Hypothetically, science proves free will isn't real

[Edwardo Piet]

Very well explained.

And again:

Determinism is the philosophical doctrine that all events transpire in virtue of some necessity and are therefore inevitable. Traditionally, the view relies on strict notions of causality, and most philosophical arguments in its favor have attempted at clear definitions of cause and effect as a basis for the belief that determinism is true. Notably, the idea that the past choices of seemingly rational agents could have been performed differently - or even the idea that the future decisions of such agents will turn out to be other than what they will - is usually challenged under this view. Thus, the "problem" of free will - or the idea of free will as being an "illusion" - often arises as a result of the main claim made by determinism, that is, that the past, present, and future is identifiable with an essentially unbreakable chain of circumstances of which no single link in such a chain could possibly be avoided or altered. Some determinists deny the idea of any true "possibility" or "randomness" within reality altogether, even asserting that such ideas are only a creation of the mind and/or merely the result of imagination - ultimately a result of ignorance in the face of real explanations for such phenomena - which could otherwise, in principle, be discovered by either reason or empirical experimentation.

(my bolding)