First of all, I got my cost figures way off. Thanks to @morizbraun5034 for pointing out that 7000 * 10000 is indeed seventy million, not seven million. BUT it seems the cost for each tube was actually $3000 (2001 dollars), which is an absolute bargain. All things considered, it cost about $30 million to restore. I'm also getting a lot of comments wondering how the engineers could possibly miss this, and how inadequate their testing was. There are 3 points to consider here: 1. I suspect they did additional tests but I can't find the info on them because it is probably exclusivley in Japanese....assuming it is online at all. 2. For a deep dive into an engineering failure that appears blindingly obvious in hindsight but much much more nuanced in reality, see the 'SRB' section of my Space Shuttle video. 3. Fluid modelling and engineering standards were nowhere near what they are today back in 1981 when these tubes were first used.
Could of, wood of, should of. Its easy for people to use experience to judge mistakes, but someone has to make that mistake for the first time so the rest of us can learn.
A lab disaster so bad it was picked up on seismometers and nobody was injured? Truly the best way that could end. Also a fascinating bit of engineering knowledge for future generations.
I hope that it wasn't known who was the person who blew the glass for the detector that imploded first. While this person wasn't to blame for what happened, the sense of honor that the Japanese tend to have might have had disastrous consequences.
A 22 minute video of a man talking about a failure I didn't know about that happened to a thing I didn't know about? splendid! I will watch the entire thing immediately
There is a very happy glas blower workshop that not only produced tens of thousands of those tubes over the last decades, but also can be assured that the next iteration of the detector will need even more. In most cases, glas blowing is a dwindling art, only used for very specialized lab equipment or for tourists. Even those will not suddenly be asked by the government, how fast they can produce, say, 20000 Serpentine Reflux Coolers. So this is a win not only for science, but also for those craftsmen.
@@Alexander-the-ok I have a lot of particle physicist friends who work/worked at CERN. They rightly get huge praise and media attention for their discoveries, but even coming from a physics background I've always found the engineering behind building such an unimaginably large yet extremely precise machine where miniscule tolerances are vital, to be the most utterly mind blowing human achievement. I mean yeah, physics behind ATLAS, Higgs etc. is awesome, but even being able to build ATLAS such that it could infer Higgs is more impressive than my chimp brain can handle and that is before considering building the bloody 27km accelerator! On a side-note, my old housemate decided to film a feature length zombie movie in CERN's access tunnels WHILE doing his PhD! It is called Decay and is hilariously awful to the point of being comedic brilliance, who knew exposure to the Higgs boson made you into a zombie?
Particle physicist here, this is one of those stories that all of us in the neutrino physics community grow up on. By the time you finish your PhD some mentor or senior would talked about this. It had the potential to be a massive setback to particle physics, even though things did end up okay!
Let's be honest. All physicist have heard this one. Usually 2nd or 3rd year. This is one of the stories that is easy to understand, grand in it's scope and really hurt only few of us, so most feel OK telling it as a 'curiosity'.
Can I ask a question? Why are people so interested in neutrinos all around the world? It seems like you typed in any first world country in a search engine and it seems like a name will come back for a facility that is built or being built. I could be wrong but I feel like there was that level of activity was like nuclear power or something. There would seem to be a bigger reason then reason then research? At least to me.
@@ace1122tw the main quest in modern particle physics is the search for physics beyond the standard model (BSM physics). We know there should be something we aren't getting, because we do not have a grand unified theory, we haven't figured out dark matter, etc. One key issue is that we do not have a lot of experimental evidence pointing us towards what that BSM physics would look like. Neutrinos are one of the few things that don't behave exactly like the standard model would suggest. As such, we expect (and hope) that precision measurements of neutrino properties would give us clues to what such BSM physics might look like.
@@ace1122tw There's a lot to unpack here, 1st, the nuclear power got way more in way of funding. The cost of Manhattan Project alone is estimated to be around $27 billion in 2023 dollars. The cost of HyperKamiokande is 1/50th of that. That's a different scale entirely. As to why Neutrinos are interesting - they carry information that we cannot access in any other way. Unlike photons, nothing occludes our view of source. Most neutrinos from center of supernova escape without interaction. This is from a center of a star - no photons make it out of there. Another example - they were among first particles that were 'freed up' from Big Bang. Some 370 000 years earlier then photons decoupling, according to wikipedia. If we want any information from before that point in time, we need to get it out of neutrinos. We also still don't understand or actually know mass of the neutrino well - as far as I understand we pretty much know it is not a zero and that's about it. This is an important part of refining standard model. Lastly - you hear about it, because to study neutrino you need a lot of mass as a detector medium. It makes no sense to make a small detector, because you would register one neutrino per year, not per day. This makes those projects good subject for news description. Few people understand the physics, but many get the huge scale. You just don't hear about myriads of smaller experimental projects. Hope that answers most of your questions. Cheers :)
As an HVAC technician that works on steam heating systems, I have a lot of experience with water hammer and vacuum. One of the most interesting phenomena that can happen in a vacuum steam system has to do with steam syphons and gauges under vacuum. Let's say you have a pressure gauge, hooked up to a boiler with a syphon (basically a U shaped pipe that holds water to protect the gauge from steam temperatures all the time), and this boiler is in a naturally induced vacuum system (goes into vacuum while the boiler is not running). Now let's say that the boiler starts up fairly soon after the next cycle, while the system is still at -10 or more inHG of vacuum. Until enough heat is put into the water to influence the pressure at the end of the dry returns and open the vent check valve, the system will still be in a vacuum, but the heat being put into the boiler can heat up the water in the syphon far beyond the level where it will start boiling at that level of vacuum. What happens next is that the water in the syphon will rapidly start turning into steam and generate intense spikes of pressure that are audible and also visible as the needle on the gauge shakes violently going to full scale and back again. If the gauge is not rated for pressures far in excess of what the system operates at, there's a good chance of it breaking. In a vacuum system without a pump, there is essentially no practical way to stop this from ever happening, so the only option is to get a gauge that can handle surge pressures of at least 5-6X normal operating pressure. In many systems I work on, operating pressure may only be measured in ounces per square inch, or even just a few inches of water, while vacuum can be as deep as -20 inHG. For those systems, the only option for a gauge is a particular gauge designed to measure differential pressure, which can also be set up for single pressure, and is rated for 500 PSI/20inHG or 600PSI/29inHG surge pressure. Extremely overkill, and extremely expensive, but it's the only option that will not be destroyed by water suddenly deciding to turn into steam inside the gauge. At least this only affects one instrument and doesn't cause a cascade effect like the disaster mentioned here. Although there are other failures elsewhere in a system that can happen and cause a cascade failure, like a steam trap failure letting steam into the dry returns, which will quickly damage every other steam trap in the system, but not on a time scale as quick as this.
thanks for sharing your professional experience, it seems that some aspects of your work really coincide with the kamiokande accident, and you clearly know a lot about what you are talking. I would never guess HVAC systems could be so complex.
Is there any way a damping material can be added to the siphon pipe, e.g. foam, or a Tesla valve if there is a significant volume of water or steam moving around? This would slow the rate of change over time by damping rapid fluctuations, but as long as you were happy to have lag in the pressure reading due to the damping, the pressure reading would still be accurate
I believe the equivalent phenomenon in refrigeration systems is called "flashover in the evaporator" and causes a loud sharp knock to emanate from the innards followed by a few weaker knocks.
Your fine video reminded me of of something I experienced in 1974. My first job out of the military was for Packard Instrument Corp final testing liquid scintillation spectrometers. Those were the TTL days and the logic "board" in the units consisted of 300+ 16 pin integrated circuits in sockets. There was no printed circuit board. All connections to the 5000 socket pins were crimped by machine, one at a time, to up to five levels on each pin, giving a theoretical maximum of 12,000 point to point wires on this single board...all blue. Naturally, the actual number was much lower, but it was into the thousands, and the pins themselves were hidden under a several inch thick mat of blue wires. Our job in final test was to find any faults, make the machines work, and calibrate them. One day, one of the other techs energized a machine to begin troubleshooting and there was a loud crackling noise, followed shortly after by a rain of integrated circuit tops that reached 30 feet from the machine, and a huge puff of acrid smoke. Nearly every one of the ICs had exploded. I wish I could say that I was cool when it happened and calmly said "I think you have a power supply problem", but I didn't, I ducked.
the phrase "blue wires" does make me think of wire wrap boards... but the basic problem of blowing up a board full of IC's is familiar (but on a much smaller scale). Those are the experiences that are a real test of your soul... and maybe heart?
The presentation on this video reminded me a lot of Plainly Difficult. Just needed a graphic of an engineer lamenting, “Balls.” 😂 This is not a bad thing. Great video, thank you for writing up such an interesting, complex failure.
"... more importantly, detecting that tiny flash is an engineering problem, so I can confidently reenter the discussion again" - proceeds to fail at multiplication. I love your videos, Sir, but please only engineer far away from me. ♥
My high school physics teacher, Mark Buchli, worked on the repair of Super-K in 2002! He was one of my favorite teachers and he talked about working on Super-K regularly!
(Particle physicist here) 4:57. Your brief foray into particle physics was quite cogent and largely correct, certainly enough for this video. Well done! Broadly, in particle physics, we shoot particles at targets. Sometimes an interaction happens, it blows apart, fragments come flying out. We detect the fragments of the collision/reaction by having some active medium that responds to the travel of a certain type of fragment by producing light, we collect and pipe the light to a photon detector, which produces a burst of charge, and then we digitize the charge to reconstruct the fragment, and then by working backwards reconstructing all the fragments, we reconstruct the original thing that happened (as we as we can, and then do it ad nauseum to build up statistical picture of that reaction in aggregate). Unusually for a particle physics experiment, the water in Super-K is the target, the active detector material, and the light pipe that gets the light to the photodetectors.
basically just a ginormous liquid scintillation counter. you can actually use water as your "scintillation cocktail" for detecting high energy beta emitters on an LSC, where the instrument detects cherenkov effect photons just like this.
The water in Super-K is also part of the radiation shielding (keeping background count out). If a Cherenkov cone starts off in the middle of all that water, it's been caused by something that's pretty penetrative!
@@fsodn there would probably be a lot more particle physicists if the field was sold as “shooting particles into targets” “blowing things up” “smashing things into fragments” etc. before saying * ᵗʰᵉʳᵉ’ˢ ᵃ ˡⁱᵗᵗˡᵉ ᵐᵃᵗʰ ⁱⁿᵛᵒˡᵛᵉᵈ
@@abarratt8869 I don't really think so. The shielding from upper-atmosphere particle production from cosmic rays is provided by the 1000 meters of earth and rock above it; that's why all of these neutrino detectors are so far underground.
Lovely write-up of the story. I'm a particle physicist who worked at Super-K for a while, so, yes, you got a few things wrong, but you got most things right. The biggest one to point out is that the oscillation wasn't detected by looking at the change in muon neutrinos detected as the earth rotated, rather, it was looking at the difference in number of muon neutrinos detected based on the direction they came from. Ones coming from straight-below travelled through the entire earth, while ones coming from closer to (but still below) the horizon travelled through a smaller distance of the earth. Plotting the number of muon neutrinos based on L/E (distance the neutrino travelled divided by the neutrino's energy) shows the oscillation behavior.
