No this is not a story about Jesus, nor is it a story of the Russian submariner during the Cuban Crisis who didn't allow the release of a nuclear weapon - although this is a fascinating part of Cold War history. Recently I reread three books out of my vault - half a double garage filled with boxes plus one or two bookshelves - on the atomic effort during WWII by the Nazis led by Werner Heisenberg, the well known co-inventor of quantum theory, and the equally well known discoverer of the uncertainty principle named in his honour. Like the uncertainty of his mathematics, there is also another uncertainty in Werner’s work and motives during the War in which he played a leading role in the effort to either build a bomb or a reactor depending on the outcome of the research effort in Nazi Germany.

Did he make a mistake in overestimating the amount of uranium needed for a sustained chain reaction? Or did he make an ethical decision to white-ant the project and tell Albert Speer, Minister for Armaments, a bomb was not feasible during wartime Germany?  He was very much a patriot, and like Max Planck, the elder statesman of German science, wanted to be there after the Nazis to rebuild German science to its pre-war glory.

Heisenberg and Bohr had a crucial role in twentieth century scientific history. Both were involved in mathematical research of the atom before the development of quantum mechanics in 1927.  Bohr developed a theory of the atom which agreed with the spectroscopic results from the 19th century including Balmer’s work on the hydrogen atom. Heisenberg was Bohr’spost-doctoral assistant in the early 1920’s, and between them with help fromsome others including Max Born and Jordan they invented quantum theory, a powerful numerical method for solving atomic configurations. They were very good friends in those early days but this friendship grew cold after a famous meeting during the War in Copenhagen in 1941 which remains to this day enigmatic and uncertain as to what actually transpired.

As someone whose life and mathematics has become inextricably entwined with Heisenberg, Bohr, and Planck, perhaps my opinion might be of interest; besides I wanted to learn everything I could about early nuclear theory and reactions. Hence my recent obsessive reading of the three books: Heisenberg’s War by Thomas Powers, Heisenberg and the Nazi Atomic Bomb Project – A study in German Culture by Paul Rose, and the stage play Copenhagen by Michael Frayn. I also read The Road from Los Alamos by Hans A.Bethe and several books about the Los Alamos project.

At first, to me it seemed that Werner had just been arrogant because I knew the Copenhagen Interpretation of quantum theory. To someone who has discovered a deterministic solution to the hydrogen atom, this view is just plain wrong. Perhaps Werner had wanted to work towards a Nazi bomb effort for his own good, the greater good of Nazi Germany and the detriment of the rest of the world. However, the more I got to read, the more I began to see Werner as someone else other than just mistaken in his estimate of the amount of uranium needed for chain reaction. He had been ‘right’ by using an upper limit of tons for the estimate, but effectively 'wrong' because the upper limit meant it was not feasible for Germany to build the bomb during the War, especially while the Allied bombing campaign was damaging the German war effort.Yet this apparently suited his purposes in that it allowed him to avoid the ethical dilemma of making a bomb for Hitler. The transcripts of Farm Hall, the manor in England where he and the other captured members of the Nazi Bomb project were interned after capture, show the error in his calculations that was corrected over a period of several days after the inmates learnt of the bombing of Hiroshima via listening to the BBC news broadcasts.

And what was the meeting about in 1941?  First of all Heisenberg had Gestapo minders and he wanted to talk in private with Bohr, so they went for a very brief, but abortive walk. We’ll never know, but one theory has it that Heisenberg was trying to offer his old friend Professor Bohr a position with the Nazi effort to develop a reactor (rather than a bomb) since Germany would soon win the war in Europe. Another theory has it that he wanted Bohr to use his contacts to let the Allies know he would attempt to white-ant the Nazi effort to develop a bomb and thus seek agreement on both sides to not develop the fearsome new weapon.

This to me is a real conundrum.  If he was asking Bohr to join the Nazi effort this would explain Bohr’s coolness at later meetings after the War and his insistence to Heisenberg on letting the spirits of the past lie undisturbed. But I don’t buy it.  Alternatively could he have been asking his old mentor for help with understanding the bomb or the reactor? Or asking how the Allies were going? Whether they were going to go ahead with the bomb? With each of these scenarios Bohr could have been similarly shocked and aggrieved.

