1. Nuclear Fusion: This is the core process that powers the Sun. Deep within the Sun's core, intense heat and pressure force hydrogen atoms to fuse together, forming helium. This process releases a tremendous amount of energy in the form of light and heat, which is what we experience as sunlight.
2. Gravitational Equilibrium: This is the balance between the outward pressure from nuclear fusion and the inward pressure from the Sun's own gravity. The energy released by fusion creates an outward pressure, trying to expand the Sun. Gravity, however, pulls everything inward. These two forces are perfectly balanced, preventing the Sun from collapsing in on itself or exploding outward.
These two processes are intricately linked. Nuclear fusion provides the energy that counteracts gravity, while gravity confines the fusion reactions to the Sun's core, allowing them to continue. This delicate balance is what allows the Sun to exist in its current state for billions of years.
