The Sun’s radiance is often described as “burning,” but this is just a figure of speech. The Sun doesn’t burn in the way we traditionally think of fire consuming wood or paper. Instead, it glows due to a powerful process called nuclear fusion occurring in its core.

  • Combustion, the process we associate with burning, requires oxygen. In a combustion reaction, carbon from fuel binds with oxygen, releasing energy as heat.
  • However, the Sun doesn’t have a sufficient oxygen supply for combustion. The trace amounts of oxygen present in stars are actually created through repeated hydrogen fusion.

The Sun’s energy comes from nuclear fusion, where hydrogen atoms are forced together under immense pressure from the Sun’s gravity. This pressure overcomes the electromagnetic repulsion between the positively charged atomic nuclei. When the nuclei get close enough, the strong nuclear force takes over, binding them together to form helium. This fusion process releases a tremendous amount of energy, which heats the Sun’s material and radiates outward as light and heat.

Think of the Sun as a giant hydrogen bomb, constantly undergoing nuclear fusion. The fusion process doesn’t need oxygen and relies on the powerful forces within the Sun’s core to generate energy.

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