Neutrinos and Neutron Stars
"In large suns when hydrogen is exhausted and gravity contraction ensures, and such a body is not sufficiently opaque to retain the internal pressure of support for the outer gas regions, then a sudden collapse occurs. The gravity-electric changes give origin to vast quantities of tiny particles devoid of electric potential, and such particles readily escape from the solar interior thus bringing about the collapse of a gigantic sun within a few days." (p. 464)
For the mid-thirties that was quite a statement. These tiny particles that we now call neutrinos were entirely speculative in the early 1930's and were required to account for the missing mass-energy of beta radioactive decay.
Hypotheses on the possible origins of the Urantia Paper's statement on solar collapse
In the early 1930's, the idea that supernova explosions could occur and result in the formation of neutron stars was extensively publicized by Fritz Zwicky of the California Institute of Technology (Caltec) who worked in Professor Millikan's Dept. For a period during the mid-thirties, Zwicky was also at the University of Chicago. Dr. Sadler is said to have known Millikan. So alternative possibilities for the origin of The Urantia Book quote above could be:
1. The revelators followed their mandate and used a human source of information about supernovae, possibly Zwicky.
2. Dr Sadler had learned about the tiny particles devoid of electric potential from either Zwicky, Millikan, or some other knowledgeable person and incorporated it into The Urantia Book.
3. It is information supplied to fill missing gaps in otherwise earned knowledge as permitted in the mandate. (1110)
Zwicky had the reputation of being a brilliant scientist but given to much wild speculation, some of which turned out to be correct. A paper published by Zwicky and Baade in 1934 proposed that neutron stars would be formed in stellar collapse and that 10% of the mass would be lost in the process (Phys. Reviews. Vol. 45)
In "Black Holes and Time Warps. Einstein's 'v Outrageous Legacy" (Picador, London, 1994), a book that covers the work and thought of this period in detail, K. S . Thorne, Feynman Professor of Theoretical Physics at Caltec, writes: In the early 1930's, Fritz Zwicky and Walter Baade joined forces to study novae, stars that suddenly flare up and shine 10,000 times more brightly than before. Baade was aware of tentative evidence that, besides ordinary novae, there existed superluminous novae. These were roughly of the same brightness but since they were thought to occur in nebulae far out beyond our Milky Way, they must signal events of extraordinary magnitude. Baade collected data on six such novae that had occurred during the current century.
As Baade and Zwicky struggled to understand supernovae, James Chadwick, in 1932, reported the discovery of the neutron. This was just what Zwicky required to calculate that if a star could be made to implode until it reached the density of the atomic nucleus, it might transform into a gas of neutrons, reduce its radius to a shrunken core, and, in the process, lose about 10 % of its mass. The energy equivalent of the mass loss would then supply the explosive force to power a supernova.
Zwicky believed cosmic rays accounted for the mass energy loss in supernova explosions
Information, extracted from Thorne's recent book, indicates that Zwicky knew nothing about the possible role of "little neutral particles" in the implosion of a neutron star, but rather that he attributed the entire mass-energy loss to cosmic rays. So, if not from Zwicky, what then is the human origin of The Urantia Book's statement that the neutrinos escaping from its interior bring about the collapse of the imploding star? (Current estimates attribute about 99% of the energy of a supernova explosion to being carried off by the neutrinos).
In his book, Thorne further states: astronomers in the 1930's responded enthusiastically to the Baade-Zwicky concept of a supernova, but treated Zwicky's neutron star and cosmic ray ideas with disdain...In fact it is clear to me from a detailed study of Zwicky's writings of the era that he did not understand the laws of physics well enough to be able to substantiate his ideas." This opinion was also held by Robert Oppenheimer who published a set of papers with collaborators Volkoff, Snyder, and Tolman, on Russian physicist Lev Landau's ideas about stellar energy originating from a neutron core at the heart of a star.