3 ms·
What's a light ring from a time perspective? Seems as close to time travel as it gets, but that's just my pop intuition around timelike curves in spacetime. If
by 6gvONxR4sf7o 6y ago
What's a light ring from a time perspective? Seems as close to time travel as it gets, but that's just my pop intuition around timelike curves in spacetime. If it's a closed timelike curve outside the event horizon, is that a big deal for causality formalisms?
- tbabb 6y agoA light ring is not a closed timelike curve.
- cma 6y agoI’m not sure of the distinction between light ring and this, but probably a good place to read: Photon sphere https://en.wikipedia.org/wiki/Photon_sphere https://en.wikipedia.org/wiki/Photon_sphere
- fhars 6y agoIt is a closed lightlike curve. There is no impact on causality, as time does not pass on a lightlike curve.
- 6gvONxR4sf7o 6y agoThanks. I'd been dividing it between spacelike and timelike. I forgot there was a third option.