Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror
×
News

Regarding the WWII Meeting of Bohr & Heisenberg 318

HarlanC writes: "The NY Times has an article (registration required) discussing the famous meeting between Niels Bohr and Werner Heisenberg in Copenhagen in 1941. The conclusion is that Heisenberg revealed to Bohr the existance of a Nazi atomic program in an attempt to obtain assistance from Bohr. The Times of London article is here (long registration process required)" The play "Copenhagen" was based on a fictionalization of this meeting, it was much better than "Proof", I assure you.
This discussion has been archived. No new comments can be posted.

Regarding the WWII Meeting of Bohr & Heisenberg

Comments Filter:
  • by Beryllium Sphere(tm) ( 193358 ) on Wednesday January 09, 2002 @05:03PM (#2812102) Journal
    "Alsos", by Samuel Goudsmit, (ISBN: 1563964155) describes the top-secret team that followed Allied forces into Europe to find out how close the Germans were to having nuclear weapons.
  • Additional reading (Score:3, Interesting)

    by OneStepFromElysium ( 549625 ) on Wednesday January 09, 2002 @05:04PM (#2812104) Homepage

    I strongly recommend the book Heisenberg's War [amazon.com] by Thomas Powers. It provides a much deeper background into this meeting (and the entire German nuclear arms program) and is quite readable. Here's a bn.com link [barnesandnoble.com] to the book if you want to avoid amazon.

    • by HarlanC ( 472074 )
      In fact, the thrust of the articles is that Powers was too sympathetic to Heisenberg, and that in fact he would have developed the Bomb had he been able.
      • by ptrourke ( 529610 )
        If you read the (can't remember where, but they are published) transcripts from Heisenberg's conversations with his fellow German physicists in Allied custody at the end of the war, it's impossible to believe that H was trying to build the bomb. Clearly H knew a lot more about how to build a bomb than he let on to his Nazi masters.
    • I second that recommendation.

      Heisenberg's War even suggests that Heisenberg worked on an atomic powered vehicle rather than a bomb for moral reasons. People tried to convince him and his family to stay in the United States as the Nazi's were becoming stronger, but he refused. His reluctance to focus nuclear energy on a bomb may have saved the world as we know it.

      • by speculums ( 317287 ) on Wednesday January 09, 2002 @05:54PM (#2812465)
        The atom bomb developed during WWII and deployed against the Japanese was not, compared to conventional air weaponry, and effective weapon. The US had to preserve certain Japanese cities from regular bombing attacks so that there would be something left to bomb when the A bombs were ready.

        On the other side of the war (lets use the two-sided model here) there was the Rocket. It, much like its spiritual predecessor the Paris Gun, was also an inneffective use of resources. More people were killed constructing the Rockets than were killed by them in combat. Development of the Rocket took away from Germany's air power and perhaps helped their loss in that arena, or at least hastened it.

        Both sides had overestimated the other sides progress in the areas in which they themselves were most advanced.

        After the war, the two technologies came together as the ICBM, a dangerous weapon which dramatically changed the nature of the global arena. The cold war was born and much human labor was lost in the making of tools which we hope will never be used.

        --
        • The A-bomb's value was primarly psychological. While it is true that conventional weaponary could be more destructive (the fire bombing of Dresden proved that), the A-bomb had an enormous psychological impact on Japan. It was just unthinkable that a single weapon could do so much damage. Also, America worked hard to make it appear as though we had a whole arsenal of A-bombs that we could use. The Japanese had no real way of knowing that thes thigns were near impossible to construct and we had only a couple. This was, in all reality, more important than the actualy destruction unleashed. When a person (or country) feels beaten, they are beaten, and history indicates that indeed the A-bomb did fulfill that purpose.
        • More people were killed constructing the Rockets than were killed by them in combat. Development of the Rocket took away from Germany's air power and perhaps helped their loss in that arena, or at least hastened it

          But it sure was psychologically devestating, no? The thought of unmanned rockets, fired from deep within Germany, able to kill Londeners. And the whirring high pitched sounds it must have made coming in, how terrifying. Plus, of course, Germany really never could have kept up with the Allies air superiority presence (especially since the Allies had radar), hence the rockets made attacking England possible late in the war.


