On this day, 57 years ago, on August 24, 1968 (July 1, 1968, the lunar calendar), France exploded a hydrogen bomb at the South Pacific test site. August 24, 1968-France explodes a hydrogen bomb at the South Pacific test site, becoming the fifth country in the world to possess nuclear weapons. Hydrogen bombs (also known as thermonuclear weapons) are a type of nuclear weapons. It mainly uses the energy released by the fusion reaction of hydrogen isotopes (deuterium and tritium) to carry out killing and destruction. In terms of its principle, it is not a "pure" fusion nuclear weapon; To be precise, it should be called a "three-phase bomb". Fission triggers fusion, and neutrons released by fusion induce more intense fission. Because of this, it has unprecedented power-the most destructive explosive device created by humans is a hydrogen bomb called the "Tsar Bomb"(codenamed "Ivan"). Its original design has a TNT equivalent of 100 million tons, but based on various considerations, its actual manufacturing equivalent is about 50 million tons. Comment: France is the fifth country to possess a hydrogen bomb after the Soviet Union, the United States, Britain and China.