Ernst Mach
Ernst Mach (Born::February 18, 1838 – Died::February 19, 1916) is the famous physicist known to argue that the only way to explain the phenomenon of inertia was to assume that all of the masses in the universe were somehow connected. Albert Einstein later identified this argument as Mach’s Principle, which is said to have played a major role in Einstein's theory of general relativity.
Mach’s Principle assumes that “a particle’s inertia is due to some (unfortunately unspecified) interaction of that particle with all the other masses in the universe; the local standards of non-acceleration are determined by some average of the motions of all the masses in the universe, [and] all that matters in mechanics is the relative motion of all the masses.”
In other words: the inertia of a body is determined in relation to all other bodies in the universe ("matter there governs inertia here") It can be viewed as an entire universe being altered by changes in a single particle.
