Gravity works the same---Mass curves space into a 4D direction, and since we have an inherent 4D motion, we follow that curve around---and thus feel a FORCE we call gravity when we get near a large mass.--its like a4D inertia we feel, similar to when we make a turn in a car.---The directions of "pull" don't make sense when we think about it, but, then again, its 4D motion involved.---We cant think in 4D properly with our 3D minds.
Gravity is not a direct "force" like electrostatic attraction or magnetism, but is a 'effect force' like inertia.
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Thomas E say: Gravity is more of an effect than a force, but at our relative size to the Universe, it seems more powerful. When you move something, are there waves or particles "causing" that motion?
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Hamdi say: Both. Einstein said that gravity is the curvature of spacetime while Newton said that gravity is a force that everything with mass has.
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Neb say: There really isn't a yes or no answer to this question. It's actually quite complicated.
Let's start out with an analogy that will be very helpful in understanding the issues. Let's say we have two people on opposite ends of a rotating platform throwing a ball back and forth. We also have a person standing stationary on the ground watching. To the person on the ground, the ball is in an inertial frame after it leaves the throwers hand. He sees it traveling in a straight line and undergoing no acceleration. However, the guys on the platform see something completely different. They see the ball traveling in a curved path. They can conclude they see the curved path because they are in a non-inertial (accelerated) frame. If they didn't realize they were in an accelerated frame, they might even conclude that there was a force acting on the ball that is accelerating the ball away from a straight line path.
Keeping that in mind, consider Dr Worm living in an apple and in free fall in a gravitational field, and Dr Newton standing 'stationary' on the ground watching the apple. Dr worm yells to Dr Newton as he passes by that according to every experiment he has made in his apple, he is NOT in an accelerated frame. He feels no acceleration, nothing in his worm lab shows any motion at all. Puzzled, Dr. Newton, who has great respect for Dr. Worm, starts wondering if perhaps HE was in a non-inertial frame. After all, he feels a 'force' at his feet. So, Dr Newton performs a general coordinate transformation to a non-inertial coordinate system that matches the observed acceleration of the apple. He concludes that he could indeed be in a non-inertial coordinate system and the observed acceleration of the apple was due to that and not some real force on the apple.