View Single Post
Feb17-12, 05:16 AM
P: 6,863
Quote Quote by DaleSpam View Post
I am not so sure that all observables are scalars, but I am pretty sure that all observations are scalars.
I don't think that is true. Imagine a variable phi(A) where A is not a point in space but rather a region. Phi is not going to transform as a scalar field. You can also have thermodynamic quantities which are undefined at a specific point and require averaging to have meaning.

Volume is an observable, but it's certainly not a scalar. Wealth is a defined observable, but it's not a scalar.