momoschili (u/momoschili)

momoschili commented on Sunlight-activated material turns PFAS in water into harmless fluoride phys.org/news/2025-08-sun... · Posted by u/bookofjoe

3eb7988a1663 · 16 days ago

Is that much of a problem for a catalyst? Presumably you do not need many of these: at water treatment plants and at the waste-stream for manufacturing processes which emit PFAS. You might not be able to justify the expense inside your home water purification system, but it could still be cost effective for large scale installations.

momoschili · 16 days ago

it depends on the scale and the required amounts. If having a limited amount of catalyst wasn't such a big problem I suspect hydrogen power would have been much more economically viable.

momoschili commented on Sunlight-activated material turns PFAS in water into harmless fluoride phys.org/news/2025-08-sun... · Posted by u/bookofjoe

SoftTalker · 16 days ago

Activated carbon filtering removes up to about 75% of PFAS. Reverse-osmosis removes almost all.

Doesn't get rid of them, to be clear. It would still be better if a way could be found to chemically (and cheaply) convert them to something less harmful.

momoschili · 16 days ago

Yes, the key here is the degradation of the forever chemical, not the removal. Removal itself doesn't really change the environmental scale of it

momoschili commented on Sunlight-activated material turns PFAS in water into harmless fluoride phys.org/news/2025-08-sun... · Posted by u/bookofjoe

nick238 · 16 days ago

The Materials Science Gameplay Loop:

1. Invent fantastic new material that does a heretofore novel reaction or one with improved performance (chemical, photovoltaic, etc.)

2. Do #1 without lead, cadmium, mercury, or arsenic.

SociallyAwesomeAwkwardPenguinMeme("Turns PFAS to fluoride", "Contains Cadmium")

momoschili · 16 days ago

3. Do #2 without platinum, palladium, rhodium, ruthenium to make it economically viable

momoschili commented on Meta invests $14.3B in Scale AI to kick-start superintelligence lab nytimes.com/2025/06/12/te... · Posted by u/RyanShook

ml-anon · 2 months ago

Cool. So what does a chief AI scientist do?

momoschili · 2 months ago

ideally lead AI science, but in reality mostly pontificate on social media. One could say that is fitting for Meta though right?

momoschili commented on TSMC bets on unorthodox optical tech spectrum.ieee.org/microle... · Posted by u/Rohitcss

ls612 · 3 months ago

I wonder if considerably more engineering and research effort will be applied here when we reach the limit of what silicon and electrons can do.

momoschili · 3 months ago

Contrary to the prior commenter, there is definitely significant engineering going toward this, but it's not clear or likely that photonic computing will supplant electronic computing (at least not anytime soon), but rather most seem to think of it as an accelerator for highly parallel tasks. Two major ways people are thinking of achieving this are using lithium niobate devices which mediate nonlinear optical effects via light-matter interaction, and silicon photonic devices with electrically tunable elements. In the past there was a lot of work with III-V semiconductors (GaAs/InAs/GaN/AlN etc) but that seems to have leveled off in favor of lithium niobate.

Photonics has definitely proved itself in communications and linear computing, but still has a way to in terms of general (nonlinear) compute.

momoschili commented on Applications of Classical Physics pmaweb.caltech.edu/Course... · Posted by u/nill0

xqcgrek2 · 3 months ago

For an idea of how far the average US physics education has been dumbed-down in the past three decades, I doubt a 3rd year US-educated physics graduate student could pass a test on any of the chapters.

momoschili · 3 months ago

The vast majority of US grad students already pass tests on chapters 1-9 (the ones that are taught) before they even begin their "true" graduate career (aka their "masters"). Most graduate E&M (Jackson) and Thermo/Stat (Landau) mech classes cover their individual topics to an even greater level of detail than these materials.

As for the uncovered subjects, it turns out quantum mechanics occupies a large space of the "new physics" that graduate students are trained to do.

There are definitely an incredible amount of utility and knowledge to be gained from the classical field theories, and obviously many outstanding and new problems that I think need more attention as well. At the same time let's not understate the utility of quantum mechanics that most grad students are specializing in.

You are speaking out of turn.

momoschili commented on Applications of Classical Physics pmaweb.caltech.edu/Course... · Posted by u/nill0

momoschili · 3 months ago

I just looked through the diffraction chapter and some chapters I'm much less familiar with. This is an incredible ~graduate level text for these subjects. I've been looking for something like this for a while! Thanks!

momoschili commented on Ultrafast Optical Detector tdk.com/en/about_tdk/inno... · Posted by u/JohannMac

jiggawatts · 4 months ago

Canada and Spain are major producers. America will be fine as long as they don’t start a trade war with every country all at once.

Oh.. ohhh… you threatened Canada with annexation too?

Oh boy.

momoschili · 4 months ago

producing raw material does not mean you can process it.

The American defense branches have been searching for Ge-free alternatives for thermal optics, etc since during Biden's presidency. The trade war is significant, but does not change the calculus here.

momoschili commented on Handheld detector for all types of ionizing radiation improves radiation safety phys.org/news/2025-04-han... · Posted by u/PaulHoule

weinzierl · 4 months ago

Agreed that a detector would not help but some UV-C lamps are sold freely with arguably insufficient warnings.

Is das folgende Geraet sicher? https://www.doctor-san.eu/luftreinigung-desinfektion/uvc-des...

https://www.doctor-san.eu/luftreinigung-desinfektion/uvc-des...

https://www.amazon.de/Doctor-San-Sanierungstechnik-Desinfekt...

momoschili · 4 months ago

interesting, you're right they are devoid of warnings. I thought maybe it was an EU/Germany thing, but looking at American listings it's similar. This may be due to the level of UV-C exposure you're getting. EG weak laser pointers won't have the same caution signs as a Class IV laser.

Edit: Looking into it a bit more, seems that "far-UVC" light is a bit higher energy than the typical "UVC". It seems that far-UVC penetrates less deeply and critically is apparently much better absorbed by the dead layers of the skin than UVC, so it is currently recognized as safe... All I could find on it was a Columbia research artcle.