BTW, "it takes a photon over 100,000 years to exit the Sun" is misleading - it sounds like there's a single photon that's generated deep inside the Sun's core a

BTW, "it takes a photon over 100,000 years to exit the Sun" is misleading - it sounds like there's a single photon that's generated deep inside the Sun's core and winds its way through like a cicada until it emerges at the surface. In reality, any photon traveling inside the Sun will almost instantly collide with some other particle, which may emit zero, one, or more photons as a result. When we say "100,000 years", I believe we're summing up the total of these photons' expected lifetimes, basically following the flux of energy rather than individual photons.