Why does the speed of sound get faster underwater, where as light speed slows?
Light DOES travel slower in water than it does air! Otherwise, how would water bend light rays? Sound DOES travel faster in water. Both sound and light are wave phenomena. Both sound and light must be regarded as Quanta under the right conditions. Their respective “Wave Equations” incorporate the physical parameters of the media they’re propagating through to determine the speed of wave propagation. Sound Wave and Light Wave, “Wave Equations,” are derived from totally different principals, hence their velocities are determined by entirely different material parameters. It’s a matter of observation that light travels fastest in a vacuum and slows down as it passes through various matter. The branch of Physics known as Quantum Electrodynamics provides a fundamental explanation for why this is so. Same story with sound waves, except, the branch of Physics known as Hydrodynamics provides the fundamental explanation.
