In physics, spacetime (or space–time)'s any mathematical model that combines space and time into a single continuum. Spacetime's usually interpreted with space being three-dimensional and time playing the role of a fourth dimension that's of a different sort than the spatial dimensions. According to certain Euclidean space perceptions, the universe has three dimensions of space and one dimension of time. By combining space and time into a single manifold, physicists have significantly sim… (More on Spacetime)