What is inertia

Assuming a fully occupied universe in states of negative energies for electrons according to Diracs hole theory the gravitational and coulomb interactions between then are compensating each other exactly. By this way these not observable electrons behave like massless and chargeless particles. Nevertheless they are reacting by the help of their magnetic momenta on fields of the physically observable particles in states of positive energies. So brack reactions on these particles of positive energies are produced, which are corresponding to the inertia of particles with finite masses. These considerations allow to calculate the total number of occupied states in the realm of negative energies and their negative Fermi limit. (orig.)