But it was the genius of Faraday’s law of induction, which demonstrated the experimental equivalence of two setups that seem so different on the surface, that first showed how unimportant the absolute motion of a system is in determining a physical outcome. Only relative motion within the system matters, not the point-of-view or frame-of-reference that you adopt. It was only a small step from Faraday’s remarkable work on induction in the 1830s to the Einsteinian revolution of 1905.