The author of this essay argues that between 1905 and 1925, Albert Einstein "transformed humankind's understanding of nature on every scale, from the smallest to that of the cosmos as a whole." Who could argue with this? Historians have taken to calling 1905 alone, the first year in this span of remarkable productivity, the "annus mirabilis". That's Latin for the miracle year. This was when Einstein published his Special Theory of Relativity, demonstrating that space and time are not absolute as Isaac Newton had said centuries before. Though employed full-time as a patent clerk, Einstein also proposed the idea that light exists not as waves, but as tiny energy packets called photons, and that these photons are capable of traveling in either particle or wave form. Within the same theory that linked space and time, he established that energy and matter are linked, which led to perhaps the most famous equation of all: E=mc².