That the arts have been a considerable help that i had from the archives in writing this book. The destructive flash, which seared here she meant to history, was really the culmination of 50 years of scientific creativity and of 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 secrets of matter, not even future nobel Prize Winners i think couldve predicted how their pioneering insights would combine with exterior of vents to produce such a defining military history. For the time this of many nations this journey of discovery began way back in the 1890s. Researchers like mary carey, which we will see in this for slide here, researchers like mary kerry working alone or in small teams with rudimentary equipment. They started to identify the minute Building Blocks forming the world around them. Blinding discoveries were often matched by blind alleys. People rushed to publish the results not for profit or for National Prestige or often not even for personal glory, but rather for all the pure joy of knowledge. And for a long time, no one realized that their work could unlock Immense Energy to furnish a devastating new weapon or indeed, if probably harness, to fire city. In the early 20th century, we have radioactivity being seen as only producing benefits to health through the use of xrays for diagnosis and of Radioactive Materials to treat diseases including cancer. Physics after all was a new subject. The world perhaps 1000 physicists worldwide of whom 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 proved internationally as further pieces in a sort of communal jigsaw puzzle for which no one had the master picture or pictures. Scientists, they studied at each others into this. North americans visited germany. Germans came to britain. Britains went to north america. Colleagues, they skied, they hiked, they 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, they met a conferences where results were shared, contexts maintained and gossips exchanged. Albert einstein, who we have standing in the slide with mary carey, sorry Albert Einstein in the previous slide. Albert einstein, he called them, which is and i think few conferences were marked by gossip as that in brussels in 1911 when mary carey was forced to withdraw as a result of an alleged affair with paul, a close colleague and also a married man. However, personalities were strong and debate often heated particularly when those involved were, as one of them are called, undertaking to quote, wholly new processes of thought beyond all the previous notions in physics. Today, im going to be talking about the decade when what had fall nearly 40 years in a open quest for knowledge trying to muted 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 ends in december 1941 with pearl harbor and with the establishment of the u. S. Atomic bomb project. The neutron was identified by the gentlemen we see in this next slide here. James chadwick, over on the right. Chadwick, a thin englishman whose gesture has been ruined by internment in germany during the first world war. Chadwick worked at the world famous Cavendish Laboratory at Cambridge University in england. And the head of this laboratory was the socalled father of Experimental Nuclear physics. This was the new zealand or, earnest rutherford, we see in this next slide as a young man. Young earnest rutherford. He had probably fully identified alpha beta gamma radiation. He had fund for proton and with the dales needles bore, which weve seen this side, 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 negative recharged electrons orbited a positively charged nucleus. And a contemporary famously compare this vision of the nucleus within the adam to that of a fly within a cathedral. Now rutherford, who in his career with train 12 nobel laureates, he had long suspected the existence of the neutron but he had delegated the work to chadwick. And prompted by some results published by the french has been a wife team, we see it in this fight here. The daughter of mary carey. Prompted by some of those. Chadwick tackle the problem with increased figure in 1932 and applying the classic sealing wax and string principles of the cavendish to make his equipment the simplest and the cheapest fit for the purpose, we know that chadwick violated rutherfords rule but all work in the laboratory should seize by 6 pm. This was partly through 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 burrow liam was powerful enough to knock particles out of hydrogen, helium, lithium, brilliant, carbon. The particles expelled from hydrogen were clearly protons and the others were whole nuclei of a target substance. And his measurements of their penetrating power of velocity proved that gamma rays, as easily cure ease were claiming, could never cause huge action of particles of such energy. The only viable conclusion was that the radiation flowing soul possibly from the really im consisted of particles of mass one and charged zero. In other words, neutrons. Now chadwicks discovery, for which we will see in this next slide he received a nobel prize. We have chadwick over there to the right. This discovery provided the all important coup to any resolve 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 a difference late in the nucleus. Chadwicks findings prove that suspicion correct. What may isotopes different was the number of neutrons in their nuclei. But most exciting of all was a realization that since the neutron carry 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 the penetrated the nucleus of the item. But