          Hitler was pretty desperate for a "miracle weapon" late in the war, and continously promised his people that Germany was close to such a weapon that would stem the tide of the war. If he had just waited another couple of years and allowed his scientists to develop jet engines before the war, rockets, maybe even A-bombs, who would have known what our world would be like today?

          • by alext ( 29323 )
            Nope, the rockets (V2s) were travelling much too fast to hear an approach and at first people didn't know what caused the explosion. The Government blamed an early hit up the road from me in Chiswick, west London, on a gas main going up. It didn't take long for people to figure out what was going on and to humorously tag them 'flying gas mains'.

            Doodlebugs or buzz-bombs (V1s), were actually much more frightening since their guidance system dependend on the engine cutting out and the missile diving down in silence. Hearing this was a trigger for people to run for cover. Fortunately my mother's family had time to hit the basement when one landed in their back-garden in Essex. (For extra points, WWII buffs can explain the story why these were landing in Essex and not London).
          • But it sure was psychologically devestating, no? The thought of unmanned rockets, fired from deep within Germany, able to kill Londeners. And the whirring high pitched sounds it must have made coming in, how terrifying.

            I've often thought it a good thing that the Germans didn't have the V-1/V-2 during the Battle of Britain. They could have created quite a bit of stress by being able to maintain a 24 hour bombardment. (Even 1-2 missiles every 1-2 hours during the time that attacks were not underway would have generated quite a stir.)
          • Plus, of course, Germany really never could have kept up with the Allies air superiority presence (especially since the Allies had radar)

            The Germans had radar as well, in fact their night fighters had far superior systems than the Allies could muster. In terms of air superiority though it came down to sheer weight of numbers. Aircraft like the Me 262 and Arado jet bombers were far and away superior to the Typhoon, Thunderbolt, etc. Germany simply couldn't produce enough of them, especially when faced with the massive number of aircraft fielded by the Russians.

        • Development of the Rocket took away from Germany's air power and perhaps helped their loss in that arena, or at least hastened it.

          Development of the V-Weapons certainly took away resources from the German war effort, but they also diverted considerable resources within England, as well as massive physiological effects. Quite a bit of effort went into rebuilding AA defenses and civil defenses that had lain largely unused since shortly after the Battle of Britain.
    • by ender81b ( 520454 ) <wdinger@@@gmail...com> on Wednesday January 09, 2002 @05:24PM (#2812240) Homepage Journal
      The book making of the Atomic bomb is also quite interesting as it goes into a great deal of detail about the Bohr-Heisnberg relationship. NY times misread the book , I believe, when they said that heisenberg simply failed. In actuality the book paints a picture of Heisenberg not wanting to develop the bomb at all - and turning the german research team away from a number of key discoveries. Now the book doesn't say that this was intentional - perhaps heisenberg was simply mistaken. Judge for yourself.

      The most interesting fact I learned from that book was this:
      To seperate,process, and manufacture the uranium nad plutonium neccassary for the a-bombs it required 32% of the United States Electrical output, 23% of the US's Silver output (144,000 Troy Ounces was the figure I believe), and 14% of the US's aluminum output to construct the plants (at Oak Ridge, Tennesse and Hartford, Washington). Remember this is 1944 people - height of america's industrial might. Now ask yourself if germany could've done the same...
      • by Goonie ( 8651 ) <robert.merkel@be ... g ['ra.' in gap]> on Wednesday January 09, 2002 @05:50PM (#2812428) Homepage
        Additionally, at the time they had most of the resources of continental Europe at their disposal if they wished.
        • by PD ( 9577 ) <slashdotlinux@pdrap.org> on Wednesday January 09, 2002 @06:36PM (#2812900) Homepage Journal
          That didn't count for much. Europe was a theatre in a war, and even in peacetime the output of Europe didn't match the US. Remember that the United States was involved in a fight to the death with two of the most powerful countries in the world, as well as supply arms to all of the other allies, AND sending a large part of the workforce overseas to fight.

