All photos: Greville E

Our ‘light of day’ begins with the sun rising and ends with the sun setting. These photos were all captured from the promenade at Sant Pol de Mar, Barcelona

We take it for granted that the earth rotates once every 23 hours, 56 minutes and 4.09053 seconds, and is called the sidereal period.

Our world’s circumference is roughly 40,075 kilometres. So, the surface of the earth at the equator moves at a speed of 460 meters per second – roughly 1,000 miles or 1609.34 kilometres per hour.