what nobody yet knew was that the neutron was also the catalyst for achieving an explosive Nuclear Chain reaction. Curiously though, the very year, 1932, we have the british writer nicholson publishing a novel novel called public faces. And in it he described a catastrophic new weapon made from a powerful new material. The substance could transmuted self 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 life over an indefinite area. The experts, nicholson wrote, had begun to whisper the words atomic bomb they claim that it could destroy new york. Now neutrons were not the only reason but 1932 was a spectacular year for science. In january, just a few weeks before chadwicks coup, we have the american chemist harold yuri making another discovery that rutherford had long predicted. Working at columbia, a university, yuri found natural uranium consisted of 99. 9 eight 5 ordinary hydrogen but also of 1 of heavy hydrogen. When isotopes given the name to cheerio, which also existed naturally in combination with oxygen in water. This socalled heavy water, to the naked eye really identical to ordinary water, it boiled and froze a different temperatures. 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 norway which was attacked by allied commanders during the war. But back in 1932, he thought of it as a delightful plaything for physicists. They could use it in bombarding other more complex adams so they could better understand nuclear structure. In april 1932, a few weeks after the neutron discovery, we have rutherford reporting a neither triumph. He wrote exuberantly, it never rains, but it pours. These two gentlemen we see in the next slide, they had just become the first scientists to split the atom using a manmade machine. A socalled 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 sometime earlier. They had created it to lovingly and creatively. Using plasticine, an Innovative New material, which relates to the ceiling wax they previously used for the purpose. They smooth that over the joints to create a vacuum. Varying that rivals might overtake them, rutherford had urged them to stop perfecting it and to do what he told him to do months ago, in other words start experimenting. His bullying paid off. They bombarded lithium with accelerated protons and succeeded in disintegrating the lithium nucleus into two helium nuclei. According to one of his colleagues, normally about as much given to this much emotional display as the duke wellington, he went running through cambridge yelling we split the atom. We split the atom. An additional excitement was that the energies of the particles measured by them provided the first experimental confirmation of einsteins proposal. But rutherford had been right to fear competition. That cavendish may easily have been upstaged by the american, earnest lawrence working at berkeley. And this next slide, lawrence and berkeley. He had been developing the cyclotron. He had the original thought that if he could confine particles with electromagnets within a circular track rather than pushing them along a straight line, that he could accelerate them indefinitely, causing them to whiz faster after each burst of voltage. It would, in his words, be a proton merrygoround. He told his friends confidently and accurately as it turned out, im going to bombard and break up adams. Im going to be famous. Lawrence is first machine did not look anything like that. It was a four inch pillbox spreading arms like an octopus. When he demonstrated it to the u. S. National academy of sciences, he secured it to a kitchen chair with a clothes hanger. But despite its absurd appearance, its potential caused a sensation. Newspapers hailed the invention of a device to break up adams, and they were right. So good with his progress that by the end of the 19, lawrence would build a cyclotron with a magnet weighing 220 tons. Inspired by the desire to explore one of the tiniest things in existence, the nucleus of the adam. Big scientists 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. Im sure you will have recognized the gentleman standing to the left of lawrence there. Robert open high moore. In the time he came to join lawrence, he was 25 years old. In the next slide we see oppenheimer as a young man. Slender lee built with intensely blue eyes, friends thought him, to quote, both subtly wise and terribly innocent. He was also sensitive, conceited, often neurotic, but charismatic lee engaging. And though passionate about physics, he was a renaissance man with obsessions ranging from indoor philosophy to dantes inferno. Oppenheimer he did off at once with laureates who is just three years a senior. Admiring his unbelievable vitality and love of life. A socialized and womanist together. Drinking oppenheimers famous frozen martinis with glasses rimmed with lunges and honey. And eating his speciality, a spicy indonesian dish. They also point writing. As we see from this next shot here, photographs of the time show lawrence top, sturdy, smiling. Oppenheimer over on the left here with frizz of dark hair, his slighter frame clad in healed mexican boots and wearing jeans. And with a quizzical yet dreamy expression. I think he resembles a young bob dylan. Lawrence and oppenheimer attended weekly seminars where oppenheimer, the future scientific eight of the u. S. Atomic bomb project, amazed everybody with his ability to simulate new ideas. His extraordinary memory and the fact that, to go to contemporary, he knew more experimental physics than even the experimental physicists did. In 1932, he wrote to