[FOM] proofs by contradiction in (classical?) Physics

[Fouche]

Can one use proofs by contradiction in Physics? And if it is possible, why
they are so rare? Is there some intrinsical problem in proving a physical
fact assuming its contrary? Is it "formally" correct, in the system we use
to build physical models? Is the "tertium non datur" true in classical or
quantum Physics?

My two cents are that everybody studying Physics must face an intrinsic
fuzzyness given by indeterminacy; but even if we restrict to a classical
framework things are not so easy: what does "assuming ~P" mean, in a
framework where P can be a _real_ phenomenon (hence true or false by mere
perception; maybe in a framework where "P is true" is a necessary truth)?
Take this as a joke, but there's a big number of mathematicians convinced
that Physics is nothing more than a branch of Geometry (classical,
differential or algebraic, it's not here the place to discuss this); can the
previous questions be restated into a more general one, say "Is geometry
intrinsically non-boolean/without tertium non datur?"

Thanks everybody,
Fosco Loregian

-- 
======
[...] this is what motivates research in higher categorical structures in
QFT. Ours is the age to figure this out. (
http://ncatlab.org/nlab/show/quantum+field+theory)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: </pipermail/fom/attachments/20110918/480133dc/attachment.html>