
The Sun’s Self-Regulating Thermostat: Fusion Keeps the Light On, Gravity Keeps It Going
Fusion barely powers the Sun; its gravity continuously compresses the core, heating it just enough to keep fusion in a self-regulating balance with hydrostatic equilibrium. If fusion stopped, the Kelvin-Helmholtz mechanism would let the Sun slowly shrink and release heat, keeping it shining far longer as a natural thermostat with no moving parts. The Sun actually heats up as it loses energy, and internal changes propagate extremely slowly. Part 3 will trace a photon’s 100,000-year journey out of the Sun.













