Name two effects produced by the atmospheric refraction.

Where in nature can you find evidence that white sunlight may be made of different colours?

Name the phenomenon which causes the twinkling of stars.

Which phenomenon makes us see the sun:

(a) a few minutes before actual sunrise?

(b) a few minutes after actual sunset?

Atmospheric refraction causes advance sunrise and delayed sunset. By how much time is:

(a) sunrise advanced?

(b) sunset delayed?