43:05 Michelson wished to use it to (dis)prove ether, ironically, 100 years later, the same basic experiment was used to demonstrate gravitational waves :)
For the explanation at 2:58 - Remember, if you wish to readout the sensor electronically, you's STILL need _quadrature_ or something equivalent. One way to achieve is to use a Vernier-disk as the stationary disk. In other words - if your main encoder wheel has 1000 stripes, you make the stationary disk with 1001. Then two detectors can resolve quadrature. If you are worried about eccentricity (as in the example of a theodolite) use four detectors, and average cross-wise.
1:16:48 - an interesting question that nobody asked: The angle alpha is lambda/d --> for non-monochromatic light, how can the beam-combiner (mirror on the blackboard-sketch) be practically implemented? Remember - the two (+1 and -1 order) beams shall now be split into a 'rainbow'.
also not clear for me. maybe some sharp filter bevor? No the different angels from different Lambda bring F1 and F2 on different places on the screen. so each frequency has there own spot ?!? Oh, You mentioned it allready and write the "rainbow" ... yes it should be a rainbow. it is very interessting to read your comments, Thanks.
@@sebaschtl9710 Cheers, mate! I take it that you have already binge-watched all 18 "rapid prototyping" videos on Prof. Gelbart's own channel, as well his other videos (lathe, metal 3d-printing, etc.?
It's an interesting question indeed. Not as easy as it looks. One way is to use a second, stationary grating instead of a mirror. Another option might be to use a lens, because the "rainbow" of diffracted points are all diverging from a common origin, and so can all be focused to a common point.
@fizzym: I'm so happy to listen, thank you so much for sharing all those videos!
Keyence's "handheld CMM" uses a camera to image a quartz cube with a fiducial grid embedded inside to measure the angle of the cube.
I like this man because he insert history of technology everywhere
43:05 Michelson wished to use it to (dis)prove ether, ironically, 100 years later, the same basic experiment was used to demonstrate gravitational waves :)
For the explanation at 2:58 -
Remember, if you wish to readout the sensor electronically, you's STILL need _quadrature_ or something equivalent. One way to achieve is to use a Vernier-disk as the stationary disk.
In other words - if your main encoder wheel has 1000 stripes, you make the stationary disk with 1001. Then two detectors can resolve quadrature. If you are worried about eccentricity (as in the example of a theodolite) use four detectors, and average cross-wise.
1:16:48 - an interesting question that nobody asked: The angle alpha is lambda/d --> for non-monochromatic light, how can the beam-combiner (mirror on the blackboard-sketch) be practically implemented? Remember - the two (+1 and -1 order) beams shall now be split into a 'rainbow'.
also not clear for me. maybe some sharp filter bevor? No the different angels from different Lambda bring F1 and F2 on different places on the screen. so each frequency has there own spot ?!? Oh, You mentioned it allready and write the "rainbow" ... yes it should be a rainbow.
it is very interessting to read your comments, Thanks.
@@sebaschtl9710 Cheers, mate! I take it that you have already binge-watched all 18 "rapid prototyping" videos on Prof. Gelbart's own channel, as well his other videos (lathe, metal 3d-printing, etc.?
@@AdityaMehendale yes I watched them all : ) can you recommend other channels?
@htl9710 AppliedScience (BenKrasnow), Alex Slocum (MIT), Matthias Wandel, StuffMadeHere, BreakingTaps, Stefan Gotteswinter, CEE Australia, HuygensOptics, AlphaPhoenix...
It's an interesting question indeed. Not as easy as it looks. One way is to use a second, stationary grating instead of a mirror. Another option might be to use a lens, because the "rainbow" of diffracted points are all diverging from a common origin, and so can all be focused to a common point.