- Ung-Jin Kim"π value appears in the equation of Einstein's field equation for General Relativity. Why? Because the mass warps the spacetime in a manner that resembles globular shape. Hence the π value is needed to describe the gravity, which is the spacetime warp induced by mass and energy. You cannot describe circles or globes without π."
GR is the same thing as spacetime ..so spacetime should have π everywhere in it.