Hello Arjen
I measure the mass of an object by weighing. Though this measures its seemingly attractive mass and involves the kind of gravity which makes things move and radiate, related to expansion of the universe, it is proportional to the mass it preserves by exchanging energy, an exchange which transmits the kind of gravity which doesn't accelerate as it is as attractive as it is repulsive. Though one kind cannot exist without the other, this inertia is expressed when we accelerate an object: the stronger we push, the greater the part of its inertia is expressed as a counterforce, the more its energy exchange with the evironment is diverted to the pusher, the farther its exchange in other directions shifts to red, the more all positions of its path become identical, the faster it moves, the more its path shrinks. Though its inertia, its opposition is as strong as the force it is subjected to and can easily be made much stronger than Earth's gravity, this counterforce cannot be distinguished from the way the Earth pushes against our soles. Though we can weigh it, its mass is in some respects a potential kind of mass, a reservoir the content of which can be brought to expression by subjecting it to a force.
If the elements are forged in stars out of hydrogen and helium, out of hadrons and leptons which are forged in even denser clusters, stars and clusters which as they implode, throw their outer layers into space and so supply the stuff to build stars and planets from, then these particles transform from the extreme conditions, the high-energy exchange inside the cluster to a much calmer world outside. Outside the oven they are forged in, they can only preserve the inertia they acquired by slowing down their clock, by contracting their field, by increasing the distance between their mass centers as measured inside their field, which is what happens as they get expulsed. Gravitationally redshifted, contracted within a tiny volume as measured outside its field, the expression of its mass also is tuned down, its interactions slowed down, its energy exchange simmering over a low flame. It is only as we start pushing it that it heats up again, its energy exchange with the pusher increasing, shifting to higher frequencies, that its inertia increasingly is expressed in the force upon the pusher.
So the definition according to which the mass of a particle is greater as its position is less indefinite, which assumes particles to create and preserve each other by exchanging energy, unifies relativity with quantummechanics. Whereas the usual reasoning why clocks slow down in a gravitational field or when moving is of a somewhat formal, mathematical kind, this mass definition shows the physical reason for these features, why spacetime has the physical properties it has, why the mathematic reasoning works, its logic derived from what to nature is logical, from its laws of physics instead of the other way around.
Anyhow, a consequence of this is that we need gravitons nor higgs particles. What's more, if the charge sign indeed only refers to the phase of particles with respect to each other, then the so-called strong force, invented to explain why the strong repulsion between supposedly positively charged protons does not prevent them forming atomic nuclei, might be less mysterious than we suppose it is, so photons perhaps suffice to do all messaging. After all, would nature be so inefficient as to create mass-challenged particles that need higgs particles to provide them with mass, and in addition fabricate gravitons to express that mass just to oblige physicists who prefer mathematic models above physics ?
As to the electron repulsion, perhaps this is due to their spin as the spin direction affects the orientation of the field lines along which it exchanges energy with its environment, the exchange fixing its compass in some particular direction. If three independent spin axes are associated with three different properties or different expressions of the same property, then some axis-up/down combinations may produce the behaviour we see, other combinations annihilating. Though this would make it easier to understand how we can manipulate such anti-electrons, that does not prevent any particle to oscillate between opposite states, to be its own antiparticle.
