A nuclear bomb is a weapon that uses the enormous amount of energy released by an explosive nuclear reaction to cause damage to a target. Explosive nuclear reaction is the use of self-sustaining and rapid nuclear fission or fusion reaction, the instant release of huge energy to produce a nuclear reaction explosion to form a huge killing and destructive effect. Nuclear bombs are very destructive, and now they are used as a manifestation of national strength and a deterrent.

The following five types of harm caused by nuclear weapons to human beings are recognized (not including psychological hazards):

1. High-pressure killing and destruction - shock wave (50%)

In a nuclear explosion, a huge amount of energy is released in less than a second, and the high-temperature and high-pressure gas produced by the explosion expands strongly in all directions, and this hurricane-like pressure wave spreads through media such as air, water, and soil. It can travel to a distance of 2 kilometers in 5 seconds, destroying everything it can push (mainly buildings), and a large number of people die directly from the high-pressure squeeze and indirectly from the collapse of the house. As the distance increases, the shock wave gradually weakens.

2. High temperature killing and destruction - optical radiation (accounting for 35%)

The glow of a fireball during a nuclear explosion can last for a few seconds, making the surrounding air temperature hundreds of thousands of degrees, and the light radiation emitted by the fireball includes X-rays, ultraviolet rays, infrared rays, and visible light. Such high temperature radiation will scorch, melt, kill most objects, and even starve the surrounding area of oxygen, and even burn the skin, destroy vision, and burn the respiratory tract if people do not die.

3. Special Destruction - Penetrating Radiation (5%)

It is a stream of alpha, beta, gamma and neutron radio, which ionizes the cells inside the human body, and the non-thermal effect (a type of radiation) makes the DNA charged, destroys the normal function of the cells, and can produce toxic substances (carcinogenic), causing people to die from acute radiation sickness in a short period of time, or have a great impact on the next generation. Most of the 140,000 people who died in the atomic bomb of Hiroshima were gradually dyed from radiation sickness after the atomic bombing.

4. Long-term hazard - radioactive contamination (10%)

Within a minute of a nuclear explosion, the first three harmful effects will disappear, but the radioactive materials released by the nuclear explosion will disperse in the earth, water and air, some will decay quickly (a few seconds), some will be very slow (tens of thousands of years), but most will weaken relatively quickly. It will weaken faster after washing. However, if radioactive materials are ingested or inhaled, they are extremely harmful.

5. Destruction of communication - electromagnetic pulse (also harmful to people)

The electromagnetic pulse is like a powerful thunder and lightning, and the electric field strength can reach hundreds of thousands of volts, which can interrupt communications, malfunction various controls, confuse electronic computer data, and disrupt normal radio wave propagation. Its propagation and destruction distance reaches hundreds or thousands of kilometers, which is much larger than the first four types of destruction distance.