[dleviwing]

My own calculations place the smallest volume of a matter particle to be at 10^-68 m^3. To say that there is a smallest limit of space that can be occupied would depend on if you view space as a pure void or as a physical entity.

I believe you are referring to a neutrino as being the particle that travels through the earth without encountering a collision. If you think about the neutrino as having an extremely short symmetry wave function, then it would not have enough time to interact with other matter unless it increases its mass. Science has only recently developed methods of measuring the mass of a neutrino.

The state of uniform motion of an environment determines the inertial reference frame used to perform quantitative measurements. Science today states this as being the space-time reference frame as it relates to General Relativity. To simplify this, we can just say that spatial density of the environmental aether increases or decreases about an object as it changes its quantity wave function motion to uniform motion (mass). Commonly called mass to energy or energy to mass conversions. No magic, just pure physical behavior of a fundamental substance.