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Oppenheimer Movie Review

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Sal Ammoniac:

--- Quote from: Stray Electron on July 28, 2023, 01:52:05 am ---Fritz Haber was a national hero in Germany between the world wars and Adolf Hitler personally offered to make an exception to the anti-Jewish laws for him but he turned down that offer and wanted to maintain his Jewish identity.
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He did convert to Christianity, so perhaps his Jewish identity really wasn't that important to him.

Sal Ammoniac:

--- Quote from: msuffidy on July 28, 2023, 07:50:21 am ---The movie sort of treated the bomb like oh it really worked.
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That was the plutonium implosion bomb. Implosion was required for the plutonium bomb because plutonium had too high a spontaneous fission rate to use the gun mechanism. A lot of theoretical work and engineering went into understanding implosion before a working bomb could be built.

The enriched uranium bomb, however, was considered to be such a sure thing that it wasn't even tested before it was used on Hiroshima.

If you look at the overall history of the Manhattan Project one thing stands out--the numerous unknowns forced the project leadership to hedge their bets by using multiple different techniques simultaneously. For example, plants to separate uranium using gaseous diffusion, thermal diffusion, and electromagnetic separation were all built on industrial scales. And an entirely separate infrastructure was built to produce plutonium and chemically separate it from the reaction byproducts.

David Hess:

--- Quote from: Sal Ammoniac on July 28, 2023, 06:12:32 pm ---That was the plutonium implosion bomb. Implosion was required for the plutonium bomb because plutonium had too high a spontaneous fission rate to use the gun mechanism. A lot of theoretical work and engineering went into understanding implosion before a working bomb could be built.
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The way I remember it from two difference sources is that pure Pu239 could have worked in a gun type design, but their plutonium had too much contaminating Pu240 leading to a high spontaneous fission rate.  The Pu240 is created from Pu239 absorbing a neutron during the production process so to avoid it, a lower concentration of Pu239 has to be accepted for chemical separation lowering throughput.  You can make a lot of Pu239 per batch and accept a higher concentration of Pu240, or make less Pu239 per batch and get a more favorable ratio.

Nuclear weapons intended for naval deployment, where they will be in unavoidable close proximity to personal, use a process that cycles the Pu239 out more often so less Pu240 is produced making the cores are less radioactive.

dietert1:
Wikipedia describes Szilards early ideas as speculation. The science happened 1938 between Otto Hahn, Fritz Straßmann, Lise Meitner and Otto Frisch. Szilard reproduced the results of the german groups in 1939 and later joined the Manhatten project. In the end he opposed using the bomb for military purposes.
When travelling to visit Einstein in the USA Niels Bohr talked about the induced fission results to his former scholar Wheeler and to others. The concept of a controlled nuclear chain reaction is attributed to Enrico Fermi and 1942 they had the first reactor setup in Chicago.

Regards, Dieter

Veteran68:

--- Quote from: fourfathom on July 27, 2023, 05:50:49 pm ---
--- Quote from: msuffidy on July 27, 2023, 04:13:57 am ---Well murdering your prof with cyanide is a pretty big personal error up there with random bombings. I am GUESSING that didn't really happen?
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According to "Modern Prometheus" Oppenheimer did indeed inject some type of poison into his professor's apple, or at least he claimed that he did.  The exact details vary, depending on who is relating the story.  The professor probably didn't eat the apple.  His father pulled strings so that Oppenheimer wasn't expelled or prosecuted, but one of the conditions was that he take psychiatric counseling.  He was definitely a troubled, brilliant, young man.

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