          Yet, in the middle of all that, the United States undertook the largest and most expensive research project of all time, and did it with what was essentially spare/leftover resources.

          THAT's how big the US economy was compared to the rest of the world at that time, and it shows a giant reason why Germany would not have been able to build a bomb in time to be used during the war.
        • Additionally, at the time they had most of the resources of continental Europe at their disposal if they wished

          But they had to convert those natural resources into bullets, tanks, guns, etc. Also, despite their control of continental Europe, they lacked food and oil, two important resources for fighting any war or building any bomb (hence the push into Russia, to get to their oil fields).

      • In a nutshell (Score:3, Informative)

        by dachshund ( 300733 )
        In actuality the book paints a picture of Heisenberg not wanting to develop the bomb at all - and turning the german research team away from a number of key discoveries.

        Despite the after-the-fact romancing (of a guy who would very probably have delivered the Nazis an atomic weapon if he could have) there's good reason to believe that the only thing preventing Heisenberg from developing the bomb were his own miscalculations. Not the least of which was his determination that the amount of fissionable material required to create a critical mass was much greater than was actually required (there's a fascinating theory vs. engineering story behind that, but you can probably look it up.) This calculation led him to believe that any atomic weapon would be enormous and hard to deliver.

        After the war Heisenberg was taken to a detention center in the UK where he was surveilled with listening devices. When the he learned that the US had dropped the bomb on Hiroshima, he was stunned, and (IIRC) initially remarked to his co-detainees that we must have found a way to deliver a colossally huge bomb or something of the sort.

        Some have theorized that Heisenberg was both extremely clever and extremely loyal to the German people-- so much so that he deliberately foiled the Nazi research effort, then faked disbelief in order to mislead the Allied eavesdroppers. Personally, I think he just blew it.

        But you're right. Judge for yourself.

      • "Now ask yourself if germany could've done the same..."

        That depends entirely on two things:

        1.) Are we talking about Germany as it was on the map before they invaded Poland, or are we talking about Germany and all the other European countries that were either Axis powers (Italy, Romania, etc.) and/or occupied by the Germans? In other words, just Germany, or "Fortress Europe?"

        2.) Just that, or do we toss in a hypothetical victory in the Eastern Front? The Soviet Union/Russia has a LOT of untapped (still) resources.

        Also don't forget that the Nazis had the "advantages" of slave labor and an essentially command economy (and the Soviets would have been used to it anyway if they got taken over), while the US had to pretty much buy all this stuff on the open market (with a little nudge here and there).
        • by ender81b ( 520454 )
          The general consensus among historians is a definite NO b/c

          1.) German industrial power was nothing like the US and didn't have access to the resource's US did.

          2.) The german effort was 2 years behind the US's in theory terms - not counting materials.

          3.) It is *highly* doubtful the US strategic command would've let anything like Oak Ridge plant be built in Germany without bombing the shit out of it. You can't hide a facility that covers hundreds of acres - nor can you protect it. The vibrations from the bombs impacting close to the seperators are enough to destroy them.

          4.) Actually the entire manhatten project was run like a command economy - everything had to provided and NOW (the silver for the seperators was actually taken out of the US Treasury, some 3$ billion dollars worth , in 1943 dollars).

          If the germans would've gotten a few more years headstart, or could've delayed the US for 2-3 more years it is possible yes. But remember this, by that time the US would've had the bomb.
      • To seperate,process, and manufacture the uranium nad plutonium neccassary for the a-bombs it required 32% of the United States Electrical output, 23% of the US's Silver output (144,000 Troy Ounces was the figure I believe), and 14% of the US's aluminum output to construct the plants (at Oak Ridge, Tennesse and Hartford, Washington).

        Over what period? Also, how many did they make, including test cores, etc?

