Dianna got better sometime last year as well, just in time to fly home to Hawaii for her father's funeral (yeah ...), but she got a lot worse again later. I really hope things will keep going well for Dianna now.

Props for her husband who's been incredible of taking care of her.

• PaulKeeble

  today at 9:24 PM

  This is the nature of ME/CFS (caused by Covid or otherwise), it does vary somewhat over time although the course is not always to improvement or around the same level but sometimes to death. She received some form of experimental treatments in order to gain the prior recovery which was at least a stellate ganglion block, she has not mentioned what else she may have received.

  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.

• dataflow

  today at 5:19 PM

  Man... I came here hoping to read she was fine now. Had no idea things got worse again :( I hope things get better for her.

  • Jeremy1026

    today at 6:15 PM

    At the moment, she appears to be progressing up. The user you are replying to was talking about a past up-swing followed by a down-swing. Hopefully there isn't a down-swing to follow this current up-swing.

  • today at 6:13 PM

• aaron695

  today at 10:02 PM

  [dead]

It's a giant long term project with a fascinating history and engineering. One notable event which is interesting from engineering perspective was a catastrophic failure of roughly half tubes in 2001. It took them five years to fully restore 6K tubes.

The Neutrino collector bit was interesting, but the best part of this video is seeing the joy in her eyes educating the rest of us about science again.

Such amazing news. She’s been bedridden due to long Covid. Got better a few times but after a while attacks came back. Both she and her husband showed great strength. So happy to see a new milestone.

• patcon

  today at 4:52 PM

  thanks so much for the context. I'm glad if she's reclaiming from her losses <3

  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 :'(

The video mentions that this image was taken during the night time. If the neutrinos do not interact with the entire Earth on their way through, then how do they interact with the sensor?

• davidmurdoch

  today at 10:39 PM

  Watch the video

  • dotancohen

    today at 10:54 PM

    Thanks. I watched half the video, but couldn't finish it. Now that I've finished it I see that the neutrinos interact with water in the tank.

    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!

Long COVID is a nightmare. I'm glad she's able to fight it off enough to do the things she loves again.

Wonderful to hear. Her long Covid was heartbreaking (saw the videos). I hope she gets stronger and stronger! Welcome back!

• hinkley

  today at 10:07 PM

  Some of my favorite YouTubers have done guest spots on her channel, which made me love them a little bit more.

  Her back catalog is good and you still get paid for people watching your old videos.

Welcome back. One of my staple YouTube Subscriptions.

I’m today years old learning that the light that we actually see on earth today came out 100s of thousands of years ago.

• gosub100

  today at 5:55 PM

  It's not the same photon though. The fusion happens in the core, then takes millennia for the energy to escape. During that time photons are emitted and absorbed by the atoms, until the surface emits one that finally travels to the earth in 8 minutes. Anyway that's taking you from the ELI5 to the ELI9 version. I'm sure someone on here can correct it further.

  • amluto

    today at 6:09 PM

    I haven’t tried to look up the history of this claim, but here are some guesses:

    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.

    • gus_massa

      today at 7:04 PM

      I agree. I read the 5000 years time a few times and I don't like it.

      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.

    • mncharity

      today at 10:22 PM

      The canonical Q/A pair "Why does the Sun shine?"/"Fusion in its core" perhaps contributes confusion here? Where the question is silently swapped out for "Why is the Sun still shining after 4+ Gyr?". You're primed for a close connection between core and surface photons. Asking "Why is there fog over the uncovered corner of the pool?", one seems unlikely to appreciate "the fog comes from a small aquarium heater somewhere on the bottom!" (IIRC the magnitudes). "The Sun is hot, and hot things glow" creates less of that association between core and light.

      > 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.

    • amluto

      today at 9:33 PM

      belated edit: My comment about “whatever, the temperature is high” is silly. The mean photon energy is about 2.7kT, which scales in direct proportion the interest bits of the Maxwell-Boltzmann and Bose-Einstein distributions (see [0] and [1]). At 2.7kT, the curves are pretty close, but you don’t have to go down that far to get a big difference. So tagging all the light would cause a substantial change in the sun’s color.

      [0] https://scholarship.haverford.edu/cgi/viewcontent.cgi?articl... Eq. 16 [1] Handy plot at https://commons.wikimedia.org/wiki/File:Quantum_and_classica...

  • teamonkey

    today at 8:38 PM

    Photons are generated in the star’s core but the core is dense. The photons move around the core, bouncing off other particles, a random walk. It takes a vast amount of time for that photon to escape the sun and reach the Earth, as per monte-carlo simulations of this random walk.

    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.

  • fsh

    today at 6:19 PM

    Any interaction between light and matter can be modeled as absorption and re-emission (stimulated or spontaneous) of photons. In this picture, there is not much difference between a photon traveling through the sun or through a piece of glass, and the analog makes physical sense. Since photons are massless elementary particles, they are indistinguishable and their number is not conserved. The notion of "the same photon" is questionable in any case.

  • Hikikomori

    today at 6:38 PM

    Similar to how infrared radiation works in our atmosphere, minus the timescale?

• PunchyHamster

  today at 5:00 PM

  [flagged]

  • MyHonestOpinon

    today at 5:10 PM

    Oh, probably skipped physics too. I haven't seen the video (yet), but I would have bet that light on earth came out 8 minutes ago from the sun.

    • pantulis

      today at 5:24 PM

      Light from the sun that is reaching us now escaped the surface of the sun 8 minutes ago, yes.

