Now before I get tackled by every physicist in the community for dissing Einstein, let me explain: this is purely THEORY. Theoretical physics is what I specialize in and its simply a thought experiment. Sound travels faster when it is put through a medium of greater density, I.E, sound will travel faster when it is sent through water, and even faster when sent through solids such as steel and even rocks. From Wikipedia, "Speed of Sound" article: https://en.wikipedia.org/wiki/Speed_of_sound "In common everyday speech, speed of sound refers to the speed of sound waves in air. However, the speed of sound varies from substance to substance. Sound travels faster in liquids and non-porous solids than it does in air. It travels about 4.3 times as fast in water (1,484 m/s), and nearly 15 times as fast in iron (5,120 m/s), than in air at 20 degrees Celsius. Sound waves in solids are composed of compression waves (just as in gases and liquids), but there is also a different type of sound wave called a shear wave, which occurs only in solids. These different types of waves in solids usually travel at different speeds, as exhibited in seismology. The speed of a compression sound wave in solids is determined by the medium's compressibility, shear modulus and density. The speed of shear waves is determined only by the solid material's shear modulus and density." A singularity in the center of a black hole, AKA the remains of a collapsed star, has been supposedly recorded to have infinite density. So, my question is this: If sound travels faster when put through objects of higher density, could sound have the potential to travel as fast, or faster, than the speed of light when put through a singularity? (Ignore the vacuum of space for a second) And if so, what would this mean for the Theory of Relativity? In order to produce informative answers to this, we would have to find the compressibility, shear modulus and, moreover, the density of a singularity. (I go on the presumption this is no easy task.) Once we find that, we simply plug that in and solve for the equation that states sound travels faster in objects with greater density. Please feel free to elaborate or ask questions. -Roy Kelly
