the other ones we are working with issues of ownership. they are available now both on the fdr library youtube channel, and there is a page on the fdr library website that will explain the collection and take you to the youtube playlist. >> paul sparrow, thank you for your time today. thank you for e today. >> i appreciate it. in 1898, marie curie discovered a new element. 47 years later, the atomic bomb named little boy was dropped on hiroshima, japan. on august 6, 1945. diana preston talks about her book before the fallout from marie curie to hiroshima, and which she investigates the scientific discoveries that led to the development of the atomic bomb. at thes recorded

national archives and washington, d.c. in 2005. it is 50 minutes. [applause] we thank you very much, indeed, and i would like to say what a pleasure it is to be back here at the national archives, and i would like to acknowledge that the arts have been a considerable help that i had from the archives in writing this book. the destructive flash which seared hiroshima into history was really the culmination of 50 years of scientific creativity and more than 50 years of political and military turmoil. generations of scientists had contributed to that moment in physics. yet, when they first began to tease out the sequence of matter, not even future nobel prize winners, i think, could have predicted how their pioneering insights would combine with exterior events to produce such a defining moment in history. for the

scientists of many nations this journey's discovery began way back in the 1890's. researchers like marie curie who is in the , first slide here, researchers -- she was working alone or in small teams with equipment, they started to identify the minute building blocks forming the the world around them. blinding discoveries were often matched by blind alleys. people rushed to publish their results not for profit or for national prestige or often not even for personal glory, but, rather, for the pure joy of knowledge. for a long time, no one realized that their work could unlock immense energy to furnish a devastating new weapon or, indeed, if properly harnessed, to power a city. in the early 20th century we

have rejectivity being seen as -- radioactivity being seen as only producing benefits to health through the use of x-rays for diagnosis and of radioactive materials to treat diseases, including cancer. physics, after all, was a new subject. the work perhaps of 1,000 physicists worldwide often may be just 10% were engaged in the study of radioactivity. consequently, all of those involved knew each other. at a time of intense national rivalries and of competition for empire, trade, and natural resources, scientific results were pooled internationally. they were pieces in a communal jig saw puzzle for which no one had the master picture or pictures. scientists studied at each other's institutes. north americans visited germany. britains we want to north korea

-- north america. colleagues skied, hiked, made music together, and allegiances and rivalries really stemmed from where and with whom people had studied, rather than from nationality or race. all of them met at conferences where results were shared, contacts maintained, and gossip exchanged. albert einstein, who is standing in the slide, in the previous slide. albert einstein called them witches, and i think few conferences were as marked by gossip as that in brussels in 1911 when courie was forceed it withdraw as a result of eh an -- an alleged affair with a french colleague and also a married man.

personalities were strong and debate often often heated. involvedrly when those were, as one of them recalled, undertaking to, quote, "wholly new processes of thought beyond all the previous notions in physics. " today i'm going to be talking about the decade when what had for nearly 40 years been an open quest for knowledge transmuted into a race between belligerent nations working in secret with large teams for high stakes. that key decade begins early in 1932 with the discovery of the neutron and pearl harbor and the bomb project. the neutron was identified by the gentleman we see in this next slide here, james chad wick over on the right. chadwick, a thin, rye englishman whose

suggest and had been where wind by internment in germany during the first world war. chadwick worked at the world famous laboratory at cambridge university in england. the head of the laboratory was ernest rutherford who we see in this next slide as a young man. young ernest rutherford. he had previously identified alpha beta gamut of radiation. he had found the proton, and with this man, sitting to the right with rutherford next to him, the two of them had worked out a model of atomic structure which we have in the next slide, a model of atomic structure where tiny negatively charged electrons orbitted a positively charged nucleus. a famously compared this vision

