Another German WWII Question

Can someone tell me again why Germany wasn’t able to develop their own atomic bomb before the US did? I vaguely remember that it had something to do with them not being able to create enough fissionable material but I may have got that completely wrong. Is there a simple answer?

The germans made a considered decision not to pursue nuclear research early in the war. They figured it would be a short-term fight and that creating an atom bomb would take years. They were half right. As it is, they built a breeder reactor for enriching Uranium but could not yet get it running before the funding was cut. The uranium was buried to hide it but the US army got them to spill the beans and dug it up and shipped (most of) it home. The Brits got some of it.

Richard Rhodes wrote a great book about the development of the atomic bomb. He covers the efforts by the Axis powers as well as the Manhattan Project.

A few reasons:

  1. A lot of notible German physicists who could have otherwise worked on the project were Jewish or opponents of the Nazi regime and fled Germany (Einstein, Born, Schroediger, Franck, Mayer, etc

  2. The Nazis politicized science and science education, so that by the time World War II rolled around, German physics departments weren’t all that good, and promising students weren’t going into physics.

  3. Heisenberg, who was the head of the program, overestimated the amount of uranium needed for critical mass, and was lukewarm on the idea of an atomic bomb being practical.

  4. Partly because of Heisenberg’s doubts, the German government underfunded the program, choosing to give priority to other weapons programs

  5. The Germans were developing a plutonium bomb with heavy water as a moderator. Not only was this more difficult, their heavy water plant in Norway was sabotaged by British special forces working with the Norwegian resistance.

And, of course, the fifth reason Captain Amazing left out is that the Nazis thought Batshit Insanity would win the war and focused on utterly insane superweapons.

(I’m largely joking, but they did do some weird shit.)

Thomas Powers’
[url=]Heisenberg’s War: The Secret History Of The German Bomb
is a good complement to that and addresses the o.p. directly; while Powers takes a few speculative leaps across some unknowns, the basic premise of the book is sufficiently clear. *Captain Amazing pretty much summed up the essential points; particularly damning was the brain drain of scientists who went to England and worked on the “Tubealloys” program, later seconded to the Manhattan Project, which was unquestionably the single greatest collusion of scientific intellect to that date. Heisenberg was a smart guy, but aside from a small staff and an underfunded laboratory, he was basically alone, whereas the Manhattan project ended up with thousands of physicists and engineers at a couple dozen locations working through various competing concepts to discover a working design. The Italian and Japanese efforts were even smaller in comparison.


There was an unrecognized problem with boron impurities in the carbon that was to be used as a neutron moderator in their reactor.

If you get a chance to check out the play Copenhagen it does an interesting job delving into this exact question for 2 hours.

Check out the user comments in the imdb link above for a good synopsis of this very interesting play.

About the only reasonably clear conclusion that can be drawn from the often bitter historical debate on the question that’s run for over half a century now is that there isn’t one. What can be summarised in fairly concensual manner are the competing groups of explanations that have been proposed, the specific issues people cannot agree on and the myths that have been dismantled along the way. Though the latter often linger in popular understanding.
Several points are worth mentioning at the start. There wasn’t a single German nuclear programme, but instead multiple groups being run by different parts of the regime. And the major archival development in the last two decades was the release of the reports compiled from bugging the conversations of the key captured German scientists as they were interned at Farm Hall in Cambridgeshire at the end of the war. These reports, which cover their reactions as they learn about Hiroshima and realise that the Allies have succeeded where they failed, were finally released in the early 90s and have shaped the later stages of the long debate.

There have been three broad camps in the debate:

