
> bounds. Gravitatational force, for example, is directly proportional to
> the product of mass, and inversely proportional to the square of
> distance, for all times and places *as far as we know*.
The connection is even closer than that -- since General Relativity
_defines_ space and time in some sense, and gravity is simply geometric
curvature of space-time, I'm not sure it would be _meaningful_ to talk
about gravity having spatio-temporal bounds!
> This ought not
> be confused with a proposition such as "All apples in this barrel are
> red." Indeed, the fact that we know that all apples are not red, and
> that we therefore know this proposition to be spatio-temporally
> constrained, suggests that we ought not consider it a law, despite the
> fact that it is of universal form.
On the other hand, I think this is an unnecessarily restrictive
definition of law. If laws must be universal (as in literally applying
across the universe), then only fundamental physics can have laws.
(Even chemistry and most of physics rely on restrictions of temperature
to ranges where baryons can exist.)
I'm entirely unconvinced that the term "law" is a useful one, anyway.
What's wrong with "well-tested theory"?