of the nucleus within the atom to that of a fly within a cathedral. now, rutherford, who in his career would train 12 nobel laureates. had he long suspected the existence of the neutron, but he had delegated the work to chadwick. and prompted by some results published by the french husband and wife team frederick and kitty. --courie. she was the daughter of marie curie. chadwick tackled the problem with increased vigor in 1932. applying the classic ceiling, wax, and string principles to make his equipment the simplest and the cheapest fit for the purpose, we know that chadwick violated rutherford's rule, but all work in the laboratory should cease by 6:00 p.m. this

was part due to enthusiasm, but also so that his sensitive equipment would not be affected by others work. and after three weeks he had shown that radiation from bombarded berilleum and powerful enough to knock particles out of hydrogen, argon, and others. the particles expelled from the hydrogen were clearly protons, and the others were whole nuclei of the target substance. his measurements of their penetrating power, of their velocity, proves that gamma rays, as has been claimed, could never have caused the ejicks of ejection oftion -- particles of such energy. the only viable conclusion was that the radiation flowing so powerfully from the bombarded berrileum consisted of powerful of mass one and charge zero. in other words, neutrons.

now, chadwick's discovery for which we'll see in this next slide he received the nobel prize. we have chadwick over there to the right. this discovery really provided the all-important clues to many unresolved problems. for example, the neutron added to the understanding of isotopes. until then no one had known what it was exactly that differentiated isotopes from their sister element. the suspicion was that the difference lay in the nucleus. chadwick's findings proved that suspicion correct. what made isotopes different was the number of neutrons on nir -- in their nuclei. the most exciting of all was the realization that since the neutron carried no electrical charge, it would not be deflected by the positive charge of the nucleus. it was the ideal missile with which to bombard and to probe elements as it could hurdle on until it penetrated the nucleus

of the asked him. knew was thaty the neutron was also the catalyst for achieving an explosive nuclear chain reaction. that very year, 1932, we have the british writer nicholson publishing a novel called public spaces. lic faces." in it he discussed a catastrophicically destructive new weapon made from a powerful new material. the sbans could transmit itself with such violence that it could cause an explosion that, to quote, "would destroy all matter within a considerable range and send out waves that would exterminate all live over an indefinite area. " the experts, nicholson wrote, had begun to whisper the words "atomic bomb." the words "atomic bomb." they claimed it could destroy new york. not the only

reason that 1932 was a spectacular year for science. in january just a few weeks before chadwick, we had an american chemist making another discovery that rutherford long predicted. working at columbia university, yuri found that natural uranium consisted of 99. 985% ordinary hydrogen, but also of not . 15% of heavy hydrogen. an isotope given the name gerterium that also existed with with oxygen and water. this so-called heavy water to the naked eye, really identify -- identical to ordinary water-t boiled and froze at different temperatures, and it was 10% heavier. of course, a decade later it would become a substance much sought after by the nazis and people would die to deny it to them.

in this next slide here we can see the heavy water plant in occupied norway which was attacked by allied commanders during the war. but back in 1932 yuri thought of it as in his words, "a delightful play thing for physicists. " they could use it in bombarding other complex atoms so that they could better understand nuclear structure. and in april 1932 a few weeks after the neutron discovery, we have rutherford reporting another trial. he wrote exuberantly, it never rains, but it pours. these two gentlemen we see in the next slide, john on the right, and ernest on the left of rutherford, they had just become the first scientists to split the atom using a man-made machine, a so-called

accelerator. in this next slide we have an image of what the accelerator looked like. this was a device that rutherford had asked them to develop some time earlier. and they had created it lovingly and carefully with an innovative new material that would replace the ceiling wax they had previously used for the purpose, smoothing that over the joints to create a vacuum. fearing that rivals might overtake them, rutherford had urged them to stop perfecting it and to do what he told them to do months ago. in other words, start experimenting. his bullying paid off. the gentlemen bombarded lithium with accelerated protons and succeeded in disintegrating the nucleus into two helium nuclei. according to one of his colleagues, normally about as much given to emotional display as the duke of wellington, went

