The sun's energy source
Earth's energy is said to come primarily from solar radiation. The sun constantly radiates enormous energy into space. If we compare this energy to money, the sun throws 22 trillion dollars of silver into space every second. The money that the earth can collect is about 10,000 yuan, and the final amount used by humans is only about 1 yuan. So where does the sun come from to get so much energy?
The infinite energy of the Sun comes from the nuclear fusion reaction at its core, which is actually similar to the principle of a hydrogen bomb. But have you noticed? They also rely on nuclear fusion reactions. The hydrogen bomb explodes into nothingness. The sun has been burning for almost 5 billion years now, and it will continue to burn like this for billions of years.
The principle of the hydrogen bomb
First of all, let's talk aboute nuclear fusion of the hydrogen bomb. To understand nuclear fusion of hydrogen bombs, you must first understand what nuclear fusion is. “Core” here refers to the nucleus. Nuclear reactions are actually divided into nuclear fusion and nuclear fission. In the literal sense, we can actually know that nuclear fusion is the fusion of several atomic nuclei with a small atomic number, and nuclear fission is actually the splitting of atomic nuclei with a large atomic number into nuclei with a small number atomic.
During this process, there will be a loss of mass before and after the reaction, and this part of the mass will be released as energy. The whole process satisfies Einstein's mass-energy equation E=mc^. 2.
Where it is the speed of light 3*10^8 m/s. Using the equations, we can easily see that even a small loss of mass can release a huge amount of energy.rgie. Atomic bombs use nuclear fission, typically using the element uranium as a raw material.
Nuclear fusion is the principle of hydrogen bombs, generally using hydrogen and hydrogen isotopes. Hydrogen bombs typically use deuterium and tritium. The whole process is: deuterium + tritium + neutron + energy (1.76? 10^7eV).
It is not easy to move the whole reaction forward. This requires extremely high reaction conditions and the required temperature is at least hundreds of millions of degrees. Therefore, in order to reach the full reaction temperature, the hydrogen bomb is not actually "pure", but consists of two parts: nuclear fission and nuclear fusion.
The method used by scientists is to first trigger a nuclear fission reaction and then produce X-rays through fissionnuclear power to compress and heat the secondary nuclear fusion fuel, thereby promoting the nuclear fusion reaction.
What we need to know is that the temperature of the sun's core is about 15 million degrees, which is still far from hundreds of millions of degrees. Logically, it cannot trigger nuclear fusion reactions. why is the core of the sun so hot? Can nuclear fusion reactions still occur?
The principle of solar nuclear fusion
The most important reason why the Sun can produce nuclear fusion reactions is that it has sufficient mass. 4.6 billion years ago, there was a molecular cloud 2 light years away near the current location of the solar system. This molecular cloud underwent gravitational collapse and the sun was gradually formed under the influence of gravity. solar system. Other celestial bodies.
AlsoThe sun is the absolute master of the solar system, representing 99.86% of the total mass of the entire solar system. Because the mass of the sun is very huge, the gravitational pull of the sun itself is extremely strong, which will compress, causing its temperature to rise sharply, and the interior of the sun will be in a plasma state.
The so-called plasma means that the electrons of the atoms that make up the material gain enough energy and free themselves from the constraints of the atomic nucleus. At this point, the material is no longer the common one of the three. gaseous, liquid and solid states, but like a slurry of particles? The same thing, with various atomic nuclei, photons and electrons wandering around.
Since 73% of the sun itself is made up of hydrogen atoms, the interior of the sun is in a plasma state. There are therefore 73% of free hydrogen nuclei (protons) inside the Sun. The nuc fusion reactionlary in the core of the Sun is actually the fusion of protons, but protons are positively charged and like charges repel each other, and there is electrostatic repulsion between protons. Only by overcoming electrostatic repulsion can nuclear fusion occur between protons. Why is the reaction still happening?
First of all, when two protons are close to each other, there will be an extremely low probability that a proton will transform into a neutron under the action of the weak force. The proton and neutron can then do this. be combined to obtain nuclear deuterium.
One more thing here. According to current major theories, we know that there are four fundamental forces in the universe, namely the strong force, the weak force, the electromagnetic force and gravity. Among them, the weak force and the strong force act at the level of the atomic nucleus. In daily life, exceptn gravity, other forces are mainly electromagnetic forces, such as elastic force, support force, etc.
Among the four forces, gravity is the weakest, followed by the weak force, and the strong force is the strongest. The weak force will change the type of particles, and the disintegration is basically caused by the weak force. At the heart of the Sun, the weak force can transform protons into neutrons.
Due to the existence of electrostatic repulsion, the weak force is too weak. The likelihood of this reaction occurring is extremely low. The event in which a proton meets another proton in the Sun and becomes a deuteron can only happen once every billion years. But if this reaction can be triggered, subsequent reactions will be easy. Eventually, 4 protons become a helium nucleus through nuclear fusion, releasing a large amount of energy at the same time.ergy. The main nuclear fusion reaction in the core of the Sun is called the proton-proton reaction.
The impact of the weak force on solar nuclear fusion
As the sun is extremely massive, the number of protons it contains is extremely large. Even an extremely low probability event becomes a high probability event when it comes to the sun. However, because the weak force is too weak, the reaction cannot proceed as quickly as a hydrogen bomb, but burns very slowly. So how slow is the response?
The nuclear fusion power of the solar core will gradually decrease as the distance from the center of the sun increases. Through model calculations, scientists have come to the conclusion that the nuclear fusion power density of the solar core is. approximately 276.5 W. /(m^3). The total power is about one tenth of the power consumed byunit by an adult weighing 50 kilograms.one. Therefore, solar energy releases such a large amount of energy, not because of the violence of the reaction, but mainly because the sun itself is large enough.
If the weak force is 10% greater than it is now, then the lifespan of the sun will be shortened by about 20%; if the weak force is even greater, the sun could die before humans appear; Earth. Therefore, the weak force is perfect, which also provides a good basis for the emergence of human beings.