nc33/multispan_quoref huggingface dataset:
The Five was among the myriad of subjects Tchaikovsky discussed with his benefactress, Nadezhda von Meck. By January 1878, when he wrote to Mrs. von Meck about its members, he had drifted far from their musical world and ideals. In addition, The Five's finest days had long passed. Despite considerable effort in writing operas and songs, Cui had become better known as a critic than as a composer, and even his critical efforts competed for time with his career as an army engineer and expert in the science of fortification. Balakirev had withdrawn completely from the musical scene, Mussorgsky was sinking ever deeper into alcoholism, and Borodin's creative activities increasingly took a back seat to his official duties as a professor of chemistry.
Only Rimsky-Korsakov actively pursued a full-time musical career, and he was under increasing fire from his fellow nationalists for much the same reason as Tchaikovsky had been. Like Tchaikovsky, Rimsky-Korsakov had found that, for his own artistic growth to continue unabated, he had to study and master Western classical forms and techniques. Borodin called it "apostasy", adding, "Many are grieved at present by the fact that Korsakov has turned back, has thrown himself into a study of musical antiquity. I do not bemoan it. It is understandable...." Mussorgsky was harsher: "[T]he mighty kuchka had degenerated into soulless traitors."Tchaikovsky's analysis of each of The Five was unsparing. While at least some of his observations may seem distorted and prejudiced, he also mentions some details which ring clear and true. His diagnosis of Rimsky-Korsakov's creative crisis is very accurate. He also calls Mussorgsky the most gifted musically of the Five, though Tchaikovsky could not appreciate the forms Mussorgsky's originality took. Nonetheless, he badly underestimates Borodin's technique and gives Balakirev far less than his full due—all the more telling in light of Balakirev's help in conceiving and shaping Romeo and Juliet.Tchaikovsky wrote to Nadezhda von Meck that all of the kuchka were talented but also "infected to the core" with conceit and "a purely dilettantish confidence in their superiority." He went into some detail about Rimsky-Korsakov's epiphany and turnaround regarding musical training, and his efforts to remedy this situation for himself. Tchaikovsky then called Cui "a talented dilettante" whose music "has no originality, but is clever and graceful"; Borodin a man who "has talent, even a strong one, but it has perished through neglect ... and his technique is so weak that he cannot write a single line [of music] without outside help"; Mussorgsky "a hopeless case", superior in talent but "narrow-minded, devoid of any urge towards self-perfection"; and Balakirev as one with "enormous talent" yet who had also "done much harm" as "the general inventor of all the theories of this strange group".

Question: What is the name of the person who badly underestimates Borodin's technique and gives Balakirev far less than his full due—all the more telling in light of Balakirev's help in conceiving and shaping Romeo and Juliet?
Answer: Tchaikovsky
Tchaikovsky finished his final revision of Romeo and Juliet in 1880, and felt it a courtesy to send a copy of the score to Balakirev. Balakirev, however, had dropped out of the music scene in the early 1870s and Tchaikovsky had lost touch with him. He asked the publisher Bessel to forward a copy to Balakirev. A year later Balakirev replied. In the same letter that he thanked Tchaikovsky profusely for the score, Balakirev suggested "the programme for a symphony which you would handle wonderfully well", a detailed plan for a symphony based on Lord Byron's Manfred. Originally drafted by Stasov in 1868 for Hector Berlioz as a sequel to that composer's Harold en Italie, the program had since been in Balakirev's care.
Tchaikovsky declined the project at first, saying the subject left him cold. Balakirev persisted. "You must, of course, make an effort", Balakirev exhorted, "take a more self-critical approach, don't hurry things". Tchaikovsky's mind was changed two years later, in the Swiss Alps, while tending to his friend Iosif Kotek and after he had re-read Manfred in the milieu in which the poem is set. Once he returned home, Tchaikovsky revised the draft Balakirev had made from Stasov's program and began sketching the first movement.The Manfred Symphony would cost Tchaikovsky more time, effort and soul-searching than anything else he would write, even the Pathetique Symphony. It also became the longest, most complex work he had written up to that point, and though it owes an obvious debt to Berlioz due to its program, Tchaikovsky was still able to make the theme of Manfred his own. Near the end of seven months of intensive effort, in late September 1885, he wrote Balakirev, "Never in my life, believe me, have I labored so long and hard, and felt so drained by my efforts. The Symphony is written in four movements, as per your program, although—forgive me—as much as I wanted to, I have not been able to keep all the keys and modulations you suggested ... It is of course dedicated to you".Once he had finished the symphony, Tchaikovsky was reluctant to further tolerate Balakirev's interference, and severed all contact; he told his publisher P. Jurgenson that he considered Balakirev a "madman". Tchaikovsky and Balakirev exchanged only a few formal, not overly friendly letters after this breach.

