Where did the massive clouds of dust and stars come fromA good question. Solar systems begin as massive clouds of dust and gas, typically the remnant of a supernova (i.e., a star that died and exploded, spraying the surrounding area with all the elements). This dust cloud eventually collapses under its own gravity, with small bits of dust sticking to others, creating larger clumps that can attract more and more clumps. This process is how stars and planets form: stars at the centre, where gravity is strongest, and attract the vast majority of material.
This large proto-star resembles a gas giant, like an enormous Jupiter: it's very large, but not quite large enough to undergo nuclear fusion. But it can still cause the proto-planets (large clumps of rock that have formed outside the centre) to begin orbiting it.
Obviously, if you have lots and lots of lumps of rock floating about, some are going to collide - that is, after all, how such lumps grow in size. Sometime, there are just glancing blows, or a gravitational torque. These will cause the lumps to spin (imagine kicking the edge of a spinny-chair - it will begin to spin, no?).
So, that's the basic principle behind the formation of the Earth (the initial dust cloud collapsing under its own gravity into a few discrete points, which ultimately become the Sun and the planets), and the spin of the Earth (interactions with other large bodies cause the Earth to rotate on an axis). There are other details, like how the Moon and asteriod field formed, how the Sun operates, etc, but that's that for now.
Upvote
0