        • They made two cores. One was used at Trinity, the other at Nagasaki. Those two cores were all the US had available for a couple months. The Pu came from Hanford Washington. The Hiroshima bomb was a gun type Uranium bomb, which was so simple it didn't require testing. Which is why people are more worried about enriched uranium getting to terrorists than they are about Plutonium. U is much easier to make a bomb out of.
  • Heisenberg (Score:4, Funny)

    by Azog ( 20907 ) on Wednesday January 09, 2002 @05:07PM (#2812129) Homepage
    Many historians have praised the historical studies that Mr. Frayn undertook before writing the play. Still, in contrast to the complex Heisenberg of the play, the physicist in reality may have been easier to understand, Dr. Bernstein said.
    Hmmm. So... historians are uncertain of Heisenberg's principles.

    heh heh heh.
  • by Hairy_Potter ( 219096 ) on Wednesday January 09, 2002 @05:07PM (#2812136) Homepage
    Otherwise, the world would be facing a unified Europe, ruled by faceless bureaucrats headquartered in a continental European country, and America would be the only country that could go toe to toe with them.
  • Uncertainty (Score:4, Funny)

    by daeley ( 126313 ) on Wednesday January 09, 2002 @05:12PM (#2812166) Homepage
    Of course, once they figured out they were in Copenhagen, it was impossible to determine what went on. Doesn't make for a very thrilling movie, either.
  • Copenhagen (Score:2, Informative)

    by donutz ( 195717 )
    I'm quite glad I got the opportunity to see Copenhagen recently at the Wilshire theater in LA, the play kicked ass. At least I thought so. My wife was too busy being distracted by the druggie making weird gestures in the on-stage seating; plus she wasn't big on the whole science aspect and said "well couldn't they have just done that whole play in 5 minutes and be done with it?" Oh well. Definitely not for everyone, but almost definitely for the /. crowd! If you've got a chance to see it, it's cool.
    • Re:Copenhagen (Score:3, Insightful)

      by elmegil ( 12001 )
      Weird gestures....seated on stage...?

      What are the odds it wasn't a druggie, but a SIGN LANGUAGE INTERPRETER?

      • Re:Copenhagen (Score:3, Informative)

        by donutz ( 195717 )
        no, this was not sign language, and that man was seriously on some type of stimulant/drugs.

        As for the on stage seating....it's part of the props for the play....there is audience seating behind the actors. So he was most certainly not on stage for any type of sign language reason.

        Also, the person he was with got pretty pissed at him cuz he was acting like such an idiot, that they left before the end of the play.

        So enjoy your ill-gotten pc-thug karma! (politically correct, that is)....
  • by gpinzone ( 531794 ) on Wednesday January 09, 2002 @05:12PM (#2812168) Homepage Journal
    How are they certain Heisenberg was in Copenhagen AND he was there in 1941 at the same time?
    • > How are they certain Heisenberg was in Copenhagen AND he was there in 1941 at the same time?

      Bohr observed Heisenberg to be there, collapsing the wave function and placing Heisenberg in Copenhagen in 1941. He just had no idea how to define the exact point at which this happened. At least, that's how he interpreted it ;-) *rimshot*

  • Both Proof and Copenhagen were disappointing. It seems the standards for "play of the year" (both won) aren't quite up to the "Long Day's Journey Into Night" days or even "Glengarry Glen Ross".
  • It Doesn't Matter (Score:4, Insightful)

    by Wyatt Earp ( 1029 ) on Wednesday January 09, 2002 @05:23PM (#2812232)
    It doesn't matter what happened and if someone decided to sabotage the bomb in German or not.

    The Reich would not have been able to build an atomic bomb because they couldn't have set up the infrastructure without it being bombed to support the atomic bomb creation.

    In Richard Rhodes' "The Making of the Atomic Bomb" he goes into alot of detail about how much industrial infrastructure was needed to make the Uranium and Plutonium for the 3 American atomic bombs.

    And don't forget the amount of money and metals it took to make the equipment. The United States built 2 cities of 50,000 people each, one at Oak Ridge and the other at Hanford.

    Germany didn't have the manpower, materials or bomb-proof infrastructure during the war to produce an atomic bomb.
    • The Germans were able to develop and deploy advanced planes and rockets near the end of the war.