Question: What is the name of the person who asked the publisher Bessel to forward a copy to Balakirev?
Answer: Tchaikovsky
This was followed up by a group of scientists at the Collège de France in Paris: Frédéric Joliot-Curie, Hans von Halban, Lew Kowarski, and Francis Perrin. In February 1939, the Paris Group showed that when fission occurs in uranium, two or three extra neutrons are given off. This important observation suggested that a self-sustaining nuclear chain reaction might be possible. The term "atomic bomb" was already familiar to the British public through the writings of H. G. Wells, in his 1913 novel The World Set Free. It was immediately apparent to many scientists that, in theory at least, an extremely powerful explosive could be created, although most still considered an atomic bomb was an impossibility. Perrin defined a critical mass of uranium to be the smallest amount that could sustain a chain reaction. The neutrons used to cause fission in uranium are considered slow neutrons, but when neutrons are released during a fission reaction they are released as fast neutrons which have much more speed and energy. Thus, in order to create a sustained chain reaction, there existed a need for a neutron moderator to contain and slow the fast neutrons until they reached a usable energy level. The College de France found that both water and graphite could be used as acceptable moderators.Early in 1940, the Paris Group decided on theoretical grounds that heavy water would be an ideal moderator for how they intended to use it. They asked the French Minister of Armaments to obtain as much heavy water as possible from the only source, the large Norsk Hydro hydroelectric station at Vemork in Norway. The French then discovered that Germany had already offered to purchase the entire stock of Norwegian heavy water, indicating that Germany might also be researching an atomic bomb. The French told the Norwegian government of the possible military significance of heavy water. Norway gave the entire stock of 187 litres (41 imp gal; 49 US gal) to a Deuxième Bureau agent, who secretly brought it to France just before Germany invaded Norway in April 1940. On 19 June 1940, following the German invasion of France, it was shipped to England by the Earl of Suffolk and Major Ardale Golding, aboard the steamer Broompark. The heavy water, valued at £22,000, was initially kept at HM Prison Wormwood Scrubs, and was later secretly stored in the library at Windsor Castle. The Paris Group moved to Cambridge, with the exception of Joliot-Curie, who remained in France and became active in the French Resistance.

Question: What country did heavy water come from?
Answer: Norway
This was followed up by a group of scientists at the Collège de France in Paris: Frédéric Joliot-Curie, Hans von Halban, Lew Kowarski, and Francis Perrin. In February 1939, the Paris Group showed that when fission occurs in uranium, two or three extra neutrons are given off. This important observation suggested that a self-sustaining nuclear chain reaction might be possible. The term "atomic bomb" was already familiar to the British public through the writings of H. G. Wells, in his 1913 novel The World Set Free. It was immediately apparent to many scientists that, in theory at least, an extremely powerful explosive could be created, although most still considered an atomic bomb was an impossibility. Perrin defined a critical mass of uranium to be the smallest amount that could sustain a chain reaction. The neutrons used to cause fission in uranium are considered slow neutrons, but when neutrons are released during a fission reaction they are released as fast neutrons which have much more speed and energy. Thus, in order to create a sustained chain reaction, there existed a need for a neutron moderator to contain and slow the fast neutrons until they reached a usable energy level. The College de France found that both water and graphite could be used as acceptable moderators.Early in 1940, the Paris Group decided on theoretical grounds that heavy water would be an ideal moderator for how they intended to use it. They asked the French Minister of Armaments to obtain as much heavy water as possible from the only source, the large Norsk Hydro hydroelectric station at Vemork in Norway. The French then discovered that Germany had already offered to purchase the entire stock of Norwegian heavy water, indicating that Germany might also be researching an atomic bomb. The French told the Norwegian government of the possible military significance of heavy water. Norway gave the entire stock of 187 litres (41 imp gal; 49 US gal) to a Deuxième Bureau agent, who secretly brought it to France just before Germany invaded Norway in April 1940. On 19 June 1940, following the German invasion of France, it was shipped to England by the Earl of Suffolk and Major Ardale Golding, aboard the steamer Broompark. The heavy water, valued at £22,000, was initially kept at HM Prison Wormwood Scrubs, and was later secretly stored in the library at Windsor Castle. The Paris Group moved to Cambridge, with the exception of Joliot-Curie, who remained in France and became active in the French Resistance.

