Saturday, June 24, 2006

Werner Heisenberg's allied interrogation

Came across a fascinating anecdote recently about the allies interrogating Werner Heisenberg after WWII.

It seems that the reason Hitler shelved Germany's heavy water experiments, late in WWII was that the Nazi scientists leading his heavy water experiments did not know that a certain amount of fissionable material would cause a chain reaction and trigger an atomic explosion.

Since Hitler and his scientists thought that tons of uranium might be needed, they instead focused on the V-1 and V-2 projects instead. It turns out that about 20 pounds of uranium or 10 pounds of plutonium is needed (a lot to be sure, but not tons).

The way we learned this information was that as Heisenberg's interrogation began, he asked his interrogator a question (yes he was supposed to be answering them I know). He wanted to know what size ship had delivered the American atomic devices to Hiroshima and Nagasaki and specifically wanted to know if carriers had been the ships to deliver them (the largest ships in the American navy).

When Heisenberg was told that it was not a ship that delivered the device, but a B-29 bomber, he then (knowing the size of the bomb bay for a B-29 bomber) did the math in his head and arrived at the size of the bomb (keep in mind this was while being interrogated).

Anyway- I found this story neat so I pass it along to you.



Anonymous said...

Assuming you were pretty hip to military technology of the day, it wouldn't take a rocket scientist to figure out the maximum payload of a B-29. Of course, this was a rocket scientist. Still it is a cool story. This type of military genius is simultaneously facinating and horrifying. They focus so intently on the math that they don't even seem to be able to comprehend the human impact.

Chuck said...


I think that's one reason why the rumors that Heisenberg attempted to sabotage the Nazi bomb project on purpose are so prevalent.

People who admire him as a scientist have a hard time wrapping their minds around him helping Hitler (of all people) build an atomic bomb.

And of course then there's the problem that if Heisenberg really was dragging his feet, why did he never tell anyone, even after the war?

Anonymous said...

I knew a guy that worked in the US Military's nuclear program doing "something". While he never talked about details he did comment that many of the scientists in the programs required handlers to keep them from doing oddball things... like leaving live isotopes out on their desks...

I dunno about Heisenberg, but I think the only way a person could actively work on projects like this is if they completely detached themselves from the reality of what they were doing. So to be that intelligent and yet so disconnected--you've have to be one heckuva loop.

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