James Franck

James Franck

James Franck was born in Hamburg, Germany, on 26th August, 1882. He studied at the University of Heildelberg before obtaining his doctorate from the University of Berlin in 1906.

Franck stayed in Berlin and with Gustav Hertz carried out experiments where they bombarded mercury atoms with electrons and traced the energy changes that resulted from the collisions. Their experiments helped to substantiate they theory put forward by Nils Bohr that an atom can absorb internal energy only in precise and definite amounts.

During the First World War Franck served in the German Army and after the war he became professor of experimental physics at Gottingen.

A strong opponent of Adolf Hitler Franck left Nazi Germany in 1933. He emigrated to the United States where he became professor of the University of Chicago in 1938.

In 1943 Franck joined the Manhattan Project at Los Alamos. Over the next few years he worked with Robert Oppenheimer, Edward Teller, Enrico Fermi, Rudolf Peierls, Felix Bloch, David Bohm, Otto Frisch, James Chadwick, Emilio Segre, Eugene Wigner, Leo Szilard and Klaus Fuchs in developing the atom bombs.

By the time the atom bomb was ready to be used Germany had surrendered. Franck and Leo Szilard circulated a petition among the scientists opposing the use of the bomb on moral grounds. However, the advice was ignored by Harry S. Truman, the USA's new president, and it was dropped on Hiroshima and Nagasaki.

After the Second World War Franck researched in the area of photosynthesis. James Franck died in Gottingen, West Germany on 21st May, 1964.

© , September 1997 - April 2014

Primary Sources

(1) James Franck was against dropping the atom bomb on Japan. He sent his views to President Harry S. Truman on 11th June, 1945.

The military advantages and the saving of American lives achieved by the sudden use of atomic bombs against Japan may be outweighed by the ensuing loss of confidence and by a wave of horror and repulsion sweeping over the rest of the world and perhaps even dividing public opinion at home.

From this point of view, a demonstration of the new weapon might best be made, before the yes of representatives of all the United Nations, on the desert or a barren island. The best possible atmosphere for the achievement of an international agreement could be achieved if America could say to the world, "You see what sort of a weapon we had but did not use. We are ready to renounce its use in the future if other nations join us-in this renunciation and agree to the establishment of an efficient international control.

(2) Philip Morrison, a scientist, worked on the Manhattan Project at Alamogordo, New Mexico. Studs Terkel interviewed Morrison about his experiences during the Second World War for his book, The Good War (1985)

James Franck, a truly wonderful man, produced the Franck Report: Don't drop the bomb on a city. Drop it as a demonstration and offer a warning. This was about a month before Hiroshima. The movement against the bomb was beginning among the physicists, but with little hope. It was strong at Chicago, but it didn't affect Los Alamos.

We heard the news of Hiroshima from the airplane itself, a coded message. When they returned, we didn't see them. The generals had them. But then the people came back with photographs. I remember looking at them with awe and terror. We knew a terrible thing had been unleashed. The men had a great party that night to celebrate, but we didn't go. Almost no physicists went to it. We obviously killed a hundred thousand people and that was nothing to have a party about. The reality confronts you with things you could never anticipate.

Before I went to Wendover, an English physicist. Bill Penney, held a seminar five days after the test at Los Alamos. He applied his calculations. He predicted that this would reduce a city of three or four hundred thousand people to nothing but a sink for disaster relief, bandages, and hospitals. He made it absolutely clear in numbers. It was reality. We knew it, but we didn't see it. As soon as the bombs were dropped, the scientists, with few exceptions, felt the time had come to end all wars.