I actually tried researching this after you mentioned it in your last video and i was struggling to find something comprehensive or understandable about it. So honestly glad you followed up on it
The moment he emphasizes the word 'hydrostatic' I think I have a good idea of where this is going. I'm no engineer, but when you put the terms 'cascade failure' and 'hydrostatic tolerance' next to each other in that tank, well... that does indeed sound exciting. Edit: Yep. That went just about exactly as I envisioned it. :D
I'm curious to know what earthquake mitigation they did (it is Japan). Plus, there's also the potential lensing effect from the difference in speed of sound between rock and water (you see the same distortion when you look through a glass of water).🤔
I kind of put two and two together as soon as I saw the stock footage? B-roll footage? Anyways, all the videos taken inside the tank in the first two minutes or so. That plus the title was all I really needed (well, also knowing what most neutrino detectors are).
I was predicting that one of them would break in a way that produced very bright sparks, which would oversaturate the other detectors in photons and make them break the same way
Me too :) 'Water hammer' is a phenomenon that (often) depends on water rushing into a vacuum, ditto cavitation bubbles collapsing. The point is, there is absolutely nothing to 'cushion' the incoming water until it 'comes up solid'. These photomultiplier tubes were just like ginormous cavitation bubbles in that respect.
"hydro-static... STATIC... moving on". I think I got the hint at that point in the video. Wonderful description and clips of all the Kamiokande science - physics and physical.
It is a cosmic understatement that trillions upon trillions pass through the Earth every second. If you just consider the nail on one of your little fingers, about 70 billion neutrinos pass through that area every second. So for the whole Earth, about 90 octillion neutrinos pass through it every second. That is 90,000,000,000,000,000,000,000,000,000 neutrinos. God I love the scales of physics.
When this incident happened, I was already an employee of Hamamatsu Photonics Germany. A colleague sent me some poor quality photos the morning after. Of course we all knew about Super Kamiokande and it was a shock for us to hear about the event. Producing replacements for the broken photomultipliers took several years. The original production building had already been repurposed, so a larger scale production had to be set up again, and even some former employees were called back from retirement. As the video showed, highly skilled manual labour plays an important role in manufacturing these photo multipliers. Personally I am not involved in our high energy physics business, but talking to my colleagues who work in that field is always fascinating. Wherever there is a need for highly specialized photon detectors worldwide, there is a high probability that our products are being used.
I work at a university, and all the photomultipliers I have seen (all at the physics and chemistry departments) are Hamamatsu. Do any other manufacturers of PMTs exist today?? I actually have a little one (one of the PMT modules with integrated HV supply) on my bench at work, waiting for me to repair the amplifier board it connects to.
3:50 It barely matters for the purposes of *anything*, but when it matters, it really matters (making it possible for 2 H1 nuclei to fuse into deuterium, thus making stars as we know them possible, dissipating 99% of the energy involved in supernovae, etc.).
Great explanations of the physics, the photomultipliers, and the hydrodynamics! One detail: typically the photocathode of a PMT is at a large negative voltage (typically -1000 to -2000 volts, depending on the type of tube. Then with each successive dynode at a successively more positive voltage to accellerate the electrons, the anode (where the electrical signal is collected) is at ground.
I remember being a kid and seeing a neutrino detector with a giant pool of water and these weird balls on the side. I had no idea how it worked, what it was called, or where it was, but was fascinated by the prospect of this enormous thing detecting the tiniest particles. I didn't know much more about it until now, and it's even more enormous than I thought it was. To hear it used vacuum tube photomultipliers brought back memories of seeing it for the first time. I didn't even know a disaster happened to it, let alone one that managed to not hurt anyone, but hearing you emphasize static pressure caused me to exclaim 'oh no. OH NO!'
At 21:05, this for some reason reminded me of the Monty Python logic that a piece of wood floats, just like a duck, therefore confirming that a witch is a witch.
Oh wow, what a throwback! My very first academical work was part of my final exams for our counterpart of highschool, and I wrote about neutrinos and their detection. Quite some of those pictures of the SuperK I used back then as well. Lovely. Thank you so much.
We have one of the old Kamiokande photomultipliers at the physics department at Ohio state university. It's super fun walking by it every day because it truly is beautiful.
I started studying theoretical physics in late 1998 and all the particle physicists were really excited by Super Kamiokande. The now-famous papers on atmospheric neutrinos AND the discovery that the expansion of the universe was _accelerating_ had only come out a few weeks before I started college, so it was a pretty exciting time in physics 😀
Random question, was this facility built before the IceCube neutrino detector in Antarctica? I'm in college for physics now and I've never heard of this facility. You seem like you are pretty knowledgeable about this topic.
@oonmm I guess it depends on your perspective. I assume the opposite. Scientific discoveries are based on all of the theory and discoveries that came before them, so really it's the difference between having a hand in completing one part of a puzzle, and getting to start on a new section that's just begun. Sure, you have the less glorious task of making sure the newly completed section matches up with all the other completed parts, but you also have the opportunity to venture into uncharted territory and make new theories about how the next sections will come together in the future.
@@greebo4446 I remember in 1997 my school physics teacher being absolutely enthralled by the Cassini-Huygens probe launch, I used my dialup to read everything I could. As a kid the thought that it wouldn't reach Saturn till 2004 felt unbearable, but it arrived just as I started my physics degree. Such a wonderful thing to have something that drove my passion to reach fruition right at the time I was surrounded by physicists. In 2005 I was at Jodrell Bank, this astrophysicist in his 70's with a huge grey beard told me about being there in 1969 relaying signals from Apollo 11 to NASA while listening to every communication, then contrasting the brilliance of this probe's arrival. When young we are privileged to see these scientific breakthroughs without having to wait decades after their inception. Scientists/engineers designing the next accelerator/detector/probe might well be retired by the time to fulfils its purpose, but in the meantime they get to enjoy the fruits of prior generations labour like retired JWST's designers having seen the Hubble Deep Field image for the first time.
@@jamesleishman8025 a quick google says that the Super-Kamiokande started operation in 1996 (the first kamiokande started service in 1983). The IceCube started construction in 2005, became the biggest neutrino telescope in the 2005-2006 season, and was finished in 2010. which mirrors what I thought - the IceCube is definitely newer, though the Super-Kamiokande has been upgraded as recently as 2020. and while I’m at it, I can tell you the IceCube2 is in the federal approval process.
I've seen my wife watch crime videos, with the barely disguised foreshadowing, her being like "i knew it !", then getting some extra info or even plot twist at the end... she loves that... i think i didn't quite understand that feeling until watching your video.... damn, first time seeing one of yours, instantly subscribing, awesome storytelling ability, fr
Another really cool neutrino observatory is the IceCube Neutrino Observatory that is on, or rather, in, the South Pole. It consists of over 5000 detectors, all buried between 1450 and 2450 meters below the Antarctic ice's surface, and spread out within the volume of a cubic kilometer (and there are plans to extend the observatory to cover a volume of 8 cubic kilometers).
@@_NaLo_ there was a series by a guy who was a support medical worker at that station. He showed about everything and everybody who was there when he was on winter sceleton crew. It was amazing. Working there must have been an adventure of a lifetime, akin to being on a space station. It's always the same people, you have to get along, only basic necessities, but still enough comfort to have some fun. They had an amazing library and reading room, everybody who went there brought a board game or a book, or a movie.
@@RoboBoddicker Which is even funnier if you know their gods are capable of chewing metal and stone, at one point the sun goddess and her brother give each other objects to eat which like...deconceptualizes said objects. So if a Shinto god bit into you'd get deleted from the universe.
And the SuperK is probably the *least* unhinged neutrino telescope! For the other ones we either drop strings of these bulbs into Antarctic ice/lake Baikal/the ocean (with an effective detector volume of like a cubic kilometer) or replace water with liquid chlorine (the higher density makes neutrino detection easier and allows for a much smaller volume to still be effective at detecting neutrino events, although with no spatial resolution) Also I like to think of photomultipliers as reverse lightbulbs
@@tsm688 cheap to get and the isotope resulting from the neutrino collision (Cl-37 to Ar-37) is radioactive but relatively stable and can be easily detected after extraction. To be precise, the tank was filled with tetrachloroetylene. Modern detectors of this type usually use gallium and gadolinium instead.
Another obscure science thing you might like to look at the engineering of: the LIGO gravitational wave detector. The tolerances on that thing are crazy small and yet they were able to detect in some detail the waves produced by two black holes colliding in some super distant galaxy. Then someone had the brilliant idea to represent the waves as sound waves. You know those things they sometimes have at museums where you roll a coin down a funnel? It sounds kind of like that, except with a weird bloop noise at the end.
@@psymar I work in the library of a university where some of our academics contribute to the LIGO-VIRGO projects and I think that manually inputting the 1000+ authors on the papers into our repository has given me some sort of psychic damage lmao
@@eilidhmm That's amazing, I wonder if you've set the record for entering the most author names on a single paper? Not being sarcastic here, you might want to send it to Guiness -- okay, never mind. I did the no-no on the internet and did some research before I posted: > A physics paper published in Physical Review Letters in 2015 set a record with the highest number of authors, totaling 5,154 contributors. This paper was a joint effort from the ATLAS and CMS detector teams at the Large Hadron Collider (LHC) at CERN, aiming to provide a more precise estimate of the mass of the Higgs boson. I guess you'll have to get a few more thousand scientists involved to get there. Edit: I also found a journal article in Springer Nature titled "How many authors are (too) many? A retrospective, descriptive analysis of authorship in biomedical publications" which the most useless-sounding meta-science paper I've seen in a while. In fact, the statistic I got online is probably out of date, considering the article references a paper with 12,000+ authors relating to COVID. I will say that the authors (I know you're curious, so I checked -- the number is three authors for this one) do seem somewhat peeved at this, which makes it all the better: > For example, 1014 authors are listed in a 2015-paper on fruit-fly genomics (Leung et al., 2015). Not less than 2080 authors are listed on a paper from high energy physics (Khachatryan et al., 2010), which “needed 165 lines on the PubMed site to spell out their surnames and initials” (Marusic et al., 2011). A 2017-paper in astrophysics had 3674 authors (Abbott et al., 2017) and in 2021, during the pandemic, the number of co-authors peaked at over 15,000 in a multi-center study on the efficacy of SARS-CoV-2 vaccination on post-surgical COVID-19 infections and mortality (Covidsurg Collaborative, 2021). I will say that typing in a thousand-ish names sounds like a pain, typing in 15,000 sounds like actual torture.
@ I can tell you just from the lead author name that the Abbott et al. astrophysics paper referenced is from the LIGO project *checks* >[...] a binary neutron star coalescence candidate [...] was observed [...] by the Advanced LIGO and Advanced VIRGO detectors. knew it haha
Thank you for one of the most interesting and educational videos I have watched in years, on a subject where I know radically less than the author and was completely enthralled the entire time.
