Thanks so much for watching! If you want to know what would happen if you swim in a nuclear spent fuel pool, please check out: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-diHG9W27XeU.htmlsi=BAmacDMhoZZNrPcM
You don't need water for Cherenkov radiation, you need a transparent medium in which light travels slower than c. Glass fulfills that requirement, so it could be that those glass/cesium rods glow by themselves.
I think you were maybe a little conservative on some of the estimates considering we are trying to predict when the last surviving example will fail. By definition this is going to be the most extreme outlier in terms of longevity. For the solar lights for example it is probably going to be the one unit out of millions who's panels won the silicon lottery, got incorporated in a robust design that was assembled on a particularly good day for the factory, and was installed in a region of the world with calm temperate weather and regular rainfall etc. It is that one that kept getting lucky with pretty much every variable favouring it's longevity more than any of it's millions of peers anywhere on the planet or at least enough of them to beat every other unit anywhere on earth.
I think he is referring to the Cherenkov glow happening the glass surrounding the cesium. So no pool or water is necessary - it's happening in the glass that's inside the dry casks.
That's exactly what he's referring to, but it's my understanding that those glass caskets are also covered in an opaque substances, i.e. concrete or something, whatever. then it becomes an argument of whether or not if you stick a light bulb inside of a box, is it still making light.
25:11 I think the argument being made here is that Cesium _mixed with glass_ would generate Checknov radiation even in the absence of water. After all, the source of the glow is the fact that the radioactive decay products are moving faster than the speed of light in the medium they are passing through, and glass, just like water, has a lower speed of light than, say, air. How realistic this is depends upon: * Do glass + Cesium rods exist? * Is the speed of light in glass low enough (& rhe decay energies high enough) to produce the desired glow? * Is glass + Cesium even transparent? If the mixture is only translucent, then the glow would be dramatically reduced * Does this even qualify as "artificial light"? If it does, then there are some very slow burning underground coal fires that need to be considered as well.
One of high-grade nuclear waste handling method is a "glassification", when waste after couple decades of wet, then dry storage, mixs with glass. Glassified waste is durable, dont leak anything including gases, dont produce dust, and overall very inert.
Glass rod do not exist but radioactive waste is many times vitrified as it is a very stable product resistant to acids, temperature and insoluble in water. Those glasses are yellowish in general and translucent not transparent (the Uranium ones at least). It can generate light but I think very little probably not visible at normal light conditions, maybe in the dark, As speed of light in glasses is smaller than in water lower energy neutrons can reach it but those vitro-ceramic materials are very better in absorbing neutrons than water and the quantity of material in those pellets is made to be small enough so less heat is generated.
The sample was cesium chloride, and reported color is similar to that which appears during a cesium chloride flame test, suggesting that it has a pretty decent likelihood of primarily being fluorescence. A flame test achieves broad electron excitation through heat, and the source in that incident wouldn't be hot like that, but energetic particles from radioactive decay are also quite capable of depositing energy into electrons. @@hardnachopuppy
12:00 Bad timing has it happen that the Svartsengi power plant is currently offline, after being evacuated around the same time the XKCD video was published. There's an ongoing volcanic eruption, with lava currently flowing within a few hundred meters from the plant.
It's worth noting that the 100 years for a call box is the luckiest of all the call boxes in that climate. We're talking about the last light, not how long a type of light is reliable, and types with independent instances get the chance to have a wide spread of lucky and unlucky individuals. Similarly, I think it's likely that the luckiest wind turbine will last 7 times as long as it was rated for.
@@Isaacrl67 and they literally will not make bulbs like that again. Look up the “lightbulb cartel” all the manufacturers made agreements when they first thought the lifespan of light bulbs was getting too high. Even with it officially dissolved now they still tend to keep to said agreements.
