(December 31, 2022 at 8:33 pm)Jehanne Wrote:(December 31, 2022 at 8:27 pm)LinuxGal Wrote: Everything on that fine man's diagram is matter, including the squiggly lines marked with lower-case Greek gamma letters, asterisks notwithstanding.
Some are photons, which are massless, but, since all photons travel, without exception, at the speed of light in a vacuum (speed varies, of course, in other substances with the frequency/wavelength), all photons have energy.
Here's the groovy thing:
Alice says the photon has x amount of energy.
Bob says the photon has y amount of energy.
Charlie says the photon has z amount of energy.
And they're all right, because the Hermitian linear operators we call "observables" are only real for the observer, who may be moving at varying velocities with respect to each other.