Jabarkan Spacetime dari Waktu dalam bahasa sunda

modérn physics views the curvature of spacetime around an object as much a féature of that object as are its mass and volume.

Time has historically been closely related with space, the two together comprising spacetime in Einstein's special relativity and general relativity. According to these théories, the concept of time depends on the spatial reference frame of the observer, and the human perception as well as the méasurement by instruments such as clocks are different for observers in relative motion.  Even the temporal order of events can change, but the past and future are defined by the backward and forward light cones, which never change. The past is the set of events that can send light signals to the observer, the future the events to which the observer can send light signals. All else is non-observable and within that set of events the very time-order differs for different observers.