Question: In what country did all the heavy water end up?
Answer: England
This was followed up by a group of scientists at the Collège de France in Paris: Frédéric Joliot-Curie, Hans von Halban, Lew Kowarski, and Francis Perrin. In February 1939, the Paris Group showed that when fission occurs in uranium, two or three extra neutrons are given off. This important observation suggested that a self-sustaining nuclear chain reaction might be possible. The term "atomic bomb" was already familiar to the British public through the writings of H. G. Wells, in his 1913 novel The World Set Free. It was immediately apparent to many scientists that, in theory at least, an extremely powerful explosive could be created, although most still considered an atomic bomb was an impossibility. Perrin defined a critical mass of uranium to be the smallest amount that could sustain a chain reaction. The neutrons used to cause fission in uranium are considered slow neutrons, but when neutrons are released during a fission reaction they are released as fast neutrons which have much more speed and energy. Thus, in order to create a sustained chain reaction, there existed a need for a neutron moderator to contain and slow the fast neutrons until they reached a usable energy level. The College de France found that both water and graphite could be used as acceptable moderators.Early in 1940, the Paris Group decided on theoretical grounds that heavy water would be an ideal moderator for how they intended to use it. They asked the French Minister of Armaments to obtain as much heavy water as possible from the only source, the large Norsk Hydro hydroelectric station at Vemork in Norway. The French then discovered that Germany had already offered to purchase the entire stock of Norwegian heavy water, indicating that Germany might also be researching an atomic bomb. The French told the Norwegian government of the possible military significance of heavy water. Norway gave the entire stock of 187 litres (41 imp gal; 49 US gal) to a Deuxième Bureau agent, who secretly brought it to France just before Germany invaded Norway in April 1940. On 19 June 1940, following the German invasion of France, it was shipped to England by the Earl of Suffolk and Major Ardale Golding, aboard the steamer Broompark. The heavy water, valued at £22,000, was initially kept at HM Prison Wormwood Scrubs, and was later secretly stored in the library at Windsor Castle. The Paris Group moved to Cambridge, with the exception of Joliot-Curie, who remained in France and became active in the French Resistance.

Question: What was the final hiding place in England for the heavy water?
Answer: Windsor Castle
This was followed up by a group of scientists at the Collège de France in Paris: Frédéric Joliot-Curie, Hans von Halban, Lew Kowarski, and Francis Perrin. In February 1939, the Paris Group showed that when fission occurs in uranium, two or three extra neutrons are given off. This important observation suggested that a self-sustaining nuclear chain reaction might be possible. The term "atomic bomb" was already familiar to the British public through the writings of H. G. Wells, in his 1913 novel The World Set Free. It was immediately apparent to many scientists that, in theory at least, an extremely powerful explosive could be created, although most still considered an atomic bomb was an impossibility. Perrin defined a critical mass of uranium to be the smallest amount that could sustain a chain reaction. The neutrons used to cause fission in uranium are considered slow neutrons, but when neutrons are released during a fission reaction they are released as fast neutrons which have much more speed and energy. Thus, in order to create a sustained chain reaction, there existed a need for a neutron moderator to contain and slow the fast neutrons until they reached a usable energy level. The College de France found that both water and graphite could be used as acceptable moderators.Early in 1940, the Paris Group decided on theoretical grounds that heavy water would be an ideal moderator for how they intended to use it. They asked the French Minister of Armaments to obtain as much heavy water as possible from the only source, the large Norsk Hydro hydroelectric station at Vemork in Norway. The French then discovered that Germany had already offered to purchase the entire stock of Norwegian heavy water, indicating that Germany might also be researching an atomic bomb. The French told the Norwegian government of the possible military significance of heavy water. Norway gave the entire stock of 187 litres (41 imp gal; 49 US gal) to a Deuxième Bureau agent, who secretly brought it to France just before Germany invaded Norway in April 1940. On 19 June 1940, following the German invasion of France, it was shipped to England by the Earl of Suffolk and Major Ardale Golding, aboard the steamer Broompark. The heavy water, valued at £22,000, was initially kept at HM Prison Wormwood Scrubs, and was later secretly stored in the library at Windsor Castle. The Paris Group moved to Cambridge, with the exception of Joliot-Curie, who remained in France and became active in the French Resistance.

Question: What was shipped to England by the Earl of Suffolk and Major Ardale Golding?
Answer: heavy water
This was followed up by a group of scientists at the Collège de France in Paris: Frédéric Joliot-Curie, Hans von Halban, Lew Kowarski, and Francis Perrin. In February 1939, the Paris Group showed that when fission occurs in uranium, two or three extra neutrons are given off. This important observation suggested that a self-sustaining nuclear chain reaction might be possible. The term "atomic bomb" was already familiar to the British public through the writings of H. G. Wells, in his 1913 novel The World Set Free. It was immediately apparent to many scientists that, in theory at least, an extremely powerful explosive could be created, although most still considered an atomic bomb was an impossibility. Perrin defined a critical mass of uranium to be the smallest amount that could sustain a chain reaction. The neutrons used to cause fission in uranium are considered slow neutrons, but when neutrons are released during a fission reaction they are released as fast neutrons which have much more speed and energy. Thus, in order to create a sustained chain reaction, there existed a need for a neutron moderator to contain and slow the fast neutrons until they reached a usable energy level. The College de France found that both water and graphite could be used as acceptable moderators.Early in 1940, the Paris Group decided on theoretical grounds that heavy water would be an ideal moderator for how they intended to use it. They asked the French Minister of Armaments to obtain as much heavy water as possible from the only source, the large Norsk Hydro hydroelectric station at Vemork in Norway. The French then discovered that Germany had already offered to purchase the entire stock of Norwegian heavy water, indicating that Germany might also be researching an atomic bomb. The French told the Norwegian government of the possible military significance of heavy water. Norway gave the entire stock of 187 litres (41 imp gal; 49 US gal) to a Deuxième Bureau agent, who secretly brought it to France just before Germany invaded Norway in April 1940. On 19 June 1940, following the German invasion of France, it was shipped to England by the Earl of Suffolk and Major Ardale Golding, aboard the steamer Broompark. The heavy water, valued at £22,000, was initially kept at HM Prison Wormwood Scrubs, and was later secretly stored in the library at Windsor Castle. The Paris Group moved to Cambridge, with the exception of Joliot-Curie, who remained in France and became active in the French Resistance.

