Who discovered that the speed of light is constant?

Answer 1

James Clerk Maxwell, the English physicist and mathematician, working with results

published by Faraday and Coulomb and Gauss and Ampere and all the other scientists

before him who worked on electricity, put all of their work together, and discovered

(mostly with math) that all of this electric and magnetic stuff should produce waves

that can travel through empty space and carry energy from one place to another.

Other smart people thought that was all very interesting, but if these waves existed,

then what would they look like ? What would they sound like ? What would they

feel like ? What would they smell like ? How would you know if there were any of

these mysterious waves around you ?

From Maxwell's math, he was able to tell what the speed of these waves would be

if they existed. It was a very high speed, and very tough to measure, but as years

went on and experimental technology got better and Physicists got smarter, a lot of

scientists made better and better measurements of the speed of light. And the more

accurate their measurements got, the closer and closer their numbers came to the

speed of these mysterious "electromagnetic" waves from Maxwell's equations.

It finally became obvious that these waves are all around us, and that light is

a form of them. Could they also exist in other forms ? What do you think ?