What is the origin of the strong nuclear force?anything to do with the grav. force of attraction btw protons?

Question

could there be any chance of the gravitational force of attraction between protons becoming large enough at a certain separation so as to cancel the electric repulsions between them?

Answer 1

It is certainly not gravity. The distance between protons in the nucleus has been measured. We know their mass, so it is easy to figure out the force of gravity between two protons. At typical distances inside a nucleus, the electric repulsion is many, many times larger.

Let's do a calculation SI units all the time):
The electric force between two charges is given by
F=k q_1 q_2 /r^2.
For two protons, the charges q_1=q_2=1.6*10^{-19} coulombs. The distance between protons ina nucleus is about 10^{-15} meters. The value of k is k=9*10^9
This gives a force of 230 Newtons between the two protons from the electric force!

For gravity, the mass of a proton is about 1.67*10^{-27} kilogram. The force of gravity is
F=GMm/r^2
where G=6.67*10^{-11}.
Calculating gives a gravitational force of 1.86*10^{-34} Newtons.
This differs from the electric force by 36 orders of magnitude!!

Answer 2

As far as I know, no one knows yet what the true nature of the "strong" nuclear force is (by the way this is the very strong but very small range force that forces protons to stick together in an atomic nucleus once they get close enough one to another).. The gravitational force of attraction between protons is much more weak that either the "strong" force or the repulsive electric force. It is interesting to note that in order to get past this repulsive electric force between protons and in the grasp of the "strong" nuclear force you have to have temperatures that exist only within the stars so as to make the heavy elements. Your body, having some heavy atoms, was, therefore, partly made within the heart of a star (a sun)!

Answer 3

There's no quantum theory for gravity but we know that on a macroscopic scale all gravity is determined by the constant G = 6.67 x 10^-11 N-m^2/kg^2 which is far too weak to hold neutrons together. Also, the equations for the strong force are pretty well understood and I don't think they bear any resemblance to the equations for gravity. Under the conditions during the first instant of the universe, all forces are expected to have had the same value and to have been united into the same force. Take this for what it's worth because my understanding of the strong and weak forces is really quite limited.

Answer 4

The strong force is something entirely different from gravity, just as gravity is something different from electric forces. There's no way for gravity to get stronger than the electric repulsion between protons at any distance because both obey inverse square laws -- if you move the protons closer together, BOTH the gravity force and the electric force get stronger by the same factor. And since the electric force is much, much stronger than the gravitational force at one such distance it will be just as much stronger at all possible distances.

Answer 5

the splitting of the atom is the activation of the strong nuclear force, defined as "the glue that holds the nucleus together"

gravity is insanely weak (10^12 times weaker!) than the electromagnetic force; this is for close distances only because obviously after a certain distance the EM cannot hold together and gravity takes over.

As with gravity, it's too weak to overcome the power of EM. However, it is distance that determines which is stronger. At close distances, the EM > grav, but as distances increase, then grav > EM (it's not that their magnitude changes, it's their interaction between the two over a certain distance).

**FYI: at great distances (tens of millions of light-years) gravity actually repels objects (Hubble saw this when making his theory that galaxies are being repeled from each other at great speeds, but had no idea that gravity was the key); scientists are still uncertain as to how this occurs (though string theorists have proposed a theory, but string theory is vague at best so don't take it at face value)

Answer 6

Part of what you see as the atomic mass makes up what is called the binding energy. The binding energy is what makes up for the mass defect you get when you add the mass of the constituent parts of the atom (protons, neutrons, and electrons) and reach a sum that is less than the mass of the atom. Sooo...constituent parts + binding energy = mass of atom. So when you are able to break the binding energy you can split the atom. The like charged protons act against this force and so as the number of protons rises, you need a rising proportion of neutrons to maintain stability. If you are really interested in some of these things you can check out the following site. All you do is click on a particular isotope such as U235 and it will give you a more in depth synopsis of the isotope (including binding energy)

http://atom.kaeri.re.kr/ton/nuc4.html

Answer 7

The strong nuclear force is a residual force from the colour charge of quarks. Quarks exchange gluons to bind together to form particles like protons. Three quarks make up each fundamental particle. The exchange of gluons changes the colour of the quark to preserve colour charge (gluons carry colour). When two protons say are close enough together there is a residual strong interaction between them because of the overlap of the colour charge field.

I know it all sounds very odd, but thats the universe for you.

Answer 8

They have pretty much determined that it is not gravity. it is a whole different force. Gravity would have to be thousands of times stronger to overcome the electrical repulsion of those tiny masses.

Answer 9

If the strong nuclear force was gravity I have a vague suspicion that the physicists would have called it gravity. They're very choosy about their forces and what to call them.