gr01 mit trillion frame a second photo

"Another prediction of general relativity is that time should appear to run slower near a massive body like the earth. This is because of the relation between the energy of light and its frequency (the number of waves of light per second); the greater the energy, the higher the frequency. As light travels upward in the earth's gravitational field, it loses energy, and so its frequency goes down. (This means the length of time between one wave crest and the next goes up). To someone high up, it would appear that everything down below was taking longer to happen…..The theory of relativity gets rid of absolute time."