In the vast universe, the sun, with its dazzling light and endless energy, provides the source power for the continuation of life on earth. Have you ever wondered what the sun is "burning" through, and why has it been burning for 4.6 billion years? Let's uncover the secrets of solar energy.
What we need to understand is that the "burning" of the sun is not the burning as we understand it in our daily lives. In everyday life, combustion usually refers to the process by which fuel reacts chemically with oxygen, releasing heat and light. The sun's energy comes from the nuclear fusion reaction inside it. Nuclear fusion is a process by which atomic nuclei combine into heavier nuclei, and this process releases large amounts of energy. The sun's energy is produced through this nuclear fusion reaction.
In the interior of the sun, high temperature and pressure cause hydrogen nuclei to collide and combine to form helium nuclei. In this process, a portion of the mass is converted into energy, which is released in the form of light and heat. This is where the sun's energy comes from. According to Einstein's mass-energy equation E=mc2, energy and mass can be converted into each other. Thus, we can say that the sun achieves a continuous output of energy by "burning" hydrogen.
Why has the sun been burning for 4.6 billion years and has not burned out? It starts with the cycle of matter inside the sun. The energy inside the sun is generated by nuclear fusion reactions in the core region, and this energy travels outward, heating the surface and other layers of the sun. In this process, the material inside the sun is constantly moving from the inside to the outside, forming a structure called the "heliosphere". The heliosphere includes the photosphere, chromosphere, corona and other layers, and the exchange of matter and energy between these layers enables the sun to continuously "burn".
In the interior of the sun, hydrogen nuclei collide and combine to form helium nuclei. This process is not done all at once. In the core region of the Sun, the temperature and pressure are so high that the hydrogen nuclei undergo a fusion reaction. And in the lower layers of the Sun, such as the photosphere and chromosphere, the temperature and pressure are relatively low enough to support the fusion reaction of hydrogen nuclei. Thus, in these layers, hydrogen nuclei can only slowly migrate towards the core region through thermal motion. When they reach the core region, they can participate in the nuclear fusion reaction, forming helium nuclei and releasing energy. In this way, the hydrogen nuclei inside the sun can continuously participate in the nuclear fusion reaction, achieving a continuous energy output.
In addition, the circulation of matter inside the sun is also affected by other factors. For example, sunspot activity on the surface of the Sun affects energy transmission and material circulation inside the Sun. Sunspots are low-temperature regions of the sun's surface, and their appearance and disappearance cause temperature changes on the sun's surface. This temperature change affects the energy transfer and material circulation inside the sun, which in turn affects the sun's energy output. Overall, the circulation of matter and energy within the Sun is very stable, which allows the Sun to continue to "burn" for 4.6 billion years.
The sun exports energy through nuclear fusion reactions. In this process, hydrogen nuclei are constantly combined into helium nuclei, releasing a large amount of energy. The circulation of matter and the transfer of energy inside the sun allow this "combustion" to continue. Although the sun has been burning for 4.6 billion years, it is still able to continue to provide us with a steady stream of energy due to its internal stability mechanism and material cycling processes.