The story
After the formula of mass–energy equivalence, an important principle discovered by the German-born theoretical physicist Albert Einstein (1879–1955). The formula entered the popular consciousness after it was included in the opening pages of the Smyth Report (1945), a widely read document that explained the United States’ nuclear weapons program to the public for the first time. Its appearance alongside a portrait of the (already well known) Einstein on a Time magazine cover the following year consolidated its fame.
Etymology from Wiktionary, CC BY-SA 4.0.