      As for working capital and manpower, the Nazis were simply stealing or forcing much of what they needed.

      • Re:Not clear (Score:2, Insightful)

        by Wyatt Earp ( 1029 )
        How many of them?

        Not enough to win the war.

        Besides, for every Nazi "Super-Weapon" something else had to be paused.

        Books on the U-Boat war argue that if the V-2s and Me-262 hadn't been built, there would have been the manpower for the advanced U-Boats to be built.

        Through-out 1944 and 1945, the German war production was a series of starts and stops when someone wanted a new "super-weapon". The huge rail-guns used to shell targets on the Russian Front used as much steel as it took to built hundreds of armored vehicles, yet the Germans lacked armor and had artillery to spare. Instead of building battle-field rockets like the Americans and Russians, the Germans built V-1s and V-2s that didn't have a marked impact on the war.

        The Germans didn't have the manpower or capital to do these things.
        • Part of the problem is that many of the programs were mismanaged due to Hitler's personal interventions; his early successes in the fact of expert advice led him to assume he was always right.

          The U-Boat example is a good one; Hitler diverted Navy building into turn of the century type battleships, which had shown in WWII they were largely obsolete in the fact of submarines and aircraft carriers; likewise, the Me262 was set back when Hitler repeatedly demanded jet powered bombers large enough to reach the United States - the impact of the Me262 would have been much higher had it arrived in, say, 1943.

          Finally, Hitler, like the US in Vietnam, over-estimated the value of sophisticated technology and terror campaigns against civilians; the V weapons were a millitary dissapointment, for example.
          • The U-Boat example is a good one; Hitler diverted Navy building into turn of the century type battleships, which had shown in WWII they were largely obsolete in the fact of submarines and aircraft carriers

            Um, no. The Kriegsmarine *asked* for Battleships. The problem was that Hitler started the war years earlier than he had promised the Armed Forces. (The Battleships were the first things started because they took longer to build, U-boats came much later in the planned sequence.) Almost all BB construction was long halted by 1943, which is when it was obvious the BB was obsolescent (not obsolete).

            Finally, Hitler, like the US in Vietnam, over-estimated the value of sophisticated technology and terror campaigns against civilians;

            Um, the US didn't use particularly sophisticated technology in Vietnam. Nor did they conduct terror campaigns, however the VC *did*...

            the V weapons were a millitary dissapointment, for example.

            The key problem was that by the time the V-1/2 reached operational status (after starting as marginal blue sky programs later seized upon as potential V-weapons), their was little logistics capabilities to support them. The (relatively) few that were launched terrified the hell out of the Allies, who spent much energy hunting down and killing launch and production sites.
        • oks on the U-Boat war argue that if the V-2s and Me-262 hadn't been built, there would have been the manpower for the advanced U-Boats to be built.

          Germanies real problem was threefold:
          • Again and again they delayed shifting production to more advanced models until too late.
          • Germany never shifted completely onto a war economy. (Indeed they didn't even really start shifting until 1942/43. Their peak production was in the last two quarters of 1944.)
          • Throughout the war, the cream of the resources and production went to Germany's historical source of strength: Their land armies.
        • Instead of building battle-field rockets like the Americans and Russians, the Germans built V-1s and V-2s

          The German army certainly did have rocket launchers - the dreaded Nebelwerfer which came in a number of forms and was employed on all fronts. They didn't feature as prominently in their arsenal as the Katyusha did in the Russians, but many Allied veterans remember the screech of the Nebelwerfer with particular loathing.

    • Re:It Doesn't Matter (Score:3, Informative)

      by rodgerd ( 402 )
      The Reich would not have been able to build an atomic bomb because they couldn't have set up the infrastructure without it being bombed to support the atomic bomb creation.

      Not true. In fact, German infrastructure was in fine fettle throughout the war until the invasion of Germany proper. One reason for this is that the Nazis refused to allow Germany to be put on a war footing until after the initial thrust of Barbarossa failed, in 1941. From that time, German industrial production more than tripled, reaching a peak in late 1944/early 1945.

