In reply to Eric Walker's message of Fri, 1 Mar 2013 22:29:00 -0800: Hi, There is also the possibility that the "mass" of the particle actually derives form it's interaction with the ZPE, and that when protons and neutrons are packed closely together, they shield one another to some extent, so that the particles in the middle then "weigh" less.
Such shielding would be least for the simplest compound nucleus (D) (it's actually zero for Protium), then increase from there. While compound nuclei remain in a spherical/cubic shape the shielding continues to increase, however at some point the accumulation of positive charge makes it energetically more likely that the nucleus will become elongated, allowing the protons to be as far removed from one another as possible. This elongation then exposes more of the nucleons directly to the ZPE, so the mass deficit per nucleon starts to decrease again. (For an elongated nucleus the ratio of surface area to volume is greater than for a sphere or cube). The maximum shielding occurs around Fe/Ni. The very heaviest nuclei such as Uranium are the most elongated, and hence also the easiest to fission - they tend to break at or near the middle. >On Fri, Mar 1, 2013 at 7:27 PM, Jones Beene <[email protected]> wrote: > > Quark mass does not have a value which can be agreed on, so how can >> protons? >> > >If I were a betting man, I would bet that the mass of a proton can change, >as well as that of a neutron. The reasoning goes like this. An atomic >nucleus is composed of protons and neutrons. Add a nucleon to a light >nucleus through proton or neutron capture, and sometimes you will get an >energy release through mass deficit. The mass-energy has to come from >somewhere in the vicinity nucleus. It can come from the protons or the >neutrons or from a magical source of mass apart from the nucleons. Setting >aside magic and mystery and dark matter and superstrings for the moment, >that leaves us with protons and neutrons. > >Does the mass deficit come only from the protons or only from the neutrons? > Here we would have to delve into quantum chromodynamics to get much >further. But from a 10,000 foot view, it seems reasonable to assume it >comes from both. > >The difference in mass between a neutron and a proton is 1.29 MeV, and if >my memory serves me, it is common for a neutron or proton capture event in >a larger nucleus to produce an exothermic energy release well beyond this >energy, including in cases where there is no change in the overall ratio of >protons to neutrons (I should vet this assumption). So the mass deficit is >not coming only from something related to the electron involved in an >inverse beta decay. All of this is suggestive that the masses of the >component neutrons and/or protons have each dropped a little to adjust to >the new atomic mass. > >Assuming neutrons and/or protons can have different masses, a follow-on >question is whether this is a property that is specific to the nuclear >context or whether this can also occur outside of a nucleus. > >Eric Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
