Question #2dfda
1 Answer
There are two things that are important when you are forming something like the solar system: gravity and the conservation of angular momentum .
Explanation:
- Gravity: When two things have mass, they are attracted to each other through the force of gravity, but that is thinking of things from the perspective of force.
From the perspective of energy, two objects that have mass (and are separated from each other) posses gravitational potential energy (just like a coiled spring possess elastic potential energy). This can be transformed into kinetic energy.
The kinetic energy of a planet's orbit comes from the gravitational potential energy of the dust particles that formed the planet, and from gravitational interactions between planets in the early solar system.
Check out this video, which puts the idea into practice:
Minute Physics:Why the solar system can exist
- Angular Momentum: Perhaps more important to why planets rotate about their axis, why the planets orbit the sun, and why solar system is a disk, is the fact that the total amount of angular momentum in a system always stays the same.
This is concept explained well in this video:
Minute Physics: Why is the Solar System Flat?
When you have a large number of particles all going in different different directions, they tend to collide and cancel out each other's momentum. A few collisions won't cancel, and that sets the preferred rotation direction. Also, when things get smaller, they end to spin faster, due to the conservations of angular momentum.
Thus way, we form spinning planets from a spinning disk of gas and dust.
