I think I should introduce my introducer thank you very much this is the third annual university science lecture sponsored jointly by the University and the Society the Sigma Chi this year's lecture is brought to us by the Hitchcock professorship ladies and gentlemen Robert Oppenheimer [Music] thank you very much for your wonderfully warm welcome and thank you sir for the best introduction I've ever had take a minute to get out my machine this will really not be a lecture about technical things but it will be about a great man of science Niels Bohr was one of the great and noble men of our time he was a little younger than Einstein and Rutherford and it fell to him to bring into harmony in the development of atomic theory Einstein's ideal of a consistent and general theory of physics and Rutherford's love of novelty and of adventure I don't want to pile adjectives upon this friend but I will tell one Episode Bohr was the first recipient of the Atoms for Peace Prize no one quite knows what that prize is for but everyone agreed that this was the right man to give it to and when they when the ceremonies were over Ralph Bunche who was a member of the awards committee said to me after this it won't be easy I think even the later recipients would agree with that appraisal but before I come to my account of Bohr's singular role in the development of atomic weapons I think I should just tell you a few things about where he was born and how he lived he was born in 1885 in Copenhagen and his family was a grave secular humorous warm and learn ed family full as doors later title you said of light and life his father was a physiologist very well known man and from the very first Bohr was interested in the understanding of what said living things apart from inanimate in inorganic nature and puzzled about whether the vitalist argument of those days had any meaning at all he was to come back to that again and again his last paper published posthumously was essentially a clarification of his views on the relation of life to the relation after physical and chemical systems Bohr's brother was a little younger Harald and he was to become a very eminent mathematician so that from very early and throughout his life Bohr had somewhat estranged love from math lexy didn't do much of it but he admired it and he used it occasionally and he recognized in it an immense enlargement of language and ability to talk about things which in words would simply be inaccessible and they were lifelong friends as a student or was eclectic he went to some lectures he read some books what he heard and read made a deep effect on him had a deep effect on him and he was always known in his family as the young philosopher he distinguished himself with his professors by telling them what was wrong with what they said [Music] and he had a preoccupation very early in life almost was a book about it which was to dominate a large part of his mature years and that was with the subtleties of the use of words and concepts he said and the fact that that the I that act is not the same thing as the I that I study or know about or someone else examines he thought of the fact that a word to be effective in use is not the same thing as a word when it is being loaded on the table undefined and he thought of life on the run time does matter and on the other hand his purpose he was not all overcast with saut he was a very distinguished football player that's a soccer and his brother was too and his brother was perhaps a little better anyway when Bohr became a very famous Dane the King asked to see him and he went for his first audience and the King said it's a pleasure to see you professor boy I understand that you're a great soccer player football player and we'll store said if he did about everything else your majesty that is my brother the King repeated professor Bohr it is a pleasure to see you I understand the true great football player and more said as he always did but that was my brother and the King said good day both started his life in science with a nineteenth-century problem which was to study the oscillations of the jet of water when it comes out of a small hole he that was his master's thesis and the Royal Danish Academy gave him the prize and he got prizes more and more and medals all his life late in life I sometimes just with him when he dressed for a state dinner and he had so much that he had to wrap his Ascar and his hope around him otherwise he sank does he move those thesis was began to take him into the heart of physics late in the 19th century jday Thomson had found this universal and remarkably active ingredient of matter called the electron and had written a good deal about the behavior of electrons in metals they play a large part in the electrical and thermal and optical properties of net metals and the magnetic properties - and those thesis was a critical examination of all as coming to the conclusion that it was mostly wrong it was wrong so then of course he went to Thompson in Cambridge was Cavendish professor there and started talking to him about it and that was no joy to Thompson at all but then something very drowned happened he heard Russell had given a lecture and after dinner lecture and he heard indirectly and with great excitement but no clarity that board found out something important about atomic structure and he went to Manchester and this was the year after Rutherford had discovered that it's a heart of an atom there is essentially all the mass and the charge which we now know is the atomic number and that around that is a relatively loose open structure of life this is very different from what had been thought before and Bohr immediately became aware and a great heap of everything with this much that this implied the separation of nuclear properties which determined radioactivity and depended on the mass and atomic properties which depended only on the atomic charge and on the behavior of the electrons and he very soon saw that this behavior would not in any way be reconciled with any well-established physics with Newton's laws or Maxwell's electrodynamics and formulated in 1913 the first brave broad rough principles of what atomic structure was a very radical break with the past which he knew and yet very clearly in some way harmonious with it when when one was not dealing with atomic systems but with large ones he said it became clear immediately that the atom was governed by the