How The Speed Of Light Was First Measured

Scientific Minds Want To Know

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.

But how was the speed of light first measured?