The Sun, the source of our life energy, is at its core a massive nuclear fusion reactor that has been running for approximately 5 billion years. Under the extreme temperatures and pressures of the Sun's core, reaching 15 million degrees Celsius, hydrogen nuclei (protons) gain enough kinetic energy to overcome their electrostatic repulsion, resulting in violent collisions. When two hydrogen nuclei fuse, they form a deuterium nucleus, releasing a positron and a neutrino; this deuterium then fuses with another hydrogen nucleus to form helium-3; finally, two helium-3 nuclei fuse to form a stable helium-4 nucleus, releasing two protons. In this series of reactions known as the "proton-proton chain reaction," a tiny fraction of mass is converted into enormous amounts of energy according to Einstein's mass-energy equivalence equation (E=mc²). It is this energy, converted from millions of tons of matter every second, that travels through space as light and heat, nourishing the Earth. Our "Sol
