Gravity and the Curvature of Space
How does the curvature of Space cause gravity?
Imagine two people are standing on the North Pole, and they walk away from each other at the same speed and at right angles.
If the Earth was flat, like this map, then they would walk away from each other, never to see each other again (red dotted line).
But the Earth isn't flat! It's a sphere. So as they walk away from each other (solid lines), the distance between them increases until they reach the equator, and then the pair begin to get closer to each other, until they eventually bump into each other again at the South Pole!
As we look down on this flat map, it looks like there could be some magical force pulling the two walkers closer together... but there isn't, the pair meet up again because the Earth is curved.
And so the same is true for space. Objects with mass curve space - and as we move along that curved space and past a massive object, it looks like there is a force called gravity.
So gravity is actually us moving along on curved space that gives the impression of a force pulling downwards. Or, at least, that's Einstein's idea...!
Gravity and the Curvature of Space
How does the curvature of Space cause gravity?
Imagine two people are standing on the North Pole, and they walk away from each other at the same speed and at right angles.
If the Earth was flat, like this map, then they would walk away from each other, never to see each other again (red dotted line).
But the Earth isn't flat! It's a sphere. So as they walk away from each other (solid lines), the distance between them increases until they reach the equator, and then the pair begin to get closer to each other, until they eventually bump into each other again at the South Pole!
As we look down on this flat map, it looks like there could be some magical force pulling the two walkers closer together... but there isn't, the pair meet up again because the Earth is curved.
And so the same is true for space. Objects with mass curve space - and as we move along that curved space and past a massive object, it looks like there is a force called gravity.
So gravity is actually us moving along on curved space that gives the impression of a force pulling downwards. Or, at least, that's Einstein's idea...!