[enriquto]

Newton was just incredible. The man polished his own lenses for his experiments. This, although there were already professional lens makers in England at the time, and they were better than him. Today, these antics would be dismissed as "bad practice", "reinventing the wheel", "losing two weeks rewriting a stupid lens" or some other corporate bullshit. But his great insights on the nature of light came from the very act of polishing a glass, using finer and finer sand until it becomes transparent when the grain of the sand is half the wavelength of the light.

[mncharity]

> it becomes transparent when the grain of the sand is half the wavelength of the light

That seemed to have intriguing potential as an educational story.

But it felt odd. Briefly googling suggests optical polishing compound grains are almost all 1+ um.[1] But maybe that <1 um tail is key? This[2] shows larger grains, with a tail growing over hours. But lens roughness is already at ~1 nm without the tail, and the growing tail only slightly improves that. On the other hand, perhaps sub-um fragments from the hydrated damaged surface are being entrained by the lap pitch or wax or slurry? Don't know. But it seems a half-lambda grain-size story has difficulties.

Oh well. :) Thank you for this. I wish I could find an online community interested in crafting improved stories for teaching science and engineering. My in-person ones... covided. :/

[1] eg, for plastic lenses, https://secureservercdn.net/45.40.144.200/i1r.357.myftpuploa... from http://www.gkci.com/opthalmic/ready-to-use-plastic-lens-poli... . [2] page 7 of https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-16-14-1...

[enriquto]

Sorry, I don't recall the specific details of glass polishing in this story; probably the datum I said does not make sense.

You can find this inspiring story, and many, many others, on Feynman lectures on physics. I'm sure the stories as written by Feynman will be exact and true.

[strikelaserclaw]

He was the ultimate "do it for somethings own sake" type of guy. He had a ton of curiosity, and just spent most of his life indulging it to the fullest. I mean, we in the modern world are so boxed in with our notions of right and wrong (most of which come from "authority"), newton wasn't like that, the man was equally comfortable studying about the bible, alchemy, as we was studying the natural world, building telescopes and as you said polishing his own lenses.

[coliveira]

Newton was the pinnacle of this kind of personality, but frankly this was the common mindset until the 19th century. Science was not a profession, people who did it were on their own dime and their work was basically an expensive hobby. Things change a lot when you have to "publish or perish".

[cercatrova]

It's the same thing as today, you learn best when you implement systems yourself. For example, I didn't learn web animations until I built my own (internal) library to do it well rather than relying on a third party one.