it's called "finite but unbounded" and it's a very important concept in geometry and has implications across all of physics. the inverse square law is also related to this, as it is about the radial spread of energy emitted from a point emitter. at distance N the linear surface of the cross section of the perpendicular square is N^2, which means that the visible brightness of an object is squared as you get closer to it.
these both relate to the properties of finite and unbounded geometry, and the primordial form of it is a 2 dimensional line, which is called a circle. the sphere is the same geometry in 3 dimensions. the sphere geometry is at the center of everything, the forces of gravity also obey the inverse square law as well, so it's not just energy that follows this, gravity also does, and because gravity does, everything in space is a sphere, all else being equal (in fact they tend to be slightly squashed due to their rotation).