[ul]The incompetence argument. The physicist Sam Goudsmit was the main scientific member of the Alsos mission, the intelligence unit sent by the Manhattan Project into Europe in 1944-5 to investigate the German efforts. His book on the subject - Alsos (Henry Schuman, 1947) - argued in the immediate aftermath that they’d failed because of a number of specific physics mistakes. He went on to attribute these failures to a general malaise of science in a totalitarian state; without freedom of communication and debate, the self-correcting mechanisms of good science had broken down. This was also broadly the line taken by Leslie Groves in his memoirs, Now It Can Be Told (1962; Da Capo, 1983). None of the allegations made by Goudsmit or Groves of specific mistakes being crucial have really stood up to later research. But after the release of the Farm Hall reports various people argued that they were convincing evidence that none of the German internees initially understood how much enriched uranium would be needed for a critical mass. The most detailed such case is Paul Lawrence Rose’s Heisenberg and the Nazi Atomic Bomb Project (California, 1998).[/ul]
[ul]The reluctance argument. That most of the German physicists really didn’t want to provide Hitler with a nuclear bomb and so either actively or passively tried to obstruct the projects. One of the most interesting features of the Farm Hall transcripts is that one can see certain of the participants in the process of formulating this as a defence of their failure. But where it really went public is with the publication of Robert Jungk’s Brighter Than A Thousand Suns in 1956. While they wrapped everything in caveats and ambiguities, both Heisenberg and the late Carl von Weizsäcker in particular pushed versions of their actions being along these lines thereafter. With the publication of Mark Walker’s initial work in the 80s (see below), Jungk retracted his earlier position. Ironically, this was more or less the exact moment when Powers published Heisenberg’s War, which at its heart is just Jungk’s thesis resurrected. Personally, while Powers amasses a fabulous amount of fascinating and reliable surrounding material, I felt that all rather obscures how thin and secondhand his evidence for his key central claims is. Powers book is then the inspiration for Frayn’s play Copenhagen.[/ul]
[ul]The rational decision argument. Unfortunately largely initially developed by David Irving. But also later by Mark Walker, first in German National Socialism and the Quest for Nuclear Power, 1939-1949 (Cambridge, 1989) and then in his Nazi Science: Myth, Truth and the German Atomic Bomb (Perseus, 1995). This argument emphasises that the prospects for the German projects shift as the war progresses. Initially, the expectation is that the war will be over quickly. There’s then the point where the regime begins to cast around for wonder weapons as the alternate solution. It’s at this point that the nuclear projects are seriously considered and pushed into the limelight. But they can’t promise a quick fix, so are deprioritised. Research then rumbles on until the end, with the participants hopeful of getting a working reactor, but without anyone expecting it to change the outcome of the war. What the “rational decision” argument argues is that that mid-war decision was basically correct: Germany had neither the time nor the resources to successfully develop a nuclear weapon. David Cassidy’s Heisenberg biography Uncertainty (Freeman, 1991), which I personally think is the best book the debate has produced, falls broadly into this camp.[/ul]

There is a fourth camp, but I’ll pick them up at the end.

In recent years, one central point of disagreement is over the origins of Heisenberg’s lecture at Farm Hall. Everyone agrees that by August 14th 1945 he understood how to make a uranium bomb, since the bugging transcipt of the bravura lecture on the subject he gave to his fellow inmates on that date survives. In terms of the physics understanding, it’s roughly on a par with the lectures Robert Serber was giving to new arrivals at Los Alamos in the spring of 1943.
Powers has argued that this was too much for him to have invented in the week since they’d heard about Hiroshima. He had to have worked this all out during the course of the war, but kept it under wraps in order to prevent the Nazis realising that a bomb might be possible. Jeremy Bernstein has counterargued that this is essentially an argument from incredulity. It may be astonishing to the non-physicist Powers, but, while not denying that Heisenberg’s progress during the week is remarkable, Bernstein thinks that he could have figured out the contents of the lecture within that time. As another theoretical physicist, I agree.
The recent representatives of the other two camps also agree about that. Where they differ is in their interpretation of Heisenberg’s comments earlier in the week (where Powers thinks that he was still simply hiding what he already knew). Rose, in the “incompetence” camp, believes that he simply misunderstood the whole concept of a critical mass until this crucial week and so had previously believed that it involved tonnes, rather than kilogrammes, of enriched uranium. Walker, in the “rational decision” camp, emphasises his comment earlier in the week that he’d never bothered to calculate a critical mass. If the exact amount wasn’t going to have made that much of a difference to a decision that Germany couldn’t build a bomb during the war, why should he have? (My physicist’s hesitation over this argument is that surely he had some intuitive, even if wildly wrong, estimate in his head. Rose, of course, argues that he did - and that it was wildly wrong.)
So we have something close to actual transcripts of key conversations, compiled by people listening in on the participants without their knowledge, and everybody can still defend their personal interpretation using these transcripts. The evidence can sharpen the disagreements in the debate, but pretty much no conceivable evidence can resolve them.
Indeed that’s one of the themes of Frayn’s play about Bohr and Heisenberg in Copenhagen: not even the participants themselves can agree on what they meant. (And indeed even the location of their famous conversation cannot be agreed on. As Angua will painfully recall; I dragged her limping round all half-dozen suggested ones on a visit to the city a couple of years back.)

