From the TED-Ed YouTube channel:
In the first two lessons of this series on space-time, we’ve dealt with objects moving at constant speeds, with straight world lines, in space-time. But what happens when you throw gravity into the mix? In this third and final lesson, CERN scientists Andrew Pontzen and Tom Whyntie explore what gravity means for space-time — or rather, what space-time means for gravity.
Lesson by Andrew Pontzen and Tom Whyntie, animation by Giant Animation Studios.