Is gravity a direct implication of the Earth’s rotating core?

Answer

1. Gravity itself has nothing to do with the rotating Earth’s core, nor with the core itself. See Newton’s model (isn’t this seen in secondary education anymore?). There’s nothing to add to explain gravity, except possibly in the philosophical field “when does it come that masses attract?” — that was a motivation for the recent Higgs boson experiments.

It’s simply an attraction between two masses: the mass of the object that “feels gravity” and the enormous mass of all the particles that make up the Earth. That force increases when a mass is heavier, and decreases with a greater distance between the masses (two times further apart corresponds to 4 times weaker force: so if you are 2 times further from the center of the Earth you will be 4 times less feel gravity). So it has to do purely with “the presence of a mass”, nothing to do with its rotation or with electromagnetic force. The Earth itself also experiences the gravitational pull of the object: when an object falls a few meters, i.e. moves towards the Earth, the Earth itself also moves towards the object, albeit perhaps only a fraction of a nanometer (I’ve never seen it before). exactly calculated) because the Earth is so much heavier.

(Physicists are now trying to draw a line between gravity and electromagnetic force in extreme conditions that you would find around/in black holes, or just after the Big Bang — but this is certainly not the level you want to consider this at, and for the Earth is completely irrelevant. You may also have heard from Einstein that “gravity is a curvature of space. This is a highly mathematical interpretation, and that curvature is about something completely different than rotating a nucleus).

2. Due to the fact that the Earth itself rotates — not the Earth’s core, but the objects themselves that are typically attracted to the Earth (people, apples,…) — the objects that rotate with the Earth actually undergo a combination of gravity and centrifugal force, which slightly reduces the perceived effect of gravity. The moon orbits so far away from Earth (weaker gravitational pull) and so fast around Earth that gravity and centrifugal force cancel each other out — that’s why it doesn’t fall on Earth. Exactly the same as for the moon also applies to the International Space Station and satellites.