3 ms·
Yep, though massless particles must follow null geodesics specifically. Yeah, the ant analogy isn't the best, though it does show off that movement on a curved
by nimish 5y ago
Yep, though massless particles must follow null geodesics specifically.
Yeah, the ant analogy isn't the best, though it does show off that movement on a curved surface needs "corrections" from the movement on a flat surface (and the degree to which that occurs happens to entirely characterize curvature itself).
If you force the ant to always travel on a great circle, then it might be a little more precise :)
- ars 5y agoIt's neither massive nor massless object that follow geodesics, it's objects with energy (including the mc^2 kind).
- nimish 5y agoYes, 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.