  • by The Wookie ( 31006 ) on Wednesday January 09, 2002 @05:25PM (#2812252)
    I managed to get a transcript of the letter from Bohr to Heisenberg, here it is:

    Dear Werner,
    Ever since your last visit, I haven't seen my cat, Fluffy. You haven't seen her, have you?
    Sincerely,
    Neils
  • by Stultsinator ( 160564 ) on Wednesday January 09, 2002 @05:27PM (#2812266)
    One of my favorite quotes is by Niels Bohr:

    There are two types of science: Physics and stamp collecting.
  • A Biography (Score:4, Interesting)

    by artlu ( 265391 ) <artlu@art[ ]net ['lu.' in gap]> on Wednesday January 09, 2002 @05:31PM (#2812298) Homepage Journal
    For my engineering/chemistry professor last year i needed to write a Biography [artlu.net]on this man. My biography is pretty in depth and a worthy read if anyone is interested. It can be found @ http://artlu.net/essays/wernerbio.html [artlu.net] Enjoy, AJ
  • See also this book (Score:4, Informative)

    by Spinality ( 214521 ) on Wednesday January 09, 2002 @05:38PM (#2812339) Homepage
    Heisenberg's War: The Secret History of the German Bomb, [amazon.com]
    Thomas Powers provides lots of interesting detail, citations, background. From reading various sources, I see Heisenberg as badly misjudged and misrepresented. I think he was basically a good guy in a very bad situation and, integrating all the available material, it feels like he basically did the Right Thing, and played a key role in keeping the German nuclear program working in directions other than building a bomb.
  • Richard Rhodes (Score:2, Insightful)

    by Anonymous Coward
    The "Making of the Atomic Bomb" was written by
    Richard (not David) Rhodes, for which he won a
    Pulitzer Prize. Doesn't exactly inspire great
    confidence in the NYT's QA program...
    • > The "Making of the Atomic Bomb" was written by Richard (not David) Rhodes, for which he won a Pulitzer Prize. Doesn't exactly inspire great confidence in the NYT's QA program...

      Ah, but you forget -- Dave Rhodes was involved. His idea is essential to the workings of the Bomb:

      "Just send five neutrons to every fissionable nucleus on this list!"

  • by Ardias ( 544478 ) on Wednesday January 09, 2002 @05:45PM (#2812391) Homepage
    Shortly after WWII, Werner Heisenberg was held captive by the British government at Farm Hall along with several other top German scientists. The British secretly taped the conversations at Farm Hall, and these tapes were declassified in 1992. (It took prolonged and strenuous efforts by several historians, and members of the Royal Society to persuade the government.) Heisenberg was at Farm Hall when the US dropped the bombs on Japan in August of 1945. When he heard the news, he was astonished that the US had separated sufficient U235 from U238 to obtain critical mass. He was also surprised that the US also made a plutonium based bomb. (The methods used to extract U238 and Pu were made by a chemist working under Enrico Fermi in Chicago. Without the knowledge provided by that chemist, the US would not have had either bomb for perhaps another year.) Since Heisenberg was surprised, we may assume he simply did not know how to get enough weapons grade uranium. Nor could he make enough and separate enough plutonium for a bomb. He had enough uranium to make a small nuclear reactor. Which he did create in a cave in southern Germany. The US army found the cave and removed the materials. The assessment by US scientists was that the reactor was never put to use. Apparently war efforts hindered Heisenberg's attempt to get all the resources he needed. And, towards the end of the war, the effort was abandoned. It is likely that Heisenberg knew he could not make a bomb and persuaded the Nazi government to allow him to make a reactor instead. Whether he had only technical reasons for the change in policy is unknown. He may have had moral reasons for preventing the Nazis from getting a bomb, but there is no public source of information to support that hypothesis. In 1941, he may have wanted to make a bomb, or knew that the Nazis wanted him to make one. In either case, I think he went to Copenhagen to ask/tell/warn Bohr about the Nazi plans. During that evening, he and Neils Bohr went for a walk. Bohr's wife, Margerethe, reported that they both left the house that evening in a good mood. The walk in the dark was short, only a few minutes. Neils Bohr came back quickly, and in a foul mood. Heisenberg followed him back inside. They did not talk about much later that evening. Later in the war, Bohr's family secretly got into a boat at night and left for England, and then America. Heisenberg stayed in England for some time, as a "guest" of the British government. In 1947, he was allowed to visit Bohr, and his British handler went with him. During that meeting, he and Bohr agreed that "we both came to feel that it would be better to stop disturbing the spirits of the past." (From Heisenberg's memoirs.) Bohr and Heisenberg continued their friendship after 1947, and until Bohr died in 1962. Bohr kept that friendship even though most Allied scientists shunned Heisenberg.
    • These Farm Hall transcripts are extremely interesting. Especially in this context. There is an excerpt [aip.org] where these researchers are arguing whether or not they could have done it.

