Truth: This is a word best avoided entirely in physics [and science] except when placed in quotes, or with careful qualification. Its colloquial use has so many shades of meaning from ‘it seems to be correct’ to the absolute truths claimed by religion, that it’s use causes nothing but misunderstanding. Someone once said "Science seeks proximate (approximate) truths." Others speak of provisional or tentative truths. Certainly science claims no final or absolute truths. Source.
Proof: A term from logic and mathematics describing an argument from premise to conclusion using strictly logical principles. In mathematics, theorems or propositions are established by logical arguments from a set of axioms, the process of establishing a theorem being called a proof.
The colloquial meaning of "proof" causes lots of problems in physics discussion and is best avoided. Since mathematics is such an important part of physics, the mathematician's meaning of proof should be the only one we use. Also, we often ask students in upper level courses to do proofs of certain theorems of mathematical physics, and we are not asking for experimental demonstration!
So, in a laboratory report, we should not say "We proved Newton's law" Rather say, "Today we demonstrated (or verified) the validity of Newton's law in the particular case of..." Source.
http://spider.ipac.caltech.edu/staff/jarrett/LiU/resource/misused_glossary.html
Nothing is science can be said to be true and you can't prove anything, only disprove it.