One hundred years ago, on September 27th, 1905, Albert Einstein's paper, Ist die Trägheit eines Körpers von seinem Energiegehalt abhängig? (Does the Inertia of a Body Depend upon its Energy-Content?), was received for publication by the editors of Annalen der Physik. This paper derived the equivalence of mass and energy in a purely logical fashion from the June 1905 special relativity paper On the Electrodynamics of Moving Bodies and introduced the concept which would become the most celebrated equation in science: E=mc² (which, however, did not appear in that form in Einstein's paper). Celebrate this anniversary by reading an English translation of this milestone in modern physics online at this site and, if you're visiting Switzerland, don't miss the special Einstein exhibition at the Historisches Museum Bern (June 2005 through April 2006).