If I had a nickle every time an in-depth youtube channel did a video centered on photomultipliers in the last week, I'd have two nickles, which isn't a lot, but weird it's happened twice. (Asianometry and night vision for those curious)
If I had a nickle every time i saw this "if i had a nickel" comment, I'd have two nickles, which isn't a lot, but weird it's happened twice in the same day...
I'm a nuclear engineer with over 30 years experience, well done on your physics explanations. I have used photomultiplier tubes and scintillating materials to detect gamma rays. They are amazing technology. Thank you for another well done video.
I know nothing about engineering or particle physics, but youtube begged me to watch this video and despite understanding maybe 1/5 of it, worth my time
Great video! Im currently working on my PhD doing analysis for SuperK and some electronics testing for HyperK, I first heard about this disaster from my future supervisor on the day of my interview so safe to say its still fresh in many peoples minds even this far along. I had never seen that photograph from the top of the tank either will all those shredded PMTs! Things to keep us up at night when HyperK gets filled in a few years time (theres also maybe a future video there about the construction of the largest man made cavern that is ongoing to house the new detector!).
The 21:48 Todd howard blink-or-you'll-miss-it reference for "8.4 times the [detail] resolution" was amazing, thank you for that one. Hyper-Kamiokande '76 will be a game changer for sure!
@@Alexander-the-ok Was that a cheeky play on words at 14:50 involving any rebukes mentioning the rebound effect? If its intentional i appreciate the wit! Also in reference to the whoosh of the displaced air, did any of your research in this touch on the potential volume of all the tubes that were broken and say how much of a drop in water level that would've been? Id imagine the numbers are there itd be easy to calculate given the known quantities but i was just curious cause it might be an interesting metric to give an idea for the scale of it all.
I don't know which is more impressive; the physicists who come up with the ideas and experiments, or the engineers who design and build those experiments.
Well, I'll be honest, it feels really odd to see someone this much more of an expert than me in physics use my video as a recap, but I'm glad I could help. Amazing video and I really love you putting it in context to show just how interesting even the failures can be, and to me I absolutely adore how for most failures like this it's not really "Engineers didn't think of it", only "Engineers did think of it, but..."
I feel like most failures are "engineers learned a lot". It sometimes fascinates me how many things people can predict or expect, because I'm used to the model where you really don't know what will happen in engineering until you try and see what might.
@@Yupppi You do not need to be an engineer to predict this... i remember that it took me few seconds to predict it when i was reading article about this setup in high-school. The fact that the engineers explained it to themselves and convinced themselves that on paper it looks OK is nothing extraordinary. The same as the fact that something was unforeseen and that the failure occurred at the lowest point of the tank where the pressure is the highest. "Murphy's law[a] is an adage or epigram that is typically stated as: "Anything that can go wrong will go wrong.". Though similar statements and concepts have been made over the course of history, the law itself was coined by, and named after, American aerospace engineer Edward A. Murphy Jr.; its exact origins are debated, but it is generally agreed it originated from Murphy and his team following a mishap during rocket sled tests some time between 1948 and 1949, and was finalized and first popularized by testing project head John Stapp during a later press conference. Murphy's original quote was the precautionary design advice that "If there are two or more ways to do something and one of those results in a catastrophe, then someone will do it that way." The law entered wider public knowledge in the late 1970s with the publication of Arthur Bloch's 1977 book Murphy's Law, and Other Reasons Why Things Go WRONG, which included other variations and corollaries of the law. Since then, Murphy's law has remained a popular (and occasionally misused) adage, though its accuracy has been disputed by academics. " I remember seeing how big the vacuum bubbles were, how close to each other and how big the tank would be -> and consequently the mass of water exerting additional pressure... -> perfect setup for massive chain reaction.
While I was aware of the Super Kamiokande neutron detector I had not heard of this accident. It is always interesting that at the bleeding edge of technology no matter how careful engineers are there is often something they overlook leading to disaster, the Apollo 1 fire comes to mind. As you posted the detector was rebuilt and has made significant contributions to atomic physics.
I worked for the Baikal neutrino project, and we had one of those tubes over from Kamiokande one year when one of their physicists visited. It was a remarkable piece of equipment. Unfortunately, we had no chance to use it as the Baikal telescope is at a ~1300m depth. On that note: We also had collapse, but it did not trigger a cascade for two main reasons: 1) PMs were spaced farther apart 2) Being open water, there was no wall to further reflect a shockwave. They were installed in pairs. The adjacent module also imploded, but the effect did not propagate. That being said, I was amazed to see the effects of such a high pressure collapse. (Titan vibes anyone?) The glass shattered into a sand-like granularity, and the shockwave instantly compressed it into something similar to sandstone. At first glance, I thought that it was some compacted snow, until I touched it. Nothing was left of the whole module. Just the twisted metal frame and a few pieces of this glass sandstone. I also liked the AMANDA (today Ice Cube) modules.
Okay, I just want to tell you that this started as a super neat video about a detector but in the end I was actually able to understand some really scientific concepts. This is incredible I cannot wait to watch and learn more.
I consider myself well informed but you manage to find topics I've never even heard of and put together super interesting videos. Thank you and great job!
Thanks very much! Honestly sometimes this channel sometimes feels like a compilation of ‘huh thats interesting. I never heard of this before’ topics I’ve stumbled across over the years.
Fantastic video of an extremely interesting topic. The exacting standards of scientific equipment manufacturing is almost as mind blowing as the ideas being tested by the experiment. The resolution of measurement at LIGO for example is utterly bonkers
Thanks for the great explanation. I actually saw one of the tubes when visiting Tokyo. Having seen one of the tubes in person really gives you a sense of scale of the complete setup.
Alex is incredible at expressing anything intuitively and I love how he does it in such a way he makes his passion infectious, the ability to make people so interested and invested into something many never knew about beforehand is a great quality to have. Quickly becoming my favourite channel on the entire platform.
This video was so cool! I always found the subject of neutrinos to be fascinating, especially considering how annoying they can be when it comes to detecting them, and seeing that massive chamber used to detect it was incredible. Of course, it was very frustrating to hear about the cascade testing they did, because as anybody who's gone scuba diving can tell you, there's a big difference between 1 meter and even just 3 meters, let alone the pressure you'd be experiencing at the bottom of a massive tank like that. Still, super informative and cool, and I applaud your ability to only make one single half life reference in the entire video, that must've taken some restraint
I was going to add a bit about my experience with that with all the drysuit diving ive done. But since I couldn’t really be bothered to do the maths or simulate it, i left it as ambiguous.
This is a very neat video on a ridiculously fascinating subject, I didn't even know such a failure occurred. But I'd pay some real money to see what this looked like in the moment
Thank you for the video. When you mentioned in the other video the Super Kamiokande Cascade Failure I looked it up. Found only the official report. It was a very nice read. I was impressed about the rebuilding efforts. You know ... super pure water also means super clean water. And that means that SUPER cleaning up the mess from the Cascade Failure. Sure, remove everything, fully test what seems usable and rebuild it "as new" ... but actually doing all of that ... WOW. And they did. A marvel of re-usability and repair :)))))
fitting the topic of the video: ッ @@ibahart3771ironically he has one of the more consistent t stopping overall, as in, he stops almost every /t/ that _can_ be affected (which isn't all of them, something something post-tonic and within the same intonational foot.. iunno, Dr. Geoff Lindsey has a video that explains it). it is just a matter of fact that this feature is associated with "casual, unclear speech" (as well as "low class" but that fortunately doesn't seem to bother him) so pretty much everyone with it will switch to using a regular [tʰ] in slow and enunciated speech (whence his [statʰɪk] instead of [staʔɪk])
I was a graduate student within the particle astrophysics community (on a different experiment). I remember when the news & rumors of Super-K’s implosion spread through the community. A little while later I saw a presentation by one of the Super-K scientists, in which a short movie of a later test was shown. At the time it was said ‘no I cannot give you a copy of this, just remember it,’ and even 25 years later I’ve never seen the movie in the public. The question was that while the dynamic pressure is incredibly high as detailed by Alexander, the tubes were designed and tested to survive the dynamic pressure of an implosion too. The super-slow motion movie showed a 3x3 grid of phototubes at depth, and the middle tube was purposefully imploded (small charge). The surrounding tubes survived the initial shock, but then the water flowed into the space left by the imploded tube and all the surrounding tubes leaned in towards the missing tube and broke *at the neck*. The tubes look like great big light bulbs, and the rush of water pushed on the large glass globes snapping off the necks. It wasn’t the shock, it was the water flowing past that propagated the implosion. The fix included baffles to slow water flow and metal supports so sideways forces were not all born by the neck of the tube. In the end the tubes had been tested against the shock of an implosion, but not the effect of water rushing past the ‘sail’ of the large glass bulbs and popping the neck.
Wow thats actually kind of interesting abd a bummer because I bet that slowmo video would be insanely cool to watch!!, I was also kind of wondering about that in relation to that woosh of air that was described in the video Id be curious to know by how much say the water level dropped, it wasnt full or it was being filled so i guess it wouldn't be as easy to tell immediately but i would think the volume of all the tubes that broke could be figured out pretty easily it would make a interesting bit of fetail.
Great video and explanation! I worked at the IMB detector located in the Morton salt mine in Fairport Ohio years ago. We also used the Hamamatsu tubes. We also use the smaller EMI tubes.
Particle physicist here! Great video, I didn't know about that cascade failure at SK! I suggest you have a look at the marvel of engineering that are the LHC and detectors like ATLAS, it's more than fascinating! There are easily a dozen subjects to be covered on the topic. Most people only know about the proton-proton collisions, but it is worth talking about the superconducting cryomagnets, the RF accelerating cavities, the beam dump, the security systems, the vacuum, the immense injection chain, the beam dynamics and focusing, about how new problems where overcome (the so-called "UFOs", the wake field, etc), and I could go on. And frankly, all the detectors are marvels of engineering too, I could easily list a dozen subjets that would require a video each. And if you have a particular interest in what we can learn from failures (and if you like cascade events that lead to destruction), have a look at the 2008 incident, where a magnet interconnect failed, leading to an electric arc which dissipated some 275 MJ. It burnt through beam vacuum and cryogenic lines, rapidly releasing about 2 tons of liquid helium into the vacuum enclosure. The pressure valves where not designed for such a high dynamic pressure, and the pressure wave propagated from one magnet to the next one, destroying everything along the way (until it reached stronger valves, if I remember correctly), delaying the start of LHC operation, costing a lost of money, forcing to operate at weaker energies, and forcing an upgrade to operate at higher energies.
Funny... I knew all the background information and immediately foresaw the basic shape of what must have happened, but as a surveyor of all physics and engineering, I sometimes miss news items. So I never heard about the fairy tale cascade failure. The conclusion of designing and testing for the worst case is very much my mantra. Now I know this one, and I thank you!
