## Nuclear Forces
## A simpler explanation for nuclear forcesThere is a much simpler explanation that fully explains how protons can
cling together without requiring the invention of peculiar short-range forces or
additional particles. This explanation fits neatly within classical mechanics and does not
violate Coulomb’s law; in fact, it’s based on it.
## A day at the beachTo better explain this, let’s imagine that we are at the beach. We have each been handed an inflatable beach ball by an eccentric scientist. This scientist has given each of these balls a static charge but has applied the charge in an unusual manner. Each ball has been identically charged such that two thirds of its surface has a positive charge and one third has a negative charge. See diagram below. Initially we stand far apart. The balls have a net (one-third) positive charge and this causes them push apart from each other. At this distance the force is one unit: Next we start walking toward each other. As we move closer together we each feel the balls push stronger against our bodies according to the inverse square law. When we are at half our initial distance the force is four times stronger. We continue walking and the closer we get, the stronger the push-back of the balls. Then as we close in and the repulsive force appears insurmountable, something strange begins to happen. Remember the one-third negatively charged area? Well the balls begin to rotate in our hands so that the negative area of one faces the positive area of another (assume that the balls can rotate in our hands without slipping out of them). At this point the oppositely-charged areas are now closer to each other than the like-charged areas. The inverse square law tells us that the attractive force from the opposite-charged regions begins to have more ‘worth’ than the repulsive force of the like-charged regions. The balls may still repel one another but the repulsion is weakened. We continue walking closer. The attractive forces become much greater, and at some point, equal to the repulsive force; at which point there is zero net force between the balls. We continue closer. The attractive force now exceeds the repulsive force. At this point the two balls pull themselves together and make contact.
## Proton beach ballsThis beach ball scenario is an analogous to the forces between protons.
Each proton has two-thirds of its ‘surface’ positive and one third negative. At
a distance they repel because they are net positive; and they will repel regardless of
orientation. But if you could somehow bring them close enough together they might
reorientate such that the attraction between their opposite charges exceeds the repulsion
between their like-charges. At this point the protons would become net attractive and
‘stick’ to each other. Notice the side view. Normally the up quarks will try to sit on opposite sides of an orbit plane because they repel each other. But let’s imagine that we had two protons and were able to bend their orbit planes at a 45 degree angle. They would look like this: Let the distance between the protons be
In the above diagram, purple lines represent repulsive forces, green lines
are the attractive forces and the black arrows show centrifugal force. As you can see
there are a multitude of forces involved in producing the equilibrium situation.
## ConclusionModern nuclear theory holds that nucleons (protons and neutrons) are held
together within an atom’s nucleus by the presence of additional particles. These
particles provide both attractive and repulsive short-range forces that overcome the
long-range repulsive electrical force and hold nucleons together at close range. However
it is possible to explain the nature of these short range forces using only the
conventional inverse-squared electrical force described by Coulomb’s law. |

Copyright © 2010 Bernard Burchell, all rights reserved.