4 ms·
It is not local. That’s what’s wild about it. It’s a minimum over all paths. Re-read that section you posted.
by alecst 3y ago
It is not local. That’s what’s wild about it. It’s a minimum over all paths. Re-read that section you posted.
- EvgeniyZh 3y ago> In other words, the principle is that light takes a path such that there are many other paths nearby which take almost exactly the same time. > the wavelength tells us approximately how far away the light must “smell” the path in order to check it. For the same reason, it doesn't even have to minimum at all, it should be extremum.