Question: What is the full name of the person who defined a critical mass of uranium to be the smallest amount that could sustain a chain reaction?
Answer: Francis Perrin
This was followed up by a group of scientists at the Collège de France in Paris: Frédéric Joliot-Curie, Hans von Halban, Lew Kowarski, and Francis Perrin. In February 1939, the Paris Group showed that when fission occurs in uranium, two or three extra neutrons are given off. This important observation suggested that a self-sustaining nuclear chain reaction might be possible. The term "atomic bomb" was already familiar to the British public through the writings of H. G. Wells, in his 1913 novel The World Set Free. It was immediately apparent to many scientists that, in theory at least, an extremely powerful explosive could be created, although most still considered an atomic bomb was an impossibility. Perrin defined a critical mass of uranium to be the smallest amount that could sustain a chain reaction. The neutrons used to cause fission in uranium are considered slow neutrons, but when neutrons are released during a fission reaction they are released as fast neutrons which have much more speed and energy. Thus, in order to create a sustained chain reaction, there existed a need for a neutron moderator to contain and slow the fast neutrons until they reached a usable energy level. The College de France found that both water and graphite could be used as acceptable moderators.Early in 1940, the Paris Group decided on theoretical grounds that heavy water would be an ideal moderator for how they intended to use it. They asked the French Minister of Armaments to obtain as much heavy water as possible from the only source, the large Norsk Hydro hydroelectric station at Vemork in Norway. The French then discovered that Germany had already offered to purchase the entire stock of Norwegian heavy water, indicating that Germany might also be researching an atomic bomb. The French told the Norwegian government of the possible military significance of heavy water. Norway gave the entire stock of 187 litres (41 imp gal; 49 US gal) to a Deuxième Bureau agent, who secretly brought it to France just before Germany invaded Norway in April 1940. On 19 June 1940, following the German invasion of France, it was shipped to England by the Earl of Suffolk and Major Ardale Golding, aboard the steamer Broompark. The heavy water, valued at £22,000, was initially kept at HM Prison Wormwood Scrubs, and was later secretly stored in the library at Windsor Castle. The Paris Group moved to Cambridge, with the exception of Joliot-Curie, who remained in France and became active in the French Resistance.

Question: What are the last names of the people who asked the French Minister of Armaments to obtain as much heavy water as possible?
Answer: Joliot-Curie, Halban, Kowarski, Perrin
At Birmingham, Oliphant's team had reached a different conclusion. Oliphant had delegated the task to two German refugee scientists, Rudolf Peierls and Otto Frisch, who could not work on Oliphant's radar project because they were enemy aliens and therefore lacked the necessary security clearance. Francis Perrin had calculated the critical mass of uranium to be about 40 tonnes (39 long tons; 44 short tons). He reckoned that if a neutron reflector were placed around it, this might be reduced to 12 tonnes (12 long tons; 13 short tons). Peierls attempted to simplify the problem by using the fast neutrons produced by fission, thus omitting consideration of moderator. He too calculated the critical mass of a sphere of uranium in a theoretical paper written in 1939 to be "of the order of tons".Peierls knew the importance of the size of the critical mass that would allow a chain reaction to take place and its practical significance. In the interior of a critical mass sphere, neutrons are spontaneously produced by the fissionable material. A very small portion of these neutrons are colliding with other nuclei, while a larger portion of the neutrons are escaping through the surface of the sphere. Peierls calculated the equilibrium of the system, where the number of neutrons being produced equalled the number escaping.Niels Bohr had theorised that the rare uranium-235 isotope, which makes up only about 0.7% of natural uranium, was primarily responsible for fission with fast neutrons, although this was not yet universally accepted. Frisch and Peierls were thus able to revise their initial estimate of critical mass needed for nuclear fission in uranium to be substantially less than previously assumed. They estimated a metallic sphere of uranium-235 with a radius of 2.1 centimetres (0.83 in) could suffice. This amount represented approximately 1 kilogram (2.2 lb) of uranium-235. These results led to the Frisch–Peierls memorandum, which was the initial step in the development of the nuclear arms programme in Britain. This marked the beginning of an aggressive approach towards uranium enrichment and the development of an atomic bomb. They now began to investigate processes by which they could successfully separate the uranium isotope.Oliphant took their findings to Tizard in his capacity as the chairman of the Committee for the Scientific Survey of Air Warfare (CSSAW). He in turn passed them to Thomson, to whom the CSSAW had delegated responsibility for uranium research. After discussions between Cockcroft, Oliphant and Thomson, CSSAW created the MAUD Committee to investigate further.