Since these three books have been published there have been other more intimate sources made available tp the public record that can contribute to our understanding of the events both within and surrounding September 1941 in Copenhagen. Aage Bohr and Jochen Heisenberg, both sons of their famous fathers, have presented additional material to allow more insight into the issues concerning the Nazi atomic bomb effort. Further, “Klaus Gottstein was a member of the Max Planck Institute for Physics from 1950 to 1970 under the directorship of Werner Heisenberg. For several years he was head of the experimental division of the Institute. In 1969 he asked Heisenberg about his visit to Bohr in 1941, and Heisenberg told him. Immediately afterwards K.G. dictated into a recorder what Heisenberg hadsaid. This record and its transcription are still available.”

Klaus writes “Recently NielsBohr Archive released 11 documents pertaining to Heisenberg's visit, includingthe much-discussed unsent letter, preceded by an article by Aage Bohr,published in 1967, on  "The War Years and the Prospects Raised by Atomic Weapons".

After Bohr's escape to Sweden and subsequent flight to Great Britain in the autumn of 1943 "it was quite clear already then, on the basis of intelligence reports, that there was no possibility of carrying out such a large undertaking in Germany before the end of the war". (Document 11 b).This is a remarkable confirmation of Heisenberg's own conclusion. It is also interesting that these intelligence reports had no influence on the progress of the Manhattan project·

Aage Bohr writes"After the outbreak of war and especially after the occupation of Denmark we in Copenhagen were completely cut off from following the allied nations' efforts in the field of atomic energy." Niels Bohr confirms this in Document 11 c. (Also Heisenberg knew that. How could he expect to do some spying, as some writers have suggested?) In a footnote to his article Aage Bohr assures the reader that no secret plan was submitted to his father by Heisenberg "aimed at preventing the development of atomic weapons through a mutual agreement with colleagues in the allied countries."

Again, in Document 11 c, this is what Bohr remembers. It is quite true, also according to Heisenberg. It had indeed been Heisenberg's intention to get Bohr's opinion on  possibilities for such an agreement or on other ways out of the impasse presented by the basic feasibility of atomic weapons. But Heisenberg never had a chance to present his questions because of Bohr's reticence and Bohr's unwillingness to continue the conversation when Heisenberg, as an introduction, had told Bohr that atomic weapons were technically possible,and that he knew it. He was not even allowed to add, as he had intended, that the technology was very difficult and would take a long time, thereby giving the small international community of atomic scientists a chance to use their influence in the meantime.Bohr had stopped listening. This is admitted by Bohr in Document 11 c where he writes "During the conversation, which because of my cautious attitude was only brief...".

There is no doubt that Werner helped a number of his Jewish colleagues before the Warto the extent that he was called a ‘white Jew’ by some Nazis. In fact since his mother knew Reichsführer Heinrich Himmler’s mother he used this relationship to ask Himmler personally to geSS-Obergruppenführer Reinhard Heydrick, chief of the Gestapo, to call off those seeking to destroy him.Jochen Heisenberg, not unnaturally, saw his father as a man of integrity and humanity and this comes across in the documents recently made available on thepublic record. Part of that record is a paper written by Heisenberg aboutreality and order that gives us a glimpse into his true feelings about workingon the bomb:

“This text is based onthe handwritten manuscript, which contains some corrections compared to thetyped copy.

