Reactions used to mean only chemical reactions. A chemical reaction involves the exchange of electrons between elements, resulting in the formation of a new compound. These reacting elements combine with each other to form compounds with new properties, but there is no change in the individual nature of the elements. But this cannot be said in the case of nuclear reactions.

In this reaction, one type of element changes into a completely new type of element. So religion changes, characteristics, even shape, color and smell also change. Chemical reactions depend on temperature pressure density etc. But scientists did not know that there could be another type of reaction apart from chemical reaction. It is a nuclear reaction.
Chemical reactions can be observed or carried out arbitrarily according to a certain rule. In most cases, the products of a chemical reaction can be returned to the starting materials through the reverse reaction. But the achievements of nuclear reaction researchers are much less. Once this reaction takes place, it cannot be reversed. Chemical reactions occur naturally. But this is not what natural phenomena really means. If you want to stop chemical reactions that occur naturally, you can use various methods to stop them. But nuclear reactions—which happen naturally—can’t be stopped at will. such as radioactive decay. Spontaneously by fission in the nucleus of radioactive material. Tried a lot to see if it can be stopped. Tried changing dimensions, creating pressure differences, placing radioactive material inside thick-walled metal boxes—there was no way to stop the reaction.

Yes, it can be done synthetically and chemically. But the task is not so easy. So only thirty countries have owned nuclear power plants before Bangladesh.

As we have already seen, when an electron is removed from an atom, the atom becomes an ion, but it does not make any difference to the original religion of the atom. But if a proton or two is removed from its nucleus, the entire atom’s religion changes radically.

Chemical reactions involve the exchange of electrons from orbitals outside of atoms. So atoms can take part in chemical reactions while maintaining their own religion and properties. On the other hand, the atomic mass number decreases when the nuclear reaction involves fission in the nucleus. Just as two small nuclei can join to form a heavy nucleus, it is also possible to break a heavy nucleus into multiple smaller nuclei. This is the breakdown or fusion of the nucleus; As a result, its characteristics change completely. The nuclear reaction that involves the breaking of the nucleus is called nuclear fission. This reaction is used in today’s atomic bombs and nuclear power plants.

The seeds of nuclear fission were also planted in Fermi’s creation of the 93rd element. Fermi first started this effort in 1934. In 39 he was pretty sure he had found the 93rd element. As mentioned earlier, Fermi was not sure whether he had found the 93rd element or not. This is because during this reaction some other atoms appear along with heavy particles.
Nuclear physicists were having trouble understanding what these particles were. Ida Nodak Tacke, one of the discoverers of uranium, said that a neutron hitting a uranium nucleus would break up the nucleus to form pachunium, which may not always be the case. The nucleus of uranium is quite large and complex. So it’s much easier to smash a neutron into pieces than to break it up into a larger nucleus. The variety of particles we see in uranium nuclear reactions may have another meaning. Perhaps the uranium nucleus breaks apart into fragments. Those little pieces are actually the nuclei of different elements. Perhaps because of Nodak’s previous reputation, other scientists did not heed his words. If particle physicists had really taken his words seriously, different results would have been obtained that year.

Year 1937 Otto Hahn, one of the fathers of the atomic bomb, was researching nuclear physics in Germany. His partner is Liz Mittner.
Hitting uranium with neutrons emits an alpha particle. But Ottohann said, is only one alpha particle emitted, or both? The atomic number of uranium is 92. The atomic number of two alpha particles is 4. So if four alpha-particles are emitted from the nucleus, the atomic number will be 88. The atomic number of radium is 88. Then uranium nucleus can turn into radium nucleus by neutron impact. Just saying it will not do, proof must be shown. He joined Meitner in that work. They found that the amount of radium obtained from uranium as a result of normal radioactive decay, the amount of radium in the nuclear reaction that occurs as a result of Newton’s impact is much higher. It is not possible to prove Autohan’s proposition if one cannot qualitatively see how much or not at all. So you have to experiment.
Marie and Pierre Curie showed how to separate radium from uranium. But they had tons upon tons of uranium ore given to them by a geologist friend. Ottohann and Meitner could have collected that much uranium ore if they had wanted to. But the uranium ore found in the mine was not worked. This is not normal radioactivity, but a nuclear reaction. For that we want pure uranium. Tons and tons of pure uranium are difficult to find even if the whole world is cultivated. So be satisfied with little. The test should be done according to this limitation. You have to find another way. Radium’s position in the periodic table is just one step below barium. Radium sits in the same column but in the next row. And according to the rules of the periodic table, no matter how different the atomic number is between the atoms in different rows of the same column, they are very similar in nature and properties. The atomic number of radium is 88 and that of barium is 56. The behavior and religion of the elements in the periodic table are close. So a barium trap has to be made to catch the radium.