quantum of action the summer of 1912 he married migrate annulment and their marriage was one of extraordinary warmth depth and beauty they had five children all boys the second one any of you may know he's a physicist also and go recur in this lecture he's director succeeding his father of the Institute in Copenhagen the eldest boy Christian was lost from a sloop in the stagger up when he and his father and baron were sailing and never recovered after hours of looking sometimes Bohr would talk about the troubles of life and it was always clear that he knew what he was talking about Bohr went back to Manchester from 14 to 16 and then in mid war returned to Copenhagen and during that whole time he was alone as in exploring the the quantum theory of the atom he had many conversations with experimental people Rutherford himself and much correspondence with Mosley while he was measuring atomic numbers with x-rays and before he was lost in Gallipoli with Heather she who was the magic chemist of the day and then in 1916 he returned to Copenhagen this professor and from then on he was never alone again others had learned that there was something in his theory he had companionship he had a school in the good sense of it Ian was the promoter and beneficiary of an international collaboration of singular intensity and depth and charm I once called this a Roy period and unborn wrote Rutherford memorial lecture he repeated the phrase in quotation marks so maybe it was in 1920 his Institute was founded it's called the Institute of theoretical physics but it had experimental facilities its focus was on understanding the at home and on understanding nature and until 1927 the great struggle to make sense out of atomic theory went on and at that point Bohr gave his interpretation of how one should understand wave and mechanics and quantum mechanics in terms of the fact that you could explore on 'litham and find out its properties but different experiments precluded one another in that they wouldn't work if you tried them together and he'd called these traits of the atomic system complimentary and began soon thereafter to talk of the analogies between this situation and those encountered with the human psyche and in biology in anthropology where loyalty to a culture and awareness of other cultures are complimentary and in many other fields perhaps the things he thought of as a youngster came back and his here occurred often to the complementary character in any social in any society of love which is the fulfillment of a man and justice which is the Equality of men in the mid thirties he returned to some problems of nuclear physics he had an incredible host of friends young physicists or physicists artists statesmen philosophers though he was very suspicious of those and I remember for instance that he was a very close friend divides man the first president of Israel and to Bukharian and Stalin had shot in the surgeries in his home and kasparek which was they built in the 19th century and was a typical 19th century brew [Music] they lived and entertained and took care of young people and they're finally bored died on the walls there was much contemporary abstract painting interspersed with decorous pictures of ancestors even in those early Manchester days Bora was that would be 1912 Bohr was of course interested in the atomic nucleus and in the first months they're paid as much attention to it as to the desperate problem of what the electrons were doing but after that the very great engagement the heroic time of understanding the quantum theory of the atom and all of its meanings were to occupy him almost fully but at the war's end in 1918 Rutherford wrote to tell about his success in making an artificial nuclear transmutation the historic change of nitrogen into oxygen nitrogen bombarded with an alpha particle to give oxygen and a fast proton which is what he detected they wrote to one another after the war was over Bohr wrote in a way which seems rather melancholy in the light of what would happen a quarter of a century later and of the story that I'm about to tell all of us he wrote all of us here are convinced to will never more be a war of such dimensions in Europe it is a new era in history when Rutherford's paper on the transmutation of nitrogen was published in 1919 door and somersault both pointed out that they were probably seeing a most interesting application of Einstein's relation between the change of mass and the release of energy in 1932 Rutherford in April of that year rosin rosin laughter - boy he said that he was convinced by Chadwicks experiments that there really was such a thing as a neutron he had predicted this 12 years earlier Rutherford in the back EURion lecture that there would be something which was neutral in which the electron was bonded to the proton in a very much more intimate way than in an atom and that this would be a very interesting particle because it could get into nuclei without any electrical repulsion and it should be very valuable in producing nuclear changes Rutherford also wrote of the successful outcome of Chadwick and wardens attempt to accelerate protons they had done it and the protons changed lithium into two alpha particles and one could check with great accuracy that the energy of the alpha particles correspond to the mass change in this reaction it was the beginning with the neutrons and the middle thirties Fermi and his collaborators began with his very famous experiments with slow down and constant he found that in many substances the neutrons caused were more active they caused more changes and the products were very often radioactive in that case it's not too hard to find out what's going on typically the reaction is that a slow neutrons will enter a nucleus the energy liberated by this is lost in gamma radiation the product may be stable in which case it's not so easy to find or it may be radioactive in which case it is the probability of these reactions were enormous corresponding to collision areas a million ten million times that of the nucleus and everyone understood that this was a typical consequence of the wave property of all of the neutrons and of all matter but there was a more startling point which was that the energy at which these probabilities was very great probability of capture very Wraiths were typical from nucleus to nucleus differed from nucleus to nucleus and we're very sharply defined so that at that