running through cambridge shouting "we've split the atom, we've split the atom." an additional excitement was that the energies of the particles measured by the two gentlemen provided the first experimental confirmation of the validity of einstein's proposal that e equals m.c. squared. rutherford had been perhaps to fear competition. he might have easily been upstaged by the american ernest lawrence working at berkeley. in this next slide you'll see lawrence at berkeley. he had been developing another machine. he had the original thought that if he could confine particles with electromagnets with a circular track rather than pushing them along a straight line, he could accelerate them indefinitely causing them to go faster after each burst of voltage. it would, in his words, be a

proton merry go round. he told his friends confidently and accurately, as it turned out, i'm going to bombard and break up atoms. i'm going to be famous. lawrence's machine didn't work anything like that. it was a four-inch pill box sprouting arms like an octopus. when he demonstrated it to the u.s. national academy of sciences, he compared it to a kitchen chair with a close hanger. despite its absurd appearance, its potential caused a sensation. newspapers hailed the invention of the device to break up atoms, and they were right. so good was his progress that by the end of the 1930's lawrence would build a machine with a magnet weighing 220 tons. inspired by the desire to explore one of the tiniest things in existence, the nucleus of the atom was coming. lawrence

had been joined at berkeley in the autumn of 1929 by a young theoretical physicist who shared his ambition to help the united states take the lead in all the world. i'm sure you will recognize the gentleman standing to the left of lawrence. by the time he came to lawrence he was 25 years old, and in the next slide we see oppenheimer, the young man, slenderly built with intensely blue eyes. friends thought him to quote "both wise and terribly innocent." he was also sensitive, conceited, often charismatic. the passionate about physics, he was a renesaince man with obsessions ranging from hindu philosophy to dante's inferno.

oppenheimer -- he admired his unbelievable vitality and love of life. they socialized and womanized together drinking oppenheimer's famous frozen martinis from glasses rimmed with lime juice and honey. and they ate an indonesian dish . they also went riding. as we see from this next shot here, that photograph of the time, sir lawrence tall, , sturdy, smilingment oppenheimer over on the left here with friz of dark hair, his slighter frame clad in heeled mexican boots and wearing tight jeans, and with a quizical yet dreamy expression. he resembles a young bob dylan. now, lawrence and oppenheimer, they attend the weekly seminars, and oppenheimer, of course, the scientific head of the u.s.

atomic bomb process, amazed everybody with his ability to assimilate new ideas. his extraordinary memory and the fact that to quote a contemporary, he knew more experimental physics than even the experimental physicists did. in 1932 he we want to his -- wrote to his brother that "we are busy making -- sorry -- we are busy studying nuclei and neutrons and disintegrations trying to make some peace between the inadequate theory and the absurd refrl useary -- revolutionary experiments. " just as oppenheimer had hoped, atomic physics was by now no longer europe's exclusive reserves. on a visit to berkeley in 1933 john cockashcroft was startled to see it run more like a factory than a laboratory. in his words, the experimenters were divided into shifts.

maintenance shifts and experimenters. when a fork developed in the psych lowtron, the maintenance crew rushed forward to plug the leaks and fix the fault at which point the operating shift rushed in again. it was far removed from the small-scale expense-conscience , world. it was a warning that they might soon be outclassed. of course, at this time the outside world was changing, and such concerns would soon become irrelevant. in 1933 hitler came to power. many jewish physicists were expelled by hitler's decrees. these included some of the very best physicists of their generation and many made their way to britain and the u.s.a. way to britain and the u.s.a. -- they understood the danger of

hitler's and the nazi is only too well, and among them was several who would help make the atomic bomb a reality. albert einstein crossed the channel to england protected by a british naval commander who had the singular experience of having once been invited to kill rasputin. the autumn of 1933 finding england too formal and preferring a life with, as einstein said, no butlers, no evening dress, he accepted a post at princeton. one french physicist remarked only half in jest that it's as important an event as would be a transfer of the vatican from rome to the new world. the pope of physician sicks has moved, -- physics has moved, and the united states will now become the center of the natural sciences. also in 1933 we have frederick and -- the couple in the next

slide here. we have them discovering so-called artificial radioactivity. -- until then , physicists had known that by bombard it with a part cam of sufficient energy, a nucleus could be disintegrated and a new stable one forms. no one had realized that in certain circumstances an unstable element in the process of nuclear decay could be created. in other words, man could force the elements to release their energy in the form of radioactive decay. over the next few years, as international tensions grew in europe as a result of hitler's territory ambitions and as tensions grew in the far east because of those of japan, scientists strove further to illucidate the secrets of the accident.