Then Ottohan came up with an idea. Ottohan wants to dissolve the uranium broken by the impact of neutrons in acid. Stable barium will be added to it during dissolution.

Later, the barium can be separated from the solution by chemical analysis. But it will come out as radioactive barium. When separating radioactive barium, it will be possible to separate radium with it. How?

Since radium and barium have close bonds. Therefore, it is possible to separate radium due to the same behavior in which barium can be obtained in acid solution. If so, why is stable radium added separately to the acid solution? Some barium was already obtained from uranium!

No, it couldn’t. Ottohan said that only radium, not barium, would come out of uranium when hit by a neutron. But the method of extracting radium from acid is still unknown. But Hahn knew how to extract barium. When barium is separated from the acid due to its close character, radium will also be separated at the same time. Then it will not be too difficult to separate the radium from that mixture of radium and barium.

This was Ottohann’s plan. Meitner had to leave Germany just as he was thinking about organizing the test. Because his family religion is Jewish. Hitler’s anti-Semitism was at its peak. Meitner’s home country of Austria was also infected by the Nazis. So Meitner sneaked into the Netherlands.
Han then needs another crafting assistant. Got it. Fritz Stresemann, whose name coincided with Attohan in nuclear physics, joined Hahn as an assistant. Otto Hahn started the experiment with him. The first phase of the test was successfully completed. Hahn and Stresemann were able to separate barium from acid solutions.

The scientists assumed that there is radium along with barium. They calculated and figured out how much radium can be obtained from that mixture, that amount too. But Hahn-Stresmann failed in the actual task. They tried to separate radium from barium in various ways, but did not get even a small amount of barium. Ottohan’s suspicions then. He thought, his previous assumption was wrong. Uranium nuclei destroyed by neutrons certainly do not turn into radium. So what is it? Hahn, then said that only barium is produced by the reaction of uranium. But that barium is no ordinary barium. It is actually an isotope of barium.

If Autohan’s new idea is true, then a problem arises. The fission in the nucleus of uranium by neutrons is not a minor fission. Because, if an alpha particle comes out, its mass will decrease by 2. Then it will turn into thorium. And if two come out, then it will turn into radium. And if three alpha particles are reduced, the atomic number will be reduced by six to 86. That is, the new nucleus will be radon. But the atomic number of barium is only 56, while that of uranium is 92. Atomic number gap 36! If Uranium were to turn into Barium, 18 alpha particles would have to be emitted! Is that possible?

Whether it is possible is a matter of experimentation. But Autohan supports the new concept of Nodak Ida. That is, the nucleus will split into two large pieces. One of which will be of barium 56, the other will be equal to 18 alpha particles. That is, its atomic number will be 36. But the new idea was incredible at the time, because few scientists believed that a tiny neutron particle would cause such a massive fission in such a large nucleus. So Han didn’t let it slip.

Meanwhile, Liz Meitner was sitting in Denmark and got the news of Guru Ottohan’s failure. But he didn’t know about Hahn’s new ideas, but he thought like the guru, surely the uranium nucleus is splitting into two parts when hit by neutrons, they are not equal to one or two alpha particles. He wrote a letter about this. Send it to the famous Nature magazine.

Another copy of the same letter was sent to his nephew Otto Robert Frisch in Copenhagen. Frisch was then working in Bohr’s laboratory. Meitner wrote the letter to his nephew to give to Niels Bohr. On the other hand Ottohan also respected Bohr. He also reported their research to Bohr. That was in 1939. With this information, Niels Bohr crossed to the United States that year.

Meitner’s nephew also conducted an experiment on Frisch. He was able to split the uranium nucleus in two by hitting the uranium in an ionization chamber with neutrons. This was the first experimental evidence of a nuclear fission reaction.

Another big question arises here. When Enrico Fermi was doing research in Italy with his colleagues, he was the one who proposed to hit the nucleus of uranium with neutrons, they did the first experiment. So why did they not find the fission reaction?
They would have got first, unless they did the test a little differently. Fermi wrapped the whole system in an aluminum foil, so that the alpha particles emitted from the nucleus could not escape. Also, Enrico Fermi did his experiments using neutrons slowed down through paraffin. Fission of uranium-238 is not possible with slow neutrons.

chain reaction
By 1939 the nuclear fission reaction was on a foundation. Then Nils Bor showed Velki again in the old bone. He calculated and showed that it is not possible to fission the nucleus of Uranium-238 by hitting neutrons. For this, the energy of the neutron to be hit should be at least 1 mega electron volt. However, Bohr suggested a way to fission uranium with slow neutrons. He said, if the kinetic energy of neutrons is low, then another isotope of uranium – Uranium 235 should be used. But Shubhankar’s evasion is also hidden here. It is seen that what is readily available is not useful, what is scarce works easily. Uranium 235 is scarce.

