# 2 strong nuclear force questions

1. Sep 24, 2010

### Archosaur

How is it possible that the strong nuclear force is directly proportional to distance?
How could all the atoms in the universe be so far apart if this were the case? The fact that I can't find an equation for the strong nuclear force makes me think it's just not that simple. Could someone tell me...
1. ...what property the strong nuclear force acts on?
2. ...what it's actual relationship to distance is?

I'm not a layman, but I obviously haven't taken much QM, so, I'd greatly appreciate details, but maybe hold the jargon, if possible.

Thank you much.

2. Sep 24, 2010

### zhermes

There is no closed form equation that relates the strength of the strong force to distance, although there are some approximate equations that seem to fit the data pretty well, i think it looks something like:
$$V_{strong}(r) \propto \frac{1}{r} + r$$
So the potential has both a linear, and inverse relationship with distance.

The strong force acts on "color charge" which is just some fundamental property of particles.

The reason why things in the universe are so far apart is that the strong force can be 'saturated.' Particles only experience strong-interactions with a handful of neighboring particles.

3. Sep 25, 2010

### Drakkith

Staff Emeritus
4. Sep 25, 2010

### tom.stoer

What do you mean by strong force? Force between colored particles like quarks, or force between color-neutral particles like nucleons.

The color-electric potential (which is a low-energy approx. as explained above) has a linear term ~r which eventually confines colored particles within color-neutral hadrons. The residual strong nuclear force between color-neutral particles has an approx with exp(-mr) where m is the pion mass.