Timeline for Time taken to reach different points on a concave mirror
Current License: CC BY-SA 4.0
3 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 14, 2020 at 15:50 | comment | added | Carl Witthoft | While this is true, it could be more simply stated this way: Yes, there is a path-length difference, which leads to a phase difference at the focal point. This is where simple raytracing fails, and we have to use diffraction theory, leading to things like Cornu spiral and Airy disks to describe the intensity pattern at the theoretical focus point. | |
| Dec 14, 2020 at 12:19 | comment | added | Brian | ", you arrange that light arriving from any part of the collimated beam will all be directed to F, because all the paths involved are equally the shortest path." Woah, this is really a big idea to digest. I liked this answer that the reflected path offsets the increased distance to reached the mirror but I think this answer really needs a diagram to go with it. | |
| Dec 14, 2020 at 11:42 | history | answered | Andrew Steane | CC BY-SA 4.0 |