The point is, Borer’s new theory is correct? It didn’t take long to prove it right. American scientists Alfred Otto Carl Near and John Ray Danning proved Bohr’s theory correct in the laboratory.

While Bohr was in the United States, another Hungarian-American scientist, Leo Gillard, was dreaming of the nuclear bomb. The mentality of all scientists is not the same, some sing the victory of humanity, some see science as a tool to destroy the enemy. Is Jillard second team? Gillard was born into a Jewish family. So Hitler’s wrath fell on him too. He was forced to leave the country to the United States. So maybe a great anger towards Hitler was born in his mind. Wanted to punish Hitler by making atomic bomb. On the other hand, there were reports that Hitler had come very close to making a nuclear bomb. So the American scientists have decided then that there is no alternative to nuclear bombs if they have to deal with Hitler.

Gillard heard from Bohr about Otto Hahn’s ideas, also about Hahn’s failed experiments with Stresemann. Ottohann’s new kind of speech caught his attention. So Gillard thought, he had come very close to fulfilling his dream. If a uranium nucleus could indeed be split in two by being hit with a neutron, a huge amount of energy would be released. But is it possible to make a bomb with this power?

If the fission reaction stops once a nuclear reaction has taken place, there is not much benefit in making a nuclear bomb with such a reaction. A new idea played in Jillard’s head. He thought a little differently. He thought of a system. A neutron in the system will hit a nucleus. As a result, two neutrons will be released from the nucleus. Those two neutrons will go and hit two more nuclei. As a result, four neutrons will be emitted from the two new nuclei. Those four neutrons will hit four new nuclei. Eight neutrons will come out as a result. Sixteen neutrons will be released by the impact of those eight neutrons. Thus neutrons will be released and will hit more nuclei. As a result, a chain reaction will be formed, in which new fusion reactions will continue to occur. And with every hit a huge amount of energy will be released. A great city can be destroyed with that power. The idea was groundbreaking, but the reality was not so simple. This was the principle of nuclear chain reaction. German scientist Ernst August Bodenstein was the first to talk about this kind of reaction, even though it was founded by Gillard. That was in 1913. At that time nuclear reactions did not stand on a solid foundation, chain reactions were far-fetched. So Bodenstein’s proposal did not hold water.

Gillard, along with the British scientist Keim Weizmann, tried several times to prepare the chain reaction. But all efforts failed. Gillard observed that the two neutrons released by a uranium nucleus hit by a high-speed neutron were of such low energy that they could not hit a new nucleus. Bor has already explained why it is not possible. Gillard attempted this reaction with uranium-238. But Bohr said experiments with uranium-235 might give better results. Gillard then experimented with uranium-235 and found that uranium-235 could be broken up by hitting it with slow-moving neutrons. In this reaction, the uranium-235 nucleus takes with it a neutron that hits it and produces the uranium-236 isotope for a very short time. This isotope has a very short life span. Within moments, uranium 236 splits into two pieces. In fact, it is wrong to say something. Two large particles will be formed and three neutrons will be released. One of the larger pieces is krypton 92, and the other is barium 141.

The three neutrons that are released here will strike three whole uranium-235 nuclei and cause three new reactions. Another 9 neutrons will be released from that new reaction. Those nine neutrons can start nine new reactions. The chain reaction, as previously thought, would produce one to two neutrons—in fact, it turns out, not two but three neutrons are being released. So the nuclear reaction is speeding up.
Can only uranium 235 e chain react? Or are there any other atoms like nuclear chain reactions. It was soon found that plutonium could cause chain reactions better with an isotope.

Uranium is the largest natural element. Plutonium, on the other hand, is created in a laboratory. Speaking of, how to use this plutonium?

As mentioned earlier, Uranium 235 is scarce. Uranium 238, on the other hand, is easily matched. But chain reaction is not possible with Uranium 238-K. Then a new idea came out. Because plutonium can easily undergo chain reactions, it can be produced in large quantities. Neptunium 239 can be produced by striking uranium 238 with alpha particles. Plutonium can be obtained by striking neptunium with an alpha-particle in a special process. But that plutonium must be of mass number 239.

The chain reaction is the key to the atomic bomb, no one left scientists to understand. But is it possible to make it? Possible if enough uranium-235 is available. Or plutonium 239 can be made. In 1941, Berkeley particle scientists led by Segre succeeded in producing one microgram of plutonium 239 in a cyclotron.

The enormous amount of energy released from a nuclear bomb is thermal. And that heat energy burns and destroys people, houses, cities.

