The European exiles who gave birth to the bomb

Eighty-five years ago Friday, two world-famous scientists who had fled Nazi Europe, Albert Einstein and Leo Szilárd, composed a letter to President Franklin D. Roosevelt, urging him to not let Germany get the upper hand in developing an atomic bomb

The letter led to the creation of the Manhattan Project.

February 1939

An article is published in the journal Nature detailing experiments by German scientists Fritz Strassmann and Otto Hahn that resulted in the splitting of uranium nuclei.

Physicist Leo Szilárd — a refugee from Nazi-controlled Hungary teaching at New York’s Columbia University — recognizes the significance of the accomplishment: In 1933, Szilárd and Enrico Fermi had patented the idea for a neutron-driven fission reactor. However, Szilárd had been unable to achieve such a reaction.

Szilárd and his Hungarian-born colleagues, Eugene Wigner and Edward Teller, realize uranium could sustain a reaction of the type needed for an atomic power generator — or for a powerful explosive. More importantly, a German annexation of Belgium could give Nazis access to the world’s largest supply of uranium in the Belgian colony of Congo.

The three decide that officials in Belgium should be warned about the repercussions should the Nazis pursue uranium deposits and build an atomic bomb.

Their colleague, Albert Einstein of Princeton, is a friend of Queen Elizabeth of Belgium. They decide to get Einstein — the most famous scientist in the world — to pass along the warning.

July 16, 1939

Szilárd and Wigner drive to Long Island, where Einstein is vacationing. They make their case to him. Grasping the significance of an explosive chain reaction, Einstein gasps: “I never thought of that!”

Einstein suggests they contact a Belgian government official with whom he’s acquainted. Wigner points out that European refugees probably shouldn’t be discussing matters of national security with foreign nationals without going through the State Department. They draft a letter to be sent to the Belgians with copies to U.S. officials.

A few days later, Szilárd is introduced to Alexander Sachs, an economist at Lehman Brothers and a friend of President Franklin D. Roosevelt. When asked for advice, Sachs says the letter should go directly to the president.

The group decides to rewrite the letter.

Einstein and Szilard compose their letter.

Aug. 2

Wigner is away, so this time, Teller accompanies Szilárd to meet with Einstein on Long Island. Einstein dictates a letter in German, which Szilárd translates into English. They prepare a long version and a short version. Szilárd takes the manuscript back to New York to be typed up.

Aug. 9

Einstein signs both letters and mails them back to Szilárd.

Aug. 15

Szilárd gives the letter to Sachs, adding a memo of his own with more details on the possibilities and dangers of fission. Sachs promises to meet with Roosevelt as soon as possible.

Sept. 1

Germany invades Poland. Two days later, France and Great Britain declare war on Germany. What would become World War II has begun.

Oct. 2

Szilárd informs Einstein that Sachs still has not met with Roosevelt, “possibly due to him being so overburdened.” Szilárd, Wigner and Teller begin to talk about moving on to “Plan B,” but it’s not clear just what “Plan B” consists of.

Oct. 11

Sachs finally makes good on his promise to visit the Oval Office. He presents Roosevelt with Einstein’s letter, a memo from Szilárd and an 800-word summary he has written on his own.

Sachs explains the situation to Roosevelt, who sums up the matter by saying, “Alex, what you are after is to see the Nazis don’t blow us up.”

“Precisely,” Sachs replies.

Roosevelt turns to his senior military aide, Gen. Edwin M. “Pa” Watson, and orders: “Pa! This requires action.”

Oct. 19

Roosevelt sends a thank you letter to Einstein, telling him he was appointing a committee to include Szilárd, Wigner and Teller.

Oct. 21

The President’s Advisory Committee on Uranium holds its first meeting.

July 1940

J. Edgar Hoover’s FBI declines to give Einstein a security clearance to work on the upcoming atomic bomb project. His left-leaning politics and his pacifism make him a security risk, they say.

Oct. 9, 1941

Roosevelt approves a plan to build an atomic bomb. This effort comes to be called the Manhattan Project.

April 12, 1945

Roosevelt dies of a brain hemorrhage while visiting his spa in Warm Springs, Georgia. Harry Truman — who had been vice president for just 82 days — is sworn in as president.

A military aide pulls him aside and informs him of a new, highly destructive weapon that was nearing completion. It’s not until April 25 that Secretary of War Henry Stimson fills Truman in on the details about the bomb.

July 16, 1945

The first atomic bomb — “Trinity” — is successfully tested in the New Mexico desert. Shortly afterward, Truman gives the OK to use atomic bombs on Japan

Aug. 6 and 9, 1945

Atomic bombs are dropped on Hiroshima and Nagasaki, Japan, prompting Japan to surrender on Aug. 14.

Einstein's Regrets

A reporter breaks the news about the bombing of Japan to Einstein as he returns from a sailing vacation on Saranac Lake in northern New York.

Einstein is startled. “Ach!” he replies. “The world is not ready for it!”

Later, Einstein expresses regret for his role in the development of the bomb.

“Had I known that the Germans would not succeed in developing an atomic bomb, I would have done nothing for the bomb,” he wrote.

Both he and Szilárd would become outspoken opponents of using the bomb. “The unleashed power of the atom has changed everything save our modes of thinking,” Einstein wrote, “and we thus drift toward unparalleled catastrophe.”

Shortly before his death, he described his letter to Roosevelt as the “one great mistake in my life.”