4 ms·
> From a four dimensional perspective—which is the correct one, let’s not forget—the distance between a photon’s emission and absorption event is always zero.
by hvidgaard 5y ago
> From a four dimensional perspective—which is the correct one, let’s not forget—the distance between a photon’s emission and absorption event is always zero.
That would require the emission and absorption events location in the space to be the same would it not? Or do you mean that a photon does not experience time, so relative to the photon it simply travel instantaneously from emitting coordinate to absorption coordinate?
- gizmo686 5y agoThe distance metric for flat spacetime is given by: ds^2 = dx^2 + dy^s + dz^2 - cdt^2 For a particle traveling at the speed of light, this gives ds=0.
- creata 5y ago> That would require the emission and absorption events location in the space to be the same would it not? I think they're referring to the distance in Minkowski space,[0] where the time component and space component cancel out for light. [0]: https://en.m.wikipedia.org/wiki/Spacetime#Spacetime_interval https://en.m.wikipedia.org/wiki/Spacetime#Spacetime_interval