What’s Einstein’s gravity? General relativity explained! Science4All 15


Last time, we saw that Einstein explains the falling of the apple by the upwards acceleration of the ground. This is Einstein’s happiest thought. But wouldn’t this imply that the surface of the Earth is expanding outwards? Well, no. Why? Because of spacetime curvature! At last, this video explains how Einstein’s gravity really works.

Warning! This video is a bit more technical than usual, and previous videos are prerequisites to fully grasp this one. They include:
Is special relativity relative? Time dilation and space contraction | Science4All 6
What’s wrong with that map? Spherical Geometry | Science4All 9
What’s a straight line? Curved-space geometry | Science4All 10
What’s the geometry of my underpants? Hyperbolic Geometry | Science4All 11
Are astronauts weightless? Einstein’s happiest thought | Science4All 14

More to understand general relativity…
Spacetime of General Relativity | Science4All Article
Is gravity acceleration or curvature? Follow-up clarifications | Science4All 16
Is Gravity An Illusion? | Space Time | PBS Digital Studios
General Relativity & Curved Spacetime Explained! | Space Time | PBS Digital Studios
What proved general relativity? Einstein’s heart palpitations | Science4All 17
What’s the destiny of the universe? Einstein’s biggest blunder | Science4All 18
What’s gravitational time dilation? Twin & Grandfather paradox | Science4All 20