3 ms·

"But that fall Heisenberg's worried father wrote to the famed Gottingen experimentalist James Franck, asking Franck to teach his boy some experimental physics.

"But that fall Heisenberg's worried father wrote to the famed Gottingen experimentalist James Franck, asking Franck to teach his boy some experimental physics. Franck did his best, but could not overcome Heisenberg's complete lack of interest and gave up the effort. If Heisenberg was going to survive at all in physics it would be purely as a theorist." I had not heard this part; and might shed some additional light onto why the German atomic project was significantly behind. When the lead of your project is a famous physicist, but who isn't strongly grounded in experiment, but who nevertheless feels like he can't simply be a manager and must have input, you're likely going to have problems. Maybe not though; be an interesting line of investigation though. Anyone know if this was a documented issue? I know that Heisenburg had seriously overestimated the amount of necessary fissile material needed for a bomb. http://blog.nuclearsecrecy.com/2013/09/13/what-did-the-nazis-know-about-the-manhattan-project/ http://blog.nuclearsecrecy.com/2013/09/13/what-did-the-nazis...

_ak 10y ago
One of the reasons why the German atomic project was so much behind because there was no concerted effort, but instead several competing organizations (Wehrmacht, SS, Post ministry, possibly others) that didn't have nearly enough fissible material in the first place.
gohrt 10y ago
Heisenberg's greatest contribution to humanity may be his (accidental or intentional) scuttling of the Nazi nuclear program.
mbreese 10y ago
I had heard that one of the issues was that the Germans preferred to do the fission calculations in the context of a plane rather than a sphere because the math was easier. I read that at one point, but I have absolutely no idea where it came from. Maybe that was why they overestimated the required amount of fissile material?
Bartweiss 10y ago
As I understand it, the overestimation was (at least partly) about a failure to understand how cascades worked. In particular, to develop a proper model of a 3D cascade in a sphere. The result was a consistent underestimation of how quickly fission would advance, implying the need for a larger reacting body than is actually required to sustain a chain reaction.

_ak 10y ago

One of the reasons why the German atomic project was so much behind because there was no concerted effort, but instead several competing organizations (Wehrmacht, SS, Post ministry, possibly others) that didn't have nearly enough fissible material in the first place.

gohrt 10y ago

Heisenberg's greatest contribution to humanity may be his (accidental or intentional) scuttling of the Nazi nuclear program.

mbreese 10y ago

I had heard that one of the issues was that the Germans preferred to do the fission calculations in the context of a plane rather than a sphere because the math was easier. I read that at one point, but I have absolutely no idea where it came from. Maybe that was why they overestimated the required amount of fissile material?

Bartweiss 10y ago

As I understand it, the overestimation was (at least partly) about a failure to understand how cascades worked. In particular, to develop a proper model of a 3D cascade in a sphere. The result was a consistent underestimation of how quickly fission would advance, implying the need for a larger reacting body than is actually required to sustain a chain reaction.