posted on Jan, 24 2006 @ 10:45 PM
Well, the most prominent forces in the universes are, in order of strength:
The Strong Nuclear Force
The Weak Nuclear Force
The Electromagnetic Force
The only thing that makes Gravity an IMPORTANT force is that it's effects continue on forever - unlike the Strong Nuclear Force which becomes
non-existant past very tiny distances.
Technically speaking, the same applies to the Electromagnetic Force, but from far away (anything larger than most molecules) the overall charge of
particles cancels out their strength. If you had one man pulling a truck one way, and another man pulling a truck another way, from far enough away it
looks like the truck is standing still by itself.
So, let's start with the basics. The weakest force these, the Electromagnetic Force, plays the biggest role in this "empty universe". Almost all
the qualities of an atom depend on the number of electrons in its orbit, and how those electrons move around. How they move around and interact with
others depends on the electromagnetic force - which is immensely powerful at those tiny scales.
It's this force which keeps things from "touching" other things. A rock sitting atop a book isn't really touching the book. Instead, the negative
charge of the electrons in the rock, once exceedingly close to the book, will be repulsed by the electrons in the book. So although from far away it
appears there is no charge, the massively powerful, but not very far reaching charges of the electrons, keeps the two objects from merging together.
If this wasn't the case, if you put two metals side by side, they would merge into one.
Now, the electromagnetic force attempts to pull the electron into the nucleus of an atom (positive attracts a negative). The Weak Nuclear Force
prevents the two from combining. This is what keeps all of that space inside an atom empty.
The Strong Nuclear Force prevents the neutrons and protons within the atom from combining, and thus keeps them seperated. Other hadrons and leptons in
the atom are similarily governed by the strong and weak nuclear forces respectively.