Time has no independent existence apart from the order of events by which we measure it.
Albert Einstein, Relativity, 1952 (via forever)
The separation between past, present, and future is only an illusion.
Albert Einstein, Relativity, 1952 (via forever)
Space and Time Diagram, c. 2009
"Two-dimensional space depicted in three-dimensional spacetime. The past and future light cones are absolute, the "present" is a relative concept different for observers in relative motion."