energy neutrons were effective and at slightly different energies not at that point intervened because he understood what was going on a well-defined energy means according to quantum theory at the time that the state lasts is very long and Bourne interpreted that roughly but rightly in terms of the fact that the neutron lost its energy to all the other particles in the nucleus and it would take a long time before the energy would come out as radiation which is slow process or before it would react umya late on some other particle that might escape the discovery of radioactivity of uranium when it was bombarded by slow neutrons was not truly interpreted by ceremony in analogy with you all all the others and indeed in large part this was right but it was somewhat puzzling that when one tried to disentangle these activities and chemically separate them one of the products appeared to be radium which isn't of course very close to uranium in atomic weight or atomic number and Hahn was an old hand and an old friend of Rutherford and the rest on and Strassman took some care to make sure of this bizarre identification and they found something very much more bizarre because the radioactivity came from barium and not from radio brought this news to this country the United States in fact to the Princeton Institute and he agreed with the suggestion which was more than a suggestion with conviction of otto frisch was in Copenhagen and Miss Mike Nura was in Stockholm that uranium sometimes came apart into two night not quite equal pieces and that sometimes one of the pieces was very him then one looked for the pieces which should have lots of energy and they were found probably more places but certainly in Colombia in Copenhagen and in Berkeley bore them analyzed the situation in more detail and wrote that the capture of neutrons in uranium 238 which is almost all the uranium the fastest occurs naturally with a normal capture leading to gamma rays and to a radioactive uranium which led as they discovered in Berkeley to uranium-235 to neptunium 239 and to plutonium and that only the relatively rare really very rare isotope of lighter isotope 235 under went fishing with slow neutrons and then with wheeler Bohr made a more or less systematic survey of what made now a nucleus undergo fission either spontaneously this had been discovered in Russia Belarus and pet rock or under Neutron bombardment from these arguments what one could have concluded that uranium 235 and uranium 233 and plutonium 239 would probably undergo fission readily and with so neutrons but in nature the last who don't exist and the first looked and in fact really was rather formidable a hard to separate so that when Bora left the United States for Copenhagen he did not expect that explosive applications of the fission process lay very close at hand it was some time before one knew that enough neutrons were liberated to sustain a chain reaction and it wasn't really until 43 or 44 that it was checked out at Los Alamos that in fast Neutron reactions the number of neutrons was adequate and the time delays small enough so that explosions could really occur blow went back to Copenhagen but the world was very different than that of the heroic days for seven years his Institute and his home at Carlsberg had been a refuge often temporary but sometimes for a long time in the first instances for colleagues from Germany and then from Austria when Fermi came to Scandinavia to get his Nobel Prize he went to Bohr's Institute instead of going back to Italy then came on here from Russia came Charlotte how Tremont's whose husband stayed in jail to a Molotov Ribbentrop pact and plot check and vise cuff Bora had in addition to his deep devotion to Denmark which had kept him there when he was asked to go to England more than 20 years earlier also a sense of responsibility for his wards and for his people these years from 40 to 43 are not publicly documented and I don't know very much about them the Institute was closed in 1940 as in Bergen von weizsäcker others as well came from Germany to Copenhagen or had the impression that they came not to tell him what they knew but see if were knew anything they didn't and I don't think it was a very rewarding experience for either in 1943 it was clear that Bohr could not stay any longer that he would he would certainly be killed he had been in touch for the Danish underground and through them with the British Secret Service and Chadwick had written him from England saying quite simply that it would be good if Bohr could come there so in the last days of September he escaped at night in a small boat to Sweden and three weeks later he was flown to England in the Bombay of an unarmed mosquito they gave him an oxygen mask and a headgear with earphones but the Royal Air Force had no such heads as Bors and it didn't fit and he was completely unconscious rather rather not fun when burka came to England a Chadwick spoke to him of what was going on and told him of the enterprises which Tabora seemed fantastic and perhaps them looked fantastic today they look sort of run-of-the-mill that were under way in the United States to separate uranium 235 by yesh diffusion of the gaseous hexafluoride by ernest lawrence method of enormous numbers of enormous mass spectrographs in which every atom flew through the vacuum and went to its pocket and to build train reactors and separate the plutonium chemically and the English were very much involved in this the possibility of making a bomb had been raised there and it's interesting that it was raised there also by two who were refugees from tyranny in Europe by Paris and by Simon and they like we made a committee called the mod committee and they made a project with a code name called the to Belarus project and they concluded the British government concluded that this was an enterprise that must be explored with the greatest vigor even if it had and were to have no effect whatever on the outcome of the war it seemed too important for the future of the world this English conclusion had I think a very important effect in transforming what was going on in this country from a rather languid and super secret set of committee meetings into an effort that might someday an adventure waiting in a piece of machinery British were concerned with only one of the many programs and not exactly along the lines of those here and it soon became clear clear to them that they didn't have