"Uh, well, in this case, it's an invasive species. it doesn't do the job of being one of my glasses as well as the others, so it *should* have low fitness, but I can't kill it so the ecosystem has different parameters for fitness now than the ones I wanted when I bought my glasses, and this is really good at them. I should not have introduced this glass."
@@demolisherman1763 as someone with an annoying disability that causes my hands to have a mind of their own sometimes, it's nicer to think of all my broken crockery merely as genetic misfits than expensive and catastrophic disasters
@@clockworkkirlia7475All his glasses share a single charactaristic which makes them indispensible, which is that they are apparently indestructible under normal circumstances. He increased their lifespan through science.
I bestow you the title of fellow software engineer, you can start rewriting systems in Rust and fight on the internet, you also get a JavaScript license to rewrite projects in the newest framework of the moment
The CEO say that the costumers need to get comfortable with the idea of paying full price for half the water due to rising costs of replacing all these broken glasses.
My parents asked me about the glass filled halfway with water as a kid and I answered "It's full". They looked at me confused until I said "well half of it is filled with water and the other half air". They were very surprised and when they mentioned it to their friends one suggested to buy me a book by the name of "what if?". To this day it's one of the most visually pleasing, engaging and fun books I've ever read. My only complaint was there wasn't more. I WILL be checking out these other books. I hope your days are filled with the same wonder I had when I first opened your book. Thank you Randall Munroe.
Yeah, since it was only the shards from around the bottom of the glass being ejected and not the entire glass exploding, minor injuries. Maybe someone gets suuuuuuper unlucky and loses an eye, but that'd be the exception.
About 20 years ago I bought a set of glass cups. Every couple years one would break. One glass remains. Invincible. Unbreakable. Striking fear into the crystal hearts of those who came after. I use it all the time, more than any other glass. Each time I think this will be the time it breaks and I will finally have matching cups... But it never does.
Your "unbreakable" glass might be tempered glass (uncommon but not impossible to find), while your others could have been regular glass. Not truly unbreakable, but a whole lot harder to shatter than normal. When it does go though, tiny shards _everywhere._
Yeah, we had those when I was a child. Supposed to be child friendly because they explode in so small pieces there are no large pieces to step on, but I can't imagine the glass dust was much of an improvement.
I had an indestructible glass cube once. I don't know if it was supposed to be an ornamental ice cube or what the actual purpose was but I saw it at an old ladie's house and she gave it to me because I kept on obsessing over it. Anyway, long story short, in my teens I smashed it with a giant hammer and it made a huge shard that gashed open the side of my foot (I was wearing safety flipflops) and had to get stitches. It did look cool when it exploded, though, and it broke the curse of the indestructible glass cube.
It will either violently explode, killing nearby bystanders since the glass has about a quadrillion times more water in it than what physics should allow. Or, the more fun answer would be that the water collapses into a black hole...
To answer this in What If style, we'd need to address that "empty space" clause -- because it's all quantum fields, which makes it hard to define what that means exactly -- and fill the glass with increasingly dense and exotic materials and see what happens at each stage. My guess is we'd eventually come to a miniaturized version of the "electron moon" situation?
Fuck it, let's fill the glass with the stuff the universe consisted of one Planck time after the Big Bang, with a density of 1 in Planck units. For an 8 fluid ounce (230mL) glass, this results in a... 2.3×10^92 kg black hole? The Schwarzchild radius of which is 10^39 times larger than the observable universe. Check my math here, but that's what I get. I think you may have beat Electron Moon's record for the most destructive scenario.
It would make a black hole half as massive as Saturn. A coin-sized black hole would be slightly heavier than earth itself (Thanks, science birds), a glass of water is like 80-90 times as big, and Saturn is 96 times heavier than Earth.
