The First War Of Physics

The Secret History of the Atomic Bomb, 1939-1949

Jim Baggott, Central 355.82511909 B1448f 2010

I read books like this, trying to imagine what the protagonists could have done differently, for a better result.

The atomic bomb was not inevitable. The "hinge of fate" was Werner Heisenberg; had he been less patriotic and honest with Neils Bohr when they met in Copenhagen in 1941, the western allies might have been convinced that Germany wasn't building a nuclear bomb, and they might have forgone the Manhattan Project and devoted more resources to conventional firebombing.

The B-29s that dropped the atomic bombs on Hiroshima and Nagasaki cost twice as much to develop ( $3.4B ) as the Manhattan Project $and the first 4 atomic bombs ($1.8B), and the fleet of 3970 B-29 bombers that did far more destruction cost another $2.5B. The Hiroshima and Nagasaki bombs killed between 130,000 and 220,000 soldiers and civilians. The "conventional" fire bombings killed 240,000 to 900,000 Japanese civilians and soldiers at the cost of 600 aircraft. While the atomic bombs did a fraction of the destruction, the threat of more bombings helped convince Hirohito to surrender.

Since World War 2, atomic bombs have been brandished but not used. Had they been used, I would not be writing this, and they may be used before anyone else reads this.

• p6-11 December 1938 Otto Hahn bombards uranium with neutrons, observes barium, with Lise Meitner decides the nuclei are splitting. Frisch names the process fission. Frisch's Danish colleague Christian Moller suggests that chain reactions are possible - reactors and bombs.
• p15 at Princeton in 1939, Bohr and Wheeler figure out that U-235 is usable for a bomb, and that isotope separation required nation-scale resources.
• p19 Einstein letter to Roosevelt dated 2 August 1939, delivered in October
• p20 Heisenberg drafted into Uranverein 25 September.
• p46 Fermi specifies graphite without boron from National Carbon Company

• p50 element 93 decays in 2.3 days ... to plutonium, McMillan and Abelson paper Physical Review published 15 June, Weizacker read in Berlin in July 1940

• .. and so on
• p68 telegram from Bohr via Meitner in Stockholm to family friend British physicist Owen Richardson:
  • MET NIELS AND MARGRETHE RECENTLY BOTH WELL BUT UNHAPPY ABOUT EVENTS PLEASE INFORM COCKCROFT AND MAUD RAY KENT
  • Cockcroft interpreted "MAUD RAY KENT" as an anagram for "radyum taken", and "M.A.U.D." became the name of the British fission advisory committee. Maud Ray was Bohr's former housekeeper, now living in Kent.

The book drags through the German attempt to build a plutonium-producing reactor without control rods. They seem to have been incompetent experimentalists. Weisacker's Lesart (German for "version") is the German physicists didn't succeed on principle.

The rest of the book describes the eventual exclusion of the British from the US effort, and the Soviet espionage that told them what worked. Beria headed the Soviet effort, which built a Fatman-style plutonium implosion bomb. Kapitza wanted a more independent effort and resigned from the project.

Yakov Zeldovich studied a half-sized twice-as-powerful plutonium implosion device, then a fusion weapon; Andre Sakharov designed it.

• P450, first Soviet test August 29 700am, 50 km northwest of Semipalatinsk in Kazakhstan, dubbed "Joe-1" by US.

The book is interesting, but a bit of a slog. If the index was better, it would be a handy reference, but many terms are missing.