Particle quantum-spin-number (§5.7)
The spin number is a fundamental entity in the Standard Model of particle physics. Quarks and leptons have all a specific spin.
Because particles are point entities in physics they cannot spin though. Yet they have side effects that coincide to angular momenta in particle physics. As Newton said because it matches the physical measurements, it makes sense mathematically; it nevertheless doesn’t make sense physically.
And in gravimotion interpretation of magnetism, while a particle may spin, and if that particle is electrically charged its spin creates a specific field, that spin is not a fundamental characteristic of the particle. The spin of a particle in gravimotion, just as the spin of a real particle in physics, can furthermore take any value instead of being limited to whole, or half of whole, value.
Unified field interpretation, the weak force (§5.8)
FYI Einstein was not looking for a unified field interpretation, which is provided by gravimotion, but for a unified field theory.
Being all formatted out of motion, physics’ fields are nevertheless unified in motion in this interpretation of Nature that is gravimotion. Gravity, strong, magnetic and electromagnetic forces are all dynamic structures of motion-inclination. The electric force is a dynamic graded-activity. I did not figure out yet why or how the latter (electrical graded-activity) takes over the former (gravitational radial-activity) at mid-range that is in between atomic scales and galaxies scales.
The weak force involves transformation of neutrons into proton electron pairs and vice versa with emission of neutrinos and antineutrinos. I mentioned the neutrino in §4.13 as being the motion that holds the particles together; an antineutrino would then be motion of type neutrino in the opposite direction. A positron in gravimotion is the lack of one electron; an electron that did not disappear though, as that electron is systematically found in a neutron once the transformation is over.
Life (§5.9)
The "spirit" of life seems not to be considered a force in physics, as there are 4 known forces and none match that of life; the fact is that while science is working hard on discovering the origin of life, science doesn’t seem interested at finding out what life is made of. In gravimotion life is very likely made of motion that doesn't need our concept of space to move-on, as life is changes that move in time only; the motion-activity that implements life, unlike the motion entities of light and gravity, involves matter though; just as temperatures and heat involve matter.
Because, in gravimotion's interpretation of Nature, it is gravity that in the first place engenders matter, and because life is assosiated to matter, I think that life is dependent on gravity. While I did not decipher, any more than anybody else, the physical characteristics of life, I think life is a motion-activity, yet of unknown-type.

Asserting motion only constitutes our own body liveliness and mind is deceitful if not offensive, as we human naturally place ourselves, and especially our minds, above any mechanical assemblies; but considering things the other way around, considering the human body and thinking complexity first and then that it is an artifact of Nature, for which Nature uses motion only, is flabbergasting. From DNA to human body functions and physical senses, from reproduction to aging that is life per se, from intellectual ability, intuition, imagination and intelligence, to feelings and emotions even instincts, all of that becomes breathtaking considering it is the fruit of the subtleness and ingenuity of Nature which only ingredient and altogether tool is motion-occurrences.