@@nathnathnI mean, also, the physics required to make the bulb last as long as it has also mean the light it produces isn't that great for everyday use. As someone who usually hates large companies doing things to make their products worse, I actually believe the Lightbulb Cartel was a good thing. After all, having your bulbs able to last through centuries of use, doesn't mean they can last through *misuse* . And if everyone buys bulbs that last seemingly forever, the industry for bulbs stops being profitable (because not enough people buy *new* bulbs after the initial wave of purchases) and dies. All of the sudden, you have a scenario where people could be relying on a product that could be broken by someone throwing something at a bad angle. Suddenly, a hospital is without light and there's no means of getting more bulbs. The Centennial Bulb was invented in the early 1900s, long before the internet. In modern day, there'd probably be loads of DIY lightbulb videos, but back then, someone had to mass produce them for us.
@@Rot8erConeX consider that new buildings are being constructed everywhere, always. The lightbulb industry was never in any danger of disappearing, merely in danger of making a handful of billionaires a few billion less per year.
22:00 the thing is, we are trying to find the last light, not design the longest light. if a solar phone station gets take out by an unlucky storm, THAT one is down, but the others are still up. if its a 1% chance any individual one will survive 100 years, its ok, there are 10000 of them
24:25 he isn't talking about in fuel pools. he is talking about places where it has been melted into blocks of glass and wrapped in concrete and shielding.
I think he mentioned something about RTG radar monitoring stations in the book entry, but I can't remember right off the top of my head. I know RTGs on some space craft were mentioned, but their problems were they either needed commands to turn on, or didn't have lights.
Yeah, my Dad worked on satellites (mostly on the testing side) and he says he always laughs at the satellites in movies all lit up with LED lights -- not only would that be a waste of the power they need to actually run the satellite, but it isn't like there's anyone there to see them!
I really liked this XKCD thing because it referenced two pretty awesome things, Alan Weisman's book "The World Without Us", and the TV series "Life After People".
Two south Korean Samsung workers were just recently hospitalized because of X-ray exposure. Might be a good topic for a video that isn't a react video.
There was actually a mistake about Svartsengi Geothermal Plant. It isn't an island. My guess is that somewhere while researching for the script they read on a source with the icelandic name "Svartsengi, Ísland", but Ísland here is the icelandic word for Iceland, not island. So yeah, Svartsengi is connected to the main grid. However, important note here: this is the ICELANDIC power grid. The power grid of an island in the middle of the atlantic, not connected to the rest of Europe. And which as it happens, is powered basically in its entirety by either Geothermal or Hydro power. So there would be no coal plants running out, and if other Geothermal plants and Hydro dams keep running, there would probably not be any under frequency issue I'd think Edit: also, fun fact, you might've heard about the Blue Lagoon? a tourist hotspot. Well, that lagoon isn't a natural one, but a man made one. It is in fact the wastewater from the Svartsengi Plant (both the power plant and the blue lagoon are in the area of Svartsengi) After using the heat to turn turbines, they dump the wastewater onto the ground. The original idea was that it would then flow back into the ground water, but it had so much minerals that deposited and made a layer on the bottom that then kept the water from flowing straight through the ground, making a big ass lagoon by the power plant Later people starting bathing in the mineral water, and found out it was really healthy. Then they built a spa there and started charging people haha
@@piratekingomega3292 So according to that logic, saying "London City Island Airport" for "London City Airport" is correct, because London City is just a region on an island
I think the winner are those pesky solar lights people stick into their backyards. When my sister became pregnant, she moved away and the tenants renting the flat had put cheap lights from a dollar store all over the place. Most of them are still glowing (faintly). And my nice is 17 years old now. Anything connected to a power grid will fail, no matter if the power sources could still be going.
If the batteries hold out, sure. Of all the one's I've ever had, the batteries die, then the cheap solar cells die, and some million years later, the LEDs stop working. (but you'd never know after the batteries fail) I have LED lights in my house that have been on for over a decade... as long as the grid works, they work. Which is pretty much the answer here. Even an incandescent bulb can last decades. (CFL's maybe a few years before the ballast fails)
@@jfbeam The solar cells don't die all that quickly, UV light reacts with the resin coating and turns it cloudy. You can polish the resin and get them working again. The 100+ year lifespan sounds possible, 80's era solar calculators are still going. There's a few projects (forever flashers) where they have a solar cell charging a capacitor & blinking a LED that have been running for over 20 years. I made a solar powered clock that uses a supercap, it's still ticking after 10 years. But yeah, batteries & corrosion are the main garden light killers.
