Fizeau et al (Fizeau's work on gas)

Fizeau’s work on gases involved studying how light travels through different gaseous environments. He conducted experiments to measure the speed of light as it passes through gases under various conditions. His research helped confirm that the speed of light depends on the properties of the medium through which it moves, supporting the idea that light’s speed varies with the medium’s refractive index. These findings contributed to a better understanding of the nature of light and the behavior of gases in optical phenomena, laying groundwork for later developments in optics and the study of electromagnetic waves.