Hello,(adsbygoogle = window.adsbygoogle || []).push({});

Let me first describe the situation I am thinking of:

suppose we consider an object in the form of a square with some thickness (e.g. a mirror). Suppose further, that the gravitational force pulling the object towards the sun and the radiation pressure due to the sunlight are in balance (so that the object has no acceleration). If the object is far away from the sun we may consider the sun as a point source such that the radiation pressure depends on the distance r>0 between the sun and the object proportional to 1/r^{2}(similar as the gravitational force). Hence, if we change the position of the mirror a "little bit", both forces will still cancel each other out. Now, I am wondering what would happen if we move the mirror 'close enough' towards the sun, such that it would not be appropriate anymore to treat the sun as a point source?

I would expect that the radiation pressure will not maintain proportional to 1/r^{2}. But I have no idea how it will depend on the distance r? Do you know how to investigate the situation?

I would appreciate your help very much! Best wishes

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# I Change of radiation pressure of sunlight w.r.t. distance

Have something to add?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**