If we are going to consider any and all light sources that humans are directly responsible for creating. Then i would say something like the centralia (or other) underground coal seam fires would take the crown
I think you are correct, and that one is expected to burn for at least 250 years. Wingen, New South Wales, AU is believed to have been burning for 6000 years. It may have been started by a human, if the old story has any truth to it: [ The Aborigines named the mountain Wingen, which means 'fire'. Their explanation of the origin of the burning mountain was that one day, a tribesman was lighting a fire on the mountainside when he was carried off deep into the earth by The Evil One. Unable to escape, he used his fire stick to set the mountain alight, so that the smoke might warn others to keep away.]
The difference is that spent nuclear fuel gives off Cherenkov radiation through a natural process but is itself artificially created (as a byproduct) whereas underground coal seam fires are natural fuel sources that were ignited (accidentally) due to human interference. I’d say that the first is a man made light source created accidentally but the second is a natural light source merely ignited accidentally. Potentially a coal seam fire could ignite through freak natural circumstance but spent nuclear fuel infused into glass is a human made waste product.
@@ChocolatierRob What about gas well flaring? The gas is deliberately lit, couldn't be accessed naturally and if left alone could stay burning for centuries depending on the reserve.
@@calebbannister Thanks! Indeed a joke, trying to lighten-up (pun intended) a very bleek situation. The mere thought of the last human is to me a true nightmare.
@@calebbannister Thank you for the suggestion, much appreciated! Using g00gle I did find some hits on 'twilight zone last human on earth' so worth looking into. Again, thank you!
10:00 Depending on what kind of light bulb it is, it could _easily_ last longer than the generator. Incandescent bulbs last a _very_ long time if they are not switched off and on again, what wears them out is the thermal shock from the filament going from room temperature to 3,000 degrees and back. If they are left on permanently, like the lights outside police or fire stations, they can last over a century. I can't see any generators doing that without refueling or maintenance. LED bulbs last a lot longer in domestic use when you are switching them on and off multiple times a day, but for continuous use long-term, they don't last as long.
how long could a nuclear power plant last if the operators knew beforehand and were motivated to keep it running as long as possible without people and without a grid?
Even in only standby power probably not as long as you would think for a commercial plant. The first maintenance issue to pop up would probably eventually trip the reactor due to lack of human response to alerts. Honestly military reactors on idle might last longer but we as far as i know we literally don’t know how long they could and if they would even power lights on idle or even stay in idle instead running a automated shutdown.
The History Channel had a series "Life After People" and they noted that some hydroelectric plants would keep running for a while. Hoover Dam power would keep going for a couple of years. (They also covered various nuclear topics, maybe take a look at some of those?)
Life After People was complete bull.... I don't know who they had writing or consulting, but they got basically _everything_ wrong. Hydro plants will _NOT_ work for very long without the people who maintain them -- mostly clearing trash from the inlets. As mentioned here, there are a ton of protective mechanisms in place that will trip a plant offline if voltage or frequency gets too far out of spec. (and frequency is very sensitive.)
16:52 When I was younger, I remember stomping around in the woods/swamp at the Hog Island Wildlife Management area. To access Hog Island, we had to drive past the Surry Nuclear power station. I bet they don't let cars get as close as we used to. EDIT: I wonder if there are status LED's on the voyager probes? They're RTG powered.
RTGs would probably break down about the same time as solar panels, since it's the electronics and wires that were said to be corroding. A problem an RTG powered light would share as well.
