alt Hacker NewsThis is edutainment. Kind of like YouTube channels like 3Blue1Brown, Veritasium or MinutePhysics. All good, it helps build intuition, and to better understand the world, but it is a bit lacking for actually using that knowledge.
Notice how few equations there are in this page, it is a common feature of edutainment, they won't give you equations unless they can't get away without. No linear algebra here, just a cosine (actually a dot product in disguise) and the inverse square law (1/r²), two equations he considered too fundamental to skip. Also notable is the lack of exercises.
But now that you have read this page, and played with the interactive elements, you probably have a good understanding of how lights and shadows work, but can you write a 3D engine or even just calculate exposure time without your camera helping you? Without prior knowledge, probably not. For that, you actually need to do the maths, with exercises and all that. And by the way, look at the source code (it is not obfuscated), all the linear algebra that is not present in the article is there!
That, I think, explain the discrepancy between edutainment and textbooks. Textbooks are for you to do actual work, do the maths, solve problems, etc... not just give you an overview. That's also why is takes way longer and requires a lot more effort on the student part.
Interactive content like this one is good, and maybe it should be given a bit more consideration by the traditional educational system. But I don't think it can replace textbooks, at least not for the "hard part".
Replies
What you said makes sense. Thanks for your perspective.
Comparing this site to Veritasium seems unfair to me. I don't see any evidence that this site generates direct revenue. I also think it's an excellent exercise in pedagogy. The best professors and brightest colleagues I remember from college - or, since you said "maths" I guess I should say "university" ;) - demonstrated extreme facility with the physical concepts and regarded their mathematical representations only as a useful tool to characterize them and communicate about them, not an end to themselves.
Maybe this is just personal preference. I knew capable students who were wrote and prescriptive in their approach to the courses, but I was closer to those who played in the conceptual end of the pool.
I once made a resource like this site for my own educational benefit when I was grappling with MR physics. You're right - I had to do the math(s)! - and came away with a much clearer understanding of the subject. Still, I received lots of correspondence from students and professors who found the visual aid helpful on their journey.