the resources and the things would work much better if they could work with us and with the Canadians in establishments on this side of the Atlantic free of bombing and the threat of bombing three of the Rockets which were not yet coming and relatively well-off in physical and material terms for those years the relations with the British went up and down they were good in the beginning and we had good communications with piles and Dirac on some of the technical points about what happens when a bomb starts exploding but as the Manhattan district was established to put this on a large-scale basis things were a bit stickier so in August of 43 Churchill talked to the President Roosevelt about it at Quebec and they signed an agreement which provided for the participation of British and Canadians in the United States undertaking for their son during missions to this country for our sharing the political and military responsibilities involved in the use and the dealing with the weapon if it ever came to be and also for sharing what was at the moment of more practical weight the uranium which didn't really belong to either of us and for postponing the question of possible industrial and so uses until a knew more about it later on the Quebec agreement had been signed when war came to England and Chadwick and his colleagues were by that was very eager that bore come to this country and that he enhanced the weight and the value of the British mission not very many English scientists but they were very very good could be spared for this enterprise there was much else to be done at home Chadwick and pals had talks with us and we had a pretty good understanding that we had the same view of the problems the technical problems ahead and they hope Thor would come play a part in it and Cibola was sent to see Sir John Anderson later Lord Waverly is a conservative and a rather door remarkably sweet man very congenial in spirit to Bohr and very deeply his friend he was Chancellor of the Exchequer and was in charge of this tube alloys project and he asked for help in maintaining and improving the position of the United Kingdom in the enterprise and helping me out a price to success by then board had his first good look I I will be reading you short passages from things that he wrote and you will hear his own words but I think it is best if I rather boldly tell you what points he had in mind at the beginning and for a long time I run the risk of oversimplifying by so doing but I do so because it is easy as history as well shown for even very wise men not to know what Bohr was talking about this one and development fell on him as great astonishment like the atomic nucleus 20 many years earlier and everything came in a great jumble to his mind first of all he was clear that this was going to be an enormous change in the situation of the world in the tolerability of world war the word Menace word threat occur over and over again in what he wrote when he came to Los Alamos his first serious question was is it really big enough maybe it wasn't but I finally got to be the second point was that he knew enough of the Soviet situation to be quite sure that the wartime alliance would not endure the peace is things than so it stood he spoke a great deal of different economic and social systems and different traditions I think he was not thinking of India or Africa or China but of Russia of the Communist world he therefore anticipated an unheard-of arms race unheard of before then though of course not now because we've had it and are having it for the great weapons he came to know something about the possibility of vast thermonuclear amplification and even mentioned it discreetly the to Roosevelt and Anderson and Churchill we didn't know much about it but we knew it was not a hopeless prospect he expected perhaps more rather more than has in fact occurred that what looked such a formidable undertaking in 1943 would look much less formidable in 53 in 63 in the way of getting materials and in the way of assembling them and he thought that it was important and necessary to start early to try to prevent the arms race he was quite clear that one could not have an effective control in this field which was picturesquely called atomic energy which would permit some beautiful applications for instance to technical and scientific things or to the generation of power that one could not have a free scientific spirit and have an active open healthy world without a very open world indeed he made this quite absolute he thought that one would like to preserve privacy some respect for individual privacy perhaps rather more than as possible and he had a great respect for the private and quiet processes of government and management in which you can say the wrong thing before you come to the right but in principle everything that might affect the security of the world might be a threat to it that would have to be open to the world he understood that the Communists took up a really quite disdainful attitude towards speaking or revealing the truth and he understood how very much this had gone beyond the tactical duplicity recommended by Lenin to the most dangerous self-delusion I he didn't say this in any of his letters to Roosevelt or Churchill but in 48 writing to general Marshall and Secretary of State he wrote what it would mean if the whole picture of social conditions in every country were open for judgment in comparison need hardly be enlarged done thus he understood that it would not be very much in character for the Soviet Union to welcome and open world and he felt that it was essential to attempt to engage it by very early consultation consultation as an ally that had been fighting in a common cause invaded occupied and struggling with a desperate defensive war very important to try to put the enterprise as a common problem of cooperation for the Russians the English the Americans the United Nations as they were then called and a sport called them and to be quite prepared to up offer with proper safeguards and with an open world full cooperation in scientific progress and if it were sensible in industrial exploitation he hoped the situation in which the Russians would find themselves and the advantages that we might have to offer and the opportunity of associating themselves with the forward-looking and very major change in the world might alter the whole character of Soviet policy Soviet society and international