I'm glad you took a look at this video. You partially answered a question that I've had for a long time about nuclear power plants. "How long does it take for decay heat to drop to a point where active cooling is no longer necessary to keep a nuclear plant that's in shutdown from melting down? Is there usually enough generator power available without intervention to account for this? Or, if every nuclear engineer on the planet stops existing, does that mean that every nuclear plant on the planet is basically going to eventually meltdown?" It sounds like the answer kind of is "yes". Or at least, the spent fuel pools will.
Isn’t XKCD talking specifically about Cherenkov radiation from spent fuel encased in glass there, not stored in water? Presumably it’s less radioactive by that stage but it seems reasonable that it’ll still be glowing dimly several half lives later. It does seem to stretch the definition of a light though, so I agree he could’ve given RTGs a mention. Are there any status lights on the Perseverance rover?
Led Lights can work 10.000 hours and if they are running at low power they can only work up to 20.000 hours problem is not the power source the problem is Light source
Candu reactors automatically switch to "passive cooling" in cases of emergancy, even with no pumps a Candu will continue cooling, continue cooling the pool, and yeah, even continue generating a small amount of power for monitoring systems as a "loop"
Honestly, when WHAT - IF makes a vid, I just wait for you to show up in my recommendations again. I might argue that the last light mentioned in the video is not an "artificial light" being that it's a natural product and it happens because physics.
The grid powering the Province of Québec in Canada runs almost entirely on Hydro and wind power. They have essentially no fossil fuel and the grid is independent from the rest of Canada and the USA In principle it could last significantly longer than the rest of the country as they would be isolated from the cascading power failure But without people to maintain the infrastructure, I have no doubt it would be down in matter of months or a few years.
If you want to be fair: When oxidizing uranium like the other fuels listed at 5:30, the energy content would be 4.6MJ/kg, much worse than most hydrocarbons. On the other hand if you were to use nuclear fusion with all the hydrogen in sugar, it would have a similar ballpark of the uranium in terms of energy density.
My only complaint from this video is 25:10 "our most toxic waste". This has a distinct anti-nuclear feel to it, feeding the fear of "nuclear waste". The waste referenced is going to be very weak in radioactivity after those 100+ years, and gets less toxic over time due to radioactive decay. Compare that to almost anything else - microplastics, mercury, lead, or a nice coal-ash tailings pile full of heavy metals. Those DON'T go away and are far more toxic.
A house with a free standing solar power can last for decades also. Several restpoints on outback roads have solar power that has not needed maintenance for 30 plus years
I was surprised he didn't mention RTGs too. My mind immediately jumped to the hundreds that were peppered around the USSR. Scrap metal sellers find them sometimes and bad things happen.
By first thought would be a isolated off-grid solar panel in a optimum region that just connected to a light the batteries would die but it would keep working in daylight hours until the panel‘s degrade to the point they cant even sustain led lights.
In his book What If, Randall did mention space probes that use RTG’s, but they generally don’t have lights on them, or they need to be turned on manually. Even satellites in geosynchronous orbit wouldn’t last more than a century or so as they succumb to space debris impacts or their orbits decay
I think the last artificial light would be the LED on the small pump that my wife has installed for automatic daily irrigation of her plants on our balcony (battery powered, solar charged), because these plants must not die under any circumstances.
Everyone is stuck thinking about the grid. The grid will fail in days, if not hours. With the scenario of all humans suddenly, and instantly disappearing, no one turned anything off, and no one is around to turn anything on, so whatever load was on the grid will pretty much *be* the load on the grid. Yes, there are things that have timers... EV's being charged, clothes drier, microwave oven, etc. But the majority of things are on until we turn them back off... lights, heaters, conventional stove / oven, TV's, computer, etc., etc. Coal fired plants could begin falling off the grid within hours - depending on how fast the coal is consumed, and when the guy that drives the dozer that fills the hopper went to lunch. As plants start to go offline, there will be a cascade of plants tripping as they can't take the load, and as remaining capacity cannot react to the load causing a low frequency trip - those things can blackout an entire grid. While there will be many fully operational power plants, they won't even attempt to power the grid alone, and with no load, they'll completely shutdown. So, the only lights remaining would be from micro-grid, or totally off-grid power sources. Solar is a good candidate, but most solar panels won't last beyond a few decades. Even if their control electronics still work, they'll make too little power to be operational. All those solar emergency kiosk lights will fail within a few years because they have lead-acid batteries in them. (5yr would be a good life out of them) Your garden gnome lights are likely to out last them - even with their even cheaper li-ion cell. RTG's would likely be the ultimate winner, but where do we have any RTG powered lights? Spacecraft don't waste the space, mass, and power with LEDs. Where are the terrestrial RTG's?