From Werner Heisenberg, Collected Works. Section C: Philosophical and Popular Writings. Volume I. Physics and Cognition. 1927-1955

Eds. Dr. Walter Blum, Dr. Hans-Peter Dürr, Dr. Helmut Rechenberg

Published by R. Piper, Munich, Zurich 1984.  Preface by the Editors*

'In September 1939 Heisenberg was conscripted for service at the Ministry of Ordnance in Berlin.He became a member of the so-called "Uranium Club" and participated in the preliminary preparation for the construction of a Uranium reactor. This secret work of Heisenberg's entailed, aside from fundamental theoretical investigations, also experiments at the University of Leipzig with hiscolleague Robert Döpel and his wife Klara, as well as the supervision of theexperiments done at the Kaiser-Wilhelm-Institute for Physics in Berlin-Dahlem.In July 1942 Heisenberg was named chief director of the Berlin institute. Hismulti-faceted activity - pure theoretical Physics also was not neglected, asthe seminal publications on the S-matrix theory of elementary particles in the years 1942 and 1944 show! - was interrupted for vacation periods in Urfeld onLake Walchen where Heisenberg had acquired a summer house in the summer of1939. There a part of a manuscript of 200 pages, philosophical in content, was created that relates very closely to the five lectures printed in this volume of his works.

The lecture in Budapest on the theory of color had been received favorably so that Heisenbergwas prompted to think more about the questions of methodology in the naturalsciences. Consequently, he not only gave another series of lectures such as in Leipzig and Zurich, but he also authored an in-depth manuscript in which hewrote down the sum total of his previous views and also enlarged on them toinclude new realms of the natural sciences and of the description of reality.

The manuscript, finished in the fall of 1942, is untitled. We have named it "Reality And Its Order" in accordance with a remark Heisenberg makes in the text. It consists of three parts, an introduction (I.), the main body (II.) and asummation (III.) It was not meant for publication, but typed copies of it weresent to reliable friends at Christmas 1942. (In the latter parts of part II.and in part III. there are political statements, which could have become dangerous for the author in the Germany of that time, especially given that he was working in a leading role on projects of wartime significance).”

“…The powerful figure who assumes the right to destroy the enemy and who throws resisters in jail is not important;it is instead the jail guard who, despite orders to the contrary, cannot refrain from slipping a piece of bread to the prisoners now and then. We need to remind ourselves again and again that it is more important to act humanely towards the other than to fulfill any professional obligations or national obligations or political obligation.” '

This is a note written sometime before autumn 1942 by Heisenberg about the primary duty to humanity that overrides any allegiancesto science, Germany or the Nazis.

For whatever it is worth, my opinion is that Heisenberg, like Bohr, and Planck, wanted science and Germany to recover after the War. All were responsible in large part for the extant knowledge of atomic processes and each had an important role to play in this regard to right the ship. I think Werner did white-ant the Nazi bomb effort, purposely. He knew the two feasible processes for chain reaction to occur, uranium or plutonium, and deliberately chose an upper limit to estimate the amount of pure uranium needed to sustain the process. This wasn’t an arithmetic error. I know General Groves published the Farm Hall transcripts; but actually this supports the white-ant theory when Hahn says “But if they have, let us say, 30kg of pure 235, couldn’t they make a bomb with it?” which is the correct estimate. Call me gullible but maybe God had arranged for the right man in the right place at the right time.

Humanity’s journey along the road to knowledge of nuclear reactions and energy has been a trial for us. Thus far we have avoided blowing ourselves off the Cosmic map. Anyone who reads Hans Bethe’s book The Road from Los Alamos, can see just how near we came to complete annihilation in the Cold War. Here too Werner has some words for us today:

“Earlier generations were able to build on the work of their ancestors. For our times the goal is of necessity a more modest one, since the old spiritual values have been molten down.Initially, we have no choice but to return to that which is simple; we must conscientiously attend to the duties and tasks which life itself places upon uswithout much questioning the whence and whither; we must pass on to the next generation that which we still deem beautiful, rebuild what was destroyed andput our trust in other people across the din of passions.”

Werner was a man of high culture; he loved music, and his theoretical prowess was able to lead us into a new era of quantum theory based on matrix methods that led to numerical computing across science.  While I am of the opinion that he purposely white-anted the Nazi bomb effort, many do not share this opinion. On the evidence. and his character before and during the War, I think we owe him the benefit of the doubt. We need men of equal conviction today just as we did in those dangerous times.