ON THIS DAY: December 28, 1934, Albert Einstein lectured at Carnegie Tech

PITTSBURGH, Pa. — Dr. Albert Einstein delivered his first major speech in the United States at Carnegie Institute of Technology (now known as Carnegie Mellon University) on Dec. 28, 1934. The world-renowned physicist’s lecture was the highlight of the four-day American Association for the Advancement of Science conference.

Einstein’s lecture on atomic theory and special relativity was held in the Kresge Theatre (known as the “Little Theaters” at that time), and was part of the Josiah Willard Gibbs Lectures for the American Mathematical Society.

The lecture, titled “An Elementary Proof of the Theorem Concerning the Equivalence of Mass and Energy,” attracted over a thousand people to the theater, which was only designed to hold 400. When the curtain rose on a grinning Einstein with his wild graying hair, the audience chuckled and applauded.

Einstein walked the audience through his theory – the first time he spoke English at a lecture – explaining how he had simplified the complicated theory down to a now-famous equation: E = mc². As he derived his theory on two small and badly-lit portable blackboards, the only known photograph of him with a variant of his famous equation was taken.

Albert Einstein 1933: German-Swiss-American mathematical physicist Albert Einstein (1879 - 1955). (Photo by Keystone/Getty Images) (Keystone/Getty Images)

Albert Einstein circa 1910: Albert Einstein (1879 - 1955), the German-Swiss-American mathematical atomic physicist and Nobel prizewinner, seen early in his career in a thoughtful pose. (Photo by Hulton Archive/Getty Images) (Hulton Archive/Getty Images)

Albert Einstein Harris & Ewing, photographer. Albert Einstein, Washington, D.C. United States Washington D.C. District of Columbia Washington D.C, None. [Between 1921 and 1923] Photograph. https://www.loc.gov/item/2016885961/. (Library of Congress)

Einstein And Wife circa 1921: German-Swiss-American mathematical physicist Professor Albert Einstein (1879 - 1955) with his wife Elsa in Egypt. (Photo by Topical Press Agency/Getty Images) (Topical Press Agency/Getty Images)

Albert Einstein circa 1930: Albert Einstein (1879 - 1955) American physicist and mathematical genius, born in Germany. (Photo by Keystone/Getty Images) (Keystone/Getty Images)

Einstein Prof. Albert Einstein uses the blackboard as he delivers the 11th Josiah Willard Gibbs lecture at the meeting of the American Association for the Advancement of Science in the auditorium of the Carnegie Institue of Technology Little Theater at Pittsburgh, Pa., on Dec. 28, 1934. Using three symbols, for matter, energy and the speed of light respectively, Einstein offers additional proof of a theorem propounded by him in 1905 that matter and energy are the same thing in different forms. (AP Photo) (ASSOCIATED PRESS)

Albert Einstein visits Pittsburgh Dr. Albert Einstein discusses Atomic Theory at the 1934 American Association for the Advancement of Science (AAAS) meeting which was held at the University of Pittsburgh between December 27 and January 2, 1935. Reporters can be seen taking notes in the background. This meeting marked Einstein's first appearance at a U.S. scientific association. (Archives & Special Collections, University of Pittsburgh Library System)

Albert Einstein circa 1939: Albert Einstein (1879 - 1955), the German physicist who formulated the theory of relativity. (Photo by Topical Press Agency/Getty Images) (Topical Press Agency/Getty Images)

Albert Einstein Aumuller, Al, photographer. America gains a famous citizen / photo by Al. Aumuller. United States, 1940. Oct. 1. Photograph. https://www.loc.gov/item/2004672481/. (Library of Congress)

Albert Einstein circa 1941: A near-profile of Albert Einstein (1879 - 1955) the German-Swiss-American mathematical atomic physicist and Nobel prizewinner, looking pensive. (Photo by Hulton Archive/Getty Images) (Hulton Archive/Getty Images)

Einstein And Compton circa 1940: German-born American physicist Albert Einstein (left) with American physicist Arthur Compton at the University of Chicago. (Photo by Keystone/Getty Images) (Keystone/Getty Images)

Einstein Lecture circa 1955: Mathematical physicist Albert Einstein (1879 - 1955) delivers one of his recorded lectures. (Photo by Keystone/Getty Images) (Keystone/Getty Images)

Einstein Lecture German-born American physicist Albert Einstein (1879 - 1955) speaking during his Science And Civilization lecture at the Royal Albert Hall, London. (Photo by Keystone/Getty Images) (Keystone/Getty Images)

Albert Einstein

Albert Einstein (1879-1955) Albert Einstein is so smart his last name is synonymous with genius. The German-born theoretical physicist, who was visiting the United States when Hitler came to power and decided to stay, developed the general theory of relativity, one of the two pillars of modern physics. His general theory implied the existence of black holes. His special theory of relativity postulates there's no constant point of reference against which to measure motion and nothing with mass can exceed the speed of light. His mass–energy equivalence formula (Energy equals Mass times the Speed of Light squared) describes the huge amounts of energy released during nuclear reactions. (SCIENCE SOURCE)

Einstein At Home 1950: Albert Einstein (1879 - 1955), German-Swiss-American mathematical atomic physicist and Nobel prizewinner, at home in Princeton. (Photo by Doreen Spooner/Keystone Features/Getty Images) (Doreen Spooner/Getty Images)

Albert Einstein FILE - In this Dec. 28, 1934 file photo, Albert Einstein uses a blackboard as he speaks at a meeting of the American Association for the Advancement of Science in Pittsburgh, Pa. In 1915, then a little known scientist, Einstein proposed his general theory of relativity, a milestone in physics that says what we perceive as the force of gravity is actually from the curvature of space and time. He couldn’t prove it, but did say there were three ways to prove it and one was to show how distant star light bends during an eclipse. In 1919, Arthur Eddington observed the right amount of bending, something they couldn’t do without the moon’s shadow eclipsing the sun. (AP Photo) (AP)

According to newspaper accounts of the hour long lecture, Einstein’s English was quite good, but he did have to solicit help from the audience at points to find the right words. He was relaxed and soft-spoken, smiling frequently under his twitching mustache, but the mathematical hieroglyphics on the chalkboards were indiscernible to all but those in the front rows.

At press conference held in an Oakland home, Einstein entertained questions from the comfort of a deep armchair by the fireplace. A reporter asked whether his equation could be used to make energy, and Einstein, reflecting the common belief at that time, stated that he did not believe that power could be unlocked. “I am not a prophet in anything. Not in science either,” said Einstein. “But I feel absolutely sure – well, nearly sure – that it will not be possible to convert matter into energy for practical purposes.”

Fission of the uranium nucleus was discovered four years later in Berlin, Germany, which in turn instigated a rush to weaponize the discovery, ultimately achieved by the U.S. Army Corps of Engineers’ Manhattan Project in 1945.