Hello again, Here to ask a few more questions. I previously asked a question about light and weather or not it could possibly have different speeds. But I recently realized that the burning of different chemicals can have different tones of light. I would like to know how exactly we first measured how fast the speed of light was, what we used as a source, and if we could conduct an experiment using the light from different burning chemicals to find out if there is a different speed- or if it already has been done let me know. Thanks -Q?