The birth of nuclear weapons began with atomic research in the early 20th century, about 19 10 years. Rutherford found that the atom is almost hollow, the nucleus is in the center, negatively charged electrons run along the outside, and there are positively charged protons in the nucleus. Later, in 1932, james chadwick discovered that there were still electrically neutral neutrons in the nucleus. Chadwick bombarded the nucleus with neutrons at high speed to see what would happen to the nucleus when the number of neutrons increased, but it was difficult to hit the nucleus at the right speed. Two years later, Enrico Fermi tried to find that slowing down neutrons could squeeze into the nucleus.
Along this great discovery, the famous German scientists Metenas and otto hahn cooperated in the Institute of Emperor William and achieved fruitful results. However, after Hitler came to power, the Jew Matnas was expelled from Berlin University and Emperor William College. Although expelled from the institute, the cooperation between Metenas and Hahn did not stop. Matenas focuses on the study of uranium, which is the heaviest element in nature. The nucleus of uranium is full of neutrons. Maitenaz wants to know what will happen if the nucleus of uranium is bombarded by neutrons, and will anything new be created? Will it get heavier? During Christmas in Sweden, Maitenaz received a letter from Hahn, in which he found some unusual phenomena. Maitenaz's nephew, Robert Frish, is a physicist who works in Denmark. He works with the famous niels bohr. At that time, Frish and Maitenaz were on vacation in Sweden. Hahn said that the bombardment of uranium nuclei triggered a radioactive phenomenon-"energy flow spurt". This result is not particularly surprising. Bohr thinks that the nucleus will split at any time because positively charged protons repel each other. The question now is: will the increase in the number of neutrons cause the original balance to tilt and then split the nucleus?
Maitenaz and Frish found that neutron bombardment would split the nucleus, but it would not make it bigger. Here they borrowed the biological word fission, which has a very important connection with Einstein's equation. In the process of splitting an atomic nucleus into two smaller nuclei, the lost mass is converted into energy, which coincides with the meaning of the mass-energy equation. Under the catalysis of World War II, the potential of this equation was quickly tapped. At this point, the race to make nuclear weapons began.
1939, Einstein's old friend and Hungarian physicist at Columbia University found him. After listening to szilard's explanation, Einstein soon realized that the study of uranium fission could have very dangerous consequences. At this time, Sachs, an economist at Lehman Brothers, gave Einstein some constructive suggestions. Later, Einstein wrote a letter to President Roosevelt, which said, "This new discovery can be used to make bombs. As you can imagine, although I'm not particularly sure, this new bomb is very powerful. As long as such a bomb is transported to a port by a ship and then detonated, it is possible to completely destroy the entire port and the facilities on the surrounding land. " It took Sachs nearly two months to find an opportunity to send this letter to President Roosevelt. Although Einstein was famous at that time, Roosevelt did not pay special attention to this matter. After reading Einstein's letter, Roosevelt set up a uranium advisory committee led by Dr. Briggs, who was then the director of the National Bureau of Standards.
However, in 1940, Meinert's nephew Frish convinced the British of the possibility of making nuclear weapons. At the same time, Germany also realized this possibility and appointed Heisenberg, a famous scientist ranked second in the world at that time, to undertake this work. 1940, Heisenberg extracted uranium from Czech mines occupied by Hitler's army and conducted the first nuclear test. However, Fermi, an American, had discovered at that time that the key point of generating energy through nuclear fission was to slow down the neutron speed. To achieve this goal, water can play an auxiliary role, and heavy water with more tritium has the best effect. The supply of heavy water is a weakness for the Germans. They had to rely on a facility in Norway to get heavy water, but it soon became the target of allied attacks. In addition, the German scientific team made some mistakes in the calculation of heavy water consumption at that time, and Germany failed to complete the manufacture of nuclear bombs before the successful test in the United States. This is also a great fortune for mankind.
Everyone knows the later story. 194 1 After the Pearl Harbor incident broke out, the United States implemented the Manhattan Project. 1In August, 945, the first atomic bomb exploded over Japan. In this way, Einstein's equation of mass and energy had a great impact on human beings for the first time, and it was disastrous.