Rather than trying to comprehensively list the myths that have fallen by the wayside, I’ll illustratively comment on points raised in this thread:

[ul]Heisenberg wasn’t building a breeder reactor.[/ul]
[ul]The impact of Nazi Deutsche Physik on German physics can be argued about. Walker makes a detailed case in Nazi Science that the inroads it made in practice were pretty limited - indeed the SS eventually wound up supporting Heisenberg and it was Stark who was the one who eventually wound up in a concentration camp. Note that this is excluding the obvious damage done by firing all the Jewish professors, but that wasn’t specifically directed at physics.[/ul]
[ul]The issue of the boron impurities was central to Goudsmit’s case. But the decision to concentrate on heavy water as a reactor moderator wasn’t obviously fatal. The equivalent decision wasn’t a no-brainer on the Allied side and indeed heavy water reactors were up and running in Canada by the time of the German surrender. Even if the Germans picked the wrong race to compete in, they lost that just as decisively.[/ul]
[ul]The heroic actions to disable the Vermork plant in Norway probably had little decisive impact on the fate of the German projects. One of those bits of the story that still looms large in public perception for various reasons, but which distorts the larger picture.[/ul]
[ul]How much the different German projects understood about plutonium is a matter of debate. Pace Goudsmit, they realised that a reactor would produce it and that it could be chemically separated - and that it was fissionable and hence possibly a route to a bomb. But it’s far from obvious that they were thinking in terms of a plutonium bomb in preference to a uranium one.[/ul]

And, as an aside, I’ll at least provocatively query in passing Stranger’s characterisation of the Manhattan Project as “unquestionably the single greatest collusion of scientific intellect to that date” (emphasis added): radar wasn’t developed by some shabby assembly of talents. (And Rabi was probably right when he assessed that that was how physicists would win the war.)

The one camp I’ve ignored in the above are those writers who claim that Alsos’s original assessment in 1945 of how far the Germans had got was wrong. In some cases claiming that they did explode test nuclear weapons in the closing days of the war. With only one possible exception, this part of the literature on the subject is basically complete rubbish. And quickly fades into taking UFOs, Velikovsky and the like seriously.
However, Rainer Karlsch created a fuss along these lines when he published his Hitler’s Bombe in German in 2005. Mark Walker, in particular, hailed Karlsch as having uncovered much new stuff. Rumours of an English translation of the book have floated about, but none has materialised to date. However, I discovered just last month, browsing in a bookshop in Bordeaux, that there’s a French translation La Bombe de Hitler (Calman-Levy, 2007). While I approach it sceptically, a copy is now in my to-read pile.

One thing a lot of people underestimate is how much effort it took to develop a working atomic weapon. The basic science was understood by everyone but it was a massive engineering project. The United States was the only country that could afford to divert the thousands of scientists, engineers, technicians, and support staff along with a couple of billion dollars (in 1940s money) in the middle of fighting a war.

According to wikipedia Schroedinger wasn’t Jewish.

(emphasis mine)
I think you missed that part. :slight_smile:

Can you expand on this? Firstly, you say Powers argues that he kept what he knew under wraps to prevent the Nazis realising that a bomb might be possible. I understood it to be common ground that the Nazis were actively pursuing a bomb. Surely it is inherent in that that they thought a bomb might be possible?

Secondly, if you accept that Heisenberg progressed remarkably during the week, how so? What did he learn, other than that bombs were dropped?

I’m sure I don’t have the capacity to understand all of it but are there any excerpts of those transcripts of Heisenberg’s lecture around on the internet to take a peek at?

Just to give everyone an idea of the scale of the Manhattan Project, the K-25 building at Oak Ridge was over 2,000,000 square feet.

The Y-12 plant “borrowed” 15,000 tons of silver from the US Government vaults due to a shortage of copper.

I can’t find a cite, but I saw a documentary on the Hitler Channel a few years ago that said that Oak Ridge consumed around 15% of all the electricity generated in the United States.

Imagine trying to build that in wartime Germany.

There’s a book out that isn’t crazy but discusses the idea as a “doubful but possible” - its all about crazy WWII weapons, like the Iceberg Aircraft carrier
“My Tank Is Fight!”. Anyway, it does discuss a possible “dirty bomb” and a sub-fission device. In any case, Diebner’s team of Nazis did *something *“atomic” in Ohrdruf, Thuringia in the last days of WWII. I have doubts it was a real and practical weapon. :dubious:

Then what was the “reactor” found by the Alsos folks? The one near where they found all the buried uranium, that is.

Two main things:

  1. Prof. Werner Heisenburg made a huge error-his idea for a bomb would have been huge and impossible-maybe the germans would have shipped it by rail?
  2. The germans never mastered uranium enrichment-their “enriched” uranium contained “poisons” (neutron absorbing substances0 that would have prevented a chain reaction.
    Had the german reactor ever gone critical, it would have killed everybody working around it, and likely have produced a gigantic steam explosion.
    Prof. Heisenburg didn’t think of that!

Also, I believe that the one time that Germany did manage to ship a barrel of Norwegian heavy water into the country the effort was sabotaged by the brilliant operation of a Col. Hogan and his team.

Annnnd that wraps up our thread! Thanks for the (mostly) insightful responses…