Why we consider sun rays approx parallel although so much atmispheric refraction?

Whose refractive index keep fluctating due to layer of atmosphere thus one ray that take a path is not necessary for other ray to take that path toi as may be atmosphere has changed a bit upto that?

Does being non parallel?


1 Answer 1


The suns rays here on earth are only approximately parallel due to the angular extent of the sun. Light coming from opposite limbs of the sun will be about half a degree from parallel.

For some purposes, that's close enough and we consider them parallel. For other purposes it isn't. The atmospheric distortion isn't going to add much more than the half degree divergence already present.

  • $\begingroup$ Could u elaborate! I need more details in easy word plsssss😅😅.... U r saying atmospheric refraction created a very less displacement as refractive index is 1.00054 something of air that is quite close that of vaccum thus R U SAYING VERY LESS REFRACTION HAPPENED??? EXPLAIN IN DETAILS PLS THAT 1/2°AND ALL!!😅😅😅😅 $\endgroup$ Jun 3, 2021 at 8:59
  • $\begingroup$ I'm saying the rays even before they get to the atmosphere are not exactly parallel. So the atmospheric distortion doesn't make it much worse. It's there, but it's not that important for sunlight. $\endgroup$
    – BowlOfRed
    Jun 3, 2021 at 16:37
  • $\begingroup$ Oo... U mean less affect??!!! On sunlight $\endgroup$ Jun 4, 2021 at 0:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.