relations so that in an essential and major way force would play a far more minor part and nations would exert an influence on history by their example their persuasion and the extent to which they could indeed contribute to the common welfare he was looking at one of those examples of complementarity of which she thought as a youth the complementarity between love and justice he spoke of all this I think very eloquently but maybe not very precisely to understand and understand was certainly most moved because just shortly before his death he told me that he had never been reconciled to the fact that Bohr had not either not been understood or not been followed and that his counsel had been of no avail late in 43 Bohr came to the United States publicly he had a cover which was to advance international cooperation in science after the war and what he really wanted to do would indeed have been the great a great measure to bring that about his official role was of course to to advance the development of the bomb and the British asked him to see if they couldn't make their position and in this enterprise a little more stronger and make them more impressive partners but most secretly of all he came to advance and this was with the concurrence and the encouragement of Anderson his case and his cause when he got here late in 43 he of course saw the ambassador of the United Kingdom Lord Halifax and his own ambassador to Kauffman who was very great bravery and gallantry represented his non-existent government in the conduct of the war and helped the Allied cause more than most men hmm the through Coptic Osman he met again justice frankfurter who had heard something of what was going on and listened to bore with sympathy and deep respect and after some tours to visit other installations brought him with his son Noah who was his companions confident his protector and helper and everything else through all these years that to the laboratory that what's now called the psalmist I will only tell you one short episode of his coming which may reawaken the memory of those who have tried those of you who have tried to listen to Bohr growth sport brought the Boers out by train that he was the commanding general of the Manhattan district and it was his business to know all he could about what the Germans were up to and he thought rather more than was true that Bohr might know something about it so they came out and groves listened all the way and then that evening he left Bohr and his son at our house for supper the next morning saw groves walking toward the laboratory very very stiff and limping badly they asked him what was wrong and he said evoking the picture of a man sitting across in a railroad compartment and listening to a low voice talking very obscurely I have been listening to Bohr at Los Alamos Bohr was simply marvelous he took a lively technical interest he we went over some of the things that what the Germans might be up to but they weren't up to much and he took an interest in what was going on I heard yesterday that he got up dick Simon early one morning and said you were fresh and if I make a mistake you will correct me all the other people are too polite will you explain what this is about hmm the yes here and there he would intervene there was a difference of opinion to put it brother cautiously on the functioning of a part of the bomb was purposes to make the sudden burst of neutrons when the configuration is just right and Bohr did not say anything about the protagonists in this fight but he said I don't see how you can make it wrong and that settled it but his real function at least I think for most of us was a different one this enterprise was not entirely a gay affair and very few people involved were light of heart but Bork appeared to make it seem hopeful he spoke with contempt of of Hitler with a few hundred tanks and a few hundred planes that hope to enslave all of Europe forever said that nothing like that would ever happen again his own I hoped that the outcome would be good and that in this the objectivity the friendliness cooperation which were so prominent in the life of science that these would play a helpful part this was something that we really wanted very very much to believe early in 44 justice frankfurter talked to Russ felt about Boris ideas and the president listened with great interest and a word of encouragement and at that time Andersen was talking to the prime minister to Churchill trying to see whether he couldn't open the subject up a little within the British government so that they might look at what to do Churchill didn't like that at all so Bohr went back to England in April with a word of encouragement for Anderson that the President had some interest in this set of ideas then an episode occurred the first secretary of the Soviet embassy in London had a letter for him from kapitza kapitza would known Bohr in Cambridge and who had been asked to stay in Russia what made to stay in Russia and who was a good friend of all the Western scientists and a remarkably lively and creative man and kapitza wrote saying we've had a terrible time but now things are better we can work at our physics and wouldn't you like to come and join us you would find all of us delighted or interpreted this as an indication that there was some interest in this Russia in the Soviet Union in the practical problems of atomic energy and wrote a a correct and friendly but negative reply saying that he was working on international cooperation in science after the Wharton then then both saw Anderson again and the chairman the president while society Sir Henry Dale and sure will who was Churchill's single scientific adviser and at the Prime Minister's suggestion they all talked to two jet general sports who had been wise before they talked together and reached the conclusion that perhaps Churchill and Roosevelt might think about the future then then war met with Churchill it was very very unhappy charville didn't think much of war he didn't prepare the great old man's and didn't tell him but what sort of a fellow Bohr was and then the Prime Minister and his advisor got to bickering and what couldn't say anything and he didn't like that under normal circumstances didn't like it at all in the solemn moment burrowed to Churchill trying to re formulate what he had said saying he was aware that the meeting hadn't gone very well but saying most definitely that he had