What holds the nucleus together?
The residual strong force.
The strong nuclear force, one of the fundamental forces in the universe according to the standard model. In occurs between the quarks which make up the neutrons and protons in the nucleus, and also binds these together. At extremely small distances, it is repulsive, but at the distances in the nucleus it is generally attractive, and acts to overcome the electromagnetic force between the protons. It comes about when the quarks exchange particles called gluons with each other, thus there is a gluon 'field' between the quarks.
Sorry, you got there first chroot.
have they ever detected a gluon?
Billions of times.
what do you mean? in what way
Billions of particle interactions involving gluons have been observed in dozens of different particle accelerators.
but how have they proved that gluons exist
Particles with a particular set of properties have appeared billions of times in particle accelerator experiments. The name given to particles with those properties is "gluon." What kind of proof do you expect there to be?
i just don't get how they would creat a strong force. it seams like magic
How do electrons "create" the electromagnetic force? Are you comfortable with electrically charged particles?
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