What travels around the Sun at an average speed of 185 miles per second.
Rømer's determination of the speed of light Rømer's determination of the speed of light Rømer's determination of the speed of light was the demonstration in 1676 that light has a finite speed, and so does not travel instantaneously. The discovery is usually attributed to Danish astronomer Ole Rømer (1644–1710), who was working at the Royal Observatory in Paris at the time. By timing the eclipses of the Jupiter moon Io, Rømer estimated that light would take about 22 minutes to travel a distance equal to the diameter of Earth's orbit around the Sun. This would give light a velocity of about 220,000 kilometres per second, about 26%
Miles per hour be used to express the speed of delivery of a ball in sporting events such as cricket, tennis and baseball. Miles per hour Miles per hour (abbreviated mph, MPH or mi/h) is an imperial and United States customary unit of speed expressing the number of statute miles covered in one hour. It is used in the United States, United Kingdom and many Commonwealth nations, particularly in the Caribbean region. Speed limits and road traffic speeds are given in miles per hour in the following jurisdictions (elsewhere kilometers per hour are used): Road traffic speeds in other countries are indicated in