Energy from the sun reaches the earth through what type of heat transfer?

The energy from the sun reaches the earth through a type of heat transfer known as radiation. Here are the steps explaining this process:

1. The sun generates energy in its core through a process called nuclear fusion. During nuclear fusion, the sun's extremely high pressure and hot temperature cause hydrogen atoms to come apart and their nuclei (the central parts of the atoms) to fuse or combine. Four hydrogen nuclei combine to form one helium atom. But the helium atom weighs less than the four hydrogen atoms that fused to produce it. Some matter is lost during nuclear fusion, and the lost matter is converted into a large amount of energy.

2. This energy is then radiated out from the core towards the surface of the sun, and then from the sun into space in the form of light and heat. This is radiation, one of the three types of heat transfer (the other two being conduction and convection). Unlike conduction and convection, which require matter to transfer energy, radiation can travel through the vacuum of space.

3. The radiated energy travels through space in the form of electromagnetic waves. These waves do not need a medium like air or water to travel through, which is why the energy can reach Earth across the vacuum of space.

4. When these waves reach Earth, they are either absorbed by the atmosphere, reflected back into space, or reach the Earth's surface. The energy that reaches the surface is absorbed and re-emitted as heat, warming the planet.