How Fast Does Light Travel in Water vs. Air? Refraction Experiment
How fast does light travel, and does it travel faster in water or air? The fastest thing in the whole universe is the speed of light in a vacuum (like outer space!), clocking in at a great 2.99 x 10 8 m/s. Light travels in waves, and we call this traveling propagation. Propagation of waves has both a speed and a direction, called the velocity. The velocity of light changes depends on the material it travels through.