The trinity test on 16. July 1945 was the first nuclear weapons explosion. Image: dod
When the atomic bomb was used 75 years ago
About 100 years, people shocked the totality of the first world war. Nobody had to introduce millions and but million dead as a result of a military confrontation. This mass destruction was only possible through new technologies (planes, machine guns, tanks, poison gas, etc.To). Worse can not come, so people thought. But in fact, she was waiting for a much worse horror: a single bomb with which hundreds of thousands of people had dead. Exactly 75 years ago, on the 6th. August 1945, the us militar threw a first atomic bomb on the japanese city of hiroshima. Three days later formed an atompiluce over nagasaki.
Their foundation had the atomic bomb in a then new physical theory, which is still synonymous with physicists a synonym for durability: the quantum theory. In the world of physicists, this had already taken care of for huge findings since the beginning of the century. She already had a whole worldscape, the world view of classic physics and coarse parts of classical philosophy -. With the description of the laws in micro and nanocosmos, exciting new technologies were offset by the world in the second half of the century (laser, microelectronics, medical technology, etc.To). But in the last war year 1945 this was not aware of the general public. To complex, bizarre and too mathematically the new physics was. But then this suddenly stepped and completely unexpectedly on the bean of the world substitute, and this with a very loud bang: the first technological application of quantum physics was the most awful weapon that has ever been used militarically.
How was this terrible weapon emerged?
Since the famous attempt of rutherfords from 1912, from which today every school kind has knowledge, the physicists knew that the atomic nucleus consists of electrically positively charged elementary particles (protons). But equally charged particles robble. How is it possible that atomic nuclei are stable? The many protons in the atomic nucleus had to fly apart. Another force in the atomic nucleus had to be far strong (attractive) on the very short distances in the atomic nucleus than the electrical force. But what should be for a power, the physicists did not know. It was one of many rats in the quantum world in which the physicists had just started to look around.
In 1934, the italian physicist enrico fermi began to bomb uranium atoms with neutrons. His hope was that some of these neutrons stick to the atomic nucleus were, which could be formed with new nuclei nuclees not occurring in nature. For fermis surprise, in its experiments, a large amount of radioactive radiation emerged, whose origin could neither explain nor other researchers. Four years later, in the summer of 1938, iron joliot curie, the daughter marie and pierre curies, observed, and her husband frederic, that in the bombardment of uranium with neutrons a completely different element arises, which has a much smaller core as a uranium. They were beamed and could not believe that such a coarse stucco out of which in themselves dismissible uranium atoms.
In december of the same year, the german researchers otto hahn and lise meitner also carried out experiments with uraniums to examine the unknown force in the atomic nucleus. Also, they shot uranium with its 92 protons and – depending on the isotope – 143 or 146 neutrons, and the "ammunition" were also slowing neutrons. It turned out that through the shelling two completely different elements arise: barium and krypton. Barium atoms who quickly love radiochemically evidence have a core charging number of 56 and are almost only half as rough as uranke.
Using theoretical quantum physical calculations, meitner came to the conclusion that the uranium core had been brought to burst by the neutron bombardment. The breaking chocolates take a lot of energy, far more than was created in every hitherto known atomic process. But where this energy came, was first another ratsel. Meitner also calculated that the two cores emerging from the cleavage (plus three neutrons free), in their sum slightly lighter than the original atomic nucleus of the uran plus the neutron, which cleared the cleavage. What had happened to the missing mass?
The answer to both questions provided einstein’s famous formula e = mc2, which had set up this more than 30 years earlier: the difference between the crowds before and after the cleavage was exactly the energy that had absorbed the breakpoints, so meitner’s results. For the first time, a process had manifested in which the equivalence formulated by einstein disclosed directly from energy and mass. At the same time it has also become clear: inside the atom, unimaginable energies! This message ran like a driving fire through the scientific world (otto hahn, but lise meitner, received for this knowledge the chemical nobel prize in 1944; however, at the time of announcement, he was still in military internment in england at the time of the leading german atomic physicists).
The physicists called this energy "nuclear energy". In the cleavage of the atom, a small part of this enormous amount of energy is free, but it is still millions of times stronger than in conventional chemical reactions. The coincidence wanted to releases three other neutrons that could be released by a neutron cleavage of a uranist, which could turn urban columns. The physicists realized that over a chain reaction in very short time a huge amount of energy release.
