Can you help me understand the concept behind general relativity? I’ve been reading about it but still can’t quite grasp how space-time curvature works and how mass impacts gravitational fields. I'd really appreciate a more simplified explanation, maybe with a real-world analogy so I can wrap my head around it better.
Sure, let's bring it down a notch. Imagine a large rubber sheet. This sheet represents the fabric of space-time. Now, place a heavy object, like a bowling ball, onto the sheet. The weight of the ball will cause the rubber sheet to curve or dip. This is similar to how a massive object, like a star or planet, bends or warps the fabric of space-time around it, creating gravitation.

Next, let's take a smaller object like a marble and roll it across the sheet. It will naturally follow the curve created by the bowling ball. In the same way, a less massive object, like a spaceship or even light, will follow the curved path in space-time created by a heavier object. The marble's path - this curve it's taking around the larger object - is due to the warping of the space by the bowling ball, just like how planets orbit larger bodies like the Sun.

This is, of course, a 2-D simplification of a 4-D concept (three dimensions of space and one of time), but it's a useful way to visualize it. Einstein's General Theory of Relativity tells us that mass and energy cause space-time to curve, and objects move along the paths determined by this curvature. This revolutionized our understanding of gravity not as a force transmitted across space, but as a feature of space-time itself.