Do we know why everything in the universe rotates? The dust clouds, stars, planets all rotate. Even galaxies rotate. Why is that? Gravity causes the dust particles to accrete into rocks and then asteroids, planets, and stars. But why the rotation. Similarly, why is our galaxy such a relatively flat spiral rather than more globular? I assume the rotation has a lot to do with that, but that does not explain why the rotation itself is in such a narrow plain to create a relatively flat spiral. I can guess at the answers but would like a more authoritative answer. Thanks.