The heat that starts high and ends low! Is there an "absolute zero" between the sun and the earth?

The Sun, as the closest star to us, provides light and heat to the Earth. However, despite the Sun's surface temperature of up to 6,000 degrees, the amount of heat it transfers to the Earth becomes very limited only at an altitude of 13-15 kilometers. Even more surprising is that the temperature of the space between the Sun and the Earth is almost close to absolute zero. So how is heat transferred from the Sun to the Earth? Why is there such a big temperature difference between the Sun and the Earth?

First, we need to understand the basic ways of heat transfer. There are three main ways of heat transfer: heat conduction, heat convection and heat radiation. For the space between the sun and the earth, the effects of heat conduction and heat convection can be ignored. The main way of heat transfer is thermal radiation, that is, objects transfer heat outward in the form of electromagnetic waves.

When the sun's heat radiates to the earth in the form of electromagnetic waves, most of the heat is reflected back into space by the earth's atmosphere, and only a small part of the heat is absorbed by the surface and heats the atmosphere. Therefore, although the surface temperature of the sun is very high, the temperature of the atmosphere above the earth is relatively low.

However, this still does not explain why there is such a big temperature difference between the sun and the earth. To understand this problem, we need to explore the concept of absolute zero. Absolute zero is the lowest possible value of thermodynamic temperature, equal to -273.15 degrees Celsius. This is the state where the molecules of an object stop thermal motion and reach complete stillness. In the universe, only the coldest objects can reach this temperature.

The space between the sun and the earth is close to absolute zero because there is almost no matter here. Due to the vastness of the universe, the matter here is very thin, so the ability to absorb and conduct heat is very weak. Although the radiation from the sun can make the space here very bright, the temperature here is still very low.

To sum up, the temperature difference between the sun and the earth is mainly due to the following reasons: First, the heat of the sun is mainly transferred to the earth in the form of thermal radiation, but most of the heat is reflected back into space by the earth's atmosphere. Second, the space between the sun and the earth is very empty, the material is thin, and the ability to absorb and conduct heat is very weak, so the temperature here is close to absolute zero.

To better understand this phenomenon, we can imagine the starry sky at night. When we look up at the starry sky on a cold night, although we cannot see the sun, we can see the stars twinkling. These stars are releasing heat and light into the universe in their own way, but because the space between them is equally empty, the temperature here is also close to absolute zero.

Through the above analysis, we can draw the following conclusions: The temperature difference between the sun and the earth is mainly due to the combined effect of the heat radiation transmission method and the rarefaction of space. Although the surface temperature of the sun is extremely high, the heat transferred to the earth is reflected back to space by the atmosphere, making the temperature here close to absolute zero. This phenomenon provides us with an opportunity to deeply understand the heat transfer and characteristics of the universe.