WHAT IS THE SPEED OF LIGHT

Light travels at an extremely fast speed; however, it is finite, as Danish astronomer Ole Røemer reasoned in 1675. Røemer observed the orbits of Jupiter’s moons and noted that they appeared to speed up when the Earth was closer to Jupiter. He deduced that this change must be a result of the decreased distance the light from the moons had to travel. From this, he calculated that the speed of light was approximately 200,000 km/s.

In 1905, Albert Eistein postulated that the speed of light was constant for any observer, no matter how fast they themselves were travelling. From this he derived the theory of special relativity, interrelating both space and time and deducing the famous mass-energy equivalence equation: E=mc². Although the implications of this theory were not immediately felt, today’s society relies on it heavily for technologies such as the global positioning system (GPS).

 The speed of light can be determined by measuring the distance light travels and the time it takes to travel that distance. This can be done using various methods, including time-of-flight measurements with lasers and mirrors, or analyzing the properties of electromagnetic waves like wavelength and frequency. The speed of light is a fundamental constant, approximately 299,792,458 meters per second in a vacuum

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