Jarek Duda
Registered Senior Member
While special relativity says inertial mass is equivalent with energy, there are at least two more types of mass, for which equivalence seems not so certain - let me briefly summarize and ask for more arguments for/against their equivalence.
Gravitational mass is hypothesized to be equal by equivalence principle, and gravitational interaction of antimatter now seems nearly certain to be the same (?) However, all these tests are for baryons and bulk matter made of them, for non-baryons I am aware only of this 1967 Witteborn, Fairbank test for electron - measuring maximal time for thermal electrons reaching upper electrode tmax=sqrt(2h/g), which turned out infinite, suggesting g=0. But later it was explained as due to gravitational charge gradient in shielding, so seems experimentally we still don't know (good slides).
de Broglie clock, zitterbewegung - e.g. relativistic QM requires E=mc^2 for psi ~ exp(-iEt/hbar). For electron it was directly confirmed ( https://link.springer.com/article/10.1007/s10701-008-9225-1 ) by observing increased absorption of 81MeV electron beam when agreeing with spatial lattice of crystal, however, they got 0.28% disagreement. The same oscillation formula was used to introduce 3 masses based on neutrino oscillations, but experimental confirmation they are equivalent to energy seems quite difficult (maybe GERDA?)
Are there some more arguments they are equal or not? Past and future experiments to improve the situation?
Gravitational mass is hypothesized to be equal by equivalence principle, and gravitational interaction of antimatter now seems nearly certain to be the same (?) However, all these tests are for baryons and bulk matter made of them, for non-baryons I am aware only of this 1967 Witteborn, Fairbank test for electron - measuring maximal time for thermal electrons reaching upper electrode tmax=sqrt(2h/g), which turned out infinite, suggesting g=0. But later it was explained as due to gravitational charge gradient in shielding, so seems experimentally we still don't know (good slides).
de Broglie clock, zitterbewegung - e.g. relativistic QM requires E=mc^2 for psi ~ exp(-iEt/hbar). For electron it was directly confirmed ( https://link.springer.com/article/10.1007/s10701-008-9225-1 ) by observing increased absorption of 81MeV electron beam when agreeing with spatial lattice of crystal, however, they got 0.28% disagreement. The same oscillation formula was used to introduce 3 masses based on neutrino oscillations, but experimental confirmation they are equivalent to energy seems quite difficult (maybe GERDA?)
Are there some more arguments they are equal or not? Past and future experiments to improve the situation?