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Physics Girl: Super-Kamiokande – Imaging the sun by detecting neutrinos [video]
- motbus3 7mo agoGreat news! I am super happy for her of course but I think it should always be remembered that her husband has been a super hero going through all of this.
- JKCalhoun 7mo ago(Typo in the title.)
- xeonmc 7mo ago(should be Psychic Girl)
- AlexeyBelov 7mo agoAs in, knows the future?
- pcdavid 7mo agoFixed
- danscan 7mo agoTIL nobody can spell phyzix
- Brajeshwar 7mo agoWelcome 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.
- PunchyHamster 7mo ago[flagged]
- JeanSebTr 7mo agoThey probably meant, as explained in the video, "light from our sun"
- MyHonestOpinon 7mo agoOh, 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 7mo agoLight 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.
- gpvos 7mo agoAnd thats a fact you don't need to learn in high school, at least you didn't in my time.
- mikkupikku 7mo agoI 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.
- pantulis 7mo agoThanks for your answer, I understand you're correct. Also, as another counterargument, if a photon is scattered... is it the same photon or a different one? Your perspective on energy instead of particles is better.
- gosub100 7mo agoIt'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 7mo agoI 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 7mo agoI 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.
- cleandreams 7mo agoWonderful to hear. Her long Covid was heartbreaking (saw the videos). I hope she gets stronger and stronger! Welcome back!
- hinkley 7mo agoSome 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.
- jwr 7mo agoSo happy to see her back! It was a grueling journey and we were all crossing our thumbs, waiting and hoping…
- ayhanfuat 7mo agoSuch 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 7mo agothanks 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 :'(
- roelschroeven 7mo agoDianna 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.
- dataflow 7mo agoMan... I came here hoping to read she was fine now. Had no idea things got worse again :( I hope things get better for her.
- deleted 7mo ago[deleted]
- Jeremy1026 7mo agoAt 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.
- PaulKeeble 7mo agoThis 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.
- Jerrrrrrrry 7mo ago>"Otherwise" Would could this possibly be referring to?
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- human_hack3r 7mo agoHappy to see her back to science!
- nickandbro 7mo agoIs 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.
- nablaxcroissant 7mo agoIt was essentially long covid. me/cfs or chronic fatigue syndrome induced by covid infection
- nickandbro 7mo agoWow, did not know that. Thanks
- deleted 7mo ago[deleted]
- dirck-norman 7mo agoAs 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 7mo agoSorry to hear. Thanks for explaining.
- KaiserPro 7mo agoDunno, 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
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- alabhyajindal 7mo agoBOOM! Let's go
- jesse_dot_id 7mo agoLong COVID is a nightmare. I'm glad she's able to fight it off enough to do the things she loves again.
- gosub100 7mo agoI 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 7mo agoThat 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 7mo agoIt was the same detector that imploded. Mark 2 was then reinforced so it didn’t happen again.
- legitster 7mo agoIt'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.
- dejongh 7mo agoWhat an amazing storyteller. I will watch many more of her videos. I hope she will make many more videos ♥
- Helloworldboy 7mo ago[dead]
- ck2 7mo agovideo about her long-covid battle and recovery here: https://www.youtube.com/watch?v=vqeIeIcDHD0 https://www.youtube.com/watch?v=vqeIeIcDHD0 (caution for those currently sick as it's a rough watch at first)
- hinkley 7mo agoI know someone whose CFS is about 10% of hers and it was still a rough watch. She got hit really fucking hard.
- shadowgovt 7mo agoOne 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.
- wintercarver 7mo agoCan confirm - worked on Super-K as a grad student and a regular part of shift work was to go through simulated supernova alert testing. Was always kind of fun, in the lotto ticket sense (alarm goes off, review to see, ah yes, simulated test, back to shift monitoring).
- naseerjan 7mo ago[flagged]
- naseerjan 7mo ago[flagged]
- flux3125 7mo agoAccording to science video thumbnails on YT, nothing should be possible
- riffraff 7mo agoAnd even if it was, you wouldn't believe it anyway
- dylan604 7mo agoI 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
- pbhjpbhj 7mo agoHa, 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-upw-friend-or-enemy.pdf 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.
- dylan604 7mo agoI found the article I was trying to remember: https://www.businessinsider.com/super-kamiokande-neutrino-detector-is-unbelievably-beautiful-2018-6?op=1#-13 https://www.businessinsider.com/super-kamiokande-neutrino-de...
- mock-possum 7mo ago> when travelling through water, neutrinos are faster than light Interesting, how could this be possible?
- tefkah 7mo agoI 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 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!
- olivia-banks 7mo agoThis is fantastic news! Long COVID is awful, so I'm glad to see that she's recovering, if only incrementally.
- hinkley 7mo agoHow much of the mass of the universe is neutrinos?
- adrian_b 7mo agoNobody knows for sure. 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.
- hinkley 7mo agoWhen I tried to look myself it was about this waffly but I’d also note that they were all talking about neutrinos at rest. But they’re wizzing around at relativistic speeds which makes them all many times heavier doesn’t it? 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.
- dotancohen 7mo agoThe 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 7mo agoWatch the video
- dotancohen 7mo agoThanks. 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!
- oxag3n 7mo agoIt'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.
- pico303 7mo agoThe 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.
- antonvs 7mo ago> "How is it possible that this photo was taken at night?!" Seems like someone's having difficulty with object permanence. The Sun doesn't actually disappear at night.
- spidrahedron 7mo agoGood to see her back!!
- userbinator 7mo agoHaving absolutely zero prior context, I thought the title was an old obscure Nintendo game.
- _zagj 7mo ago[flagged]
- _zagj 7mo ago[flagged]
- jffry 7mo agoFor a sense of how crazy 30 detections per day is: Super-K is a cylinder 41.4m tall and 39.3m in diameter [1] and neutrino flux on Earth is 65 billion per square centimeter per second [2] 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 https://en.wikipedia.org/wiki/Super-Kamiokande [2] https://en.wikipedia.org/wiki/Neutrino 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.
- burnt-resistor 7mo agoCool for looking at the Sun, although I think SK was changed to be more specialized towards hunting supernovae. There's also sky surveys like IceCube does. [0] 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/ https://neutrino-map.science/ (ICNO) 1. https://www.nature.com/articles/srep13945 https://www.nature.com/articles/srep13945 (KamLAND and frmr Borexino)
- Schlagbohrer 7mo ago"Super-Kamiokande" remains the best name for anything ever