from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun Absence of
mass; the state or condition of being massless.
from Wiktionary, Creative Commons Attribution/Share-Alike License
Parallel plants exhibit "masslessness," seem frozen in time, lack internal structure, and generally collapse to dust at a human touch.
The dark photon comes from a gauge symmetry, just like the ordinary photon, and its masslessness is therefore completely natural.
Coulomb's law seems to be valid at the longest distances so it must be set up by the photons close to masslessness.
When two charges are far away the uncertainty relation gives little freedom and the photon is closer to masslessness, We know that
If we put the energy and the tree-dimensional momentum together into the four-momentum we see that it is not constrained by the masslessness condition, we say that the photon is virtual and consequently has a (virtual) mass.
Although the masslessness is ultimately destroyed by the Majorana mass terms (or by ordinary