Kamiokande is one of the worlds greatest and most underrated experiment. That said, I'm also reminded of the similar arctic ice cube neutrino/particle detector! They're soooo cool.
Thank you, sir! Your explanation clicked right along with me, even though I am an electrical engineer, specifically computer networks, but your flavor of description is easy for me to follow. In high school and college, my father (Masters degree in zoology) had filled me with such a love of science I was fascinated with astrophysics and quantum physics, and padded my course load with subjects I knew I wouldn’t pursue in work. I was part of a team of students in Omaha, Nebraska, USA who, along with other groups the world over, provided proof calculations to the MIT study that predicted the proper stable orbit radius for light circling a black hole. Still theoretical, as we have a lack of singularities locally, but… LOL! I’m retired now and still dig through science here on RUclips to keep my brain running!
I think the cost of PMTs you quoted is in Yen. From what I have seen the main PMTs cost around $3000 and the outer PMTs cost $1000 so the total cost was somewhere around 22 million USD(very rough approximation) adding the additional clearance costs. Apart from that, splendid video. Asking the researchers permission for footage was a very nice thing to do, anyone else would've used small clips to try and skirt fair use. Can't wait for the next one(silently hoping for more particle physics)
Best sub I've made in months, years maybe! This channel is likely to be a big deal on RUclips, or I'll eat my hat. Superb writing, subject matter, diction, humor, absolutely outstanding and fascinating content that sheds light ( no pun, swearsies) and shreds ignotance, can't wait to binge every video. I put you in the class of channels like The Entire History of the Universe, Technology Connections, Kurzgesagt, hbomberguy, Vsauce, Then and Now, and Folding Ideas. Channels like yours enrich my mind and life and I can't thank you and channels like yours for your hard work informing and encouraging our minds to be more nimble, funny, and thoughtful.
I have a good friend who got to work here during his post doctorate years. I have an e-mail he sent from under that mountain. He also had one of the vacuum tubes from that. He explained what happened with this 'oops' and it was one of those things one could excuse the engineers for missing that could happen. What was more cool is he explained how the whole thing worked in language even I could understand. Oh and he keeps his PHD certificate in the envelope it was mailed to him in. He passed it around at a house party at one point. I asked him once to show me the math behind what he did. I followed it for like the first two steps. He told me it was far more important to understand the overall concept than the equations. He's now working as a professor in the UK. His students are incredibly fortunate.
For an incident in a similar vein look up the 2008 LHC "incident" where, during power tests in the process of bringing the LHC online, an electronical connection was less superconducting than it was supposed to be. It quenched. The result: An insane amount of electrical energy had nowhere to go but to through a now normal conductor, instantly boiling significant amounts of liquid helium and ripping the LHC apart in the process.
Yes I remember that. It was also very embarrassing for the US university that had worked on the design of these magnets. Still, they got the LHC right in the end. It’s an amazing machine. The beam energy is fantastic. I once calculated that the amount of kinetic energy in the bunches of particles was about the same as the USS Nimitz doing 10knots (if I remember my sums correctly!). That’s a lot. Even more amazingly, they have a means of dumping this energy if they have to. There’s a beam dump, basically a large magnet that can be turned on quickly which redirects the beam out of the machine and into a cavern which they filled with graphite blocks. The particles hit the carbon and the energy is converted into heat. It’s a bit like stopping the Nimitz inside a few metres braking distance!
I used to participate in Oceanographic Research and we would use light bulbs as a sound source after environmental concerns were raised about using explosives. It’s been many years but I want to say 150W Philco manufactured light bulbs were my colleagues favorite. It gave a really high intensity wideband acoustic source.
I just think you are so neat. I love that you talk about what interests you, and in such an interesting and compassionate way. I am always hoping to find channels like this from genuine people who aren’t sharing their learning for money but for the sake of sharing something interesting to them and creating. I am glad I found your channel, it makes me reflect on risk within my own industry and work too.
Thanks very much. As a full disclosure, I do make profit from most videos. But I also turn down a lot of money by not taking sponsors/talking about topics I don't care about that would get more views etc etc.
Congratulations! This is a very well conducted video, that doesn't require a previous MSc in Theoretical Physics - it can be understood by anyone with a minimum knowledge of Physics!
Wouldn't it be something if, many years from now, at the end of his life, a technician admitted that he dropped a tool on that specific tube and didn't want to tell anyone because of the aggressive anti-failure culture in Japan.
@@natejohnson6269 Normally crew aren’t told they are getting made redundant whilst on a rig for this exact reason. But someone found a line in the financial report for the company that the rig was being mothballed, the implication being that the crew would be released (most were contractors). Guy threw a chain in a generator gearbox and shut the rig down for a week. No one ever figured out who the person that threw the chain was. The total cost in repairs and lost time was probably in excess of $1 million.
1:55 I can hear that "They're waiting for you Gordon, in the test chambeerrrr" anywhere. Good reference. 9:03 That's an object of beauty. And the photomultiplier is neat, too. 16:05 That phenomenon is basically an insane version of waterhammer, which is an engineering nightmare by itself. 21:48 Does it also have 16 times the detail?
He says 8.4x volume, that is like 4.13x area (if tank proportions stay the same), the tubes are supposed to be the same, so a little over 4x the resolution or twice as much "pixels" in each dimension
@@samuels1123 I think they don't care as much about it to risk denser packing and increasing the chances of another cascade. I think if they would, they'd make a smaller detector with smaller tubes, packed as dense as possible (maybe even hexagonal tubes) for more precise measurements. I don't remember the number, but since they detect quite a few neutrinos daily, trading quantity for precision doesn't seem like a bad idea. The scientists must have their reasons to just want a bigger detector instead, I have no idea
This might be one of my new favorite channels. Congrats on 100k! Cant wait to see the Mriya video! I really like the Buran and Shuttle videos!!! Very well done!
Thank You for your simple explanation... I'm a physics "curious" myself (self teached...) and always have been curious about the Super Kamiokande... and other neutrino detectors, and more about the one more near where I live... The KM3NeT that is located in the near bottom of the Mediterranean Sea...
First of all, I got my cost figures way off. Thanks to @morizbraun5034 for pointing out that 7000 * 10000 is indeed seventy million, not seven million. BUT it seems the cost for each tube was actually $3000 (2001 dollars), which is an absolute bargain. All things considered, it cost about $30 million to restore.
I'm also getting a lot of comments wondering how the engineers could possibly miss this, and how inadequate their testing was. There are 3 points to consider here:
1. I suspect they did additional tests but I can't find the info on them because it is probably exclusivley in Japanese....assuming it is online at all.
2. For a deep dive into an engineering failure that appears blindingly obvious in hindsight but much much more nuanced in reality, see the 'SRB' section of my Space Shuttle video.
3. Fluid modelling and engineering standards were nowhere near what they are today back in 1981 when these tubes were first used.
Could of, wood of, should of. Its easy for people to use experience to judge mistakes, but someone has to make that mistake for the first time so the rest of us can learn.
@@ChainsawFPV that is so true
At $3k 2001, I'd buy one!
A detail video of how those are made would be cool :=) Se if you can get a tour inthere facility :D
@@ChainsawFPV could have, would have, should have
I never thought I'd see a resonance cascade, let alone create one.
@@JinKee 'thank god your here' *scrambles around for my beloved crowbar* who's ready to crawl through some ducts and flinch at every sound.
Resonance casserole incident
It wasn't a resonance cascade, it was just a shock wave created by collapsing bubbles.
@@YolandaPlayne OP is making a half life reference, look it up :)
@_VI701 Resonance cascade is a real thing though
A lab disaster so bad it was picked up on seismometers and nobody was injured? Truly the best way that could end. Also a fascinating bit of engineering knowledge for future generations.
Discovering the extent of the damage must have been gut-wrenching. I'm so glad the experiment continued to be a great success.
@@EdwinSteiner the equivalent seeing the meltdown of a reactor that was deemed completly safe
Imagine being the person that had to make that phone call explaining what happened.
The fact that the facility was repaired and continues to produce data is a testament to the people and government of Japan
@@sirfer6969 Absolutely. Their dedication to science funding is something I respect profoundly.
I hope that it wasn't known who was the person who blew the glass for the detector that imploded first. While this person wasn't to blame for what happened, the sense of honor that the Japanese tend to have might have had disastrous consequences.
*The lesson here is when carrying out destructive testing, you need to carry it out in conditions as similar as possible to the actual use case.*
I'm positive that the individuals involved in the HK experiment are aware of this and are preparing thoroughly.✌
sideways glance at boeing...
@@jweir2010 Implosion tests of the PMTs of the HK telescope in collaboration with PLOCAN💡
The Hyper-Kamiokande experiment people are doing implosion tests in Spain.
@@jweir2010 👍
A 22 minute video of a man talking about a failure I didn't know about that happened to a thing I didn't know about?
splendid! I will watch the entire thing immediately
To be fair, i know nothing about the falure either, but i know about both Kamiokande since university
@@matsv201 well then, if not even you knew about it...
@@DuXQaK I checked it on wikipedia and relize it happened 2 month after my last day in unversity. So that is probobly why
@@matsv201 ...keep digging that hole deeper
@@matsv201 What do you research
There is a very happy glas blower workshop that not only produced tens of thousands of those tubes over the last decades, but also can be assured that the next iteration of the detector will need even more. In most cases, glas blowing is a dwindling art, only used for very specialized lab equipment or for tourists. Even those will not suddenly be asked by the government, how fast they can produce, say, 20000 Serpentine Reflux Coolers.
So this is a win not only for science, but also for those craftsmen.
I think it’s pretty cool that the university I work at still has a glassblowing shop, and that it even trains apprentices.
Quantum phycisists: "blah blah blah blah photon emitted"
Alex: *engineer brain switches back on* "So you want to detect photons sweet got it."
This is hilariously accurate
That's the right mindset honestly for us humble people implementing stuff
@@Alexander-the-ok I have a lot of particle physicist friends who work/worked at CERN. They rightly get huge praise and media attention for their discoveries, but even coming from a physics background I've always found the engineering behind building such an unimaginably large yet extremely precise machine where miniscule tolerances are vital, to be the most utterly mind blowing human achievement. I mean yeah, physics behind ATLAS, Higgs etc. is awesome, but even being able to build ATLAS such that it could infer Higgs is more impressive than my chimp brain can handle and that is before considering building the bloody 27km accelerator!
On a side-note, my old housemate decided to film a feature length zombie movie in CERN's access tunnels WHILE doing his PhD! It is called Decay and is hilariously awful to the point of being comedic brilliance, who knew exposure to the Higgs boson made you into a zombie?
@@beardedchimp Is this movie on RUclips or available somewhere else?
Edit, found it on YT.
@@GoGoGoRunRunRun I just typed "decay cern movie", it's here on yt
Gordon-san does not need to hear all this, he's a highly trained professional!
@pyrokinethic they're waiting for you
@@KatanamasterV in the test chamberrr
Just one of those days, I guess...
@AnonNopleb Catch me later I'll buy you a beer
@@pyrokinethic I have a bad feeling about this.
your use of the Japanese serif typeface is a subtle but brilliant touch.
