TED-ED: Sunlight is way older than you think - Sten Odenwald

The video explains the journey of photons from the Sun's core to its surface, a process that takes thousands of years due to the random walk problem. Photons are produced in the Sun's core and interact with matter, losing energy and changing form. The random walk problem is used to calculate the distance photons travel, but initial calculations are incorrect due to assumptions about uniform density and photon interactions. The Sun's density varies, affecting photon travel time, which is now estimated at 170,000 years. The video concludes with the potential for future discoveries to refine this understanding.

What factors contribute to the discrepancy in the estimated travel time of photons from the Sun's core to its surface?

How does the density of the Sun's core compare to that of the material near its surface?