As we all know everything spins in the universe. But what causes everything to spin? To know about all the facts, first of all we should know the reason behind the rotation of different objects including planets around the solar system.
About 450 crore years before, there was no solar system in the universe. At that period there was only the presence of interstellar dust and the clouds formed by the different gases and these clouds moved in their own axis which resulted in the formation of constant matter inside the cloud and it is all caused by the gravitational force caused by the rotation of the different matter. Those clouds rotated around the black hole of the Milky way galaxy. The rotation of interstellar dust and the clouds can be termed as the angular movement. Angular movement is the product of moment of inertia and angular velocity.
Then what does the angular velocity and the moment of inertia mean? Angular velocity is the speed of the rotating body and moment of inertia is the tendency of an object to resist the change(i.e forms rest to motion and from motion to rest) until the external force is applied to the body. According to the law of conservation of angular movement, if any body is not applied with the external turk then its angular movement is conserved, that means the body is moved at the same speed without changing its motion.
Before 450 crores years ago because of the supernova explosion or because of other external factors, the strong bombardment took place in the clouds and the collision of matters took place. Because of this, an anti-clockwise rotating interstellar cloud breaks down into smaller particles because its total angular movement is also divided into smaller parts.
And the rotation of these small particles increases with time and the matter inside the particles starts to collide in the center which results in the formation of the sun.
With time the formation of akrison disc took place around the sun in which there was the presence of interstellar dust and the gadgets of the matter in some amount which helps in the formation of other planets and asteroids. The angular movement of every movement has been divided for every particle so all the planets start to rotate in its angular movement around the sun and there is no other external force to affect the angular movement so every planet is moving around its own axis.
Till the recent days scientists are still in the dilemma about the distribution of angular movement. All the objects of the solar system are rotating in the anti-clockwise direction unlike venus and uranus. And scientists said that the different movement of these two planets- Venus and Uranus are caused by the collision in the past years.
After the big bang theory, when the clouds collided with each other and matter started to scatter, the density of every particle/matter was not the same. According to scientists, Earth is rotating at the speed of 460m per second around its own axis but we human beings do not feel its rotation and it is all because of frame of reference.
To understand it we can take an example of a moving bus. While we are inside the moving bus, we don’t see the movement of our bus. But while looking outside from the moving bus we see that other objects are moving away from us. And when we come outside of that bus, and it goes away from us then we can know that our bus was moving before.
The same phenomenon is applied with the rotation of earth but we don’t see and feel the rotation. But when we go to the other planets or on the moon,then while observing from there we get to know that our earth is moving at a very fast speed.