I noticed it too! :D
Particle physicist here, this is one of those stories that all of us in the neutrino physics community grow up on. By the time you finish your PhD some mentor or senior would talked about this. It had the potential to be a massive setback to particle physics, even though things did end up okay!
Let's be honest. All physicist have heard this one. Usually 2nd or 3rd year. This is one of the stories that is easy to understand, grand in it's scope and really hurt only few of us, so most feel OK telling it as a 'curiosity'.
The setback hasn’t happened until observed
(Dont look at the funny machine please)
Can I ask a question? Why are people so interested in neutrinos all around the world? It seems like you typed in any first world country in a search engine and it seems like a name will come back for a facility that is built or being built. I could be wrong but I feel like there was that level of activity was like nuclear power or something. There would seem to be a bigger reason then reason then research? At least to me.
@@ace1122tw the main quest in modern particle physics is the search for physics beyond the standard model (BSM physics). We know there should be something we aren't getting, because we do not have a grand unified theory, we haven't figured out dark matter, etc. One key issue is that we do not have a lot of experimental evidence pointing us towards what that BSM physics would look like.
Neutrinos are one of the few things that don't behave exactly like the standard model would suggest. As such, we expect (and hope) that precision measurements of neutrino properties would give us clues to what such BSM physics might look like.
@@ace1122tw There's a lot to unpack here, 1st, the nuclear power got way more in way of funding. The cost of Manhattan Project alone is estimated to be around $27 billion in 2023 dollars. The cost of HyperKamiokande is 1/50th of that. That's a different scale entirely.
As to why Neutrinos are interesting - they carry information that we cannot access in any other way. Unlike photons, nothing occludes our view of source. Most neutrinos from center of supernova escape without interaction. This is from a center of a star - no photons make it out of there. Another example - they were among first particles that were 'freed up' from Big Bang. Some 370 000 years earlier then photons decoupling, according to wikipedia. If we want any information from before that point in time, we need to get it out of neutrinos.
We also still don't understand or actually know mass of the neutrino well - as far as I understand we pretty much know it is not a zero and that's about it. This is an important part of refining standard model.
Lastly - you hear about it, because to study neutrino you need a lot of mass as a detector medium. It makes no sense to make a small detector, because you would register one neutrino per year, not per day. This makes those projects good subject for news description. Few people understand the physics, but many get the huge scale. You just don't hear about myriads of smaller experimental projects.
Hope that answers most of your questions. Cheers :)
As an HVAC technician that works on steam heating systems, I have a lot of experience with water hammer and vacuum. One of the most interesting phenomena that can happen in a vacuum steam system has to do with steam syphons and gauges under vacuum. Let's say you have a pressure gauge, hooked up to a boiler with a syphon (basically a U shaped pipe that holds water to protect the gauge from steam temperatures all the time), and this boiler is in a naturally induced vacuum system (goes into vacuum while the boiler is not running). Now let's say that the boiler starts up fairly soon after the next cycle, while the system is still at -10 or more inHG of vacuum. Until enough heat is put into the water to influence the pressure at the end of the dry returns and open the vent check valve, the system will still be in a vacuum, but the heat being put into the boiler can heat up the water in the syphon far beyond the level where it will start boiling at that level of vacuum. What happens next is that the water in the syphon will rapidly start turning into steam and generate intense spikes of pressure that are audible and also visible as the needle on the gauge shakes violently going to full scale and back again. If the gauge is not rated for pressures far in excess of what the system operates at, there's a good chance of it breaking. In a vacuum system without a pump, there is essentially no practical way to stop this from ever happening, so the only option is to get a gauge that can handle surge pressures of at least 5-6X normal operating pressure. In many systems I work on, operating pressure may only be measured in ounces per square inch, or even just a few inches of water, while vacuum can be as deep as -20 inHG. For those systems, the only option for a gauge is a particular gauge designed to measure differential pressure, which can also be set up for single pressure, and is rated for 500 PSI/20inHG or 600PSI/29inHG surge pressure. Extremely overkill, and extremely expensive, but it's the only option that will not be destroyed by water suddenly deciding to turn into steam inside the gauge. At least this only affects one instrument and doesn't cause a cascade effect like the disaster mentioned here. Although there are other failures elsewhere in a system that can happen and cause a cascade failure, like a steam trap failure letting steam into the dry returns, which will quickly damage every other steam trap in the system, but not on a time scale as quick as this.
thanks for sharing your professional experience, it seems that some aspects of your work really coincide with the kamiokande accident, and you clearly know a lot about what you are talking. I would never guess HVAC systems could be so complex.
... for five years, my 300 H.P. boiler operated continuously ... weird ....
I must say, I wish I understood the units to have a context.
Is there any way a damping material can be added to the siphon pipe, e.g. foam, or a Tesla valve if there is a significant volume of water or steam moving around? This would slow the rate of change over time by damping rapid fluctuations, but as long as you were happy to have lag in the pressure reading due to the damping, the pressure reading would still be accurate
I believe the equivalent phenomenon in refrigeration systems is called "flashover in the evaporator" and causes a loud sharp knock to emanate from the innards followed by a few weaker knocks.
Your fine video reminded me of of something I experienced in 1974. My first job out of the military was for Packard Instrument Corp final testing liquid scintillation spectrometers. Those were the TTL days and the logic "board" in the units consisted of 300+ 16 pin integrated circuits in sockets. There was no printed circuit board. All connections to the 5000 socket pins were crimped by machine, one at a time, to up to five levels on each pin, giving a theoretical maximum of 12,000 point to point wires on this single board...all blue. Naturally, the actual number was much lower, but it was into the thousands, and the pins themselves were hidden under a several inch thick mat of blue wires. Our job in final test was to find any faults, make the machines work, and calibrate them. One day, one of the other techs energized a machine to begin troubleshooting and there was a loud crackling noise, followed shortly after by a rain of integrated circuit tops that reached 30 feet from the machine, and a huge puff of acrid smoke. Nearly every one of the ICs had exploded. I wish I could say that I was cool when it happened and calmly said "I think you have a power supply problem", but I didn't, I ducked.
lol
Thank you for sharing your experience
but then, did you 'cover' ?
people don’t believe my revolutionary theory of electrical component maintenance. replacement is necessary when you let the smoke out 😉
the phrase "blue wires" does make me think of wire wrap boards... but the basic problem of blowing up a board full of IC's is familiar (but on a much smaller scale). Those are the experiences that are a real test of your soul... and maybe heart?
The presentation on this video reminded me a lot of Plainly Difficult. Just needed a graphic of an engineer lamenting, “Balls.” 😂
This is not a bad thing. Great video, thank you for writing up such an interesting, complex failure.
Wonderful video!
One thing: 6000*11000=66 million, quite a bit more than the nearly 7 million dollars mentioned.
Oh man how on Earth did I get that wrong!? Thanks, I’m pinning this!
@@Alexander-the-ok Past a certain point money is just a number :D a zero more or less makes little difference :D
Aww man I was hoping to be the first to catch it!
"... more importantly, detecting that tiny flash is an engineering problem, so I can confidently reenter the discussion again" - proceeds to fail at multiplication.
I love your videos, Sir, but please only engineer far away from me. ♥
@@simdimdim that makes 0 sense.
My high school physics teacher, Mark Buchli, worked on the repair of Super-K in 2002! He was one of my favorite teachers and he talked about working on Super-K regularly!
(Particle physicist here)
4:57. Your brief foray into particle physics was quite cogent and largely correct, certainly enough for this video. Well done!
Broadly, in particle physics, we shoot particles at targets. Sometimes an interaction happens, it blows apart, fragments come flying out. We detect the fragments of the collision/reaction by having some active medium that responds to the travel of a certain type of fragment by producing light, we collect and pipe the light to a photon detector, which produces a burst of charge, and then we digitize the charge to reconstruct the fragment, and then by working backwards reconstructing all the fragments, we reconstruct the original thing that happened (as we as we can, and then do it ad nauseum to build up statistical picture of that reaction in aggregate).
Unusually for a particle physics experiment, the water in Super-K is the target, the active detector material, and the light pipe that gets the light to the photodetectors.
basically just a ginormous liquid scintillation counter. you can actually use water as your "scintillation cocktail" for detecting high energy beta emitters on an LSC, where the instrument detects cherenkov effect photons just like this.
My family does something similar with used appliances and Tannerite every year after Halloween.
The water in Super-K is also part of the radiation shielding (keeping background count out). If a Cherenkov cone starts off in the middle of all that water, it's been caused by something that's pretty penetrative!
@@fsodn there would probably be a lot more particle physicists if the field was sold as “shooting particles into targets” “blowing things up” “smashing things into fragments” etc. before saying * ᵗʰᵉʳᵉ’ˢ ᵃ ˡⁱᵗᵗˡᵉ ᵐᵃᵗʰ ⁱⁿᵛᵒˡᵛᵉᵈ
@@abarratt8869 I don't really think so. The shielding from upper-atmosphere particle production from cosmic rays is provided by the 1000 meters of earth and rock above it; that's why all of these neutrino detectors are so far underground.
Lovely write-up of the story. I'm a particle physicist who worked at Super-K for a while, so, yes, you got a few things wrong, but you got most things right. The biggest one to point out is that the oscillation wasn't detected by looking at the change in muon neutrinos detected as the earth rotated, rather, it was looking at the difference in number of muon neutrinos detected based on the direction they came from. Ones coming from straight-below travelled through the entire earth, while ones coming from closer to (but still below) the horizon travelled through a smaller distance of the earth. Plotting the number of muon neutrinos based on L/E (distance the neutrino travelled divided by the neutrino's energy) shows the oscillation behavior.
Ahhhh!! I thought I may have got that part wrong but couldn’t convince myself why. Thanks very much, I’ll add a correction to my pinned comment.
The G-Man hammering a single imperfection into that one detector right before shipping to the detector site.
A little...*inhales* nudge, hm?
I could offer you a battle you have no chance of winning….
It’s time to choose.
Turns out that the he does not really have any sinister goals, he just really hates particle physics.
This is an amazing mental image 😂
I actually tried researching this after you mentioned it in your last video and i was struggling to find something comprehensive or understandable about it. So honestly glad you followed up on it
The moment he emphasizes the word 'hydrostatic' I think I have a good idea of where this is going. I'm no engineer, but when you put the terms 'cascade failure' and 'hydrostatic tolerance' next to each other in that tank, well... that does indeed sound exciting.
Edit: Yep. That went just about exactly as I envisioned it. :D
I'm curious to know what earthquake mitigation they did (it is Japan). Plus, there's also the potential lensing effect from the difference in speed of sound between rock and water (you see the same distortion when you look through a glass of water).🤔
I kind of put two and two together as soon as I saw the stock footage? B-roll footage? Anyways, all the videos taken inside the tank in the first two minutes or so. That plus the title was all I really needed (well, also knowing what most neutrino detectors are).
You’re smort can we be friends?