Question: What were the last names of the two people who were enemy aliens?
Answer: Peierls, Frisch
At Birmingham, Oliphant's team had reached a different conclusion. Oliphant had delegated the task to two German refugee scientists, Rudolf Peierls and Otto Frisch, who could not work on Oliphant's radar project because they were enemy aliens and therefore lacked the necessary security clearance. Francis Perrin had calculated the critical mass of uranium to be about 40 tonnes (39 long tons; 44 short tons). He reckoned that if a neutron reflector were placed around it, this might be reduced to 12 tonnes (12 long tons; 13 short tons). Peierls attempted to simplify the problem by using the fast neutrons produced by fission, thus omitting consideration of moderator. He too calculated the critical mass of a sphere of uranium in a theoretical paper written in 1939 to be "of the order of tons".Peierls knew the importance of the size of the critical mass that would allow a chain reaction to take place and its practical significance. In the interior of a critical mass sphere, neutrons are spontaneously produced by the fissionable material. A very small portion of these neutrons are colliding with other nuclei, while a larger portion of the neutrons are escaping through the surface of the sphere. Peierls calculated the equilibrium of the system, where the number of neutrons being produced equalled the number escaping.Niels Bohr had theorised that the rare uranium-235 isotope, which makes up only about 0.7% of natural uranium, was primarily responsible for fission with fast neutrons, although this was not yet universally accepted. Frisch and Peierls were thus able to revise their initial estimate of critical mass needed for nuclear fission in uranium to be substantially less than previously assumed. They estimated a metallic sphere of uranium-235 with a radius of 2.1 centimetres (0.83 in) could suffice. This amount represented approximately 1 kilogram (2.2 lb) of uranium-235. These results led to the Frisch–Peierls memorandum, which was the initial step in the development of the nuclear arms programme in Britain. This marked the beginning of an aggressive approach towards uranium enrichment and the development of an atomic bomb. They now began to investigate processes by which they could successfully separate the uranium isotope.Oliphant took their findings to Tizard in his capacity as the chairman of the Committee for the Scientific Survey of Air Warfare (CSSAW). He in turn passed them to Thomson, to whom the CSSAW had delegated responsibility for uranium research. After discussions between Cockcroft, Oliphant and Thomson, CSSAW created the MAUD Committee to investigate further.

Question: What was the full name of the person who attempted to simplify the problem by using the fast neutrons produced by fission?
Answer: Rudolf Peierls
At Birmingham, Oliphant's team had reached a different conclusion. Oliphant had delegated the task to two German refugee scientists, Rudolf Peierls and Otto Frisch, who could not work on Oliphant's radar project because they were enemy aliens and therefore lacked the necessary security clearance. Francis Perrin had calculated the critical mass of uranium to be about 40 tonnes (39 long tons; 44 short tons). He reckoned that if a neutron reflector were placed around it, this might be reduced to 12 tonnes (12 long tons; 13 short tons). Peierls attempted to simplify the problem by using the fast neutrons produced by fission, thus omitting consideration of moderator. He too calculated the critical mass of a sphere of uranium in a theoretical paper written in 1939 to be "of the order of tons".Peierls knew the importance of the size of the critical mass that would allow a chain reaction to take place and its practical significance. In the interior of a critical mass sphere, neutrons are spontaneously produced by the fissionable material. A very small portion of these neutrons are colliding with other nuclei, while a larger portion of the neutrons are escaping through the surface of the sphere. Peierls calculated the equilibrium of the system, where the number of neutrons being produced equalled the number escaping.Niels Bohr had theorised that the rare uranium-235 isotope, which makes up only about 0.7% of natural uranium, was primarily responsible for fission with fast neutrons, although this was not yet universally accepted. Frisch and Peierls were thus able to revise their initial estimate of critical mass needed for nuclear fission in uranium to be substantially less than previously assumed. They estimated a metallic sphere of uranium-235 with a radius of 2.1 centimetres (0.83 in) could suffice. This amount represented approximately 1 kilogram (2.2 lb) of uranium-235. These results led to the Frisch–Peierls memorandum, which was the initial step in the development of the nuclear arms programme in Britain. This marked the beginning of an aggressive approach towards uranium enrichment and the development of an atomic bomb. They now began to investigate processes by which they could successfully separate the uranium isotope.Oliphant took their findings to Tizard in his capacity as the chairman of the Committee for the Scientific Survey of Air Warfare (CSSAW). He in turn passed them to Thomson, to whom the CSSAW had delegated responsibility for uranium research. After discussions between Cockcroft, Oliphant and Thomson, CSSAW created the MAUD Committee to investigate further.