      But photons are generated in the core through nuclear reactions, where they take their sweet amount of thousands of years bouncing around until they get out.

      • mikkupikku

        today at 7:10 PM

        I think this is right in a certain sense, but not precisely. From what I understand no visible light photons are created in the core from nuclear fusion, it's mostly a bunch of gamma rays that get almost immediately absorbed. The energy, but not the photons from fusion, gets transfered up through the layers of the sun, through radiation and convection, eventually heating the photosphere. It is then the photosphere, white hot, which ultimately radiates the visible light we see as sunlight.

      • gpvos

        today at 5:35 PM

        And thats a fact you don't need to learn in high school, at least you didn't in my time.

  • JeanSebTr

    today at 5:04 PM

    They probably meant, as explained in the video, "light from our sun"

  • smarf

    today at 5:16 PM

    ...did you skip human socialization?

I think Super-K is the place with water so pure that it will leach pretty much anything which was discovered when one of the tech's hair got wet while leaning over the water. The hair looked bleached after it went into the water. My googlfu is not finding anything to confirm though

• hi41

  today at 10:54 PM

  Reminds me of the scene in Kung Panda 1 where one feather of the goose, Peng, falls into the tunnel which Tai Lung uses to unlock his cage and escape.

• pbhjpbhj

  today at 9:00 PM

  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.

• hinkley

  today at 10:14 PM

  Isn’t that also the one where a sensor imploded and caused a chain reaction that destroyed like a third of the other sensors?

  • magicalhippo

    today at 10:38 PM

    Yes, except about half. This[1] article goes into how and why, without the fluff.

    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...

What an amazing storyteller. I will watch many more of her videos. I hope she will make many more videos ♥

So happy to see her back! It was a grueling journey and we were all crossing our thumbs, waiting and hoping…

How much of the mass of the universe is neutrinos?

It's really cool to see her back and making videos again.

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.

According to science video thumbnails on YT, nothing should be possible

One of my favorite bits of astrophysics trivia is that the neutrino detection experiments serve as an early-warning system for supernovae, to allow astronomers to prioritize telescope time and swing the scopes around to see the first visible-light and radio signals of the event.

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.

This is fantastic news! Long COVID is awful, so I'm glad to see that she's recovering, if only incrementally.

BOOM! Let's go

I can't remember where I heard of it, but decades ago there was another neutrino detection center, also in Japan I think, that had those vacuum tube detectors, but care wasn't taken in systems design. One of them broke and the implosion caused the neighbors to break. Leading to a catastrophic of almost all the sensors! I feel bad for them, I'm sure someone here knows the exact name and date. But man, what a tough lesson to learn.

Edit: on another note, way to go on your recovery Diana. We've been rooting for you.

• 0PingWithJesus

  today at 6:26 PM

  That was Super-K, the same detector she's talking about in the video. The incident occurred in 2001 and set back the start of the data taking for them quite a bit, they were able to begin data taking by re-distributing the unaffected photo-detectors to cover the gap where the imploded detectors were. Eventually (2005/2006) they replaced all the destroyed photo-detectors and took data from then on out with a full-suite of sensors. Following this incident all Japanese experiments with these types of photo-detectors take the risk of implosion seriously and have mitigation built in to the design. Super-K has been running continously since then with some interruptions for upgrades & maintenance, and is still taking data today (as far as I'm aware).

  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.

• tomasphan

  today at 6:30 PM

  It was the same detector that imploded. Mark 2 was then reinforced so it didn’t happen again.

Happy to see her back to science!

Is this long Covid or depression or Major Depressive Disorder (MDD)? Because in her earlier videos she talks about becoming bed-bound again due to her emotional state after finding news her friend who had a similar condition died.

• dirck-norman

  today at 5:30 PM

  As someone who suffers from a complex autoimmune disorder which has caused dysautonomia and suspected mitochondrial dysfunction, stress flares and exacerbates symptoms. This has a physiological basis in the complex way the HPA axis/cortisol affects us at the cellular level. My primary diagnosis is sarcoidosis with small fiber neuropathy, but they don’t fully understand all the mechanisms of auto-immune fatigue and dysregulation.

  • nickandbro

    today at 5:31 PM

    Sorry to hear. Thanks for explaining.

• nablaxcroissant

  today at 5:21 PM

  It was essentially long covid. me/cfs or chronic fatigue syndrome induced by covid infection

  • nickandbro

    today at 5:23 PM

    Wow, did not know that. Thanks

• KaiserPro

  today at 5:43 PM

  Dunno, personally I don't think its that much of my business. Sure I'm curious, but that doesn't mean I have a right, or that its a nice thing™ to publicly speculate

  • hinkley

    today at 10:17 PM

    She’s been pretty open about it. She even touched on it at the end of this video.

• today at 5:22 PM

• ChrisClark

  today at 5:55 PM

  I'm quite sure being that terribly sick could cause depression yeah, but that's not the reason

video about her long-covid battle and recovery here:

https://www.youtube.com/watch?v=vqeIeIcDHD0

(caution for those currently sick as it's a rough watch at first)

• hinkley

  today at 10:21 PM

  I know someone whose CFS is about 10% of hers and it was still a rough watch. She got hit really fucking hard.

(Typo in the title.)

• danscan

  today at 4:57 PM

  TIL nobody can spell phyzix

• pcdavid

  today at 4:52 PM

  Fixed

• xeonmc

  today at 4:36 PM

  (should be Psychic Girl)

  • AlexeyBelov

    today at 4:57 PM

    As in, knows the future?

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