1."The charged protons and the uncharged neutrons of the nucleus of the atom are held together by the reciprocating function of the mesotron, a particle of matter 180 times as heavy as the electron. Without this arrangement the electric charge carried by the protons would be disruptive of the atomic nucleus.

2. "As atoms are constituted, neither electric nor gravitational forces could hold the nucleus together. The integrity of the nucleus is maintained by the reciprocal cohering function of the mesotron, which is able to hold charged and uncharged particles together because of superior force-mass power and by the further function of causing protons and neutrons constantly to change places. The mesotron causes the electric charge of the nuclear particles to be incessantly tossed back and forth between protons and neutrons. At one infinitesimal part of a second a given nuclear particle is a charged proton and the next an uncharged neutron. And these alternations of energy status are so unbelievably rapid that the electric charge is deprived of all opportunity to function as a disruptive influence. Thus does the mesotron function as a "energy-carrier" particle which mightily contributes to the nuclear stability of the atom.

3. "The presence and function of the mesotron also explains another atomic riddle. When atoms perform radioactively, they emit far more energy than would be expected. This excess of radiation is derived from the breaking up of the mesotron "energy carrier," which thereby becomes a mere electron. The mesotronic disintegration is also accompanied by the emission of certain small uncharged particles.

4. "The mesotron explains certain cohesive properties of the atomic nucleus, but it does not account for the cohesion of proton to proton nor for the adhesion of neutron to neutron. The paradoxical and  powerful force of atomic cohesive integrity is a form of energy as yet undiscovered on Urantia." (P.479)

      In recent years, a considerable amount of information has been forthcoming on the history of development of the present "standard model" for atomic structure. Though recognized as being incomplete, the standard model has enormously increased our understanding of the basic nature of matter. The electromagnetic force and the weak force of radiocactive decay have been successfully unified to yield the "electroweak" theory. As yet this has not been unified with the theory of the "strong" force that holds the atomic nucleus together. The force of gravity remains intractable to unification with the others.

   Para's 1-3 above from The Urantia Book, ostensibly presented in 1934, could have come directly from the mind of Hideki Yukawa. In the quantum theory of electromagnetism, two charged particles interact when one emits a photon and the other absorbs it. In 1932 Yukawa had decided to attempt a similar approach to describe the nuclear force field. He wrote, "...it seemed likely that the nuclear force was a third fundamental force, unrelated to gravitation or electromagnetism...which could also find expression as a field...Then if one visualizes the force field as a game of 'catch' between protons and neutrons, the crux of the problem would be to find the nature of the 'ball' or particle." This work was published in Japanese in 1935, but was not well known in the U.S.A.

   At first, Yukawa followed the work of Heisenberg and used a field of electrons to supply the nuclear force between protons and neutrons. This led to problems. In 1934 he decided "to look no longer among the known particles for the particle of the nuclear force field. He wrote: "The crucial point came one night in October. The nuclear force is effective at extremely small distances, on the order of 0.02 trillionth of a centimeter. My new insight was the realization that