A lot of energy in a small space that loves released – that quickly awoke the interest of militars in the ruling wartime. Already in 1939, the nephew lise meitners, otto frisch, together with his british colleague rudolf peierls wrote a memorandum, which described the technical construction of a bomb based on nuclear energy. Now do not keep this non-physicist. Adolf hitler had stopped poland shortly before and started world war ii. As a leading nation in research and technology, the national socialist germany seemed prudentinated to use the first country to use nuclear energy military and produce atomic bombs.
A bomb with such a huge explosive power in the hands of hitler had catastrophic effects for the world, so not only the two jews lise meitner and otto fresh thought. The hungarian physicist leo szilard had suffered like meitner and freshly strongly under national socialist germany, and he also invented him the terror image of an atomic hitler germany. He killed the hitherto strict pacifists albert einstein, a letter to the american prassident franklin d. To write roosevelt and give it the suggestion to set the construction of an american atomic bomb. This took up the pace.
Under highest secrecy (not even the vice-prassident was inaugurated), the american government started a team of high-ranking scientists and engineers from 1941. The goal of the "manhattan project", which should be the most complex and hardest technical project of history, was the construction of a nuclear bomb. With such projects you already had some experience. So the second world war was already one "physicist war" to become developed in front of the atomic bomb technologies such as radar, rocket drive and magnetic mining defense.
The first step in the manhattan project was to prove that actually a chain reaction of neutron releases excludes and maintain. This succeeded in december 1942 enrico fermi, who had emigrated from the hitler compound italy. Below a sports field at the university of chicago, fermi had constructed the first nuclear reactor of history. This was the way to bomb free. The research were centered in a place named los alamos in the waste of new mexico.
The scientific director of the manhattan project and therefore later than "father of the atomic bomb" viewed robert oppenheimer, who had received his scientific education under max born in germany. Already breakfast had two gearboxes signed: a first by means of the cleavage of uraniums and a second with plutonium cores. Since the physicists were not sure, which was the promising way, they decided to pursue both concepts at the same time. After four years more intense and strictly kept held work, they managed to develop both types of bombing. In july 1945 they had completed four atom bombs.
"Now we are all hurens without."
At 16. July 1945 exploded on a test stand in the wissen of new mexico the first atomic bomb of world history. Her force overtrauces the most optimistic expectations of the physicists. But when the powerful atompilc of the horizon looked, she had a feeling of deepest discomfort. Robert oppenheimer quoted how he will write later, at this moment inwardly from the "bhagavad gita", a central font of hinduism: "now i have become death, destroyed by the worlds." one of his colleagues, the director of the test, kenneth bainbridge, printed it more plastic: "now we are all hurens without." the queasy feeling of the physicists should prove funified. Already three weeks later, the second atompilment was drew, this time over the sky of the war opponent japan. The third followed only three days after.
In one of the most controversial and today’s most controversial decisions of the us history, the new prasident harry truman was decided on shortly before only the possiter of the existence of an atomic bomb, which was completely unsuspecting new prasident harry truman, to use the bomb against japan. In the two disturbed 200.000 people directly. In the course of the coming years followed by radioactive spat shops many more. From the scientific discovery of the columnability of the uranium atomic nucleus to the atompilents of hiroshima and nagasaki were not even seven years ago.
Originally, the american atomic bomb for hitler-germany had been intended, which had already surrendered in may 1945. Germany also had an atomic bomb project. But the so-called uranium club under the guided by werner heisenberg had not obsessed neither the necessary resources nor developed the necessary technical methods to make a bomb in fact. To date, there is disagreement under historians why the scientific nation leading before the war with a rough distance the atomic bomb did not develop. Heisenberg himself said that he did not want to give such a bomb in the hands of hitler’s. Whether this was really his motivation, is still controversial. Other reasons were sure that national socialist militar guide had not recognized the importance of atomic bomb.
The physicists had to realize with the atomic bomb that their knowledge is not only the ruling worldview, but also the world can reduce. Many of the scientists who had participated in the project pursued the qualifying question until their lives, whether they do not bear an immediate responsibility for the death of many people. Robert oppenheimer plagued his conscience such that he was even persecuted later from the american intelligence service, who believed his remorse konnen the us in the cold war against the soviet union. With los alamos, hiroshima and nagasaki, the activity of the physicists has won a dimension, which she has not got rid of today: the social responsibility.
Lars jaeger studied physics, mathematics, philosophy and history and researched several years in quantum physics as well as chaos theory. He lives in the near zurich, where he has built two own companies, advising institutional financial investors, and at the same time regular blogs on science and time-evidence. In september 2019 his book appeared "trust more!"