--atom. and in rome we have the gentleman in the next slide here, enriqueo. photograph taken of him on his wedding day. fermi following up the discovery of artificial radioactivity. it was while he was in the process of irradiating elements with made what he he regarded as his most important finding that the most slowly neutrons traveled, the more likely they were to penetrate the target nucleus. and like many of the great discoveries, it really came about through intuition. he just decided on impulse to see what would happen if he filtered the neutrons he was filing as his target through a barrier of paraben. to his surprise, this increased the level of artificial radioactivity, but it was produced by about 100 fold. suspecting that the larger amount of hydrogen in the paraffin might be a factor, he experimented with another substance, also containing large

amounts of hydrogen. water. fermi's assistants carried it up from buckets from the gold fish fountain in the garden behind his laboratory which we'll see in the next slide. his laboratory had the institute of physics in rome. the affect was the same as with the paraffin. the level of artificial radioactivity was enormously enhanced. he deduced that the cause must be the protons in the hydrogen filter. they had a similar mass to the neutrons and colliding with them made the neutrons bounce elastically back and forth absorbing some of the momentum. by the time that the neutrons moved on to the target, their speed, which was ordinarily tens of thousands of kilometers a second had been sufficiently slowed or to use the terminology, moderated, for them to slide more easily into the target nuclei. on loan to fermi, the process would prove critical to the

development of the atomic bomb. now, germany had, of course, long been an international center of physics. not only for the pioneering of theoretical work of vana heissenberg. sitting there with fermi over to his right. he was doing important pioneering work. there was max bovends, irvin, and others. they were working on quantum and wave mechanics, but also on experimentedal work. on the experimental side the leaders were the chemists auto han and lisa. we see them in the next slide. initially, lisa's progress had been blocked by her gender rather than by her race. hitler's an exaches of --

annexation of austria had to mean she had to flee. auto hahn gave him his mother's diamond engagement ring to finance her journey. they continued to correspond in secret about science and to meet in neutral countries. one of the key topics was an experiment on uranium that hahn had been carrying out with another colleague, fritz strauseman. now, they had created what they firmly believed to be isotopes of radium. however, when they had attempted to use barium as a carrier to radium andract the the use of carrier chemicals to separate out substances produced by a neutron bombardment had by then become a standard technique, they found that they just couldn't separate the barium from the radium. she -- she listened carefully, and she advised auto hahn exactly what experiments he should

conduct to cross check his findings. 1938 lisa mitner was in sweden with her nephew who we have in the next slide. auto frish also a physicist had many distractions. they were deeply worried about his parents, who were still trapped in austria, and they were glad to look at some further information sent them by hahn as a distraction. as they walked and skied in the snow, they began to realize that what hahn had achieved was actually the splitting of the uranium nucleus. wrote to hahn, "you really do have a splitting of barium. wonderful finding. a really beautiful result." when frish returned to copien hagen where -- copenhagen where he was working with others, he was

invited to produce a paper. in so doing, he found a name for the new phenomenon. he asked an american colleague, the biologist william a. arnold, what he called the process by which single cells divide into two. arnold replied frishen. frish conducted experiments to determine their conclusions were right, and, thus, he became the first person to provide experimental proof of the fission of uranium atom when hit by a neutron. he went to bed in 1939 only in his words to be knocked out of bed four hours later by the post man bringing a telegram to say that his parents had been granted visas to emigrate to sweden. his happiness was complete. meanwhile, back in berlin hahn

