Mirrors don't have to be flat ( Uranus and Neptune)

On 16 May 2012 03:57, hitssquad wrote:

> Then don't use *flat* mirrors. Use ones that *aren't* flat -- like this
> one:
> https://www.google.com/search?q=hubble+telescope+curved+mirror
>

Look, it's kind of subtle, but it doesn't make any difference, any
particular part of the mirror that is optically flat reflects rays from all
parts of the sun's disk, and for each ray,the angle of incidence and
reflection is the same, so the angle that the sun makes is conserved before
and after it hits the mirror.

With a mirror, you can make more of the solid angle that the receiver sees
contain the sun, but you can't change the difference in angles between each
side of the Sun for any part of the mirror, or all parts of the mirror. The
rays coming off the mirror diverge at the same rate they hit it, whatever
the shape of the mirror is.

--
-Ian Woollard