Question: What was the first name of the person who calculated critical mass of a sphere of uranium in a theoretical paper?
Answer: Rudolf
At Birmingham, Oliphant's team had reached a different conclusion. Oliphant had delegated the task to two German refugee scientists, Rudolf Peierls and Otto Frisch, who could not work on Oliphant's radar project because they were enemy aliens and therefore lacked the necessary security clearance. Francis Perrin had calculated the critical mass of uranium to be about 40 tonnes (39 long tons; 44 short tons). He reckoned that if a neutron reflector were placed around it, this might be reduced to 12 tonnes (12 long tons; 13 short tons). Peierls attempted to simplify the problem by using the fast neutrons produced by fission, thus omitting consideration of moderator. He too calculated the critical mass of a sphere of uranium in a theoretical paper written in 1939 to be "of the order of tons".Peierls knew the importance of the size of the critical mass that would allow a chain reaction to take place and its practical significance. In the interior of a critical mass sphere, neutrons are spontaneously produced by the fissionable material. A very small portion of these neutrons are colliding with other nuclei, while a larger portion of the neutrons are escaping through the surface of the sphere. Peierls calculated the equilibrium of the system, where the number of neutrons being produced equalled the number escaping.Niels Bohr had theorised that the rare uranium-235 isotope, which makes up only about 0.7% of natural uranium, was primarily responsible for fission with fast neutrons, although this was not yet universally accepted. Frisch and Peierls were thus able to revise their initial estimate of critical mass needed for nuclear fission in uranium to be substantially less than previously assumed. They estimated a metallic sphere of uranium-235 with a radius of 2.1 centimetres (0.83 in) could suffice. This amount represented approximately 1 kilogram (2.2 lb) of uranium-235. These results led to the Frisch–Peierls memorandum, which was the initial step in the development of the nuclear arms programme in Britain. This marked the beginning of an aggressive approach towards uranium enrichment and the development of an atomic bomb. They now began to investigate processes by which they could successfully separate the uranium isotope.Oliphant took their findings to Tizard in his capacity as the chairman of the Committee for the Scientific Survey of Air Warfare (CSSAW). He in turn passed them to Thomson, to whom the CSSAW had delegated responsibility for uranium research. After discussions between Cockcroft, Oliphant and Thomson, CSSAW created the MAUD Committee to investigate further.

Question: What were the full names of the two people who calculated the critical mass of uranium?
Answer: Rudolf Peierls, Francis Perrin
At Birmingham, Oliphant's team had reached a different conclusion. Oliphant had delegated the task to two German refugee scientists, Rudolf Peierls and Otto Frisch, who could not work on Oliphant's radar project because they were enemy aliens and therefore lacked the necessary security clearance. Francis Perrin had calculated the critical mass of uranium to be about 40 tonnes (39 long tons; 44 short tons). He reckoned that if a neutron reflector were placed around it, this might be reduced to 12 tonnes (12 long tons; 13 short tons). Peierls attempted to simplify the problem by using the fast neutrons produced by fission, thus omitting consideration of moderator. He too calculated the critical mass of a sphere of uranium in a theoretical paper written in 1939 to be "of the order of tons".Peierls knew the importance of the size of the critical mass that would allow a chain reaction to take place and its practical significance. In the interior of a critical mass sphere, neutrons are spontaneously produced by the fissionable material. A very small portion of these neutrons are colliding with other nuclei, while a larger portion of the neutrons are escaping through the surface of the sphere. Peierls calculated the equilibrium of the system, where the number of neutrons being produced equalled the number escaping.Niels Bohr had theorised that the rare uranium-235 isotope, which makes up only about 0.7% of natural uranium, was primarily responsible for fission with fast neutrons, although this was not yet universally accepted. Frisch and Peierls were thus able to revise their initial estimate of critical mass needed for nuclear fission in uranium to be substantially less than previously assumed. They estimated a metallic sphere of uranium-235 with a radius of 2.1 centimetres (0.83 in) could suffice. This amount represented approximately 1 kilogram (2.2 lb) of uranium-235. These results led to the Frisch–Peierls memorandum, which was the initial step in the development of the nuclear arms programme in Britain. This marked the beginning of an aggressive approach towards uranium enrichment and the development of an atomic bomb. They now began to investigate processes by which they could successfully separate the uranium isotope.Oliphant took their findings to Tizard in his capacity as the chairman of the Committee for the Scientific Survey of Air Warfare (CSSAW). He in turn passed them to Thomson, to whom the CSSAW had delegated responsibility for uranium research. After discussions between Cockcroft, Oliphant and Thomson, CSSAW created the MAUD Committee to investigate further.

