Here's why:
* Nuclear Fusion: The process of fusion involves combining four hydrogen nuclei (protons) into one helium nucleus. However, a helium nucleus has slightly less mass than the four hydrogen nuclei combined.
* Mass-Energy Equivalence: This difference in mass is not lost entirely; it's converted into energy according to Einstein's famous equation E=mc², where E is energy, m is mass, and c is the speed of light.
* Energy Released: The energy released during fusion is what powers the sun and provides light and warmth to Earth. This energy is primarily in the form of photons (light) and neutrinos.
Therefore, while the sun does not lose mass in the absolute sense, it experiences a net loss of mass during fusion. This loss of mass is converted into energy that sustains the sun and radiates outward.
