In the previous article, Chinese woman wearing a cheongsam, building a nuclear bomb: her achievements and patriotism are as outstanding and respectable, we gave a brief introduction to the legendary female scientist - Wu Jianxiong, among her series of honors, the title of "mother of nuclear bombs" is probably the most contrasting, this weak-looking Jiangnan woman, with her extraordinary talent, not only accelerated the development of nuclear weapons during World War II, but also profoundly changed the historical course of World War II.
It can almost be said that without her participation, the development of nuclear weapons will most likely be delayed, and without the successful development of nuclear weapons, there would be no actual combat applications in Hiroshima and Nagasaki, Japan. I am afraid that the war of aggression against China by Japanese imperialism will last longer, and the disasters and losses suffered by the Chinese people will inevitably be even greater, so in this sense, we should all thank her.
Mushroom clouds in Hiroshima and Nagasaki
As Oppenheimer said, without Dr. Go's involvement, the nuclear bomb would never have been developed so quickly.
In today's article, we will mainly focus on how Wu Jianxiong participated in the top secret operation of the United States to develop nuclear weapons - the "Manhattan Project" as a Chinese.
And if combined with the background of the times, Wu Jianxiong's contribution to the Manhattan Project and the end of World War II are more worthy of historical memory. On the dark eve of discrimination against women, exclusion of foreigners, and the rise of racial movements in the United States, it was already history that a Chinese woman could break out in the physics community, and it was unimaginable to participate in the "Manhattan Project" as a Chinese.
First, the dark years of American madness, the difficulties of Chinese women in the field of Western science
Before introducing the history of Wu Jianxiong's involvement in the development of nuclear weapons, it is necessary to understand the serious gender discrimination in American society at that time, especially physicists, and the racial discrimination suffered by Chinese in the United States even more than the black community.
(1) The male-dominated physics community has long discriminated against and excluded women
In recent years, the topic of equality between men and women has been much discussed, and it must be recognized that the equal rights movement between men and women is now deeply rooted in the hearts and minds of the people. But if in the field of scientific research, the circle with the highest gender inequality at present, the physics community, must be the one that deserves the most attention.
Even today, stubbornness and prejudice against "physics is inaccessible and masculine" persists, such as the suspension of a senior scientist at the European Nuclear Research Centre at an academic conference in Geneva in 2018 for sexist comments in his speeches.
In the era when Wu Jianxiong studied in the United States, the breadth and intensity of discrimination against women in the whole society were extensive and deep, especially in the field of physics research, this style of gender discrimination was almost suffocating.
Wu
Perhaps the most typical example is the experience of Wu Jianxiong and Lizze Meitner, two female physicists who have been called the "mother of the nuclear bomb".
German physicist Lizzer Meitner was once praised by Einstein as "Madame Curie of Germany". At the beginning of the 20th century, it was she who first explained the principle of atomic fission at the theoretical level, and calculated the huge energy released by fission according to Einstein's mass-energy equation, and named it "nuclear fission" for the first time, precisely because of the breakthrough in theory, the academic community usually ranks her with Wu Jianxiong's achievements at the practical level, and recognizes their title of "mother of nuclear bombs".
But in an era of severe exclusion of women, their sexist style in physics was even more unbridled. It is in this context that as led by Lise Meitner, the academic achievements shared by her and Hahn Otto Hahn alone swallowed Hahn, Hahn also won the Nobel Prize, while Lise Meitner, who made major contributions, was not recognized by the Nobel Prize.
Even in the publishing world at the time, research manuscripts submitted by women alone would be rejected, and Meitner encountered this situation many times, and the publisher editors refused on the following grounds: "We never thought of publishing an article written by a woman." So many times Meitner had to invite Otto Hahn for the publication of his paper, which also bought a huge hidden danger for her later stolen academic results.
Lise Meitner and Hahn
And the same encounter also happened to another "mother of nuclear bombs" Wu Jianxiong.
As a proud disciple of several giants in the physics community at that time - Lawrence, Segrey, Oppenheimer, Wu Jianxiong's campus academic research was relatively smooth, but after graduation, although her research talent was beyond reproach, it was only because of her gender and Chinese status that she could not get a research job in the university where she could use her talents. After graduating, she had to work as an obscure researcher in an unknown laboratory.
However, for Wu, the difficulties she faced at that time were far more than gender, but also ethnic barriers formed by her Chinese identity that she had never wanted to give up.