@@misterms Manic: Glass overspilling full. Depressed: No glass, no liquid. Milk, then Cereal, then Bowl: Full under Glass, but Glass empty. Rain Drinkers: Rain or Clear Glass Eaters: Full of Glass
@@arahman56 Same as vacuum on top I would assume, as there is an area that the vacuum and air are in contact with. The water is also heavier than the air so it would settle down forcing the vacuum upwards and probably end up like the vacuum on top glass. That is at least what I think would happen.
@@arahman56 I'd imagine a combination of the two The top half of is quickly filled by air pressure, while the bottom half is filled by air and water If the glass survives the uneven vacuum collapse, it may tip over towards or away from the side that was filled with water, jumping a few inches off the table.
@@geolykt Sometimes weird Chinese copies of such things find their way into American stores, but it's just as likely it was polycarbonate or some other glass-like polymer.
Star Trek was never really specific about air travelling with the intended targets. Would expect there to be a large pressure difference between the air being brought into the ship and the ship air already present, so would expect a few nanoseconds of the person being transported either exploding or imploding until pressure equalizes. On the other side should be large pressure wave as a vacuum being left behind gets consumed by the surroundings.
If the glass were larger, at some point the force involved is sufficient that the sound and shockwave could become an incident. You're creating a non-incendiary explosion. All you need for incident purposes is to scale it up.
3:30 Perhaps it's "Superfest" glass? It was a glass designed and developed in East Germany and quite a handful of East German bars use them. Quite a lot of material to research I'd assume.
I was just reminded how in school at my friend was bouncing a Dasani water (Coke) bottle lightly with his hand on the table at lunch. One of the bottom things indented and shot a triangle through the cap and the water hit the (admittedly low) ceiling.
This What If hits differently when it's spoken out loud as opposed to read at your own pace. 1:55 "Around this time the glass on the right starts to visibly lift into the air" is the kind of surprising statement that is worth a few seconds of pause to really let that concept sink in. I remember stopping at that point, rereading it to confirm, that yes it just said that, before continuing on. In a video I have to have the reaction time to pause here so I can readjust before continuing. Granted, I'm at an advantage here because I knew what was coming having read the question before in the book, but still. It's a solid example of how the medium changes the message slightly.
I had the exact same feeling at the exact same point. That line is actually one of my favourites from the book with how suddenly witchcrafty it sounds amidst the science.
I exactly thought same think whan I saw magnitude 15 video. On last part of it, story said about minus magnitude. I read that part slow and peacefuly but in video narrator said same as other parts.
Optimist: Glass is half Full Pesimist: Glass is half Empty Physicist: DUCK AND COVER! Engineer: Container is twice the size it needs to be. Let's optimize it. Linguist: Depends if you are filling, or emptying the cup. Realist: Stop being so melodramatic, it's just a cup of water.
@@christianadam2907 nah, dude l. You are absolutly wrong. We don't know how long that glass flied up, cuz it's hit the celling. ( I think He don't want to calculate that too)
That would depend on the volume of vacuum, and how much force was imparted onto the glass. It's quite possible the glass would reach escape velocity, and escape the pull of the earth.
The “unbreakable” glass might be Arcoroc. Those accumulate stresses from impacts and like to explode into a shower of glass crumbs at a time of their choosing: Instantly, if flying shards or crumbs of glass hits them, but sometimes days later.
I really appreciate the effort that Randall must have put in to illustrate realistic looking vibrational modes and shockwaves on the glasses. Excellent work as usual!
You know, maybe that one oddball glass is just a duralex glass? That sort can take a real beating - up until it hits some until then unknown threshold and explodes into lots of tiny little pieces.
This is great 😁❤ Please do neutron star matter next??? Every astronomy textbook says something inane like "if you had a teaspoon of neuton star matter, it would weigh as much as a mountain." But... they never state what would HAPPEN if you had a teaspoon of neutron star matter? Would everything nearby get sucked in by gravity? Would it explode? Would it just radiate beta radiation? If do how much? Enquiring minds want to know: what would happen if you actually had a teaspoon of neutron star matter???
