Nothing is ever 100% proven by science or anything else. I can't prove I'm not a brain in a vat, nor can you. It could be the case that a demon keeps us in our vats and feeds us fake experiences to make us believe we are interacting with a "real" world that doesn't exist. There is no solution to the problem of hard solipsism. One of the unproven axioms we must adopt to live a meaningful life is that other people, the ground we walk on, etcetera, do exist. Neither of us will likely deliberately step off the ledge into the Grand Canyon to prove that gravity is an illusion.

Science doesn't set out to prove things. It seeks to find the best available explanation for how a phenomenon works and keeps looking for ways to improve that explanation. Theory colloquially means a hunch or guess, but that would be a hypothesis in scientific terminology. In science, a theory is the term applied to our best available explanation after it becomes the consensus of the relevant scientific community. Science is far from perfect, but it is the best path to knowledge currently known to humanity,