Early Sun-Rise

Description:

The Earth is always spinning around its own axis – sometimes from where you stand on the Earth you can see the Sun this is called daytime and sometimes the part of the Earth where you are located is facing away from the Sun so it is dark this is called nighttime.

The time when Sun appears is called sunrise, and the time when it disappears is called sunset.

Sun rays travel from free-space into the earth’s atmosphere which is made up of air. As air is denser than free-space, sun rays are refracted and they bend towards normal.

Due to this bending of the ray, the sun ray reaches the observer before the actual sunrise time and the observer can see an apparent image of sun, this phenomenon is known as early sunrise. Therefore, in morning we see the sun before it actually appears.

Similarly, due to refraction on sun ray there is delayed sunset.

Early Sun-rise and delayed Sun-set is due to refraction of sun rays through atmosphere.