Amen to that. If you cannot prove it, it’s not science just supposition.
Science works with evidence, not proof. Here are a couple of definitions (from a long list on my FR home page) that might help:
Proof: Except for math and geometry, there is little that is actually proved. Even well-established scientific theories can't be conclusively proved, because--at least in principle--a counter-example might be discovered. Scientific theories are always accepted provisionally, and are regarded as reliable only because they are supported (not proved) by the verifiable facts they purport to explain and by the predictions which they successfully make. All scientific theories are subject to revision (or even rejection) if new data are discovered which necessitates this.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