Question: What marked the beginning of an aggressive approach towards uranium enrichment and the development of an atomic bomb?
Answer: the Frisch–Peierls memorandum
At Birmingham, Oliphant's team had reached a different conclusion. Oliphant had delegated the task to two German refugee scientists, Rudolf Peierls and Otto Frisch, who could not work on Oliphant's radar project because they were enemy aliens and therefore lacked the necessary security clearance. Francis Perrin had calculated the critical mass of uranium to be about 40 tonnes (39 long tons; 44 short tons). He reckoned that if a neutron reflector were placed around it, this might be reduced to 12 tonnes (12 long tons; 13 short tons). Peierls attempted to simplify the problem by using the fast neutrons produced by fission, thus omitting consideration of moderator. He too calculated the critical mass of a sphere of uranium in a theoretical paper written in 1939 to be "of the order of tons".Peierls knew the importance of the size of the critical mass that would allow a chain reaction to take place and its practical significance. In the interior of a critical mass sphere, neutrons are spontaneously produced by the fissionable material. A very small portion of these neutrons are colliding with other nuclei, while a larger portion of the neutrons are escaping through the surface of the sphere. Peierls calculated the equilibrium of the system, where the number of neutrons being produced equalled the number escaping.Niels Bohr had theorised that the rare uranium-235 isotope, which makes up only about 0.7% of natural uranium, was primarily responsible for fission with fast neutrons, although this was not yet universally accepted. Frisch and Peierls were thus able to revise their initial estimate of critical mass needed for nuclear fission in uranium to be substantially less than previously assumed. They estimated a metallic sphere of uranium-235 with a radius of 2.1 centimetres (0.83 in) could suffice. This amount represented approximately 1 kilogram (2.2 lb) of uranium-235. These results led to the Frisch–Peierls memorandum, which was the initial step in the development of the nuclear arms programme in Britain. This marked the beginning of an aggressive approach towards uranium enrichment and the development of an atomic bomb. They now began to investigate processes by which they could successfully separate the uranium isotope.Oliphant took their findings to Tizard in his capacity as the chairman of the Committee for the Scientific Survey of Air Warfare (CSSAW). He in turn passed them to Thomson, to whom the CSSAW had delegated responsibility for uranium research. After discussions between Cockcroft, Oliphant and Thomson, CSSAW created the MAUD Committee to investigate further.

Question: What was the full name of the committee that delegated responsibility of uranium research to Thomson?
Answer: Committee for the Scientific Survey of Air Warfare
The breakthrough with plutonium was by Bretscher and Norman Feather at the Cavendish Laboratory. They realised that a slow neutron reactor fuelled with uranium would theoretically produce substantial amounts of plutonium-239 as a by-product. This is because uranium-238 absorbs slow neutrons and forms a short-lived new isotope, uranium-239. The new isotope's nucleus rapidly emits an electron through beta decay producing a new element with an atomic mass of 239 and an atomic number of 93. This element's nucleus also emits an electron and becomes a new element with an atomic number 94 and a much greater half-life. Bretscher and Feather showed theoretically feasible grounds that element 94 would be fissile—readily fissioned by both slow and fast neutrons, with the added advantage of being different from uranium, and therefore could be chemically separated from it. Bretscher even devised a chemical method to separate.This new development was also confirmed in independent work by Edwin M. McMillan and Philip Abelson at Berkeley Radiation Laboratory also in 1940. Nicholas Kemmer of the Cambridge team proposed the names neptunium for the new element 93 and plutonium for 94 by analogy with the outer planets Neptune and Pluto beyond Uranus (uranium being element 92). The Americans fortuitously suggested the same names. The production and identification of the first sample of plutonium in 1941 is generally credited to Glenn Seaborg, using a cyclotron rather than a reactor at the University of California. In 1941, neither team knew of the existence of the other.Chadwick voiced concerns about the need for such pure plutonium to make a feasible bomb. He also suspected that the gun method of detonation for a plutonium bomb would lead to premature detonations due to impurities. After Chadwick met Robert Oppenheimer at the Los Alamos Laboratory in 1943, he learned of a proposed bomb design which they were calling an implosion. The sub-critical mass of plutonium was supposed to be surrounded by explosives that were arranged to detonate simultaneously. This would cause the plutonium core to be compressed and become supercritical. The core would be surrounded by a depleted uranium tamper which would reflect the neutrons back into the reaction, and contribute to the explosion by fissioning itself. This design solved Chadwick's worries about purity because it did not require the level that would be needed for the gun-type fission weapon. The biggest problem with this method was creating the explosive lenses. Chadwick took this information with him and described the method to Oliphant who then took it with him to England.

Question: What is the full name of the man that met with the person who had worries about pure plutonium at the Los Alamos Laboratory in 1943?
Answer: Robert Oppenheimer
The breakthrough with plutonium was by Bretscher and Norman Feather at the Cavendish Laboratory. They realised that a slow neutron reactor fuelled with uranium would theoretically produce substantial amounts of plutonium-239 as a by-product. This is because uranium-238 absorbs slow neutrons and forms a short-lived new isotope, uranium-239. The new isotope's nucleus rapidly emits an electron through beta decay producing a new element with an atomic mass of 239 and an atomic number of 93. This element's nucleus also emits an electron and becomes a new element with an atomic number 94 and a much greater half-life. Bretscher and Feather showed theoretically feasible grounds that element 94 would be fissile—readily fissioned by both slow and fast neutrons, with the added advantage of being different from uranium, and therefore could be chemically separated from it. Bretscher even devised a chemical method to separate.This new development was also confirmed in independent work by Edwin M. McMillan and Philip Abelson at Berkeley Radiation Laboratory also in 1940. Nicholas Kemmer of the Cambridge team proposed the names neptunium for the new element 93 and plutonium for 94 by analogy with the outer planets Neptune and Pluto beyond Uranus (uranium being element 92). The Americans fortuitously suggested the same names. The production and identification of the first sample of plutonium in 1941 is generally credited to Glenn Seaborg, using a cyclotron rather than a reactor at the University of California. In 1941, neither team knew of the existence of the other.Chadwick voiced concerns about the need for such pure plutonium to make a feasible bomb. He also suspected that the gun method of detonation for a plutonium bomb would lead to premature detonations due to impurities. After Chadwick met Robert Oppenheimer at the Los Alamos Laboratory in 1943, he learned of a proposed bomb design which they were calling an implosion. The sub-critical mass of plutonium was supposed to be surrounded by explosives that were arranged to detonate simultaneously. This would cause the plutonium core to be compressed and become supercritical. The core would be surrounded by a depleted uranium tamper which would reflect the neutrons back into the reaction, and contribute to the explosion by fissioning itself. This design solved Chadwick's worries about purity because it did not require the level that would be needed for the gun-type fission weapon. The biggest problem with this method was creating the explosive lenses. Chadwick took this information with him and described the method to Oliphant who then took it with him to England.