      I find it particulary interesting what Carl Friedrich Freiherr von Weizsäcker exclaimated in this conversation:

      I don't think we ought to make excuses now because we did not succeed, but we must admit that we did not want to succeed.

      OK, there are many ways to interprete this, but it is a very interesting statement.

      Actually, I asked Joseph Rotblat what he thought happened in Copenhagen that day. He didn't answer, really, he just pointed out the many different possibilities, but he did put some emphasis on the possibility that the group did block the development.

    • There is a very nice German made for TV movie called Ende der Unschuld [imdb.com] (= end of innocence). It deals with the German attempt of creating a nuclear bomb and the scientists at Farm Hall.
    • He worked at Berkeley.
    • American Scientist had a really good article [americanscientist.org] on this back in 1996.

      Heisenberg had estimated that a ton of U-235 was needed to reach critical mass, which was, of course, a huge overestimate. This is the reasoning he gave in a conversation with Otto Hahn immediately after being surprised by the news of Hiroshima (the conversation was secretly taped by the Allies):

      "If I have pure 235 each neutron will immediately beget two children and then there must be a chain reaction which goes very quickly. Then you can reckon as follows. One neutron always makes two others in pure 235. That is to say that in order to make 10^24 neutrons I need 80 reactions one after the other. Therefore I need 80 collisions and the mean free path is about 6 centimetres. In order to make 80 collisions, I must have a lump of a radius of about 54 centimetres and that would be about a ton."

      Can you see the mistake in his logic?
      • > Heisenberg had estimated that a ton of U-235 was needed to reach critical mass, which was, of course, a huge overestimate. This is the reasoning he gave in a conversation with Otto Hahn immediately after being surprised by the news of Hiroshima (the conversation was secretly taped by the Allies):

        > "If I have pure 235 each neutron will immediately beget two children and then there must be a chain reaction which goes very quickly. Then you can reckon as follows. One neutron always makes two others in pure 235. That is to say that in order to make 10^24 neutrons I need 80 reactions one after the other. Therefore I need 80 collisions and the mean free path is about 6 centimetres. In order to make 80 collisions, I must have a lump of a radius of about 54 centimetres and that would be about a ton."

        > Can you see the mistake in his logic?

        Mistake 1: The neutron release number is 2.3, not 2. So he only needs 66 collisions to produce 10^24 collisions.

        Mistake 2: The mean free path is less than 6 cm since the U235 cross-section is larger than he estimated. (He should have done the experiment and known for certain instead of relying on theory alone.)

        Mistake 3: The minimum radius is actually slightly less than the average free path length. Meaning that if one of the 2.3 neutrons escapes the uranium before hitting another nucleus, then the remaining 1 or 2 are sufficient to continue the chain reaction.

        Mistake 4: He needs less than 10^24 collisions.
  • I just saw Frayn's play "Copenhagen" last night in SF and really must urge all of you to see it if you can. Regardless of what truly motivated Heisenberg the issues raised are far more reaching. I walked away with the following: -we sometimes lack the perspective to understand our own motivations -mechanistic thinking is flawed, we should move to a a more systemic approach (the aspect of Heisenberg's Uncertainty theory applied similarly as in Fritof Capra's work "Turning Point") my 2cents. thoughts?
  • Our Man Heisenberg (Score:3, Interesting)

    by fm6 ( 162816 ) on Wednesday January 09, 2002 @05:49PM (#2812427) Homepage Journal
    I often wonder if anyone has seriously explored a pet theory of mine. It may sound far-fetched, but I don't see another way to explain Heisenberg's wartime activities.