Y'know its easy to miss RTGs as these are really not normally part of the everyday human infrastructure power grids, both on or off line because their power output levels are too small for any normal human use. They're perfect for remote operated drones that operates on microwatt power levels over the course of multi years or decades long missions. Perfect example are the Voyager probes, whise RTGs have managed to last for nearly 50 years, far longer than they were intended to operate, LOL! The New Horizon operates on a slightly more powerful RTG (actually, most of the improvements are in the increased efficiency of the infividual on-board component's power consumption levels coupled with a slightly mire efficient RTG design. Twill be interesting to see how long the New Horizon mission will last ...assuming it survives budgetary cuts, that is.
Some very sturdy solar-powered lighthouse, probably European made in Norway or something. I bet that would be the last light to ever go out permanently. There are some really sturdy automatic lights out there.
There's gonna be a solar powered LED porch light that survives for 100 years or more, even though the battery life will be shit, it'll still come on for a few seconds every night. House lighting in off-grid houses, boats, etc will have the same odd survivor or two as well. EDIT: Wait. The Darvaza Gas Crater is a man-made disaster. There are other gas flames that were lit by humans that are fed by natural gas wells. Those could last thousands of years in some cases.
I believe that the svartsengi power plant supplies a majority of the power for Iceland which I would assume has an isolated grid so I’m guessing it wouldn’t be susceptible to grid collapse because it *is* the grid
I operate a cogen (power) boiler, as long as nothing catastrophic happens it would run without humans for about two days. That's without a load. With a normal load it would run for 10 to 12 hours before fuel ran out.
Cherenkov radiation can still happen in glass, as light speed in glass is even slower than in water requiring less energetic electrons, but electrons are absorbed more too.
@@xyzaxy230 The Cherenkov radiation peaks in UV what we see is the tail end of the spectrum in blue. The dependency spectrum on particle energy is complex and is given by Frank-Tamm formula (look Wipedia for that) and is a continous spectrum. But less energetic particless will not produce it so not peak in visible wavelenghts. I corrected the comment as Neutrons don't cause Cherenkov radiation, just charged particles (I don't know why I wrote it wrong). The Cherenkov radiation in glass is used in particle detectors, usually discriminating light particles that are faster for the same energy than heavy ones.
very interesting, thank you! regarding how green wind turbines are... the thing that bothers me is, that they, as anything else, don't produce energy, but rather take the energy of the wind which in it self has the potential of not being too green (as it is directly interferring with climate). i would imagine that the effect is quite small, but on the other hand i couldn't find anything about it in literature.
Any sort of light on a console or beacon or whatever the bulb/LED would burn out, so it doesn't matter if an RTG has one connected to it, the light went out sooner than the RTG. It would need to be an LED and also extremely intermittent, which I think someone needs to find a clear example of to claim it as an answer, not just assume "something like that probably exists"
the problem with solar: the backsheet will fall apart after years of sun abuse. also a bat that lasts 100 years? i dunno.. even if u baby a lipo bat.. it will fail in some years
18:21 So basically anything capable of decreasing the safe lifespan of dry cask storage is likely to be a much bigger immediate issue than the fact that your radioactive waste is escaping 🤣
You mentioned that the light bulb would probably go out first, I don't think that's true. Even an incandescent light bulb would last around a thousand hours. Turning lights on and off is what lowers the life of any bulb. Leave the bulb on in a cool environment it would probably last 1k+ hours.
