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Why do planets orbit? (With Dan Burns)


less than 1m read
·Nov 10, 2024

The explanation for gravity is that matter bends space.

And so, you put mass in a place in space; it warps SpaceTime. Objects are not feeling a force of gravity; they're just following the natural curvature.

Um, and so you put matter and it warps SpaceTime. If I have another object, it also warps SpaceTime. They feel that, and they're attracted to each other.

And so that's Einstein's picture of gravity: objects warp SpaceTime, feel that curvature, and move accordingly.

You have more mass; it's going to bend SpaceTime more. And so if you have objects here, they are going to respond to that, right?

And so you put something there; now it's attracted. Well, instead of just letting go of one, what if I give it a sideways push?

Now it orbits. Now it's losing energy, which wouldn't happen in the solar system, right? Not noticeably.

There's some perturbations from other planets and things, but this one does lose energy and spirals in different directions.

But there was a preferred direction that distant formed from; it had a slight preference one way versus another.

And things going the opposite way got eliminated.

When it's all said and done, everything's going the same way.

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