"collective" atomic forces

[gre]

How do physicists categorize forces such as coulombs, gravity, etc. that accumulate as the "group" of atoms increases (or density increases). Or is this just standard behavior of all forces (including strong, weak).

 

Any thoughts?

 

I guess it comes down to can strong and weak force exist outside of an atom's electron shell (edit: or proton, rather). Any ideas?

Edited December 30, 2008 by gre
multiple post merged

[swansont]

Forces are vectors, and add as vectors. There is no need to categorize them according to this type of behavior, since they all act this way.

 

Inverse-square forces (electrostatic and gravitational) have an added bonus that if the collection of matter exerting the force is distributed uniformly in a sphere, it behaves as if all of the matter is a point at r=0. If not, or it's another force, you sum/integrate over the distribution of the force-generator (e.g. all mass or all charge)

[ydoaPs]

Forces are vectors, and add as vectors. There is no need to categorize them according to this type of behavior, since they all act this way.

Are the nuclear forces additive? I could have sworn that the weak force was saturable. It doesn't make much sense to be saturable and additive. Then again, it's been a while since I looked at that stuff.

[swansont]

Are the nuclear forces additive? I could have sworn that the weak force was saturable. It doesn't make much sense to be saturable and additive. Then again, it's been a while since I looked at that stuff.

 

Any force with a finite range saturates, but that is a separate issue. The vectors still add; the finite range means the magnitude may go to zero.