Question on time dilation, a physics concept about changes in the passage of time, caused by general relativity.

Time dilation is the difference in the elapsed time as measured by two clocks. It is either due to a relative velocity between them ("kinetic" time dilation, from special relativity) or to a difference in gravitational potential between their locations (gravitational time dilation, from general relativity). When unspecified, "time dilation" usually refers to the effect due to velocity.