The discovery by Albert Einstein of the ability of substances to release a large amount of energy at the atomic level marked the beginning of nuclear physics. In the 1930s, researchers were engaged in modeling an airborne nuclear explosion in laboratory conditions, but the experience gained endangered a peaceful life on Earth.
Operating principle
For an air nuclear explosion, certain conditions must be created that provoke detonation. Typically, trotyl or hexogen are used as detonators, under the influence of which a radioactive substance (usually uranium or plutonium) is compressed to a critical mass within 10 seconds , and then a powerful release of energy occurs. If the bomb is thermonuclear, then the process of transformation of light elements into heavier ones takes place in it. The energy released in this case carries an even more powerful explosion.
A nuclear reactor can also be used for peaceful purposes, since fission can be controlled. For this, neutron absorbing devices are used. The processes taking place in such an installation are always in equilibrium. Even if there are any minor changes in the parameters, the system extinguishes them in time and returns to operating mode. In emergency situations, elements that stop the chain reaction are automatically reset.
First experience
Discovered by Einstein and further studied by nuclear physicists, the release of energy interested not only scientists, but also the military. The possibility of obtaining new weapons, with the help of which it will be possible to create powerful explosions from a small amount of substance, has led to experiments with radioactive elements.
Physically, the possibility of an explosion with significant damaging effects was proved by the French scientist Joliot-Curie. He discovered a chain reaction that became a powerful source of energy. Further, he planned to conduct experiments with deuterium oxide, but in the conditions of the Second World War it was impossible to do in France, so in the future, British scientists began to develop atomic weapons.
The first explosive device was tested in the summer of 1945 in America. By today's standards, the bomb had a small power, but at that time the effect obtained exceeded all expectations. The force of the explosion and the impact on the surrounding territory were enormous.
results
To determine the characteristics of an air-nuclear explosion, tests were conducted. Those present subsequently described the sight seen. They watched a bright luminous point at a distance of several hundred kilometers. Then it turned into a huge ball, a very loud sound was heard, and a shock wave swept for kilometers. The ball exploded, leaving a twelve-kilometer cloud in the shape of a mushroom. At the site of the explosion, a crater remained, tens of meters wide and deep. The earth around it for several hundred meters turned into lifeless, pitted soil.
The air temperature during a nuclear explosion increased significantly, and the atmosphere itself seemed to be denser. Even eyewitnesses who were far from the epicenter in the shelter felt this. The scope of what he saw was astounding, since no one imagined what kind of power they would encounter. It was concluded that the tests were successful.
The damaging factors of an air nuclear explosion
The military immediately realized that new weapons could decide the outcome of any war. But at that time no one was thinking about the impact of the damaging factors of a nuclear explosion. Scientists drew attention only to the most obvious of them:
- shock wave;
- light emission.
Nobody knew about radioactive contamination and ionizing radiation then, although subsequently it was penetrating radiation that turned out to be the most dangerous. So, if the devastation and destruction were localized at a distance of several hundred meters from the epicenter of an air nuclear explosion, then the dispersion area of the radiation decay products extended to hundreds of kilometers. A person received the first exposure, which was subsequently weighed down by radiation fallout in the surrounding areas.
Also, scientists did not yet know that under the influence of an air shock wave of a nuclear explosion, an electromagnetic pulse is generated, which can disable all electronics at a distance of hundreds of kilometers. Thus, the first testers could not even imagine how powerful the weapon was, and how catastrophic the consequences of its use could be.
Types of explosions
Aerial nuclear explosions are carried out at the height of the troposphere, that is, within 10 km above the surface of the earth. But besides them there are other types, for example:
- Ground or surface are conducted on the surface of the earth or water, respectively. A ball of fire expanding from a flash, in this case, looks like a sun rising from behind the horizon.
- Altitude conducted in the atmosphere. The luminous flash in this case is very large, it freezes in the air and does not touch the earth or water surfaces.
- Underground or underwater occur in the interior of the earth's crust or in depth. Usually, a flash is not observed.
- Cosmic. Such occur hundreds of kilometers from the globe, outside the near-planet space and are accompanied by a cloud of luminous molecules.
Different types differ not only in flash, but also in other external characteristics, as well as damaging factors, the intensity of the explosion, its results and consequences.
Ground tests
The first bombs were tested directly on the surface of the earth. It is precisely these types of explosions that are accompanied by a distinct mushroom cloud in the air and a crater that extends over several tens, or even hundreds of meters in the soil. A ground explosion looks the most frightening, since a cloud that hangs low above the ground attracts not only dust, but also a significant part of the soil, which makes it almost black. Particles of soil are mixed with chemical elements, and then fall to the ground, which makes the territory radioactively infected and completely unsuitable for life. For military purposes, it can be used to destroy powerful buildings or facilities, infecting vast territories. The destructive effect is the most powerful.