and fritz strassmann were publishing their own experimental work. i'll just mention as sideline that fritz who used to work on the nazi bomb program, he was also during the war concealing a jewish pianist in his apartment in berlin. you can imagine the danger of that. this was something for which he would later be commemorated in jerusalem. back at this stage, strauseman and hahn were working on their own experiments, and they published the results. their publication made no mention of the contribution made by lisa mittner and auto frish because they could have hardly done so given the political climate in germany. soon after it was bore on a visit to the united states who announced the discovery of fission there, and we know that even before he had finished speaking, scientists went

rushing out of the room to try it for themselves. began working on at princeton, and in early february while he was puzzling over why the rate of uranium fission that he was observing was some 100 times less than he would have expected, he had one of those bursts of inspiration that characterizes the story. perhaps he reasoned the two isotopes present in uranium, the dominant i238, with 92 protons and the much rarer u2 35 with its 92 protons, but 1 3 -- 133 neutrons, perhaps they were behaving differently when bombarded with neutrons. if it only u2345 had uranium split and .ot the natural uranium

was almost entirely composed, this would explain the low rate of fission. bombarding for fissions to find a suitable target. afterr began talking row row on his blackboard, he made his calculations, his underlying hope that was if he was right u235 wasare isotope the key to nuclear fission, this an atomic bomb unviable. massive industrial effort would be required to separate out sufficient quantities of the isotope from natural uranium. u235ngth, convinced that was essential, bohr told a group who had gathered in his office princeton that, quote, you would need to turn the entire

factory.nto a however, some scientists, including the somewhat eccentric hungarian born refugee physicist, leo villard, who we in this next image here would be, they were worried. villard began to campaign amongst his colleagues to keep work on fission secret to hinder world'smpts by the actatorships to use it as weapon. that a had long believed nuclear bomb might be feasible patented34, he had such an idea while in britain and assigned the patent to the british admiralty. hethe u.s. in 1939, persuaded several colleagues not to publish their work. less successful with the french team under frederick joliot-curie who

marche his urgings, in 1939, published results suggesting that a self-sustaining chain reaction uranium might be possible. villard, he felt so strongly the dangers that in the persuaded1939 he einstein to write to president roosevelt, alerting him to the dangers of atomic weapons. the next slide we have the first page of what has become a famous letter. this stage, little action was taken since most believed,cientists that the engineering problems in producing the very large amounts of u235, which thought was required, were just insuperable, even if all other problems could be overcome. and they would need to be invinced by scientists

britain. britain and france had gone to with germany in september 1939. britain's scientists were concentrating hard on war work. in particular, on the radar.ment of however, many of the refugee in britainsettled work ont, as aliens, such classified projects. among them was otto frisch who refugee, theother gentleman we see in this next rudolph peiles. him in the physics department of birmingham university. winter andvery cold frisch only had a small gas fire in his bedroom. for warmth, he began to ponder exactly how much u235 would really be needed to make a bomb. peieles began to

workedte using a formula peieles for the so-called needed critical mass, the material needed to be brought together to start a chain and the result amazed them. others who tried to calculate critical mass had, according to frisch, tended to come out with tons. joliot-curie team estimated it at around 40 tons. peieles's first a pound,was about which as frisch observed, was not, after all, such a lot. frisch calculated that using the message of icen topic separation, he could produce a pound of reasonably just a matter of weeks. men also calculated whether the chain reaction would

causease enough to catastrophic explosion. backbling literally on the of an envelope, they worked out that a substantial amount of uranium would fissure, releasing energy equivalent to thousands of ordinary explosive. peieles later recalled, we were started by these results. possible, atb was least in principle. as a weapon, it would be so devastating that from a military view, it would be worth setting up a plant to separate the isotopes. in a classic understatement, we said to ourselves, even if this costs as much as a battleship, it would be worth having. further understatement, frisch said, thoughtfully to peieles, look, shouldn't somebody know about this. composed thethey famous frisch-peieles