He actually has answered this question in his first What If book. The question there is titled: If a bullet with the density of a neutron star were fired from a handgun (ignoring the how) at the Earth's surface, would the Earth be destroyed? He actually covers what it would look like if you tried to touch it. It's one of my favorite chapters. Since all of his videos so far have been previously answered in his blog or one of the books, it's likely that the neutron star question will eventually make it to UA-cam, too.
There's no pressure left around it to keep it compressed into its degenerate state, so it's going to expand veeeery rapidly ("explode"), probably resulting in some of those neutrons fusioning with atmospheric gasses along the edge of the wavefront, others decaying into proton/electron pairs again (and some of those fusioning) and just generally being a gigantic space kablooey. Briefly things would be drawn towards its centre of mass and the top layer of atoms on the teaspoon might start the process of spagettification or tidal disruption, but the explosion is going to make that a bit of a moot point as it fixes the density gradient by distributing everything. Everything in the neutronium, and everything else in the area. If there's anything coherent left over it might be iron dust, but I don't think so. My money is just on high-speed neutron nonsense.
my roommates in college had to demonstrate the point of glass shattering for a project. took them like 1hr of dropping glass cups from a 3rd story balcony to get one to actually break. its weird how glass is sometimes indestructible like that and other times a 1 inch drop will shatter it
Yeah. As kids, my sister and I found our way into a residential construction site - house foundations were as far as they'd gotten but no one was there. We found an empty beer bottle and tossed it down onto the concrete and it just bounced around! We couldn't believe it.
Great video!! I think it would be interesting to see if the glass was literally half full in the sense that there are no gaps between the water molecules.
Back in my chemlab days, I had some access to high pressure equipment. Water compressibility is noticeable if you put around 1000 atm of pressure on it, but even then it's only around 5% more dense than water at atmospheric pressure
Speed of sound would be infinite in an incompressible medium since a disruption to one part would force instant reshuffle of the molecules everywhere. But to be fair, a lot of hydrodynamics assume water completely incompressible just to make calculations actually solvable.
@@anastasiao4036 yes, but I'm pretty sure it was intended for the person above me. seems like a problematic assumption to make when designing submarines, for example.
That one unbreakable glass reminds me of „Superfest“ a Glass company from the former GDR that made chemically hardened glasses in a similar process as Corning make their Gorilla Glass. Iirc east Germany had the problem that didn’t have the manufacturing capability to resupply all the bars and restaurants in the country, so the government paid scientists to develop a new kind of glass that was next to unbreakable and they were successful. Some say it wasn’t widely adopted as the drinking glass companies rely on steady income from replacing broken glasses…
Superfest was significantly more expensive to produce. And the companies that sold drinking glasses did not see a market in it. besides normal glass is not expensive at all. Notice that Gorilla glass basically only produce phone screens and not drinking glasses. I hear very similar arguments all the time were misinformed people yap about how the space pen is proof of how stupid the americans are, or that light bulbs are designed to fail to make the consumers buy more bulbs.
@dexis9412 Exactly, like if you're drinking from it or refilling it. I think the problem is when you just stumble upon half a glass out in the wild, you don't know if it's being emptied or filled. Strange thing is, in my language, we almost always say half a glass or half full glass, so I never really think about half empty glasses.
@@dexis9412 No, a glass that was filled to 50% an hour ago is not still being filled. If someone new shows up who has no idea if the glass was last filled or emptied they would still need a way to describe it at rest. This isn't tricky to understand
@@maskettaman1488 yes but it was in the process of being filled. Just because construction workers weren’t working overnight doesn’t mean the building isn’t half built when they aren’t there. If you half fill the glass then leave, it’s still half full. However yes, sponge brought up an interesting point. A half glass in the wild would still need to be described, so I’d probably opt to say it’s half empty as evaporation would be slowly emptying it at all times unless it’s 100% humidity. So in conclusion, if you don’t know what was last being done to the glass, wether or not the glass is half full or half empty depends on the humidity.
