The backstory of diffraction gratings is part of the ongoing story of precision. The first ones were created shortly after Newton's use of the prism to demonstrate dispersion, and by the late 1800s, https://en.wikipedia.org/wiki/Henry_Augustus_Rowland was quite good at making high quality gratings that were used in astronomy to figure out some of the most fundamental details. They were highly sought after- effectively he was the only person who could make high quality gratings for a while (and he shared them widely).
however, diffraction gratings do not use dispersion, so the page is confused
this error is not contained in the tech ingredients video the page links; unlike, for example, nighthawkinlight, tech ingredients is careful to get the science correct
Dispersion is the name for the process of separating the light into individual frequency components but there is more than one mechanism. The term 'dispersion' to refer to what diffraction gratings do is already well established.
usually the term 'dispersion' is contrasted to what diffraction gratings do. 'dispersion' normally refers to the frequency-dependency of phase velocity in a wave medium, which can result in separating waves into separate frequencies but does not always (for example, a pulse train traveling through a one-dimensional dispersive medium is a case of great practical interest). but it's true that from time to time people do use the term 'dispersion' to refer to separating light into individual frequency components with a diffraction grating. it just isn't the normal meaning, and it isn't one i'd seen before
the comment you are replying to already explains that people sometimes use the term 'dispersion' in that way, but puts it in a broader context:
> but it's true that from time to time people do use the term 'dispersion' to refer to separating light into individual frequency components with a diffraction grating. it just isn't the normal meaning, and it isn't one i'd seen before
> In optics and in wave propagation in general, dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency;[1] sometimes the term chromatic dispersion is used for specificity to optics in particular. (...) In optics, one important and familiar consequence of dispersion is the change in the angle of refraction of different colors of light
diffraction gratings do not in any way depend on this phenomenon; they just replicate the consequence through a different mechanism. so where dekhn said, 'The fundamental physical mechanism is known as "dispersion"', linking to the same page i linked above explaining the mechanism that diffraction gratings do not use, they were mistaken
The backstory of diffraction gratings is part of the ongoing story of precision. The first ones were created shortly after Newton's use of the prism to demonstrate dispersion, and by the late 1800s, https://en.wikipedia.org/wiki/Henry_Augustus_Rowland was quite good at making high quality gratings that were used in astronomy to figure out some of the most fundamental details. They were highly sought after- effectively he was the only person who could make high quality gratings for a while (and he shared them widely).
If you really want to go down the rabbithole, see https://en.wikipedia.org/wiki/Dividing_engine (fans of the screw cutting lathe will appreciate that the same technology is used) and https://www.edmundoptics.jp/ViewDocument/MKS%20Diffraction%2... and http://snl.mit.edu/pub/papers/WP/Nanoruler-White-Paper.pdf