The Manhattan Project was the name of a United States project to develop an atomic bomb in which the United Kingdom actively cooperated. The successful detonation of the atomic bomb developed through this project ended World War II. It has been called the greatest methodological, artistic and scientific endeavor in the history of the world.

The project cost about US$2 billion in 1945 prices and employed a total of 175,000 people. The work of the project was carried out in complete secrecy and very few people there knew its true purpose. Some of the people at the top of the project were aware of the development of the atomic bomb, the world’s most powerful weapon at the time. The Manhattan Project ushered in a new era in world history called the “Atomic Age”. The project made it clear how terrible and devastating an atomic bomb could be, and what the reaction would be. A new arms race emerged after the development of the atomic bomb. As a result, nuclear bombs have been produced in such quantities that they can destroy human civilization and most of the world’s biological resources in an instant.

The Manhattan Project produced 4 atomic bombs. The first bomb, the Trinity, was detonated near Alamogordo, New Mexico. The other two bombs were detonated on August 6 and August 9, 1945, respectively, in Hiroshima and Nagasaki, Japan. The last bomb was readied to be dropped on Japan in late August. But before that, Japan surrendered and World War II ended.

First let’s know what is radiation?

In Yuki’s Kathkhotta language, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.

Basically there are two types of radiation in nature.
Ionizing, and Non Ionizing.

Ionizing radiation that has the energy to remove electrons from atoms, or break bonds. Touching human skin (made of human atoms) can alter DNA structure. Mutation is mainly due to this radiation.

And non-ionizing radiation does not have the energy to remove electrons from atoms. Since this radiation does not have that much power, it will not have any great effect on the human body.

These electromagnetic radiations constantly enter our environment. We live in it. The shorter the wavelength of the electromagnetic wave, the greater the risk of damage, meaning the breaking of atomic bonds. Beta, gamma, alpha rays are typical examples. They are ionizing radiation.

And if the wavelength is large, it will not be possible to break the inter-atomic bond. or will not harm the body. Examples of microwaves, radio waves. These are non-ionizing radiations.

Note the chart below, also in Inter’s book, it will be easy to understand.

And a little fact about ionizing and non-ionizing radiation,
Hopefully it will be clear if there is any damage to the body.

After that comes mobile towers, Wi-Fi, Bluetooth and all wireless mediums use waves of different wavelengths for data transfer. Most of which occurs through microwaves. Mobile towers, 5G or millimeter wave also transfer data through microwaves.

First, there must be groundbreaking work. There must be novelty. That will challenge the conventional understanding of that subject in the field and may spawn a branch in itself. In fact, the novel can be in many research papers, but the level or significance of all of them is not the same. It seems reasonable to use the word groundbreaking for this.

Second, it must have direct or broader implications for human welfare or have clear indications that it will benefit humanity in the future.

Third, for a particular research over a long period of time and for making significant contributions to that subject over a consistent period of time. Many people jokingly say that if you don’t reach the age of 70, you can’t be eligible for the Nobel Prize in Physics. Again Lawrence Bragg probably got the Nobel when he was only 24-25 years old.

I told Angi what I knew about the Nobel Prize in Physics. Maybe in chemistry or medicine.

The Sun generates heat and light through a process known as nuclear fusion, specifically a type called thermonuclear fusion. This process occurs in the Sun’s core, where immense pressure and temperature conditions are present.

Here’s a simplified explanation of how the Sun creates heat and light through nuclear fusion:

Hydrogen Nuclei Fusion:
The primary fuel for the Sun’s energy production is hydrogen, which is abundant in its core. High temperatures and pressures in the core cause hydrogen nuclei (protons) to collide and fuse together to form helium nuclei. This process is known as nuclear fusion.

The most common fusion reaction in the Sun involves four hydrogen nuclei fusing to create one helium nucleus, along with releasing a tremendous amount of energy in the form of light and heat.

Energy Release:
The fusion process converts a small portion of the mass of the hydrogen nuclei into energy according to Einstein’s equation E=mc^2.

Where E is energy, m is mass, and c is the speed of light. The released energy manifests as light and heat, which is what we observe and feel as sunlight and warmth.

Radiation of Light and Heat:
The energy released during nuclear fusion in the Sun’s core is in the form of high-energy photons, primarily in the form of visible light, ultraviolet (UV) light, and other electromagnetic radiation. These photons travel through the Sun’s layers, eventually reaching the surface and being emitted into space as sunlight.

The sunlight, containing both light and heat, then travels through space and reaches Earth and other celestial bodies in the solar system, providing the necessary energy for life and various processes.

This continuous process of nuclear fusion in the Sun’s core is what sustains its energy output, creating the heat and light that power our solar system. It’s important to note that the Sun’s core is incredibly hot and under immense pressure, conditions necessary for nuclear fusion to occur at the scale observed in stars like the Sun.