I was predicting that one of them would break in a way that produced very bright sparks, which would oversaturate the other detectors in photons and make them break the same way
Me too :) 'Water hammer' is a phenomenon that (often) depends on water rushing into a vacuum, ditto cavitation bubbles collapsing. The point is, there is absolutely nothing to 'cushion' the incoming water until it 'comes up solid'. These photomultiplier tubes were just like ginormous cavitation bubbles in that respect.
Super Kamiokande has to be one, if not the best name for a science facility.
"I never thought I'd see a resonance cascade, let alone create one."
"hydro-static... STATIC... moving on". I think I got the hint at that point in the video. Wonderful description and clips of all the Kamiokande science - physics and physical.
I laughed ha
Apparently, I chuckled so loud at that point that a waiter at the café I was sitting in gave me a _very_ concerned look... 😀
So did I.
It is a cosmic understatement that trillions upon trillions pass through the Earth every second. If you just consider the nail on one of your little fingers, about 70 billion neutrinos pass through that area every second. So for the whole Earth, about 90 octillion neutrinos pass through it every second. That is 90,000,000,000,000,000,000,000,000,000 neutrinos.
God I love the scales of physics.
How many pass through me? Feels good to be a neutrino garden hahaha
So if they do have mass, that could really add up. Interesting.
I'm sure you're being hit by more photons though
Neutrinos see us and they’re like
“Yeah I’d hit that” 😏
@@Starbrow31 the neutron star would like to discuss the “scale” of objects that behave like atoms 😂.
When this incident happened, I was already an employee of Hamamatsu Photonics Germany. A colleague sent me some poor quality photos the morning after. Of course we all knew about Super Kamiokande and it was a shock for us to hear about the event.
Producing replacements for the broken photomultipliers took several years. The original production building had already been repurposed, so a larger scale production had to be set up again, and even some former employees were called back from retirement. As the video showed, highly skilled manual labour plays an important role in manufacturing these photo multipliers.
Personally I am not involved in our high energy physics business, but talking to my colleagues who work in that field is always fascinating. Wherever there is a need for highly specialized photon detectors worldwide, there is a high probability that our products are being used.
I work at a university, and all the photomultipliers I have seen (all at the physics and chemistry departments) are Hamamatsu. Do any other manufacturers of PMTs exist today??
I actually have a little one (one of the PMT modules with integrated HV supply) on my bench at work, waiting for me to repair the amplifier board it connects to.
3:50 It barely matters for the purposes of *anything*, but when it matters, it really matters (making it possible for 2 H1 nuclei to fuse into deuterium, thus making stars as we know them possible, dissipating 99% of the energy involved in supernovae, etc.).
Great explanations of the physics, the photomultipliers, and the hydrodynamics! One detail: typically the photocathode of a PMT is at a large negative voltage (typically -1000 to -2000 volts, depending on the type of tube. Then with each successive dynode at a successively more positive voltage to accellerate the electrons, the anode (where the electrical signal is collected) is at ground.
I remember being a kid and seeing a neutrino detector with a giant pool of water and these weird balls on the side. I had no idea how it worked, what it was called, or where it was, but was fascinated by the prospect of this enormous thing detecting the tiniest particles. I didn't know much more about it until now, and it's even more enormous than I thought it was. To hear it used vacuum tube photomultipliers brought back memories of seeing it for the first time. I didn't even know a disaster happened to it, let alone one that managed to not hurt anyone, but hearing you emphasize static pressure caused me to exclaim 'oh no. OH NO!'
The way the glass is manually blown and made is just fascinating!
At 21:05, this for some reason reminded me of the Monty Python logic that a piece of wood floats, just like a duck, therefore confirming that a witch is a witch.
Oh wow, what a throwback! My very first academical work was part of my final exams for our counterpart of highschool, and I wrote about neutrinos and their detection. Quite some of those pictures of the SuperK I used back then as well. Lovely. Thank you so much.
“Gather round and take heed” YES CHEF
are you also her
wo
No, please, don't launch your missiles into the- *IMPLOSION.WAV*
Omg you are also here. Love your videos
Omg it’s Lafayette Systems! Love your videos!
Fascina'ing! Disaster works via same kind of mechanism as the actual PMT tubes themselves.
We have one of the old Kamiokande photomultipliers at the physics department at Ohio state university. It's super fun walking by it every day because it truly is beautiful.
I started studying theoretical physics in late 1998 and all the particle physicists were really excited by Super Kamiokande. The now-famous papers on atmospheric neutrinos AND the discovery that the expansion of the universe was _accelerating_ had only come out a few weeks before I started college, so it was a pretty exciting time in physics 😀
Random question, was this facility built before the IceCube neutrino detector in Antarctica? I'm in college for physics now and I've never heard of this facility. You seem like you are pretty knowledgeable about this topic.
@@mrkeogh Must've felt pretty bad to miss out on all the break throughs and only get to study about it right after the fact!
@oonmm I guess it depends on your perspective. I assume the opposite. Scientific discoveries are based on all of the theory and discoveries that came before them, so really it's the difference between having a hand in completing one part of a puzzle, and getting to start on a new section that's just begun.
Sure, you have the less glorious task of making sure the newly completed section matches up with all the other completed parts, but you also have the opportunity to venture into uncharted territory and make new theories about how the next sections will come together in the future.
@@greebo4446 I remember in 1997 my school physics teacher being absolutely enthralled by the Cassini-Huygens probe launch, I used my dialup to read everything I could. As a kid the thought that it wouldn't reach Saturn till 2004 felt unbearable, but it arrived just as I started my physics degree. Such a wonderful thing to have something that drove my passion to reach fruition right at the time I was surrounded by physicists. In 2005 I was at Jodrell Bank, this astrophysicist in his 70's with a huge grey beard told me about being there in 1969 relaying signals from Apollo 11 to NASA while listening to every communication, then contrasting the brilliance of this probe's arrival.
When young we are privileged to see these scientific breakthroughs without having to wait decades after their inception. Scientists/engineers designing the next accelerator/detector/probe might well be retired by the time to fulfils its purpose, but in the meantime they get to enjoy the fruits of prior generations labour like retired JWST's designers having seen the Hubble Deep Field image for the first time.
@@jamesleishman8025 a quick google says that the Super-Kamiokande started operation in 1996 (the first kamiokande started service in 1983).
The IceCube started construction in 2005, became the biggest neutrino telescope in the 2005-2006 season, and was finished in 2010.
which mirrors what I thought - the IceCube is definitely newer, though the Super-Kamiokande has been upgraded as recently as 2020.
and while I’m at it, I can tell you the IceCube2 is in the federal approval process.
I've seen my wife watch crime videos, with the barely disguised foreshadowing, her being like "i knew it !", then getting some extra info or even plot twist at the end... she loves that... i think i didn't quite understand that feeling until watching your video.... damn, first time seeing one of yours, instantly subscribing, awesome storytelling ability, fr
Another really cool neutrino observatory is the IceCube Neutrino Observatory that is on, or rather, in, the South Pole.
It consists of over 5000 detectors, all buried between 1450 and 2450 meters below the Antarctic ice's surface, and spread out within the volume of a cubic kilometer (and there are plans to extend the observatory to cover a volume of 8 cubic kilometers).
@@_NaLo_ there was a series by a guy who was a support medical worker at that station. He showed about everything and everybody who was there when he was on winter sceleton crew. It was amazing. Working there must have been an adventure of a lifetime, akin to being on a space station. It's always the same people, you have to get along, only basic necessities, but still enough comfort to have some fun. They had an amazing library and reading room, everybody who went there brought a board game or a book, or a movie.
Quick! before it melts!
@@AllisterCaine Like being on a space station but at least you can go outside and get some fresh air!
glad they didn't choose the north pole.
@@AllisterCaine is this joe spins the globe?
Congrats on 100k!
Thanks very much!
I thought with traditional japanese naming, the third one would be called the Kamiokande64
There is a neutrino detector in Antarctica called iceCube…..which kind of fits in with that convention I guess
Fun Fact: Kamioka-NDE is actually a play on words.
'Kami o kande' means 'biting into god' : )
@@RoboBoddicker Oooh, cool!
They're following the Street Fighter naming scheme. The next one after Hyper would be Ultra.
@@RoboBoddicker Which is even funnier if you know their gods are capable of chewing metal and stone, at one point the sun goddess and her brother give each other objects to eat which like...deconceptualizes said objects. So if a Shinto god bit into you'd get deleted from the universe.
"Super Kamiokande" is possibly the greatest name for an experimental facility ever
And the SuperK is probably the *least* unhinged neutrino telescope! For the other ones we either drop strings of these bulbs into Antarctic ice/lake Baikal/the ocean (with an effective detector volume of like a cubic kilometer) or replace water with liquid chlorine (the higher density makes neutrino detection easier and allows for a much smaller volume to still be effective at detecting neutrino events, although with no spatial resolution)
Also I like to think of photomultipliers as reverse lightbulbs
why chlorine? why not something far less deadly?
Don't forget SNO, which is the same idea as super-K but filled with heavy water (D2O).
@@tsm688 cheap to get and the isotope resulting from the neutrino collision (Cl-37 to Ar-37) is radioactive but relatively stable and can be easily detected after extraction. To be precise, the tank was filled with tetrachloroetylene. Modern detectors of this type usually use gallium and gadolinium instead.
@@tsm688 Chlorine just like Lead, are amazing materials. Unfortunately, they are extremely intolerant to living things.
@@Deadly_Laser the reverse of a light bulb... So, like Dumbledore's de-luminator? 😁
1:45 the most physically catastrophic failure I can name off the top of my head involved a piece of metal perched precariously atop a screwdriver.
Demon-strating what?
We need to get to the core of this conversation..blue light
I think the crane and turbine faults are their own type of art, a self-disassembling structure.
To me that's one of the least physically catastrophic, just a small movement and a flash and then it was too late.
Another obscure science thing you might like to look at the engineering of: the LIGO gravitational wave detector. The tolerances on that thing are crazy small and yet they were able to detect in some detail the waves produced by two black holes colliding in some super distant galaxy. Then someone had the brilliant idea to represent the waves as sound waves. You know those things they sometimes have at museums where you roll a coin down a funnel? It sounds kind of like that, except with a weird bloop noise at the end.
@@psymar I work in the library of a university where some of our academics contribute to the LIGO-VIRGO projects and I think that manually inputting the 1000+ authors on the papers into our repository has given me some sort of psychic damage lmao
@@eilidhmm That's amazing, I wonder if you've set the record for entering the most author names on a single paper? Not being sarcastic here, you might want to send it to Guiness -- okay, never mind. I did the no-no on the internet and did some research before I posted:
> A physics paper published in Physical Review Letters in 2015 set a record with the highest number of authors, totaling 5,154 contributors. This paper was a joint effort from the ATLAS and CMS detector teams at the Large Hadron Collider (LHC) at CERN, aiming to provide a more precise estimate of the mass of the Higgs boson.
I guess you'll have to get a few more thousand scientists involved to get there.