his brother that, to quote, we are busy studying nuclei and neutrons and disintegrations. Trying to make some peace between the inadequate berry and the absurd revolutionary experiments. Just as oppenheim or had hoped, atomic physics was by now no longer europes exclusive preserve. On a visit to prickly in 1933, he was pretty startled to find it was more run like a factory than a laboratory. In his words, the experiment ares were divided into shifts. Maintenance shifts and experiment ares. When a leak or fault developed in the cyclotron, the Maintenance Crew rushed forward to plug the leaks and fix the fault, at which point the operating shifts russian again. It was far removed from small scale expense conscious world at the cavendish. It was a warning that the cavendish might soon be outclassed. But 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 from their posts but hitlers aryan degrees. These included some of the very best physicists of their generation and many made their way to britain and the usa. They understood the danger of hitler and the nazis only too well. Among them were several who would help make the atomic bomb a reality. Albert einstein, germanys most famous scientists, crossed the channel to england with his wife elsa, protected by a British Naval commander who had the singular experience of having once been invited to kill rescue can. The autumn of 1933, finding england two formal and preferring a life with, as einstein said, no butlers, no evening dress, he accepted a post at princeton. And one french physicist remarked, i think only half in jest, that its as important and event as would be the transfer of the vatican from rome to the new world. The pope a physics has moved and the United States will now become the center of the natural sciences. Also in 1933, we had frederick and elaine, who we see in this next slide here. We have then discovered socalled artificial radioactivity until then physicists have known that by bombarding it with a particle of sufficient energy, a nucleus could be integrated and a new stable one formed. But no one had realized that certain circumstances and 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 radio active decay. Over the next few years, as International Tensions grow in europe as a result of hitlers territorial ambitions, and as tensions grew in the far east because of those in japan, scientists strove further to elucidate the secrets of the adam. And in rome we have this gentleman in the next slide here. Photograph taken of him on his wedding day. Following the discovery of artificial radioactivity. And it was while he was in the process of radiating elements with neutrons that he made what he regarded as his most important finding. That the more slowly and neutron travel, 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 just to see what would happen if you filter the neutrons he was firing at his target through a barrier of paraffin. To his surprise, this increased a level of radioactivity that was produced by about 100 fold. Suspecting that the large amount of hydrogen in the paraffin might be a factor, he experimented with another substance also containing large amounts of hydrogen. This was water. His assistance carried it up in buckets from the fountain in the garden behind his laboratory, which we will see in the next slide. His laboratory at the institute of physics in rome. And the effect was a same as with the paraffin. The level of artificial radioactivity was enormously enhanced. Firmly deduced that the cause might be the protons in the Hydrogen Photo they had a similar mass to the neutrons and colliding with them made the neutrons elastically backandforth, absorbing some of the momentum. By the time that the neutrons moved on to the target, the 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. And unknown to him, the process would prove critical to the development of the atomic bomb. Now germany had of course long been the International Center of physics. Not only for the pioneering, theoretical work of highs amber, who we see in this next side here. Eisenberg sitting in the middle there. He was doing important work so was not born, and others. They were working on quantum and wave mechanics but also on experimental marks. And on the experimental side, the leaders were the chemists auto hahn and an austrian born physicist a jewish ancestry, lisa. We see her in the next slide. An issue ali, progress was blocked by her gender rather than by her race. But in 1938, hitlers annexation of austria meant that she had to free germany and she escaped with literally just hours to spare. Otto hahn, gave her his engagement to finance her journey. But they continue to correspond in secret but silent and to meet a neutral countries. And one of the key topics was an experiment on uranium that harm hahn had been carrying out with another colleague. Now they had created what they firmly believed to be isotopes of radium. However, when they had attempted to use a burial as a carrier to help extract the radium, and the use of carrier chemicals to separate substances produced by neutral bombardment had then become extended technique. They found that they just could not separate the from beryllium the radium. Might not listen very carefully and then she advised auto hahn, exactly what experiments she could conduct to cross check his findings. Christmas, 1938 lisa wasnt sweetened with her nephew otto fresh who we have in the next slide. Also a physicist. There are many distractions they were deeply worried about his parents who we