It's so much fun manipulating things, exploring and getting surprising feedback.
I know it's not really fair to compare this highly scientific masterpiece to the artistic flash websites of the past, but for me at least it immediately evokes the same feelings.
Exporting this site for example in a future proof way is not that obvious. (Exporting as pdf wont work with the webgl applets, exporting the html page might work but is error prone depending in the website structure)
50 years from now, flash emulators will still work on swf files, but these sites might be lost. Or is there a way to archive sites like this?
Cameras and Lenses - https://news.ycombinator.com/item?id=25357315 - Dec 2020 (213 comments)
I am always on the lookout for the classic sin of making it look like electromagnetic waves wiggle in space like a snake. I know it's convenient to glue the tangent space to the underlying physical space, but I think it confuses students.
To be clear: the amplitude of the electric and magnetic fields (and hence their components in each direction) oscillate in space/time. Any particular wave though should travel in a straight line (usual caveats apply). Of course you may incidentally also get e.g. sinusoidal variations in intesity perpendicular to the wavevector, but that will be because of the overall beam characteristics.
I don't mean to say I know a better way to show this, and I am aware of many complicating factors. I just think lots of people (my former students and self included) can come away with a wrong idea about how these waves work.
Most people who are smart and creative are nowhere near as productive. And most people who are extremely productive don't get sidetracked by side projects.
(maybe we already can, I'm simply asking)
The way he builds up the mental model from a simple photon bucket to a pinhole and finally to a lens system is just incredible. I particularly loved the section on the circle of confusion. I've read dozens of explanations on depth of field, but being able to interactively drag the aperture slider and see exactly how the cone of light narrows and the blur reduces makes it click in a way that static text never could. This really should be the standard for digital textbooks.
Makes me wish for a similar resource that would teach 3+ element optics, moving elements, and sortof get closer to modern lens design.
To be honest, though, this seems like ideal content for an LLM to produce. It's basically fact regurgitation.