[nicbn]

But to know via scientific method requires proof (or disproof) by experimentation

[pmontra]

Technically speaking there can be "disproof" but there is never "proof".

We have theories and experiments.

An experiment giving a result not in accord with the theory is an immediate disproof.

An experiment giving a result in accord with the theory is a confirmation possibly waiting for another experiment resulting in a disproof.

Proof exist only in mathematics.

[rhn_mk1]

You can get knowledge (e.g. mathematical) without observation. You can't get information without observation.