We don't really know why the world is made up of quantum waves rather than of little dot-like things, or some other possibility. That's just how it is. The Heisenberg uncertainty principle isn't really the reason for the quantum form of things, just one of the many mathematical consequences. read more
In this view, it appears as if the electron does fall into the nucleus! Battle of the infinities. But it doesn't stay there! As you know, the potential energy of an electron becomes more negative as it moves toward the attractive field of the nucleus; in fact, it approaches negative infinity. read more
In classical physics, electrons should fall into the nucleus even if they weren't attracted by the charge of the proton. Early models of atoms had electrons orbiting the nucleus the way a planet orbits a sun. read more