Matter....mass...and inertia are distinct concepts. There are related, but not the same thing. Mass and inertia are properties of matter. There is only one form of matter, our science calls it charge. But know little about it. -e and +e is the only matter, the only physical entity in this cosmos. You may think of it as a set number of E field lines, or a specific density at a certain size. One may also consider it to be a constant length. However you happen to think of an E field.
The area of space that this constant occupies, can be varied. THAT area, gives us the property of mass. When we squeeze or stretch that area......we change the mass of the matter. The matter remains constant and when we vary the density of that matter it is called mass. Mass is adjustable, matter is not. Inertia is the force necessary to accelerate mass. If mass is stationary, it takes a certain force to accelerate it. If the mass is moving with momentum, it will take more acceleration to change it. So it will have more inertia. Inertia depends on the motion of mass.
Matter is a constant amount, mass is the density of matter, and inertia is the acceleration needed to change that motion of mass.
Where does the motion come from? Why does matter move? Why and How does matter move?
All -e and all +e have an internal electrical pressure which is powered by the self-repulsiveness of the e itself. e is always trying to explode out into space. e hates itself. It's trying to super nova. At c.
This outward c acceleration of e, generates a common M field, because of the common outward e direction. This M field rolls and turns the little bits of e. The outward V of e, has been turned into a rotation of e at c. This expanding super nova has turned and rotated to a certain size. This happens at c. At c, M = E. And the charge spins, a self powered spin. By the conversion of linear V to angular V.
This rotation has TWO spins, not one. The E is rotating and the M is rotating. In the right handed e(+e), the M and the E are rotating in the same direction. In this configuration, the mass adds, because the E and the M momentums are moving in the same direction. You will measure and experience high mass.
In the left handed e(-e), the E and M are in opposite directions. The mass subtracts. The mass you measure is the difference in the directions......and measures very light. Almost no mass. But that is only apparent. Because the momentum is in opposition.
Giving the left e an empty personality. Light and no energy or mass.
And giving the right e, a full personality, heavy and lots of energy and mass.
Two personalities with the same amount of matter.
Physicality is much simpler than the standard model.