Why is the atomic bomb so powerful

During the Second World War, the Manhattan Project, led by American theoretical physicist Robert Oppenheimer, successfully produced the world’s first atomic bomb. The first test was conducted on July 16, 1945. The United States eventually used atomic bombs to strike Hiroshima and Nagasaki, forcing Japan into unconditional surrender and bringing the war to an end. From the moment the atomic bomb appeared, the world had entered the nuclear age. The destructive power of the atomic bomb is beyond imagination, and after years of development, its force has only increased, to the point where it could annihilate civilization. Why does it possess such immense power?

The visible matter in the world is primarily composed of atoms. At the center of each atom lies a nucleus, which is made up of protons and neutrons. Protons carry a positive charge, while neutrons are electrically neutral. The number of protons in the nucleus determines the element: oxygen has 8 protons, carbon has 6. Within a single element, atoms may contain different numbers of neutrons; these variations are called isotopes. For example, carbon-12 has 6 protons and 6 neutrons, while carbon-13 has 6 protons and 7 neutrons. Thus, carbon-12 and carbon-13 are isotopes: they share the same number of protons but differ in neutrons. Isotopes not only differ in mass but may also vary in stability.

Because protons are positively charged, they repel one another under Coulomb force. Neutrons, however, provide a “glue-like” effect through the strong nuclear force, binding protons together and counteracting their repulsion, thereby stabilizing the nucleus. This explains why isotopes differ in stability. Although neutrons can enhance stability, having too many disrupts the balance and increases instability. Each element has an optimal ratio of protons to neutrons for stability—for instance, oxygen-16 (8 protons and 8 neutrons), iron-56 (26 protons and 30 neutrons), and uranium-238 (92 protons and 146 neutrons). In general, the greater the number of protons, the stronger the repulsive force, and thus more neutrons are required to maintain stability.

When certain heavy elements (with many protons and neutrons) are unstable, they may undergo nuclear fission, splitting into two lighter nuclei while releasing neutrons and energy. If this energy is harnessed and controlled, it can be used as a weapon. Fissile materials such as uranium-235 are commonly used to construct atomic bombs. Uranium-235, upon absorbing a neutron, readily undergoes fission. When a large quantity of uranium-235 is assembled, a single neutron striking one nucleus can trigger fission, releasing more neutrons and energy. These neutrons then strike other uranium-235 nuclei, causing further fission. This chain reaction proceeds rapidly, releasing an enormous amount of energy in a very short time.

When an atomic bomb explodes, it releases multiple forms of energy and matter almost instantaneously. First, an extremely hot fireball forms at the center, with temperatures reaching millions of degrees. This causes the surrounding air to expand violently, generating a powerful shockwave that destroys buildings and inflicts widespread damage. Next, the fireball emits intense thermal radiation, igniting combustible materials and causing severe burns. The explosion also produces prompt radiation, including high-energy gamma rays and neutrons, which inflict acute radiation injuries on nearby living organisms. If the explosion occurs at or near the ground, the fireball draws in large amounts of soil and debris. These particles combine with radioactive fission products to form fallout, which disperses with the wind and settles, creating long-term radioactive contamination. If in the case of a high-altitude nuclear detonation, an electromagnetic pulse may be generated, capable of disabling electronic equipment and power systems.

In modern military practice, atomic bombs are no longer deployed as simple free-fall bombs. Instead, they are designed as nuclear warheads mounted on various delivery systems. These systems fall into three main categories—sea-based, land-based, and air-based—collectively known as the “nuclear triad”. Sea-based delivery relies on submarine-launched ballistic missiles. Submarines can travel undetected beneath the ocean, making them difficult to locate and providing both high survivability and the ability to strike unexpectedly. Land-based delivery includes fixed missile silos and mobile launch vehicles. Silos offer stability and protection, while mobile launchers enhance flexibility and survivability by moving across terrain. Air-based delivery depends on strategic bombers, which can carry nuclear bombs or cruise missiles, fly directly over targets, and select flexible flight paths. Each method has distinct advantages: submarines are the most concealed, land-based systems are the most stable, and air-based systems are the most versatile. Together, they form a comprehensive nuclear delivery network, ensuring that nuclear deterrence can be maintained under any circumstances.