Seems like someone's having difficulty with object permanence. The Sun doesn't actually disappear at night.
Props for her husband who's been incredible of taking care of her.
Hopefully she maintains a higher baseline from here on out and the production of these videos doesn't produce further Post Exertional Mailise that could worsen her condition.
Would could this possibly be referring to?
The tank's cross sectional area relative to the sun depends on its relative orientation to the sun. We'll ballpark it at somewhere between its circular endcaps (Pi x ((39.3/2)^2) = 1213 square meters) and its curved cylindrical face (which, pointed right at the sun, has a rectangular cross section of 41.4 x 39.3 = 1627 square meters).
So, conservatively, the neutrino flux through Super-K's tank is 1400 m^2 x (100cm/m)^2 x 6.5e10 neutrino/second/(cm^2) x 86400 seconds/day = 7.86e22 neutrinos/day passing through the tank. Of which 30 are detected.
[1] https://en.wikipedia.org/wiki/Super-Kamiokande
[2] https://en.wikipedia.org/wiki/Neutrino (end of intro section, just before History). Wikipedia says only that the "majority" of the 65 billion flux is from the sun, so we might be off by a factor of two-ish in the worst case.
i want to be more appreciative every day for my health post-covid... not everyone was so lucky, and I can only imagine the gut-punch it is to know everyone went through a thing, but you got singled out for some perpetual daily punishment :'(
This is because the electromagnetic energy of the supernova can take hours to force its way through all the star's mass to the surface when the core dies, but the gravitational crush turning protons and electrons into neutrons releases a massive burst of neutrinos in every direction. And the neutrinos are so weakly-interacting with the matter in the star that they get out first. Then, a million years later, arrive in our solar system at such a high fraction of lightspeed that they presage the coming electromagnetic shock-front because the constant difference in escape time between neturinos, which are particles of matter, getting out of the star without interacting with anything and the electromagnetic waves moving through the star's matter at a fraction of lightspeed created a gap that the light never caught up to.
The universe is a profoundly wild place.
I’m today years old learning that the light that we actually see on earth today came out 100s of thousands of years ago.
Edit: on another note, way to go on your recovery Diana. We've been rooting for you.
Construction is underway on the next version of the experiment "Hyper-Kamiokdande" which is similar in design but significantly bigger. If I recall correctly Hyper-K will be two 200 kilo-tonne detectors, compared to Super-K which is a measly 50 kilo-tonne detector.
Her back catalog is good and you still get paid for people watching your old videos.
And for terrestrial sources (geoneutrinos) from natural and artificial sources, there are/were efforts that could detect terrestrial reactors in operation like AGM2015. [1] Irrespective of the current geopolitical instability, I'm surprised that the IAEA doesn't have its own network of geoneutrino detectors to proactively look for proliferation concerns.
0. https://neutrino-map.science/ (ICNO)
1. https://www.nature.com/articles/srep13945 (KamLAND and frmr Borexino)
After seeing her status updates 2 years ago I was honestly really concerned she would be gone for good. It sounds like she had a serious case of myalgic encephalomyelitis brought on by Covid.
Part of why we know so little about these types of conditions is they are incredibly unfair. Women are 4x as likely to have some sort of constant fatigue disorder as men, and you see this reflected in literature going back centuries when describing women who just flat out disappear from public life.
One of the things about being bedridden for a long period of time is that there is a high risk of becoming more or less permanently bedridden. Especially if you have a chronic fatigue syndrome, you become weaker and any activity can retrigger fatigue. So her pushing herself to make new content sustainably is important very encouraging.
Thirty interactions on average per day, that's crazy - earlier in the video the host mentions that the cross section of a thumbnail has a billion neutrinos flowing through every second!
The uncertainties about the masses of the various kinds of neutrinos are very high.
Also their abundance in the Universe is much less accurately known than for electrons and nucleons, because many processes generate neutrinos or antineutrinos and only few of those are absorbed in later collisions, so the total amount of neutrinos and antineutrinos is increasing continuously, even if the difference between the number of neutrinos and antineutrinos varies only little.
For the mass of nucleons and electrons one can make reasonable estimates, even if the uncertainties about the densities of interstellar and intergalactic matter are also very high. On the other hand, for the mass of neutrinos + antineutrinos the uncertainties encompass many orders of magnitude.
The detectors of neutrinos can detect only high-energy neutrinos. There may be much more undetectable low-energy neutrinos.
Between things like black holes and neutrinos I wonder how much Dark Matter will end up being dark matter. And I think the cosmological crisis indicates we are measuring space curvature wrong somehow.
Like neutrinos interact with gravity, which means they can be lensed, and ejected from pulsar and black hole jets. And particles moving faster than visible matter would pass that matter and accelerate it, increasing blue shift and decreasing red shift the farther you are from the source.
https://www.youtube.com/watch?v=vqeIeIcDHD0
(caution for those currently sick as it's a rough watch at first)
1. There’s a sort of diffusion process going on. Photons from the core have some mean free path as a function of radial position (and, obnoxiously, of wavelength as well, so maybe we ignore that). You could calculate the mean time for a hypothetical object emitted from the core and traveling according to those mean free paths to escape.
