Seventy-five years ago the last act of World War II began innocently enough with the arrival in Sweden at Christmas time of a scientific paper with the cumbersome title, “On the detection and characteristics of the alkali earth materials formed by the irradiation of uranium with neutrons.” It was about to be published by Germany’s premier scientific journal, Naturwissenschaften. Its authors were Otto Hahn and Friedrich Strassmann; the recipient was their Jewish-born former collaborator Lise Meitner, a refugee from Hitler. Unbeknownst to the authors, it would ultimately end the war, and end the world as they knew it.
When Hahn and Strassmann bombarded uranium the element barium mysteriously appeared.
Neither Hahn nor Strassmann knew what their results meant. It would take Meitner and her nephew Otto Frisch, a Jewish refugee working in Copenhagen with Niels Bohr, a few hours of work while at a ski resort to explain the mystery. Unbelievably, Meitner realized, the uranium nucleus split into two roughly equal chunks, one of which was likely to be barium. The reaction was accompanied by an enormous release of energy. Frisch and Meitner called it “fission.”
Hahn’s paper was published Jan. 6, 1939. Meitner and Frisch’s explanation was sent to the printer on Jan. 16, 1939.
The news crossed the Atlantic with Bohr who planned to attend a meeting in Washington where the report was quickly confirmed. It did not escape attention that if so much energy could be released with nuclear speeds in a chain reaction, a bomb of unprecedented destructiveness could be built.
Enrico Fermi, an Italian refugee who had won the Nobel Prize just the previous December, tried to attract government attention during a meeting with Admiral Stanford Hooper, the father of electronics in the U.S. Navy. However, the Italian apparently gave a boring and overly technical lecture, and was dismissed with an ethnic slur.
In a further effort to warn the government, several refugee physicists persuaded renown physicist Albert Einstein to write to President Franklin D. Roosevelt.
“This new phenomenon would also lead to the construction of bombs,” Einstein warned. “A single bomb of this type, carried by boat and exploded in a port, might very well destroy the whole port together with some of the surrounding territory.”
The letter reached Roosevelt’s desk after a twisting path, delivered in person by a Roosevelt confidant. Roosevelt grasped the idea, and ordered action. Nine days later Dr. Lyman Briggs, director of the National Bureau of Standards, convened the “Advisory Committee on Uranium.”
The Briggs Committee took barely a week to deliver a report to FDR, suggesting paper studies for a nuclear powered submarine — just a little short of “do nothing.”
Scientists in Europe were able to take more-active steps. Frisch left Copenhagen for Birmingham University in England, where he was joined by another refugee, Rudolf Peierls. In 1939, Peierls made the first tentative computation of the amount of material needed for a bomb: many tons, which made developing a weapon improbable. There was no way to transport it by air; sending it to the enemy by rail or road was good for a laugh and sea delivery too slow.
But in early 1940 Frisch took a second look at an isotope of Uranium, known as Uranium-235. The result was astonishing: Only a pound or two of U-235 would produce an explosion with a fireball as hot as the sun and the power of thousands of tons of TNT. Separating enough U-235 suddenly looked plausible; Frisch and Peierls were already working on a technique that might produce results in weeks or months.
Given what two young men working without funding could calculate in a week or two, surely an industrial nation such as Nazi Germany could implement in metal in time to affect the war. Unknown to the public and to the governments concerned, a five-way race had begun: The United States, the United Kingdom, the Soviet Union, Germany and Japan had all joined a race to build an atomic bomb.
[READ: Hiroshima, Nagasaki and How the H-Bomb Split the Manhattan Project Team]
The United States lagged behind. Lyman Briggs, a miserly bureaucrat, feared wasting the taxpayers’ money on a boondoggle. Nonetheless, progress was made: an initial federal allocation went to Enrico Fermi’s laboratory at Columbia University to buy pure graphite for an experiment. The United States bought into the atomic age for $6,000, probably the best bargain since the Louisiana Purchase.
More was to come for what would later be called the Manhattan Project — as yet without name, director or budget other than the $6,000 already spent. The critical meeting took place over lunch between Vannevar Bush, Arthur Compton and James B. Conant, the leaders of American physics, at Washington’s Cosmos Club where they decided to tell Roosevelt to proceed. Management of the work was provisionally assigned to the Office of Scientific Research and Development.
That same day — Dec. 6, 1941 — scientists at the University of California–Berkeley separated the first visible sample of U-235.
Early the next morning, Japanese Admiral Chuichi Nagumo led his aircraft carriers on an attack of Pearl Harbor, disabling the United States’ Pacific fleet and leading the U.S. to enter World War II. Less than four years later, the U.S. would drop an atomic bomb on Nagumo’s home base, Hiroshima, Japan, ending World War II.
The decision to build a nuclear weapon was likely the most significant taken by an American president in the 20th century. The consequences are embodied in our enduring strategy that nuclear weapons should never be used again, that they are only for deterring other nations, and that if they are once again used, the United States should not be the first. This is a lesson that every incoming president must learn.
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Discovering Nuclear Fission and the Means to End War originally appeared on usnews.com
