Gravity Mysteries: What Is Gravity?

Image: We tend to think of gravity as a force that affects objects, but Einstein showed it was something else entirely (Image: Alex Telfer Photography Limited / Getty)

From New Scientist:

You jump up, and gravity brings you back down to Earth. You reach the brow of a hill and gravity accelerates you down the other side. All neat and tidy then: gravity behaves in the way Newton thought of it, as a force that affects and changes the motion of something else.

That, at least, was how it seemed until Einstein came along. His general theory of relativity tells us that gravity is not quite that simple.

General relativity provides a framework under which the laws of physics look the same for everyone at every moment, regardless of how they are moving. Einstein achieved this by making gravity a property of the universe, rather than of individual bodies.

Read more ....