99.99% of matter is empty space between the nucleus and electrons of atoms, so i’d argue that the glass is very empty. Now create a scenario where the subatomic particles of water in the cup are so clumped together, making it truly half full. (And a black hole may or may not obliterate our existence)
About that one glass: "Superfest, also called CV-Glas[1] or Ceverit[2] until 1980, was a brand of drinking glasses in the GDR. Due to being made of chemically strengthened glass, they were notably strong. The Superfest glasses were produced between 1980 and 1990 in what was then state-owned Sachsenglas Schwepnitz." Wikipedia It was developed as a export product, but nobody wanted to buy it. Because you could never sell replacements.
Alchemist: The glass contains 65% oxygen, 18% carbon, 10% hydrogen, 3% nitrogen, 1.3% calcium, 0.6% phosphorus, 0.3% sulfur, and trace amounts of 15 other elements. This mixture can be turned into a living being via Human Transmutation, but _what could equal the value of a human soul???_
@@blueyoshi8517 The amount of impurities like salt ions in typical fresh water is less than 0.1%, so the actual value for water here is >49.95%, which rounds up to 50%. Same goes for traces of other gases that are typically present in the air. - Another chemist
And a cameo from Black Hat. Have those two ever faced off? I feel Like they’ve shown up in the same comic, but I don’t think they’ve ever really interacted with each other that much.
@@Cudddlefish No, Black Hat and Beret Guy been in the same comic 14 times, but the two of them have never interacted before. I go into much more detail in the video on my channel. At 1:31:29 I discuss Black Hat and Beret Guy interactions. I tried to link my video, but that comment got taken down. To summarize the segment: Beret Guy has 105 appearances (as of the making of that video, that number has since increased to 106) and Black Hat was at 174 appearances (also increased since), they have been in the same comic 14 times, they have been close enough to interact 3 times, and they have interacted 0 times.
Did you actually specify liquid water? Using ice (solid water) the first and second glasses would be about the same, but the third glass would have an ice plug suddenly rammed into the glass. If the fit was perfect, this would stay static until the ice starts to melt or sublimate into the bottom half. If not a perfect fit, air will leak past the ice plug to fill the vacuum.
This is a language question. When someone says water, noone assumes it to be ice unless there is some context. By saying Water, he specified liquid water. You can't just say it could mean ice within reason here.
For a fraction of a microsecond, when the water hits the bottom of the vacuum on bottom glass, small bubbles of water vapor will be symmetrically compressed (due to extremely high surface tension at the micro scale) and the vapor will be converted to a white hot plasma of perhaps 10,000 K, and produce a shock wave audible as a sharp ping in the glass. You can see this elsewhere here in a demonstration the germans call "der wasserhammer rohr" or just "wasserhammer". Briefly, in the mid 2000s it was thought the temperatures could reach millions of K and achieve fusion in deuterated solvents, but this was a fraud.
You may already know this, but General Fusion in Canada is developing an inertial compression fusion reactor that uses fluids to compress plasma enough to get fusion. It's not water, of course. The fluid is lithium, and the fuel is deuterium and tritium. The impetus comes from high speed piston drivers striking the sides of a cylindrical vessel with melted lithium being spun at a high enough velocity to leave a very low pressure hollow in the centre that plasma can be injected into. The timing is tricky, but according to modeling and testing, it looks plausible. The heat and other products of fusion are largely absorbed by the lithium, and can be drawn off to supply heat to a conventional steam turbine for electricity generation, and breed tritium for fuel.