brought a message from the President of the United States the board came back to this country and out to New Mexico again and late in August after he'd prepared a memorandum which justice had shown to the president he met with the President and they had a long talk of course I don't know and it may be that no one does just what transpired Bohr wrote what he said but he never he was correct and he never wrote of what anyone else said but the bora was enormously encouraged and I will read you three paragraphs from the first memorandum Boris words are not easy indeed it would appear that only when the question is taken up among the United Nations of what concessions the various powers are prepared to make is their contribution to an adequate control arrangement it will be possible for any one of the partners to assure themselves of the sincerity of the intentions of the others of course the responsible statesmen alone can have the insight into the actual political possibilities it would however seem most fortunate that the expectations for future harmonious international cooperation which have found unanimous expression from all sides within the United Nations so remarkably correspond to the unique opportunities which are known to the public have been created by the advancement of science many reasons indeed would seem to justify the conviction that an approach with the object of establishing common security from ominous menaces without excluding any nation from participating in the promising industrial development which the accomplishment of the project entails will be welcomed and will be responded to by a loyal cooperation on the enforcement of the necessary far-reaching control measures after that Bor wrote a supplementary memorandum which may in part have had unhappy consequences in pointing out and many other things how close the relations between members of the scientific community had been and saying that although States must decide and make proposals and act but scientists who had known each other could help prepare the ground in September Churchill came over and he and Roosevelt met again at Quebec but they saved discussion of atomic problems until hide part of this discussion there is an ed memoir initialed by both men it embodies three conclusions they were based apparently on a substantial if not total misunderstanding a fart bore was up to the first conclusion was the Bohr suggestion that the world be told about the development be rejected my board didn't propose or won't to tell the world about anything he thought it important for Roosevelt or someone bearing Roosevelt's authority to tell Stalin or if there was such a man someone bearing Stalin's authority about the future proposal and the need for common responsibilities and the deep need for an open world only if that went well what went well and there was some meeting of the minds and the thing was worked out in a practical way and there was in fact such a thing as an atomic bomb would one them think that one might tell the world of what could be done about it as well as that it could be made but Churchill immersed felt harshly rejected this approach and said that the highest secrecy should be maintained that was of course being tried working pretty well but not too well in the second place Roosevelt and Churchill said but from the bombs Ferengi then after mature deliberation they might be used against Japan and third they said they would like to have a very careful watch on war they didn't quite trust him there wasn't anything funny about that it was it was really very grave for one thing it shows how very wise and experienced men dealing with a very great man can be quite wrong it worked itself out the British were completely sure that this was nonsense and so was the Navy Bush and other people in this country and Bohr was you would say today he was cleared but the fact is that it stopped and ended entirely his communication with the President and it very seriously clouded and impeded his communication with our government he never talked to secretary Stimson Secretary of War although he wanted to very much in March of 45 many months later Bohr wrote another memorandum by then the dates for the coming of the bombs were last almost entirely determined by production schedules were pretty well known the United Nations were to meet out in San Francisco for the first time and Bohr had a great sense of urgency that the question of the atom of the bomb not be let go too long I shall read you one more long ish passage I don't apologize for its length as as as argued in the memorandum this is the one I've quoted it would seem most fortunate that the measures demanded for coping with a new situation brought about by the advance of science and confronting mankind at a crucial moment of world affairs fitting so well with the expect patience for a future intimate international cooperation which have found unanimous expression from all sides within the nations united against aggression moreover the very novelty of the situation should offer a unique opportunity of appealing to an unprejudiced attitude and it would even appear that an understanding about this vital matter might contribute most favorably toward the settlement of other problems where history and traditions are fostered divergent viewpoints with regard to such wider prospects it would in particular seem that the free access to information necessary for common security should have far-reaching effects in removing obstacles borrowing neutral knowledge about spiritual and material aspects of life in various countries without which respecting goodwill with that with it between nations can hardly endure participation in a development largely initiated by international scientific collaboration and involving immense potentialities as regards human welfare would also reinforce the intimate bonds which were created in years before the war between scientists of different nations in the present situation these bonds may prove especially helpful in connection with the deliberations of respective governments and the establishment of control I skipped two paragraphs all of such opportunities may however be forfeited if an initiative is not taken while the matter can be raised in a spirit of friendly advice in fact a postponement to await further developments might especially of preparations for competitive efforts in the meantime of reached an advanced stage give