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I'm a physic student of Italy. I'm moving my first steps in this beautiful world, and as every new entry, my simple and stupid questions are sometimes not so simply resolved. I'm trying to know the why planets aren't falling on each other, like the moon on the earth.
I thought it could be explained with the Lennard Jones potential, which says us there is a $r_0$ that before or after the potential is repulsive and attractive. But I read that this potential is designed for the atomic model. Could I extend this concept also for planets?
I tried to think to the uniform circular motion, where the centripetal force constantly modify the velocity direction: so the body would escape (also for the planet) but is redirected every time. Through this example I imagined that the moon is trying to escape as the body in the circular motion but is constantly redirected. This could work, but I think this is not correct because, according to Einstein theory, the spacetime near Earth should be curved and constantly pull the moon toward Earth. This means it should be a collision. But collision doesn't happen, so according to my last theory, it should exists a force opposite to the gravitational one that should make all radiant forces null. I think the best reason is about Lennard Jones potential.