The age and life span of the sun
The sun constantly radiates energy into space in the form of electromagnetic waves. This energy is released by the condensation of four hydrogen nuclei into one helium nucleus at high temperature and high pressure. We know that the atomic weight of a hydrogen nucleus is 1.00728, the atomic weight of a helium nucleus is 4.00 15, and the mass of four hydrogen nuclei should be 4.0292. When four hydrogen nuclei fuse into 1 helium nucleus, it will lose 0.0276 unit mass, of which 1 gram hydrogen will lose 0.0069 gram. In other words, the generation of solar energy is at the cost of consuming mass, which is converted into solar radiation and no longer belongs to the sun. The sun loses about 4 million tons of mass every second, which is negligible for the great mass of the sun. From the birth of the sun to the present 5 billion years, the sun has only consumed 0.03% of its mass, and even in another 5 billion years, it will only consume 0.06% of its mass. But the problem is that the mass of the sun, however great, is still limited. How long can the life of the sun last? What is the impact on the earth?
The life of the sun begins with nebulae and ends with red giants and white dwarfs, becoming the bones of the sun. This process will take about 654.38+0 billion years, which means that another 5 billion years will be the death of the sun, and the earth we live in will be swallowed up by the sun when it becomes an expanding red giant. If we humans can live to that time, we will fly to other planets to live.
What happens inside the sun is nuclear fusion.
The initial high temperature of the sun comes from its internal pressure. According to the principle of universal gravitation, the greater the mass of an object, the greater the gravity. In the early years, when the sun snowballed, with the increase of mass, the gravity was stronger, and the more substances attracted around it, the more the mass increased, and so on, the mass of the sun became bigger and bigger. At the same time, the greater the mass, the greater the internal pressure, so that the temperature continues to rise. The conditions of thermonuclear fusion are sufficient pressure (called critical pressure) and suitable ignition temperature. With the increasing mass of Taiyang Yuan and the increase of internal pressure and temperature, the sun began to glow and become a star after meeting the thermonuclear reaction conditions. Generally speaking, a gas planet must have a certain mass in order to become a star, so that its internal pressure and temperature can meet the conditions of thermonuclear reaction. This mass is called critical mass. A typical example is Jupiter, the largest gaseous planet in our solar system, which is also a gaseous planet composed of hydrogen. However, because its mass is less than the critical mass, its internal pressure and temperature cannot meet the conditions of thermonuclear fusion, it can only be a gaseous planet. However, it is a potential sun. Some scientists speculate that after the destruction of the sun in the future, Jupiter, which is not restricted by the sun, will attract the surrounding planets to form a small solar system by virtue of its position as the leader of the solar system, and at the same time continuously absorb the surrounding substances to increase its mass. After reaching the critical mass, it will shine and become another sun, but that will be 5 billion years later.