General relativity posits that the universe is composed of spacetime, a phenomenon which for reasons I cannot fathom is frequently referred to as a fabric. Spacetime is four-dimensional, thus the three dimensions of space are equivalent to a single axis on a 2D graph with relation to time as the other axis. So, the faster one traverses space, the slower one traverses time, and vice versa.
2) An often overlooked implication of this is that since space and time are two facets of the same thing, it follows that time is a dimension, and thus, it doesn’t flow, it merely is. We perceive the flow of time due to our only remembering the past at any given point in spacetime. Our forward momentum through time is just an illusion. Time is real, but it doesn’t flow…………K.Grice…2012