The movie Interstellar does a decent job demonstrating this (well the gravity piece anyway with the proximity to black holes). I also think satellite clocks ha

The movie Interstellar does a decent job demonstrating this (well the gravity piece anyway with the proximity to black holes). I also think satellite clocks have to take time relativity it into account (both due to distance from earth's gravity and their speed). Randall Munroe has a pretty entertaining write up that does a decent job giving a high level overview in pretty easy to understand terms: http://www.newyorker.com/tech/elements/the-space-doctors-big-idea-einstein-general-relativity http://www.newyorker.com/tech/elements/the-space-doctors-big...