"Prove" is an extremely loaded word. Everything we think we know about anything is theoretical. Science = "evedence seems to support the hypothesis". Even Einstein may be wrong.
Einstein was especially probably wrong. Remember that Einstein didn't do much science. He did a lot of math and thinking, theorizing connections btwn existing scientific laws.
theory of relativity over time (dropping cosmo. constant, grav waves, etc.). He didn't one day think he figured it all out and write a formula/theory which is yet to be proven wrong.
Einstein was often wrong, even by his own admission. Such is the nature of working on such complex and ultimately abstract theories. For example, he changed numerous aspects of his...