Question: What is the name of the person that the man who learned about implosion took that information to?
Answer: Oliphant
The MAUD Committee reports urged the co-operation with the United States should be continued in the research of nuclear fission. Charles C. Lauritsen, a Caltech physicist working at the National Defense Research Committee (NDRC), was in London during this time and was invited to sit in on a MAUD meeting. The committee pushed for rapid development of nuclear weapons using gaseous-diffusion as their isotope separation device. Once he returned to the United States, he was able to brief Vannevar Bush, the director of the Office of Scientific Research and Development (OSRD), concerning the details discussed during the meeting.In August 1941, Mark Oliphant, the director of the physics department at the University of Birmingham and an original member of the MAUD Committee, was sent to the US to assist the NDRC on radar. During his visit he met with William D. Coolidge. Coolidge was shocked when Oliphant informed him that the British had predicted that only ten kilograms of uranium-235 would be sufficient to supply a chain reaction effected by fast moving neutrons. While in America, Oliphant discovered that the chairman of the OSRD S-1 Section, Lyman Briggs, had locked away the MAUD reports transferred from Britain entailing the initial discoveries and had not informed the S-1 Committee members of all its findings.Oliphant took the initiative himself to enlighten the scientific community in the U.S. of the recent ground breaking discoveries the MAUD Committee had just exposed. Oliphant also travelled to Berkley to meet with Ernest Lawrence, inventor of the cyclotron. After Oliphant informed Lawrence of his report on uranium, Lawrence met with NDRC chairman James Bryant Conant, George B. Pegram, and Arthur Compton to relay the details which Oliphant had directed to Lawrence. Oliphant was not only able to get in touch with Lawrence, but he met with Conant and Bush to inform them of the significant data the MAUD had discovered. Oliphant’s ability to inform the Americans led to Oliphant convincing Lawrence, Lawrence convincing Compton, and then Kistiakowsky convincing Conant to move forward with nuclear weapons. These actions from Oliphant resulted in Bush taking this report directly to the president.

Question: What is the first name of the person who was was able to brief Vannevar Bush after he returned to the US?
Answer: Charles
The MAUD Committee reports urged the co-operation with the United States should be continued in the research of nuclear fission. Charles C. Lauritsen, a Caltech physicist working at the National Defense Research Committee (NDRC), was in London during this time and was invited to sit in on a MAUD meeting. The committee pushed for rapid development of nuclear weapons using gaseous-diffusion as their isotope separation device. Once he returned to the United States, he was able to brief Vannevar Bush, the director of the Office of Scientific Research and Development (OSRD), concerning the details discussed during the meeting.In August 1941, Mark Oliphant, the director of the physics department at the University of Birmingham and an original member of the MAUD Committee, was sent to the US to assist the NDRC on radar. During his visit he met with William D. Coolidge. Coolidge was shocked when Oliphant informed him that the British had predicted that only ten kilograms of uranium-235 would be sufficient to supply a chain reaction effected by fast moving neutrons. While in America, Oliphant discovered that the chairman of the OSRD S-1 Section, Lyman Briggs, had locked away the MAUD reports transferred from Britain entailing the initial discoveries and had not informed the S-1 Committee members of all its findings.Oliphant took the initiative himself to enlighten the scientific community in the U.S. of the recent ground breaking discoveries the MAUD Committee had just exposed. Oliphant also travelled to Berkley to meet with Ernest Lawrence, inventor of the cyclotron. After Oliphant informed Lawrence of his report on uranium, Lawrence met with NDRC chairman James Bryant Conant, George B. Pegram, and Arthur Compton to relay the details which Oliphant had directed to Lawrence. Oliphant was not only able to get in touch with Lawrence, but he met with Conant and Bush to inform them of the significant data the MAUD had discovered. Oliphant’s ability to inform the Americans led to Oliphant convincing Lawrence, Lawrence convincing Compton, and then Kistiakowsky convincing Conant to move forward with nuclear weapons. These actions from Oliphant resulted in Bush taking this report directly to the president.

Question: What are the first names of the three people Oliphant contacted about what significant data the MAUD had discovered?
Answer: Ernest, James, Vannevar