What causes the earth to rotate?
The main reason the Earth is rotating now, is that there is nothing to stop it. The Earth and everything on it, including you, me, the ocean, and the atmosphere is spinning, revolving, and moving through the emptiness of space. Our planet moves through a vacuum. There is hardly anything out there to drag on us. The air is held here by gravity. Above it, space gets emptier and emptier. The Earth got started spinning a little over four and a half billion years ago, when it formed from cosmic dust. Tiny as they may be, specks of dust have gravity. Check out a dusty shelf sometime. The Earth isn’t just pulling the dust down. The dust is, ever so slightly pulling the Earth up. (Weird, yes?) The particles left over from the explosions of distant stars pulled themselves together and formed our Sun, the asteroids, the other planets and moons, and our own Earth. The Earth and the other planets are enormous balls of deep-space dust. The dust particles came from all diffe
The fundament reason that the Earth rotates is related to conditions in the early solar system. Before discussing this aspect it is interesting to note that almost everything in the solar system not only rotates in the same manner but also goes around the Sun in the same direction. In fact the Sun itself rotates every 27 days or so again in the same sense. If you are in the Starship Enterprise approaching the Sun from the direction of the north star and look at the solar system, the sense of all these orbits and rotations are counter-clockwise. This sense of rotation is the same as that of the proto-solar system which consisted of the atoms, molecules and dust which eventually collapsed under its own gravity to form the Sun and the rest of the solar system. But you might ask, why after all this time is the earth still rotating? One of the fundamental Laws of Physics is that the angular momentum of a system is constant if there are no torques (which are forces applied at an edge of a ro
