The Universe is Full of Swirling Motion

More of Universe Wallpapers

The Universe is full of rotation: planets, moons, stars, asteroids, clouds of gas, globular clusters, and galaxies orbit around their axis, and things orbit around each other (moons and rings around their planet, planets around their star, stars around the center of their galaxy or globular cluster, galaxies around the center of their galaxy cluster). That is because rotating is a conserved quantity: the total amount of rotation in the whole Universe (measured in a certain way) is constant. So, rotation cannot just disappear, but only if it combines with rotation that is equally great but in the opposite direction.

Rotation can be generated in a medium that did not rotate before, but only with equal amounts of rotation in one direction and in the opposite direction, so that the total is zero as before. If you pull a spoon through a fluid in the middle of a cup or pot, then you'll see that part of the fluid starts rotating, but with equal amounts in both directions.

So, if there is a certain amount of rotation in a large cloud of gas, then that rotation must end up in the star and planets that are formed from the gas. If the rotation is distributed fairly evenly, then all of those things will rotate in about the same direction. For example, the planets all rotate in about the same direction around the Earth, and the Sun rotates in about that same direction around its axis, and most moons orbit in about the same direction around their planet.

 Images are samples from over here. (full hd resolution wallpapers)