the approach the appearance of an attempted coercion in which known a great nation can be expected to acquiesce indeed it need hardly be stress how fortunate in every spected would be if at the same time as the world will know of the formidable destructive power which has come into human hands it could be told that the great scientific and technical advance has been helpful in creating a solid foundation for a future peace for cooperation between nations I do not know if whether Roosevelt ever read that moment memorandum he died very shortly thereafter when he died he was writing a speech since published but never delivered on the new powers of science in war and the need to take thought men could live together and work together in peace the hour that Roosevelt died the Lord Halifax and justice frankfurter were walking in Lafayette Park just by the White House talking of the bomb and de Bourgh's ideas with Roosevelt's death Bohr's memoranda were given to Stimpson the Secretary of War shortly thereafter Stillson appointed a committee of which Kyle Compton Bush and Conant were the technical members in which state war Navy and the Office of the President were represented this was the interim committee just supposed to think about the future of course in an important sense Bohr was not alone at all Bush in Compton and Conant were clear that one must drive for an international control of these new techniques and these new dangers Stinson understood this and he understood how deep a problem it was and he understood that central to it lay our relations with Russia the authors of the front report working in Chicago was so clear that this was the hope and so two of the scientists who banded together after the war and finally formed the Federation of American scientists and many many of you I'm sure but there were differences war was for action for responsibility for responsible and timely action he realized that it had to be taken by those who had the power to commit and to act he wanted to change the framework in which this problem would appear early enough so the problem with itself would be altered he spoke of statesman he was not very much for committees and the interim committee was a committee it proved that by making another committee it appointed a scientific panel Stimson did of which Arthur Compton Fermi Lawrence Ernest Lawrence and I were members we met with them on the first west of May and we talked just about the question of the relations with Russia the future of science the future of civilized intercourse other people remember that there was talk about the use of the bomb but that was not in a committee session and I was not party to it I was deeply impressed for the wisdom of general Marshall was very grave and very deep and honest about it and the secretary Stimson that I went over to the British mission where Bohr was and tried to comfort him but he was much too as a man and I couldn't comfort him he went back doing and very unsure and very troubled about what would happen in June the scientific panel was asked questions and we had an occasion to answer a different one we recommended that be for a firm decision on the use of the bomb our government talk of the future with our allies on the 21st of June the interim committee met and agreed that this was this was right and they thought it best tried to do it at the planned meeting on July 16th in Potsdam meeting of the of the heads of state of England Russia in the United States we had to make some sort of a test for technical reasons and we planned and managed to do it in time to get word of it Protestant because we thought it would make a difference whether things worked or not and it did work and yet there was no talk with the Russians this history has been well written in the last chapters of Churchill Roosevelt Stalin by Herbert Feist Stimson was horrified when he saw the Red Army and took something of its measure he himself said they lost his nerve and probably that maybe that's soul burns had always been rather against talking to the Russians and Churchill was against talking to them very much but they all agreed that if the president said something to Stalin they using the New Mexico explosion as the occasion it would relieve us of the worst reproaches of double-dealing so when the news came from New Mexico rather more lurid and it would seem now the president dismissed him his interpreter was Charles Bolden he didn't want things to be too solemn and he went over to Stalin who by accident did he have his interpreter Pavlov but another man whose name nobody knows and the President remarked that we had a new weapon which was quite powerful and which we were thinking of using against Japan according to President Truman he is our witness Stalin said he wished us luck and hoped it would work that seems to have been casual enough then with the use of the bombs which raised other questions of course nothing is entirely separate but rather separate there were pronouncements coming rather slowly about international control in late 45 the delay and Mackenzie King came to Washington and they agreed with President Truman that we should seek some international action and secretary Burns was asked to take up the matter with the Russians to see whether they would approve the creation within the United Nations of Commission to discuss the atom the secretary was rather afraid that they would ask him how to make a bomb he didn't know but he didn't want to have to say so but they were very much less eager to talk about it than he was and really nothing was said except that they would make a commission at that point two of the most responsible senators began to be worried about what we were up to and he asked the secretary what were these controls so the secretary appointed a committee under the chairmanship of the undersecretary mr. acheson to devise controls and a few days later the Under Kotori appointed a panel under the chairmanship of david lilienthal to devise what it was that was to be controlled we it was a good committee his committees grow very good we took two months I think more out of respect for each other and they the solemnity of the problem thinking about what things really had some danger in them and how they could that danger could be eliminated or reduced and what things were completely innocent and how these were related to one another and how one could encourage discovery and how international at