It may be a weird thing to think about, but I’ve been wondering about uranium fission. Up until a couple days ago, I’ve always thought Einstein discovered what was needed for the atomic bomb. But I’ve heard that two other scientists discovered what was needed, and then Einstein wrote his letter to Roosevelt.
Who were these scientists?
What year was the discovery made?
And can anyone explain uranium fission in real layman’s terms for me? (They shoot the ____ atoms full of uranium atoms?)
Robert Oppenheimer is considered the father of the atomic bomb as much as anyone else. Einstein discovered the theoretical basis for E=MC[sup]2[/sup] but Bob took it further and made it work. The ultra short version is that big, heavy atoms are split by striking the nucleus with a neutron. This splits the atom into two lighter atoms, actually a different element, with a few bits left over. Some of those bits are neturons to split still more atoms and some is turned into energy, AKA cataclysmic, earth-shattering kaboom. That and heat and gamma rays.
There are several pairs of names you may have heard. The experiment that led to the discovery of fission was carried out by Otto Hahn and Fritz Strassmann in Germany, who published their results in January 1939. They’re usually described as the discoverers.
However, they weren’t sure what they’d seen and so it was Otto Frisch and Lise Meitner who shortly thereafter first suggested that this was what we now call fission.
Einstein’s letter is dated August 2nd 1939 and cites work by Enrico Fermi and Leo Szilard as his reason for writing. What Fermi and Szilard were doing in the summer of 1939 was important, but him using their names has more to do with what and how he’d happened to have learnt about fission.
Finally, and independently of the Einstein letter, arguably the first people to really realise “what was needed” were Rudolf Peierls and Frisch (by then in Birmingham in the UK), early in 1940. The memorandum they wrote for the British government probably had a greater effect on events than the more famous letter to Roosevelt.
At a guess, you’re thinking of Hahn and Strassmann.
Fermi was the guy who got the first atomic pile working on the racquetball court at the University of Chicago.