# Atmospheric refraction help

1. Feb 28, 2013

### cris9288

1. The problem statement, all variables and given/known data
Explain, with the relevant equations and a clearly labeled figure, what is actually happening as you view a sunset. Make sure to include a clearly labeled ray diagram for full credit.

2. Relevant equations

n1sin(θ1) = n2sinθ2

1/f = 1/o + 1/i

3. The attempt at a solution
This was a midterm problem that I got wrong. We are having an extra credit quiz tomorrow and this is the only problem I don't have solved.

My attempted solution involved using snells law, in both equation and diagram form. However I was given no credit as I had the "wrong approach". I'm guessing I should be using a ray diagram, but i'm unsure how to set up the f and i variables. Since the sun is very far away from the sun, I can set o in my lens equation to infinity. This would make the focal length equal to the image distance, but this really doesn't make any sense to me. Any help is appreciated, thanks.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Feb 28, 2013

### tiny-tim

welcome to pf!

hi cris9288! welcome to pf!

can you show us (or describe) your diagram?

(and you don't seem to be mentioning colour)

3. Feb 28, 2013

### rude man

Thing is, the atmosphere represents a medium with continuously varying index of refraction, both as a function of atmospheric density and dispersion (n varies with f).