Question for you (has nothing to do with *this* video -- that Natrium (Sodium cooled) breeder reactor Gates is building - (Terrapower) is that at risk for a Bethe-Tait style meltdown disaster if cooling fails?
Why does that RTG in the beginning have a pressure relieve valve? Gasious fission products have a shorter lifetime then their solid parents or products right? So what pressure is it relieveing? One atm to space vacuum?
Most cities will burn due to gas stoves, ovens even irons being left on. These fires might trip sections of the power grid shedding the load. I believe in the instant disappearence of entire humanity, grid might survive, at least in some places, much longer than mentioned in the video.
21:06 Here is a thought if the light of the wind turbine or solar panel turns off due to weather but turns on later is it back in the running for last light? 24:31 What about a rain fed pool?
Have you seen the channel, "That Chernobyl Guy"? I ask because I first found your channel from your commentary from the HBO miniseries and he has a video, "Top 10 Chernobyl Propaganda Myths vs Reality" that references the show and I would love to see your reaction to that
Interesting I'm always interested in what would happen without people. Hydroelectric plants would continue for a while maybe until a fault to ground our turbine bearings fail. What about solar and wind farms. 🤔
Why would a reactor rely on the grid for turbine power? Why would it not use a fraction of its output? To bootstrap I can see, but why shut off when you're producing enough energy to keep going by yourself?
The turbines shut down when the grid goes down. They can't produce tiny amounts of electricity, only megawatts, and with nowhere for the power to go they have to disconnect, so would not be available to the plant's systems any more than the grid would.
I enjoy watching your reaction videos and have been subscribed for some time. I have relatives who go to and work at Georgia Tech, which I think is the university over your shoulder. Anyway, I wish that you wouldn't stop/interrupt quite so often. Simply making a quick comment without stopping the playback might be more useful and less... interruptive but to be fair, you do that occasionally. Thanks for the entertainment.
If he talks over the video then he will miss things. I wish more reactors would pause what they are watching if they have a comment more than a few words long.
A show Life after people in 2009 exampled with a cooling pond running out of diesel backup boiling off and burning. ALL ACROSS THE WORLD. So Chernobyl everywhere all at once :) for years. Key point, don't survive the apocalypse unless you wanna experience the truest hell on earth.
16:20 soo this is the thing i dont get right because ... i mean your whole thing right as a power plant is taking thermal energy and turning it into electrical energy right ... and here you have a souse of thermal energy ... but are like oh know we have no electricity to make the pumps go ... and i just stand here and look at the hot think in the pool of warming waters and be like uhhh ..
9:10 i'll be honest i woul d have thought a power plant would use battery rather than a diesel generator ... as as for a nuclear power plant ... i mean even once its shut down .. you still have a lot of decay heat in that core im suppressed that cant be used to generate steam for a back up turbine or even and old school triple expiration steam engine cant remember where i heard it bbut i think rule of thumb was a nuclear power plant needs like 10%? of its rated out put just to cool itself also dont those spent fuel rods in those pools still give off like enough heat that if you dont top them up every so often they will eventually boil themselves dry ? could you not run a Stirling engine off that .. or even just straight up use thermocouples to power the cooling pumps nd back up systems
Would we consider the trail left by a satellite an artificial light? With all the junk up there some could take centuries or even millennia to finally hit the atmosphere and cause their brief light show. Suppose you could also argue the blinking reflection of the sun off of an orbiting satellite is artificial as it would never exist without humans. If so, those would be the winners.
Icelander her. What do you mean "not contacted to the grid if it is on an island"? We are an island nation and hydro-power and geothernal the our entire grid, as far I understand them term
16:18 mm you sort of liek want all you power plants of any kind linked up to each other on a sepreate grid from you main power gid so like for instance a Fukushima if they had have like so really earth quake resistante power cable that just went from there to like another power station on the other side of japan like a high voltage Dc interconnect just for them then they could have kept the coolent flowing ...either that or just alot of AA batterys
