In 1983 the speed of light was defined as exactly 299,792,458 meters every second giving some insight as to how fast is the speed of light. This is considered to be perhaps the best vital physical constant present in the world. Apart from being the particular speed at which light can travel it is also the worldwide limit of speed. In the world no signal or wave can actually go over this particular speed. This was proved by Einstein himself who depicted that this speed of light is also basically linked with time and space.

From the beginning of the 17th century, a number of scientists have come out with a lot more precise means of getting to know and answering the question of how fast is the speed of light. One of the most accurate came from Ole Roemer a Danish astronomer in the year 1676. He observed the movement of the moon on Jupiter with the earth on both the far and near side of the sun to come up with a correct measurement of the speed of light. Despite all this the estimate he made was about 26% off the exact measurement but this was still quite good as it was one of the first ever experiments on light to be made which had a finite value.

In the 18th century also a number of scientists made several experiments concerning how fast the speed of light travels. They also developed methods which are similar to their predecessors. Indeed one of the first came from Fizeau, a popular French physicist who used the terrestrial method. He used a rotating toothed method coupled with a quite distant beam of light in order to do a correct measurement of the speed of light. All this was to help us in answering the question how fast is the speed of light.

There is no doubt that light is an electromagnetic wave. In view of this the speed of light could also be seen as the speed of some other electromagnetic waves like that of X-rays, gamma rays and radio waves. One of the fascinating discoveries relating to Einstein"s theory is that the speed of light is always constant no matter how fast an object is travelling in relation to it helping to solve the question of how fast is the speed of light.