3 ms·
Yes, and "massive" and "massless" exhaustively covers both, with the special highlighting of massless particles which are further constrained to follow null geo
by nimish 5y ago
Yes, and "massive" and "massless" exhaustively covers both, with the special highlighting of massless particles which are further constrained to follow null geodesics.
Massive particles don't have that limitation but they only travel time-like geodesics (as far as we know).
- ars 5y ago> with the special highlighting of massless particles which are further constrained to follow null geodesics. Only to an approximation. Photons generate gravitational fields, and the planets they travel near are attracted to the photons (not much obviously). (See: Kugelblitz) Gravity does not treat photons specially, the rules are the same as for other particles. For extra credit imagine a Kugelblitz traveling by at light speed - it's moving so fast, it doesn't have time to add any mass. Yet, mass transited inside the event horizon of this object.