Edit: I also found a journal article in Springer Nature titled "How many authors are (too) many? A retrospective, descriptive analysis of authorship in biomedical publications" which the most useless-sounding meta-science paper I've seen in a while. In fact, the statistic I got online is probably out of date, considering the article references a paper with 12,000+ authors relating to COVID. I will say that the authors (I know you're curious, so I checked -- the number is three authors for this one) do seem somewhat peeved at this, which makes it all the better:
> For example, 1014 authors are listed in a 2015-paper on fruit-fly genomics (Leung et al., 2015). Not less than 2080 authors are listed on a paper from high energy physics (Khachatryan et al., 2010), which “needed 165 lines on the PubMed site to spell out their surnames and initials” (Marusic et al., 2011). A 2017-paper in astrophysics had 3674 authors (Abbott et al., 2017) and in 2021, during the pandemic, the number of co-authors peaked at over 15,000 in a multi-center study on the efficacy of SARS-CoV-2 vaccination on post-surgical COVID-19 infections and mortality (Covidsurg Collaborative, 2021).
I will say that typing in a thousand-ish names sounds like a pain, typing in 15,000 sounds like actual torture.
@ I can tell you just from the lead author name that the Abbott et al. astrophysics paper referenced is from the LIGO project
*checks*
>[...] a binary neutron star coalescence candidate [...] was observed [...] by the Advanced LIGO and Advanced VIRGO detectors.
knew it haha
Thank you for one of the most interesting and educational videos I have watched in years, on a subject where I know radically less than the author and was completely enthralled the entire time.
If I had a nickle every time an in-depth youtube channel did a video centered on photomultipliers in the last week, I'd have two nickles, which isn't a lot, but weird it's happened twice.
(Asianometry and night vision for those curious)
Oooooh, time to check my subscriptions!
alpha phoenix recently too!
The aplifiers immidiatly reminded me of how nvgs work
While i knew that from other creators
I will also watch that video
Huh that’s cool. Off to watch that video now…
If I had a nickle every time i saw this "if i had a nickel" comment, I'd have two nickles, which isn't a lot, but weird it's happened twice in the same day...
I'm a nuclear engineer with over 30 years experience, well done on your physics explanations. I have used photomultiplier tubes and scintillating materials to detect gamma rays. They are amazing technology. Thank you for another well done video.
I know nothing about engineering or particle physics, but youtube begged me to watch this video and despite understanding maybe 1/5 of it, worth my time
Great video! Im currently working on my PhD doing analysis for SuperK and some electronics testing for HyperK, I first heard about this disaster from my future supervisor on the day of my interview so safe to say its still fresh in many peoples minds even this far along.
I had never seen that photograph from the top of the tank either will all those shredded PMTs! Things to keep us up at night when HyperK gets filled in a few years time (theres also maybe a future video there about the construction of the largest man made cavern that is ongoing to house the new detector!).
Oooh I knew about the Super-Kamiokande, but didn't know it had a failure that exploded ~6000 tubes.
@@orangejuche bro? Spoiler alert
@@jamieclarke321 watch the video before watching people comment about what happens in the video
@@Furko08 Comments appear at the bottom of the video?
@@jamieclarke321 did you not do the required reading?
Same mtrfkr
Gotta love the dedication. Even with the failure in the experiment this is truly an amazing task to take on.
The 21:48 Todd howard blink-or-you'll-miss-it reference for "8.4 times the [detail] resolution" was amazing, thank you for that one. Hyper-Kamiokande '76 will be a game changer for sure!
'That's why I give my kids Hyper Kamiokande 76'
* All 40000 photomultipliers simultaneously implode
@@Alexander-the-ok did someone say 40k... praise the emeperor
@@Alexander-the-ok Was that a cheeky play on words at 14:50 involving any rebukes mentioning the rebound effect? If its intentional i appreciate the wit!
Also in reference to the whoosh of the displaced air, did any of your research in this touch on the potential volume of all the tubes that were broken and say how much of a drop in water level that would've been? Id imagine the numbers are there itd be easy to calculate given the known quantities but i was just curious cause it might be an interesting metric to give an idea for the scale of it all.
I don't know which is more impressive; the physicists who come up with the ideas and experiments, or the engineers who design and build those experiments.
Well, I'll be honest, it feels really odd to see someone this much more of an expert than me in physics use my video as a recap, but I'm glad I could help.
Amazing video and I really love you putting it in context to show just how interesting even the failures can be, and to me I absolutely adore how for most failures like this it's not really "Engineers didn't think of it", only "Engineers did think of it, but..."
'More of an expert in physics'. Nah I'm clueless about most physics (especially particle physics). Your video was exactly the explanation I needed.
You could say that his video really helped "MAKiT Happen" [insert wheeze here]
I feel like most failures are "engineers learned a lot". It sometimes fascinates me how many things people can predict or expect, because I'm used to the model where you really don't know what will happen in engineering until you try and see what might.
Wow shit cool to see you here!
@@Yupppi You do not need to be an engineer to predict this... i remember that it took me few seconds to predict it when i was reading article about this setup in high-school.
The fact that the engineers explained it to themselves and convinced themselves that on paper it looks OK is nothing extraordinary. The same as the fact that something was unforeseen and that the failure occurred at the lowest point of the tank where the pressure is the highest.
"Murphy's law[a] is an adage or epigram that is typically stated as: "Anything that can go wrong will go wrong.".
Though similar statements and concepts have been made over the course of history, the law itself was coined by, and named after, American aerospace engineer Edward A. Murphy Jr.; its exact origins are debated, but it is generally agreed it originated from Murphy and his team following a mishap during rocket sled tests some time between 1948 and 1949, and was finalized and first popularized by testing project head John Stapp during a later press conference. Murphy's original quote was the precautionary design advice that "If there are two or more ways to do something and one of those results in a catastrophe, then someone will do it that way."
The law entered wider public knowledge in the late 1970s with the publication of Arthur Bloch's 1977 book Murphy's Law, and Other Reasons Why Things Go WRONG, which included other variations and corollaries of the law. Since then, Murphy's law has remained a popular (and occasionally misused) adage, though its accuracy has been disputed by academics. "
I remember seeing how big the vacuum bubbles were, how close to each other and how big the tank would be -> and consequently the mass of water exerting additional pressure... -> perfect setup for massive chain reaction.
While I was aware of the Super Kamiokande neutron detector I had not heard of this accident. It is always interesting that at the bleeding edge of technology no matter how careful engineers are there is often something they overlook leading to disaster, the Apollo 1 fire comes to mind. As you posted the detector was rebuilt and has made significant contributions to atomic physics.
I worked for the Baikal neutrino project, and we had one of those tubes over from Kamiokande one year when one of their physicists visited. It was a remarkable piece of equipment. Unfortunately, we had no chance to use it as the Baikal telescope is at a ~1300m depth.
On that note: We also had collapse, but it did not trigger a cascade for two main reasons: 1) PMs were spaced farther apart 2) Being open water, there was no wall to further reflect a shockwave.
They were installed in pairs. The adjacent module also imploded, but the effect did not propagate.
That being said, I was amazed to see the effects of such a high pressure collapse. (Titan vibes anyone?) The glass shattered into a sand-like granularity, and the shockwave instantly compressed it into something similar to sandstone. At first glance, I thought that it was some compacted snow, until I touched it.
Nothing was left of the whole module. Just the twisted metal frame and a few pieces of this glass sandstone.
I also liked the AMANDA (today Ice Cube) modules.
Okay, I just want to tell you that this started as a super neat video about a detector but in the end I was actually able to understand some really scientific concepts. This is incredible I cannot wait to watch and learn more.
I consider myself well informed but you manage to find topics I've never even heard of and put together super interesting videos. Thank you and great job!
Thanks very much! Honestly sometimes this channel sometimes feels like a compilation of ‘huh thats interesting. I never heard of this before’ topics I’ve stumbled across over the years.
Fantastic video of an extremely interesting topic.
The exacting standards of scientific equipment manufacturing is almost as mind blowing as the ideas being tested by the experiment.
The resolution of measurement at LIGO for example is utterly bonkers
When I served in HECU marines we were also tasked with resonance cascade event containment. Oh those were the days.
Having seen material on the Kamiokande disaster I’m appreciative that you expanded on this topic in greater detail.
I haven't encountered this many dropped tees since my time at the Klutz's Golf Equipment Convention!
Thanks for the great video.
I was quiet puzzled by that. Unda wo-a :)
Thanks for the great explanation.
I actually saw one of the tubes when visiting Tokyo. Having seen one of the tubes in person really gives you a sense of scale of the complete setup.
Wait I’ve actually been so interested in this since you mentioned it offhand in that oceangate video thank you Alexander the OK
Alex is incredible at expressing anything intuitively and I love how he does it in such a way he makes his passion infectious, the ability to make people so interested and invested into something many never knew about beforehand is a great quality to have.
Quickly becoming my favourite channel on the entire platform.
This video was so cool! I always found the subject of neutrinos to be fascinating, especially considering how annoying they can be when it comes to detecting them, and seeing that massive chamber used to detect it was incredible. Of course, it was very frustrating to hear about the cascade testing they did, because as anybody who's gone scuba diving can tell you, there's a big difference between 1 meter and even just 3 meters, let alone the pressure you'd be experiencing at the bottom of a massive tank like that. Still, super informative and cool, and I applaud your ability to only make one single half life reference in the entire video, that must've taken some restraint
I was going to add a bit about my experience with that with all the drysuit diving ive done. But since I couldn’t really be bothered to do the maths or simulate it, i left it as ambiguous.
you dont know what got left on the cutingrome flore
xkcd 73 - neutrinos are just a tiny bit too elusive for any "simple" solutions :P
This is a very neat video on a ridiculously fascinating subject, I didn't even know such a failure occurred. But I'd pay some real money to see what this looked like in the moment
1:58 Finally, the Resonance Cascade *in real life.*
Those are really a thing of beauty. The picture of the imploded tubes is just eye watering.
“STATIC…pressure”
Oh boy. Slooshy shloshy, splishy splashy, your bulbs are now battered smashy!
Thank you for the video.
When you mentioned in the other video the Super Kamiokande Cascade Failure I looked it up.
Found only the official report.
It was a very nice read.
I was impressed about the rebuilding efforts.
You know ... super pure water also means super clean water.
And that means that SUPER cleaning up the mess from the Cascade Failure.
Sure, remove everything, fully test what seems usable and rebuild it "as new" ... but actually doing all of that ... WOW.
And they did.
A marvel of re-usability and repair :)))))
"Photo multiplier" -- Holy glottal stop Batman!
As a wannabe voice-actor, I had a go at imitating Alexander's accent while watching this. The inconsistency of the glottal stop is killing meeeeee
fitting the topic of the video: ッ
@@ibahart3771ironically he has one of the more consistent t stopping overall, as in, he stops almost every /t/ that _can_ be affected (which isn't all of them, something something post-tonic and within the same intonational foot.. iunno, Dr. Geoff Lindsey has a video that explains it).
it is just a matter of fact that this feature is associated with "casual, unclear speech" (as well as "low class" but that fortunately doesn't seem to bother him) so pretty much everyone with it will switch to using a regular [tʰ] in slow and enunciated speech (whence his [statʰɪk] instead of [staʔɪk])
If you want to really twist a non-native speaker’s tongue, have them say “the sixth physicist”! 😂
Thank Alex, I found your ‘self critical’ overview of Japan’s Kamiokande failure very interesting and in consequence learned a great deal as a result.