compelling the three-page document dealt with scientific, strategic, but also ethical issues. it suggests that one might think one kilogram of uranium as a suitable size for the bomb. they also described how to explode a bomb with a mechanism oft would force two pieces uranium, constituting the together, at, tremendous speed. but the memorandum, it also addressed the human consequences. not only of the blast, which could probably destroy the theer of a big city, but of subsequent effect of radiation quote, would be fatal to living beings even a long explosion.the most of it, note predicted, would probably be blown into the air and carried away by a wind. this cloud of radioactive

kill everybody within a strip estimated to be several miles long. peielse and frisch suggested the high likely number of civilian casualties may make it unsuitable as a weapon for use by britain but they pointed out at that germans might be working a bomb. with no effective defense other than threat of retaliation of would worthpon, it developing as a deterrent, even the bombtended to use as a means of attack. the british government's advisers took the document seriously when it reached them and they created a to reviewed committee it. but difficult times. summer of 1940, the committee worked quickly, aware of britain's perilous position

but as they labored, they became more convinced that a bomb was feasible and they managed to france justrom before that country's surrender, heavyf europe's supply of water. james chadwick, who we see in slide, james chadwick the familiarwith features of general leslie groves on the left. thees, later the head of u.s. manhattan project, chadwick, who discovered the central to thew british project and he was out monitoring bomb craters during blitz with his geiger counter. he was checking that the germans dirty bombs,g dispersing nuclear material by conventional explosives. 1941 ofovery in in one of lawrence's

cyclotrons made him and other too,tists think this, might be another possible bomb fuel. the british scientists produced the summer report in of 1941 recommending that britain proceed with an atomic bomb project. churchill approved it with mordant wit writing that i am content with existing explosives, i feel we must not of improvement. meanwhile, the germans were, indeed, working on an atomic and it later turned out that the japanese, too, had an atomic project. what was going on in the united states? even before british scientists their final report to their own government, they colleagues ins to the neutral united states to to advance itsca own program. the leadership of the u.s. government's scientific programs

man,hanged to two dynamic bush and coinant. when they saw the report's content, they determined to show it to president roosevelt, having got confirm federation scientists, like ernest was,nce, that a bomb indeed, practicable. on saturday, december 6, 1941, held a meeting in washington to allocate tasks new and expanded atomic program, now sanctioned president roosevelt. thatlso in washington, busy saturday, in the u.s. navy cryptographyer's department, a young woman translated a decoded japanese telegram sent four days previously from tokyo the japanese consol in on u.s.o report

berthing positions and ship harbosh. at pearl concerned, she took the message to the head of department who told her he would get backing to it on monday. later, the4 hours commander-in-chief of the piped a board was his flagship to hear the first theages coming in about success of the surprise attack planes. harbor by his and this brings me to the end of decade. the story of what happened over years, although perhaps better known in outline, many intriguing twists. but these i have to leave for time, or perhaps to now questions. thank you very much, indeed. thank you. [applause]

and if anybody does have any questions, i will do my best to try and answer them. yes, sir. >> telegraph, german, japanese. tona: i was very interested find out what was going on in the axis countries. the situation was, when war you were starting with a level playing field. and interpretation of fission was out in public. it was the same in neats germany as in the allied countries so the allies were worried, they were many clever scientists in germany who could be making swift progress towards the bomb. like, that was the catalyst for the allied program. if you look at what was going to earlymany, you find that in the war, later by reports of -- of nuclearreports fission, the army set up a group

thecientists, called it uranium club, and identified a number of tasks and sent groups away to look at them but they a fairly small group of scientists. they were not cohesive. there were rivalries among them and they didn't agree on the same approaches and they began mistakes.chnical and that's also a factor at work early stages of the war, it looked as though things were going well for germany. sweeping across europe, the surrender of france, britain looking at if it would be any moment. invaded at the moment. do the germans have to invest money in this new won thegy if they had war quickly, anyway? but you find after the russians after pearl pearld harbor, that the question of developing a nuclear device is effort is seriously, put into it, levels of funding are debated and increased. have albert sper, the

