How the Speed of Light was First Measured

The speed of light in a vacuum stands at “exactly 299,792,458 metres per second“. The reason today we can put an exact figure on it is because the speed of light in a vacuum is a universal constant that has been measured with lasers; and when an experiment involves lasers, it’s hard to argue with the results. As to… » 8/14/13 3:50pm 8/14/13 3:50pm