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Arcing?

How would one point camera at the magnetron and still keep it safe

https://old.reddit.com/r/askscience/comments/3ittew/what_is_...

(The plasma acts as a sort of antenna-- we maybe don't want 2 magnetrons pointing at each other :)


Yep! focussed light anything is a hassle really-- mirrors have to be maintained and positioned. For anything larger than a family, mirrors have to be unrealistically large..

There was a concentrated light power station in north of Vegas, but it bankrupted the company that built it. They didn't think about storage at the time

https://en.wikipedia.org/wiki/Crescent_Dunes_Solar_Energy_Pr...

>As of 2023, it is operated by its new owner, Vinci SA, and in a new contract with NV Energy, it now supplies solar energy _at night only_, drawing on [molten salt] thermal energy stored each day.


Sorry my wording was misleading. SolarReserves lived and died on the thermal storage hill. The point about mirrors being a hassle is still relevant, though:

>When the plant finally opened in 2015, solar panels had left the Concentrated Solar Power technology in the dust [desert sand?] in terms of efficiency and cost.

https://jpt.spe.org/becoming-obsolete-how-high-tech-solar-pl...


Let me contribute my Europeanist sentiment by pointing out that the harmonious design of the fab is pure tatemae.

The Japanese professional class care fuckall about PFAS and environmental issues have always been low on the list of priorities. Sorry. I love the Hokkaido produce.

https://www.americanchemistry.com/chemistry-in-america/chemi...


It's certainly something to be concerned about. Even the building where MOS Technology made the 6502 (in Norristown PA) is still a contaminated EPA superfund site. It's an industry with very nasty chemicals and a long history of leaking them.

Some of the regulations make sense, like PFAS (correlated with chip manufacturing because HF is needed to etch Silicon and so fluoro-organics make great complements) And they seem to be sincere about it.

https://www.americanchemistry.com/chemistry-in-america/chemi...

As for the Japanese professional classes, environmental issues are always an afterthought. Don't let the "harmonious" design philosophy of the fab fool you..that's tatemae. (Remember Jobs and pancreatic cancer? There's the price to pay for the shiny toys)

I wont be eating from Hokkaido if this pans out (their milk is overrated imho, but the seafood is top)

Maybe I'll get to eat more Austrian millet in the near future..


Needham is one of my favourite books..

But Iirc he doesn't really cover this perspective much (excepting those parts where he hints at hypercomplex numbers)


He takes reals to be "stretch" and imaginaries to be "rotate". As in, real space, not an abstraction like "complex plane".

Then the imaginary unit becomes, not just rotation by pi/2 but a "basis vector" for rotation.

Putting on my physicst/engineer hat. this identifies rotations with the axis of rotation, which points outside the plane. (Disclaimer: this is not exactly how the author thinks about it.)

(In contrast. The basis vector of "stretches", btw which include 180-degree rotations, stay in the plane:)

The math is not novel but the perspective is.

Now this can be generalized to 3D rotations, whence you think of (the unit) quaternions as 3 independent axes of rotations.

(Euler angle and Euler formula become muddled :)

There's also the "rotational derivative" (angular velocity) bit which is THE THING worth mulling over. I think is the really novel bit (again. perspective, not math-- but I have not worked out his [degree] arithmetic )

(He calls it the fundamental equation in the video)

The physicist gets reminded of Legendre transforms (think <p,q> (- H)), where p here means angular momentum :)

It will be most cool if he can use this style to explain the "Feynman belt trick" without symbols or animation :)

https://en.wikipedia.org/wiki/Tangloids

https://en.wikipedia.org/wiki/Plate_trick#The_belt_trick


The author has a version for adults (or older students)

https://youtu.be/sehioJvr_eo?t=10m40s

(There's also a video in that channel that's made for elementary teachers, but it's not as pretty as you might hope)


The video for elementary teachers, that is prob closer to the book, for anybody interested https://www.youtube.com/watch?v=R43XpPZ6PKg

Looks like a "visual thinker":

https://www.eoas.ubc.ca/courses/atsc113/snow/met_concepts/07...

His other research

had involved discovering the mechanism of ICE CRYSTAL GROWTH HABIT CHANGE, an outstanding problem for more than 50 years in cloud physics that is closely related to the “thousands’ variations” in snowflakes.


If I'd to guess: all that exp. characterization to-date has revealed no anomaly (See my other comment)

This team might have looked at bandstructure. or not (they didn't say, & I'd guess not)


Seems to be a minor typo . Paper:

>17.5% of the measured value for Terbium-Gallium-Garnet (TGG) at 800 nm, and up to 75% at 1.3 µm.

Here's what the crystal looks like

https://www.photonchinaa.com/tgg-terbium-gallium-garnet/

Here's transmission plot (UV-IR)

https://www.samaterials.com/terbium-gallium-garnet-crystal.h...

Note there's almost no effect on transmission

Relevant? https://dspace.mit.edu/handle/1721.1/51819


Yes, the paper and magphys talks about rotation, not transmission.

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