Bending Light From Sun
Most recent answer: 03/09/2015
- Noah (age 16)
Pittsburgh, PA, 15044
The gravitational bending is really small. Roughly, it must be about gR/c2 radians, where g is the acceleration near the surface, R is the Earth's radius, and c is the speed of light. That's roughly 10-9 rad. The number will end up different for different planets, being bigger for say Jupiter.
There's a much bigger effect from the light bending as it goes through the atmosphere. Unlike the gravitational bending, the atmospheric bending depends on the frequency of the light. When I was a student at La Jolla, there was a sort of cult of trying to see a "green flash" just as the sun was setting over the ocean. The idea is that the bluish light bends more and thus sets after the reddish light. It's not a blue flash, though, because the bluest light scatters a lot. So it's supposed to end up kind of green.
Mike W.
(published on 03/09/2015)