Surface explosions
Tests are also conducted above the surface of the water surface. In this case, the cloud will consist of water dust, which reduces the intensity of light radiation, but carries radioactive particles over great distances, as a result of which they can fall out along with precipitation thousands of kilometers from the test site.
For military purposes, this can be used to destroy naval bases, ports and ships, or to infect water and the coast.
Aerial explosions
This species can be produced at a large distance from the ground (in this case it is called high) or at a small (low). The higher the explosion occurred, the less the rising cloud resembles the shape of a mushroom, since a column of dust from the ground does not reach it.
The flash in this form is very bright, so it can be seen hundreds of kilometers from the epicenter. A ball of fire exploding from it, with a temperature measured in millions of degrees Celsius, rises up and sends powerful light radiation. All this is accompanied by a loud sound remotely resembling peals of thunder.
As it cools, the ball transforms into a cloud, which creates a stream of air that picks up dust from the surface. The resulting pillar can reach the cloud if it is not very high above the ground. In the future, the cloud begins to dissipate, and the air flow decreases.
As a result of such an explosion, objects in the air, buildings, and people nearby can be affected.
Military use
Hiroshima and Nagasaki are the only cities to which nuclear weapons have been used. The tragedy that happened there was second to none.
Residents experienced the effects of an air nuclear explosion initiated at a short distance from the surface of the earth and classified as low. At the same time, infrastructure was completely destroyed, about 200 thousand people died. Two thirds of them died instantly. Those at the epicenter broke up into molecules from monstrous temperatures. Light radiation left shadows from them on the walls.
People who were farther from the epicenter died from the shock wave and gamma radiation of a nuclear explosion. Some of the survivors received a lethal dose of radiation, but the doctors did not yet know about radiation sickness, so no one understood why, after imaginary signs of recovery, the condition of patients worsens. Doctors considered this to be dysentery, but within 3-8 weeks, patients with severe vomiting were dying. The strange disease of the people who survived the atomic bombing of Hiroshima and Nagasaki became an incentive to start research in the field of nuclear medicine.
High explosions
After the bombing of Japanese cities, nuclear weapons were not used for military purposes, but the study of its capabilities continued in different places. Exercises in the atmosphere made it possible to understand what happens in an explosion at a height. It turned out that when the center is located 10 km from the earth's surface, a relatively small wave of nuclear explosion occurs, but the light and radiation radiation increase. The higher the explosion was made, the stronger the ionization increases, which is accompanied by the failure of radio equipment.
From the surface, it all looks like a big bright flash, giving way to a cloud of evaporating molecules of hydrogen, carbon and nitrogen. The air flow does not reach the ground, so a column of dust does not occur. Also, there is practically no infection of the territory, since at high altitude the air masses move poorly, so the purpose of such a nuclear explosion may be to destroy planes, missiles or satellites.
Underground tests
Recently, an agreement exists between the countries that regulates nuclear tests and requires them to be carried out only underground, which minimizes pollution and unsuitable areas around the landfills.
Underground tests are considered the least dangerous, since the effect of all the damaging factors is on the rocks. It is impossible to see luminous flashes or a mushroom cloud, only a pillar of dust remains from it. But the shock wave leads to an earthquake and collapse of the soil. Usually it is used for peaceful purposes, to solve economic problems. For example, this way you can destroy mountain ranges or form artificial ponds.
Underwater tests
Explosions underwater have more formidable consequences. First, a column of spray appears, rising to a cloud of radioactive fog. At the same time, meter waves form on the surface of the water, destroying ships and underwater structures. Then, contamination of adjacent territories occurs due to a scattering cloud spilled by radioactive rain.
Protective measures
A nuclear explosion kills everything in its path and destroys all material objects. People who have fallen into its epicenter have no opportunity to escape, they instantly burn to the ground. In this case, the bomb shelter is absolutely useless, since it will immediately be destroyed.
Only those who are far enough from the explosion can be saved. At a distance of more than 1-3 km from the epicenter, the impact of the shock wave can be avoided, but for this you need to quickly find a reliable shelter as soon as a bright flash has arisen. For this, a person has from 2 to 8 seconds, depending on the distance. In the shelter, direct exposure to gamma radiation will not occur, but there is still a very high probability of radioactive contamination. You can reduce the risk of radiation sickness by using personal protective equipment and avoiding contact with any objects located on the territory.
Nuclear weapons are one of the most terrible inventions of mankind. Used for peaceful purposes, it can be of great benefit, but its military use carries a terrible threat to life on earth. A launched chain reaction cannot be stopped, therefore there is a nuclear disarmament treaty designed to protect the planet from disaster.