inaments minister, involved this. as all of this boiled down to as the allies found when the intelligence team swept into europe on the heels of the invading forces, what they actually found when they arrested any german scientists they could find and when they found their experiments, which had been mostly evacuated from berlin, taken southwest in germany and concealed in places was alles, it small-scale stuff. they found an attempt to build what looked like a small reactor like a big dust bin thing. it was nothing that bore any to the massive allied project which reached the u.s. cars of the industry so for political the warations during which made the pendulum swing back and north germany, some attempts to construct a uranium burning reactor but no progress woulds anything we recognize as an explosive device

and the point about japan, i mentioned that in the early people wouldthis, work together, it was a scientific brotherhood and a japanese physicists had started in europe and in america and prime amongst them was a very talented scientific, who started particularly with rutherford and back in japan he was given the task by both the japanese army and the navy, who were in competition each other at this, because they had so few scientists who ofw about this new area science. at various in charge stages of projects for both arms forces to find methods of separating out uranium but he wasn't very successful. as side light, to show the cooperation before the war, that a device messina did have at his

cyclotron because lawrence had given him the it but machina's destroyed during bombing raids and although the japanese were investigating, they weren't far down the path at all. sir. espionageult of specifically in britain. diana: that's a very good point. go into this in detail in the book. what you have, i mentioned the of fission made on the eve of war. all of a sudden there's a lot scientificing in the literature as the shutters come the manyin russia, scientists, again, many started in germany and britain and america. this strange silence on the

subject of nuclear matters is by young particular whontist called flooroff alerted the authorities and stalin. he was suspicious of the dogs not bark in the night. what happened to the science that was going on. so under carchartoff, not bark e flamboyant practice of not beard, he was put in charge of a nuclear progress. theirare progress -- progress with this, russia was fighting a different war, germans. by the but in the later stages of the war, they were tremendously helped by very good information that was reaching them from the manhattan project, who was furnishing a lot of this gentleman called a lutheran, son of

pastor, communist, dedicated antinatser. he had come to england. his soviet handler told him to lie low. attention of british physicists, including rudolph pils, and when the team who came over from the manhattan put together, what would be more natural than that to take claust hooks with him. general groves who took a grim view of the arrival of the congingent at los alamos and no, no, we will put our own people through the security checks and everyone who comes to los alamos will be fine. this was notes true. claus hooks arrived at loss working on alclations in new york.

he worked on one of the most areas, the implosionalclations for the feedingm bomb and information back to the soviets. popular with people, always will be to babysit, very sociable, lends his old buick to a colleague. very quiet but everybody's friend. nobody notices some of the were saying,as you the soviet program significantly what hooks -- fo oks was telling them. was get the date right, it 1949 that the russians were able device and also the reason for stalin's calm and conferencese at the when president truman wandered

to him having decided it was the moment to tell stalin ande was a new weapon stalin said he's very glad to hear about this and hopes the british will use it on japan. doesn't ask questions. doesn't need to. question? this gentleman first. true that thenot germans managed to shoot themselves in both knees because best german nuclear physicists were jews who were the country? diana: absolutely. some of the most talented about rudolphlked parting fromstein departing germany and many who proved key to the building of the bomb or interpretation. you're exactly right.

we have that slide up here of day. on his wedding his wife, laura, was the italian armyn and theiro was jewish chance to escape from becausei's italy came fermi won the nobel prize. they packed up, went off to to receive the prize and never went home. they went to america and on have enrico fermi announcing he founded the u.s. br family.f the fermi you're absolutely right. some of the most talented people nazi germany and other countries overrun by the nazis. book, the ironic title -- [indiscernible] read that and that gives you a very good encapsalation of the individual people of many of these and i think there we've come to the end of our time but i'd like to thank you so much for coming this event ifr there are more questions people

have, i will be delighted to do them.t to answer thank you so much. thank you. >> does everyone know how to get the museum shop. it's very simple. you take the elevator. announcer: on history bookshelf, hear from the country's best known american history writers of the past decade every saturday at 4:00 p.m. eastern. of our can watch any programs at any time when you visit our website, c-span.org/history. you're watching american history weekend onend, every c-span3. sunday night on "q&a." like?t must that sound [crying]

