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Ha, I had never heard of this effect despite having studied Kamiokande (well neutrinos, at least) as part of a mini-dissertation for my B.Sc.

However, looking for sources relating to leaching by ultra pure water (UPW) not much turned up.

I did however find on Google Scholar a paper "Ultrapure Water: friend or foe?"... which lead me to https://www.balazs.com/sites/balazs/files/2023-03/pub0039-up... . Reading between the lines, Marjorie Balazs appears to have made a career out of UPW; she says in that paper:

"The ability for UPW to absorb and dissolve or react with all kinds of materials complicates other aspects concerning its use in the processing of wafers."

Seems like UPW dissolves anything, so lends credence to the anecdote.

Interesting topic, hadn't thought about UPW for wafer fabrication before.



I found the article I was trying to remember:

https://www.businessinsider.com/super-kamiokande-neutrino-de...


> when travelling through water, neutrinos are faster than light

Interesting, how could this be possible?


I didn't read the article, but it's likely they are faster than light is when traveling through that water. light can have different speeds through different media.

for charged particles (so not for neutrinos) this leads the Cherenkov radiation, often observed in the cores of nuclear reactor: https://en.wikipedia.org/wiki/Cherenkov_radiation

as to why in this case: it can be somewhat intuitive to think that photons would be forced to take a somewhat longer path when traveling through a medium they interact with a lot (water, anything with a charge) then something which is almost going at the speed of light and famously doesn't interact with almost anything!


This is the way: faster than the local speed of light in water.


[I was going to write an explanation, but these sentences of Wikipedia article ar better.] From https://en.wikipedia.org/wiki/Super-Kamiokande

> A neutrino interaction with the electrons or nuclei of water can produce a charged particle that moves faster than the speed of light in water, which is slower than the speed of light in vacuum. This creates a cone of light known as Cherenkov radiation, which is the optical equivalent to a sonic boom. The Cherenkov light is projected as a ring on the wall of the detector and recorded by the PMTs.




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