2. You could imagine you have marked a photon and watched it travel. This is quite problematic. First, photons in thermal equilibrium obey Bose-Einstein statistics because they are indistinguishable bosons, and anything that could mark them would change the statistics to that of distinguishable particles. But whatever, the temperature is high and maybe this doesn’t matter. Also never mind that those core photons are mostly much shorter wavelength than the photons we see. But you can still imagine. (The answer is probably quite similar to #1 since this is sort of the same problem depending on how you think about the interactions with matter in the sun.)
3. You could calculate how long it would take to notice anything if the core suddenly stopped fusing.
However, as the photon collides with other particles during its random walk, some of its energy is transmitted to those other particles. Sometimes a collision transfers energy to it too.
In a simple model, the energy that originally belonged to the photon gets transmitted from particle to particle through convection, and can escape the star through radiation long before the original photon reaches the surface. I don’t think that model is supposed to be physically accurate, rather to be an illustration about the convention process inside a star.
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.
https://www.businessinsider.com/super-kamiokande-neutrino-de...
It's the reverse problem: because the water is so pure it easily gets contaminated by minor things. So all the equipment has to be carefully cleaned.
From the closing of the first graph in the Wiki for water: Due to its presence in all organisms, its chemical stability, its worldwide abundance, and its strong polarity relative to its small molecular size, water is often referred to as the "universal solvent"
https://en.wikipedia.org/wiki/Water
Edit: after enough searching I was finally able to find this article [0] that I was originally trying to find. The leaching part was right, but the bleaching part looks to have been as misremembered
[0] https://www.businessinsider.com/super-kamiokande-neutrino-de...
The chain reaction escalated uncontrollably, and within ten seconds, approximately 6,800 of the 11,129 PMTs were destroyed.
[1]: https://physicscommunication.ie/neutrino-detector-in-peril-t...
When you have a transparent medium like water or glass, the photon that enters and the photon that exit share a lot of properties, in particular energy/color/frequency. Perhaps they have a shift in the phase or a different polarization (like in water with sugar or if you want to be fancy a quarter wave plate). You can still split a beam before in enter and make interference experiments after half of it passed though water or glass, and other weird experiments, so I think it's fair to call them "the same photon".
But in the Sun, the original photons in the center of the Sun have a few very specific values of energy/color/frequency, that are totally lost. (But the neutrinos have so few interactions that they don't lose this information, and it's possible to do neutrino spectroscopy!)
Also, the photons emitted by the "surface" of the Sun have a wide spectrum of energy/color/frequency that is very close to black body radiation at something like 5000K-6000K.
So in my opinion it's better to think that the original photon in the center is absorbed shortly after it's emitted, and transformed into heat. The heat takes 5000 years to get to the surface. And then the hot surface emits a few new photons unrelated to the original one.
I'm not sure what is the main transmission method inside the Sun: conduction, convection or radiation.
[0] https://scholarship.haverford.edu/cgi/viewcontent.cgi?articl... Eq. 16 [1] Handy plot at https://commons.wikimedia.org/wiki/File:Quantum_and_classica...
> You could calculate how long it would take to notice anything if the core suddenly stopped fusing.
FW(little)IW (very not my field, just AI, quick&sloppy), for a Sun magically switched to contraction-dominated heating, I'm sloping order 10^6-7 yr for a 1% increase in surface temp, with core contraction dynamics being just one uncertainty.
I wonder if the successor has any pressure buffering built into the design to absorb pressure waves or if they're just gonna make them 1) stronger or 2) fail more gracefully (it's okay if a sensor crumples as long as it doesn't implode)
- photons travel at the speed of light in a vacuum
- it takes 90k years (or whatever) for a photon to travel from the sun's core to your retina?
Ok, the core of the sun is not a vacuum, quite the opposite, but the path is fraught with being continuously absorbed and emitted. It's not one photon travelling at a few km/hr is it?
And I don't think photons are reflected in hydrogen, although I have no proof. I just thought reflection was done with things like flat surfaces or mirrors.
This is why I said "not the same photon", but I admit I have only YouTube-spectator level knowledge
The hydrogen in the sun isn't regular molecular H2. It is a plasma or maybe even has a liquid metallic phase (depending on temperature and pressure).
https://duckduckgo.com/?t=ffab&q=hydrogen+plasma+phase+diagr...
Also: I appreciate you found a source, unfortunately it's not true what they said. It's not possible to "leech nutrients through the hair to the scalp", the wrench story is not true either - there is zero chance a lab with the standards they have would just leave a wrench at the bottom of the pool - it would contaminate the water. Not to mention the bottom is filled with more of those light tubes, so there is no place for a wrench to sit. (And if someone dropped one it would break a tube.)
I don't know why someone would tell businessinsider such stories, but they are not true.
And see: https://chemistry.stackexchange.com/questions/7467/is-pure-w...
It's hard when a supposedly reliable news place writes things that are not true, but that's the world we live in. I guess technically they are just quoting stories they were told.
(My personal pet peeve is a news source that made everyone think you can't leave eggs outside the fridge if they were washed, (as they are in the US). This is not true, but "there's a news source".)
DI water is AN AMAZING SOLVENT. Waaay more powerful at dissolving low-solubility solids than tap water, or even distilled water. It's stunning IRL to see how much better it cleans optical surfaces, where single-molecule layers can visibly change the appearance.
But if left open to the atmosphere, as in these pools, it would soon be just plain old (pure) water. Ultra-clean, but not an ultra-solvent.
Interesting, how could this be possible?
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!
> 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.
