All articles tagged with #photon diffusion
Light from the Sun reaches Earth in about eight minutes, but the energy that becomes sunlight spends roughly 170,000 years diffusing through the Sun’s dense interior via countless absorptions and re-emissions. The 500,000-year figure is not supported by peer‑reviewed sources. After escaping the photosphere, photons traverse space to Earth in about eight minutes.
Light takes about eight minutes to reach Earth, but the energy it carries was generated in the Sun’s core tens of thousands to millions of years ago. In the radiative zone, photons undergo a slow, random-walk diffusion, with a commonly cited average travel time of ~170,000 years from core to surface. The photons that finally escape the photosphere are new particles carrying energy that’s been migrating outward for a very long time, and the famous phrase “the photon you see now is 100,000 years old” is a simplification. Some analyses (Kelvin–Helmholtz considerations) push the relevant energy-migration timescale to tens of millions of years, meaning the eight-minute Earthward leg is only the final step in a prolonged solar interior journey.