    He was an OSS operative.

    There's nothing that specifically indicates this, of course. But look at the human site of the game. Here was a man who worshipped Einstein, who had many other associations with Jewish scientists, and who himself narrowly escaped academic blacklisting when the Nazis took power. And somehow he ends up as scientific chief of a major German weapons project!

    There's actually a well-documented meeting with an OSS agent in Geneva. Official histories state that Heisenberg was there to give a talk, and the agent, Moe Berg, was there to determine the progress of the German bomb effort and (at his own discretion!) terminate Heisenberg. Supposedly Heisenberg told Berg that the project wasn't going well, and Berg took his word for it and let him live. Not, in my opinion, a very plausible story.

    OK, no evidence at all for this theory. But it's worth thinking about.

  • by fm6 ( 162816 ) on Wednesday January 09, 2002 @06:28PM (#2812776) Homepage Journal
    The Times of London article is here (long registration process required)
    Actually, there's no such newspaper. The link is to the web site for The Sunday Times [sunday-times.co.uk]. But you're probably thinking of The Times [slashdot.org], which isn't The Times of anything, it's just The Times. They have exclusive rights to that name -- other newspapers have to use qualified names ("The Times of Sunydale" or "The Centerville Times") or face the traditional trademark letter.

    The Sunday Times and The Times have always been separate publications. Nowadays Rupert Murdoch owns them both, and has been combining some of their operations. But that's a recent development.

    The Sunday Times registration process has an amusing flaw. Tried to tell it I was born in 1830. Not acceptable. 1890? Nope. 1899? Get serious. I meant to try "1900" next, but typed "2000" by mistake. That was acceptable! Apparently 1-year-olds read the Sunday Times, but not centenarians!

  • I just finished reading "Inside the Third Reich" by Albert Speer. Speer was Hitler's architect and later Minister of Armaments and War Production. Thus any program to develop an atomic bomb was under Speer's ministry. He said that they were working on one, but due to Hitler's poor leadership and executive decisions, it never got the priority it should have. Speer claimed that Nazi Germany could have produced an atomic bomb by 1947. That of course, he said, was inconsequential because the United States produced theirs by August of 1945.
  • by Animats ( 122034 ) on Thursday January 10, 2002 @02:13AM (#2814988) Homepage
    There's quite a literature on this, as others have mentioned. Some points:
    • Heisenberg's numbers on neutron cross-sections were wrong, and made it look much harder to get a chain reaction going than it actually is. Whether or not this was deliberate isn't known.
    • It's known that German scientists were very worried that if Hitler got the idea that an atomic bomb was possible, he'd demand that it be produced in a short time, something the scientists knew they couldn't do.
    • The German bomb program never got beyond the lab stage. The U.S. Manhattan Project ended up building more plant than the U.S. auto industry had at the beginning of the war.
    • Isotope separation wasn't something one person figured out. Four different processes were tried, and two were brought to full production.
  • The Germans never *had* a bomb program.

    They were doing some studies on nuclear materials with a view towards military applications, but had no specific usage in mind. The 'bomb program' was created by lazy journalists and editors who (in 1945) conflated 'nuclear' with 'bomb' in that same way they do with 'computer' and 'Wintel' today. The myth of the 'bomb program' has persisted despite the utter lack of evidence that Germany was pursuing a bomb. (Almost every study of the 'bomb program' has started with the assumption that it existed, which is poor logic and poorer scholarship. Very few have started from zero and seen what conclusions come from examining the evidence without bias.)

    The myth of the 'ethical scientists' is largely the same face saving nonsense that came postwar from almost every German who had any affiliation with the Party or the Military.

UNIX was not designed to stop you from doing stupid things, because that would also stop you from doing clever things. -- Doug Gwyn

Working...