That is a good one. We can say something about it, but what it is must remain a mystery for the time being. It is like gravity in a way; it pulls 2 particles together. It is like electromagnetism in a way; it is much stronger than gravity. But the nuclear force acts over very short distances, so it is not inverse square like gravity or electrical force. The nuclear force is what causes protons and neutrons to stick together in atoms heavier than the hydrogen atom. Neutrons would not stick together at all without the nuclear force, being electrically neutral. Protons would fly apart, being of like charge.
Still doesn't say what it is, does it?
Your reply does raise issues I hadn't thought about e.g. protons sticking together but yet being of like charge. Neutrons "hanging out" for no apparent reason. Etc.
Does an atomic explosion release this nuclear binding force?
I find it unfortunate that United States did not build the super collider in Texas if for no other reason than to find the answers to these questions. I hear from time to time scientists are unsuccessful in controlling a sustained fusion reaction which would change the whole economic picture of playing patsy with 3rd world countries with oil. This has been a good thread and I appreciate your posts. I don't have any background in physics just a general fascination with it. Just grasping a little understanding of Einstein's theories are great mind ticklers. Thanks!