I was a graduate student within the particle astrophysics community (on a different experiment). I remember when the news & rumors of Super-K’s implosion spread through the community.
A little while later I saw a presentation by one of the Super-K scientists, in which a short movie of a later test was shown. At the time it was said ‘no I cannot give you a copy of this, just remember it,’ and even 25 years later I’ve never seen the movie in the public. The question was that while the dynamic pressure is incredibly high as detailed by Alexander, the tubes were designed and tested to survive the dynamic pressure of an implosion too. The super-slow motion movie showed a 3x3 grid of phototubes at depth, and the middle tube was purposefully imploded (small charge). The surrounding tubes survived the initial shock, but then the water flowed into the space left by the imploded tube and all the surrounding tubes leaned in towards the missing tube and broke *at the neck*. The tubes look like great big light bulbs, and the rush of water pushed on the large glass globes snapping off the necks. It wasn’t the shock, it was the water flowing past that propagated the implosion.
The fix included baffles to slow water flow and metal supports so sideways forces were not all born by the neck of the tube. In the end the tubes had been tested against the shock of an implosion, but not the effect of water rushing past the ‘sail’ of the large glass bulbs and popping the neck.
Wow thats actually kind of interesting abd a bummer because I bet that slowmo video would be insanely cool to watch!!, I was also kind of wondering about that in relation to that woosh of air that was described in the video Id be curious to know by how much say the water level dropped, it wasnt full or it was being filled so i guess it wouldn't be as easy to tell immediately but i would think the volume of all the tubes that broke could be figured out pretty easily it would make a interesting bit of fetail.
Great video and explanation! I worked at the IMB detector located in the Morton salt mine in Fairport Ohio years ago. We also used the Hamamatsu tubes. We also use the smaller EMI tubes.
"A resonance cascade scenario is extremely unlikely."
"Gordon doesn't need to hear about all this, he's a highly trained professional."
Particle physicist here!
Great video, I didn't know about that cascade failure at SK!
I suggest you have a look at the marvel of engineering that are the LHC and detectors like ATLAS, it's more than fascinating! There are easily a dozen subjects to be covered on the topic. Most people only know about the proton-proton collisions, but it is worth talking about the superconducting cryomagnets, the RF accelerating cavities, the beam dump, the security systems, the vacuum, the immense injection chain, the beam dynamics and focusing, about how new problems where overcome (the so-called "UFOs", the wake field, etc), and I could go on. And frankly, all the detectors are marvels of engineering too, I could easily list a dozen subjets that would require a video each.
And if you have a particular interest in what we can learn from failures (and if you like cascade events that lead to destruction), have a look at the 2008 incident, where a magnet interconnect failed, leading to an electric arc which dissipated some 275 MJ. It burnt through beam vacuum and cryogenic lines, rapidly releasing about 2 tons of liquid helium into the vacuum enclosure. The pressure valves where not designed for such a high dynamic pressure, and the pressure wave propagated from one magnet to the next one, destroying everything along the way (until it reached stronger valves, if I remember correctly), delaying the start of LHC operation, costing a lost of money, forcing to operate at weaker energies, and forcing an upgrade to operate at higher energies.
Amazing! I have read about all 3 of these machines over the years. Not once did I come across this disaster. Thanks for fully explaining it!
Funny... I knew all the background information and immediately foresaw the basic shape of what must have happened, but as a surveyor of all physics and engineering, I sometimes miss news items. So I never heard about the fairy tale cascade failure. The conclusion of designing and testing for the worst case is very much my mantra. Now I know this one, and I thank you!
Kamiokande is one of the worlds greatest and most underrated experiment. That said, I'm also reminded of the similar arctic ice cube neutrino/particle detector! They're soooo cool.
Thank you, sir! Your explanation clicked right along with me, even though I am an electrical engineer, specifically computer networks, but your flavor of description is easy for me to follow.
In high school and college, my father (Masters degree in zoology) had filled me with such a love of science I was fascinated with astrophysics and quantum physics, and padded my course load with subjects I knew I wouldn’t pursue in work. I was part of a team of students in Omaha, Nebraska, USA who, along with other groups the world over, provided proof calculations to the MIT study that predicted the proper stable orbit radius for light circling a black hole. Still theoretical, as we have a lack of singularities locally, but… LOL! I’m retired now and still dig through science here on RUclips to keep my brain running!
I think the cost of PMTs you quoted is in Yen. From what I have seen the main PMTs cost around $3000 and the outer PMTs cost $1000 so the total cost was somewhere around 22 million USD(very rough approximation) adding the additional clearance costs. Apart from that, splendid video. Asking the researchers permission for footage was a very nice thing to do, anyone else would've used small clips to try and skirt fair use. Can't wait for the next one(silently hoping for more particle physics)
Best sub I've made in months, years maybe! This channel is likely to be a big deal on RUclips, or I'll eat my hat. Superb writing, subject matter, diction, humor, absolutely outstanding and fascinating content that sheds light ( no pun, swearsies) and shreds ignotance, can't wait to binge every video. I put you in the class of channels like The Entire History of the Universe, Technology Connections, Kurzgesagt, hbomberguy, Vsauce, Then and Now, and Folding Ideas. Channels like yours enrich my mind and life and I can't thank you and channels like yours for your hard work informing and encouraging our minds to be more nimble, funny, and thoughtful.
the fucking Todd Howard split second killed me
I have a good friend who got to work here during his post doctorate years. I have an e-mail he sent from under that mountain. He also had one of the vacuum tubes from that. He explained what happened with this 'oops' and it was one of those things one could excuse the engineers for missing that could happen. What was more cool is he explained how the whole thing worked in language even I could understand. Oh and he keeps his PHD certificate in the envelope it was mailed to him in. He passed it around at a house party at one point. I asked him once to show me the math behind what he did. I followed it for like the first two steps. He told me it was far more important to understand the overall concept than the equations. He's now working as a professor in the UK. His students are incredibly fortunate.
For an incident in a similar vein look up the 2008 LHC "incident" where, during power tests in the process of bringing the LHC online, an electronical connection was less superconducting than it was supposed to be. It quenched. The result: An insane amount of electrical energy had nowhere to go but to through a now normal conductor, instantly boiling significant amounts of liquid helium and ripping the LHC apart in the process.
Yes I remember that. It was also very embarrassing for the US university that had worked on the design of these magnets.
Still, they got the LHC right in the end. It’s an amazing machine. The beam energy is fantastic. I once calculated that the amount of kinetic energy in the bunches of particles was about the same as the USS Nimitz doing 10knots (if I remember my sums correctly!). That’s a lot.
Even more amazingly, they have a means of dumping this energy if they have to. There’s a beam dump, basically a large magnet that can be turned on quickly which redirects the beam out of the machine and into a cavern which they filled with graphite blocks. The particles hit the carbon and the energy is converted into heat. It’s a bit like stopping the Nimitz inside a few metres braking distance!
Appreciate the use of CJK font for a video about japan :)
Absolutely stellar work as always, mr Alexander the Overly Modest!
I used to participate in Oceanographic Research and we would use light bulbs as a sound source after environmental concerns were raised about using explosives. It’s been many years but I want to say 150W Philco manufactured light bulbs were my colleagues favorite. It gave a really high intensity wideband acoustic source.
Excellent video, and I also greaty appreciate your font choice
I just think you are so neat. I love that you talk about what interests you, and in such an interesting and compassionate way.
I am always hoping to find channels like this from genuine people who aren’t sharing their learning for money but for the sake of sharing something interesting to them and creating. I am glad I found your channel, it makes me reflect on risk within my own industry and work too.
Thanks very much. As a full disclosure, I do make profit from most videos. But I also turn down a lot of money by not taking sponsors/talking about topics I don't care about that would get more views etc etc.
i got a kick out of the full width font used for English in Japan and Asia generally, very nice
Same! It’s a very nice touch.
Congratulations! This is a very well conducted video, that doesn't require a previous MSc in Theoretical Physics - it can be understood by anyone with a minimum knowledge of Physics!
Wouldn't it be something if, many years from now, at the end of his life, a technician admitted that he dropped a tool on that specific tube and didn't want to tell anyone because of the aggressive anti-failure culture in Japan.
Like the opposite of the guy that threw a chain into a generator of an oil rig I was working on in protest to being made redundant.
@@Alexander-the-ok bro what. You've gotta tell us the full story there
@@natejohnson6269 Normally crew aren’t told they are getting made redundant whilst on a rig for this exact reason. But someone found a line in the financial report for the company that the rig was being mothballed, the implication being that the crew would be released (most were contractors). Guy threw a chain in a generator gearbox and shut the rig down for a week.
No one ever figured out who the person that threw the chain was. The total cost in repairs and lost time was probably in excess of $1 million.
I love how you say "pho'omul'iplier"
@@Pentalaimon indeed, it's like the letter T is as rare as neutrinos in his accent!
Bravo for your accurate representation of the compressibility of water.
I really appreciate the time you took to explain how photomultipliers work, great video as always!
1:55 I can hear that "They're waiting for you Gordon, in the test chambeerrrr" anywhere.
Good reference.
9:03 That's an object of beauty. And the photomultiplier is neat, too.
16:05 That phenomenon is basically an insane version of waterhammer, which is an engineering nightmare by itself.
21:48 Does it also have 16 times the detail?
He says 8.4x volume, that is like 4.13x area (if tank proportions stay the same), the tubes are supposed to be the same, so a little over 4x the resolution or twice as much "pixels" in each dimension
@@perz1val I don't think the goal is so much "more resolution" as much as it is "Seeing more interactions"
Glad I'm not the only one who giggled at the Todd "16x the detail!" Howard reference.
@@perz1val I still wonder, why not use a hexagonal packing for the sensors? It's the optimal packing for circles on a plane or cylinder.
@@samuels1123 I think they don't care as much about it to risk denser packing and increasing the chances of another cascade. I think if they would, they'd make a smaller detector with smaller tubes, packed as dense as possible (maybe even hexagonal tubes) for more precise measurements. I don't remember the number, but since they detect quite a few neutrinos daily, trading quantity for precision doesn't seem like a bad idea. The scientists must have their reasons to just want a bigger detector instead, I have no idea
This might be one of my new favorite channels. Congrats on 100k! Cant wait to see the Mriya video! I really like the Buran and Shuttle videos!!! Very well done!
22:15 man now Im sad seeing it again
Thank You for your simple explanation... I'm a physics "curious" myself (self teached...) and always have been curious about the Super Kamiokande... and other neutrino detectors, and more about the one more near where I live... The KM3NeT that is located in the near bottom of the Mediterranean Sea...