>> what we're hearing are the children, immigrant children, who had just been separated from their parents in border patrol detention facility and it was an audio obtained a month and a so through -- with the help of a lawyer, civil rights attorney on the border, wray. jennifer hart and she obtained the tape and thought it was important and asked whatith me and i thought about it and i told her that i thought we should try to publish it. it wasn't an easy decision for tape who feltthat that, you know, the tape could put them at risk for being fired but the source ultimately agreed to

allow me and propublicca to publish the audio. announcer: ginger thompson talks covering mexico and the u.s. government's immigration 8:00y, sunday night at eastern on c-span's "q&a." announcer: each week, american tv's reel america brings you archival films that provide context for today's public affairs issues. >> they, the united states, keenly aware of its strategic the free leader in world, has allied itself with other nations dedicated to the peace andon of welfare of mankind. cameras today focus on one of the most important of these alliances. narrator, edward r. murrow, tells the story behind the north atlantic treato

organization , 1945, the war in end.e came to an been the price of europe's unpreparedness. our hard-won peace seemed at last secure. before, allied forces from the west joined hands with the russians from the east. cordiallyes men met atialitia and pots stan. the countries they occupied should be liberated and freely elected governments set up as soon as possible. andin a few months, europe

scandinavia were free and independent but for the countries occupied by russia, had other ideas. europe,ut eastern elections were held but the communists ind key government positions and in the secret police. thein a short time, non-communist leaders had been liquidated. russia swallowed up eight european countries without firing a shot, other than those of the execution squads. britain and the united states protested but these countries had been coerced by russiaof force and that had broken her treaty but russia ignored the protests. knew that the greater part of the allied forces had rusthome, leaving arms to in the fields of europe. in the west, men were impatient to be demobilized. the war was finished and they other work to do.

russians had not demobilized. they retained, overwhelmingly, in europe. force a small group of men in the had along ago dedicated themselves to the spreading of possible means. they knew in a an army can be used not only to fight wars, it to intimidate. to the south lay two more possible victims -- greece and turkey. march 1946, the russians denounced their treaty with turkey. they offered to renew it if the turks would give up part of ther territory and allow russians to establish bases.

the turks refused. hadreece, the communists already started civil war. arms to themnding through the neighboring satellite states to bring bitterness, despair and death to people.k perhaps turkey, were not also to be swallowed needed from the west. march 1947,is in president truman asked the states congress to modify its traditional policy of neutrality. that it must be the policy of the united states to who arefree peoples subjuigationempted

by armed minorities or outside pressures. announcer: you can watch this other american history programs on our website where all our video is archived. c-span.org/history. >> tonight at 8:00 p.m. eastern, america in turmoil, we look at women's rights. women protesting the 1968 miss america pageant and how women's rights became the national conversation, transforming workplaces across the country and society itself. turmoil,8, america in tonight at 8:00 p.m. eastern on c-span3 history tv on and also nine programs are available on spotify as a any time atatch c-span.org on our 1968

>> this year marks the 50th anniversary of the 1968 poor people's campaign, which martin luther king junior in vision to shift the focus of the civil rights movement to economic issues. reverend king was assassinated a few weeks before the campaign got underway in washington, d.c. next, former staffer to robert f. kennedy, peter edelman, and student nonviolent coordinating committee founding member, bernard lafayette, sat down at the smithsonian national museum of african american history & culture to discuss the people behind the campaign and how it started. this is one hour . panel, it iscond my pleasure to welcome a dear friend and inspiration. after winning a peabody award and raising the confidence of audience for