collaboration and under national efforts could be set up to explore things things like the possibility of thermonuclear bombs and many others it was the committee document that I think for that and for the times not to bed but Bohr was not happy with it he thought it not centered enough on the to him absolutely central theme of complete openness well when it came before the United Nations in reform of the broof plan the officers of the United States military mission thought difference I said if justice happens everything will be open and there will be no military secrets of any kind it wouldn't work if the work I think it did understand and make provision for this but it didn't it didn't get accepted and a document that doesn't get accepted is not a very great contribution to human welfare and their boss said something which is deeper and truer he said this situation calls for action it was an action to make them on board didn't quite hope or didn't quite hope that one could now really talk to the Russians in a way which would change their hostility and alienation from the West but he still felt that it was a great cause to do away with barriers to information a great cause to model the state of the world whether it had to do with technical things or economic or political or military on the cultural on the world of science he talked in 1946 to the Acting Secretary of State and then in 1948 he had a long thoughtful interview with general Marshall the Secretary of State was to go to Paris to present the American argument at the Assembly of the United Nations and Bohr hoped that Marshall would be led to say we are for doing away with secrets and we are prepared it in the proper time to do just that but the secretary didn't say that so in 1950 after the first Soviet explosion and the decision which was pretty obvious that this country had to intensify its our moments Bohr wrote just before the Korean War an open letter to the United Nations telling in discrete terms of what he had thought and what he had written I will read you the last quotation that I will only what he wrote it's not now addressed to the heads of government but to people and at large to you and to me the efforts of all supporters of international cooperation individuals as well as Nations will be needed to create in all countries an opinion to voice ever-increasing clarity and strength the demand for an open world I cannot tell I'm not sure that anyone can whether early timely thoughtful action along the lines suggested by Bohr would have changed the course of history there is nothing that I know of Stalin's behavior or his beliefs that gives one gives me any shred of hope on that score but Bohr understood this too I think and he understood that this action would create a deep change in the situation and he believed that with change situations also chests changed ways of thinking are called for and do our brought forth I think myself that if we had acted wisely and thoughtfully in accordance with what what he said we might have been freed of our rather blast from a sense of omnipotence and our delusions about the effectiveness of secrecy and that we might have turned our society toward a healthier vision of a future worth living for an increased dedication to knowledge the truth with the development of the arms race and its intensification the bitterness of the Cold War and the multi Megaton warheads and rockets Bohr turned more and more to what he knew he could do international cooperation in science good communication understanding friendliness reasonable institutions great goodwill his own Institute in Copenhagen the little Scandinavian center called nor D temperature is housed in the same building where early examples Bohr spoke that the first Athens for Peace Conference which though a modest thing was a very important beginning in the erosion of of barriers to communication some certain barriers to communication or took pride in the fact that the only Danish contribution to the second Atoms for Peace Conference was a joint paper by an American and Russian played a most helpful part not only in establishing the great nuclear laboratory for high energy physics sound their Geneva but in keeping sound free of the provincialism of the six and of your atom and free of the military orientation and preoccupation of NATO he traveled to Russia shortly before his death as he had thought over and over again of doing after the war but he abhorred no message from the President of the United States for the Prime Minister of England he traveled extensively in this country in England in Israel he had a very tiring trip to India and in October of 1961 he spoke retrospectively at the 50th anniversary of the Solvay Congress on the development of atomic physics in June in 62 at lindau with other nobel laureates he had a light stroke seemed to be recovering and in October in November he recorded the first five interviews of what were to be a history of quantum physics and so in partially his own history he died on the 18th of the November with the retrospect incomplete Bohr often spoke with deep appreciation of mortality mortality that screens out the mistakes failures and follies that would otherwise encumber our future that makes it possible what we have learned and what's proved itself be transmitted for the next generation on November 18th this board died his son Ora was returning with his wife from a month in China where he had been lecturing on nuclear structure it was much earlier in September of 1945 that Colonel Stimson left Washington for good he was not young and he was not well on that day he was to have a cabinet meeting where he would add the Kate but lated Lee but very eloquently an open approach to the Russians an open and friendly approach and an open approach on the possibilities of collaborating on atomic control later in the day general Marshall was planning to have every general officer in Washington out on the runway to salute and say goodbye to their teeth for all this colonel Stinson had to have his hair trimmed and he asked me to sit with him when he was in the barber's chair when it was time to go he said now it is in your hands poor never said anything like that to any of us he never needed thank you [Music] thank you for thank you for the wants of your applause very grateful [Applause] [Music] when heimer the audience has spoken for itself thank you meeting is adjourned [Applause] [Music]