(2) At that time, the United States was on the eve of the rise of the far-right movement
We know that in the United States from 1950 to 1954, McCarthyism was prevalent, and far-right American political forces viciously slandered and wantonly oppressed progressives and even all political dissidents.
In fact, long before the beginning of McCarthyism, when Wu Jianxiong participated in the Manhattan Project, the hostility of American society to the Chinese at that time had begun to spread in the academic community, and if it were not for Wu Jianxiong's irreplaceable physics research skills, she was doomed to participate in a highly classified project like the "Manhattan Project" in the social context at that time.
2. Wu Jianxiong's outstanding contribution to the "Manhattan Project"
In 1942, the United States learned of Nazi Germany's secret plan to develop nuclear weapons, and in order to develop nuclear weapons before the Nazis, the United States recruited the most outstanding scientists in almost the entire Western world at that time and began to implement a nuclear weapons development project called the "Manhattan Project". Naturally, due to gender and nationality, Wu Jianxiong did not and could not be invited to participate.
Manhattan Project
But in the process of tackling the problem later, a group of top scientists encountered a threshold that could not be crossed - the ignition of a nuclear explosion is very easy, but the imaginary chain reaction is always suddenly interrupted.
In a perfect theoretical model, the energy of a nuclear weapon comes from a nuclear fission reaction, in which a heavy nuclear atom splits into two lighter atoms after being hit by neutrons and releases several neutrons, releasing photons in the form of gamma rays. The released neutrons continue to hit other heavy nuclear atoms, forming a chain reaction that spontaneously splits.
However, in the actual test, the chain reaction of the nuclear explosion has never been sustainable, and the neutrons generated by the impact will disappear inexplicably, thus losing the power to keep the chain reaction continuous, and the sudden disappearance of neutrons has made Oppenheimer and Fermi and other most well-known scientists feel extremely tricky, and the development of nuclear bombs is facing a major crisis of stagnation.
But at the same time, many of the top scientists involved also speculated that one of the nuclear fission products, xenon-135, was most likely the culprit of this failure, and believed that xenon-135 was a "neutron poison". But they are not sure enough about how to solve it.
(The book card has been added here, please go to the Toutiao client to view)
It was at this time that Oppenheimer, who led the Manhattan Project, thought of her student, the Chinese who was working as a researcher at the Edge Institute, Wu Jianxiong.
Oppenheimer
In fact, since 1938, Wu Jianxiong has been conducting nuclear experiments, and in 1939 she had completed the experiment of "exploring the fission products of uranium nuclei" alone, and found in her experiments that uranium produces a large amount of radioactive isotope xenon -135 in the process of nuclear fission, and proposed that this isotope has a certain absorption of neutrons. The results of research in this area were at the forefront of that era.
It was precisely from this that Oppenheimer found her for the first time as the "chief head of the Manhattan Project", but in the face of the social environment at that time, Wu Jianxiong was about to be responsible for the most core and secret "nuclear splitting reaction" content of the "Manhattan Project", and she was still Chinese at this time, and was unwilling to give up this identity, and finally under Oppenheimer's decision to exclude the public, she gave her this most core task and gave this "foreigner" a special confidentiality permission.
In the end, Wu lived up to this trust, and she quickly determined that xenon 135 was the culprit for the unsustainable failure of the chain reaction, mainly because this isotope has a large neutron absorption cross-section, which absorbs a large number of neutrons generated by the impact, causing the reaction to lose power and stop.
Later, Wu Jianxiong continued his efforts to develop a device that could be used to isolate the radioactive isotope xenon -135 produced during nuclear fission, and successfully retrieved the disappeared neutrons, so that the nuclear bomb was successfully developed.
The completion of the development of the nuclear bomb on schedule is indeed a great innovation that changes the course of history. With the United States dropping two in Japan, it hastened the end of World War II and ended the disaster of the Chinese nation as soon as possible.
However, for the outstanding contribution of a Chinese to the Manhattan Project, Americans choose to avoid talking about it, or even deliberately conceal it. Because the American scientific community, which was full of nationality and sexism at the time, was reluctant to admit that it was a Chinese woman who helped them overcome the nearly insurmountable obstacles in technology.
It was not until 1992, when Columbia University awarded Wu the Pubin Prize, the highest honor in the American science and engineering industry, that the secret was officially made public, and Wu Jianxiong's contribution to the first nuclear bomb in human history was known to the world, and it has been nearly half a century since her work.
It can be seen that as the "mother of nuclear bombs", Wu Jianxiong lives up to his name.