Time Dilation
Time Dilation - The slowing of time as noted by a comparison between a clock in a moving reference frame relative to a clock in a stationary reference frame or a clock in a low-gravity field relative to a clock in a strong gravitational field. Moving clocks or clocks in high gravitational fields run slower, as viewed from an outside observer.
This is an artist drawing of the New Horizons spacecraft (see arrow) flying by Jupiter, which is drawn in the upper right; Mercury, Venus, Earth, and the Sun are drawn from left-to-right in the upper left. Time dilation tells us that a clock on the New Horizons spacecraft, which is cruising at ~16,000 km/s, would tick ~1/2 second slower compared to a stationary clock at Earth’s equator after 10 years of travel.
https://apod.nasa.gov/apod/ap031204.html
Author: Ploy Saengpet, UCF Undergraduate 2017
Editor: Patrick Joiner, UCF Interdisciplinary Studies, Class of
2018
Senior Editor: M.M. Montgomery, Ph.D, UCF Physics