Key Takeaways:
- Nuclear reactions within the Sun's core generate light and other forms of radiation.
- Photons produced in the core undergo numerous scattering events with electrons and atomic nuclei.
- These scattering events significantly prolong the transit time of photons from the core to the Sun's surface.
- The average time for a photon to travel from the Sun's core to its surface is approximately 200,000 years, despite the constant speed of light.
Nuclear reactions in the Sun’s core produce light and other types of radiation. As light photons leave the core, they run into electrons and atomic nuclei, scattering off each one. These interactions cause photons to take, on average, 200,000 years to move from the Sun’s core to its surface.
Astronomy: Roen Kelly
The speed of light is constant, but the problem is that the light (or more generally, radiation) doesn’t travel directly from the Sun’s center to the surface. The light that originates at the Sun’s core is scattered many times — sometimes toward the surface, sometimes back toward the core, sometimes sideways — before finally arriving at the surface and escaping into space.