@@seabream I am, I've been casually following their work for 2 decades now. It's a form of magneto-inertial confinement rather than pure inertial, because the plasma collapsed at the core of the machine is a magnetically confined spherical tokamak configuration. My interest has progressively waned over the intervening years because they still haven't shown any neutron production, but there's nothing in the physics that fundamentally rules out the scheme. I believe Commonwealth Fusion, with its far more conventional tokamak using high temperature superconductors in the US and Tokamak Energy doing a similar thing in the UK now have the best chance at breakeven and burn in the MFE world. I come from the laser ICF world. We hit breakeven at the capsule level and tn burn a few years ago as you know, but it's not going to produce net power to a grid anytime soon. Just pure science for a while.
Water hammers are no joke. When a nearby zoo would clean its polar bear tank, they'd partly empty and refill the tank, and when it was done filling they'd shut off the water supply quickly enough to cause a water hammer that kept breaking water mains in a neighboring town. They had to start closing the supply more gradually to reduce the effect, but I still hear it in our pipes when they do it, and I'm more than a mile away.
1:54 "Around this time the glass on the right starts to visibly lift into the air" is one of my favourite "What if?" lines ever, hands down. Timing is everything, and even the written answer delivers it at exactly the right time. :mwa: chef's kiss.
my question is: if the glas is standing there, where does the air pressure from below come from? I mean it depends on the surface of course, but lets say it stands in a flat metal sheet while having a flat bottom.
When you said "the pessimist is probably more right than the optimist" at the beginning, I was expecting a city-leveling blast. A smashed glass and some water damage on your shirt is far more optimistic than anything I was guessing at the beginning of the video. lol
Lol true. I'm guessing the optimist and pessimist in this cartoon were not aware they were in an XKCD scenario, or they would both have been pessimists 😄
Tbh several glass shards propelled at your upper half body with speed greater than 10m/s at less than a meter of distance seems like a pretty bad day to me
I like this one. There's not enough energy involved to cause unthinkable cataclysmic mayhem yet enough energy to cause an interesting thought experiment.
The world needs more of this. This is the kind of thing that makes physics fun and approachable to regular people. Regular people getting more interested in and reverent of Science is the only way we persist as a species.
@@alveolate pretty sure they did in the original, i was waiting for that to show up in the video but ig they're keeping it more pg?? idk way more deadly situations have been covered in the past
When I heard ”literally half full” I thought of the water occupying exactly half of the glass’s volume, to infinite precision (though I guess it is up to the resolution of one water molecule).
Old joke: The optimist says the glass is half full. The pessimist says the glass is half empty. The engineer says the glass is twice as large as it needs to be.
Good question. My guess is, as above, a lot like the vacuum-on-top one since the air has direct access to it. But, the air can only get in through that narrow opening... Yeah, I can't picture it 🤷🏻♂️
I imagine it will be much less impactful, though more chaotic. Not only will the vacuum fill with air quickly, but water will also fall down a bit, so there will be much less energy. Still, once the mass of water get's going into the vacuum, it won't stop just because there is some air in the way. Then at some point you have water smashing the side and half of bottom of the glass, you have boiling water mixed with air, hard to guess how much splash there would be and if the glass survives. But definitely much less "destruction" than bottom vacuum case.
02:55 It looks like the bottom level of the glass (on the "inside") is half the height of the vacuum/water. It is like that only if the weight of the glass and water are the same. Otherwise the lift is proportionally to the weight ratio of water to glass
This youtube channel reminds me a lot of oldschool youtube science videos, like the guys who would do science questions like this on whiteboards. Middle school me would have LOVED this channel, luckily I get to enjoy it now as a college student. :)
People always overestimate the pressure difference between our atmosphere and a vacuum. It's not really all that much. About the same difference as scuba diving 10m deep. You could probably survive a vacuum for a while if you had a mask (0.2atm, pure oxygen) that let you breathe normally and prevented your mucus membranes/eyes from drying out. And a rubber second skin suit would be nice, to keep your skin from drying too fast. It's not even cold, since you are only losing heat through black body radiation. Our bulky space suits are mostly just to prevent the sun from burning us, since there's no air to protect us from the full heat. The majority of the weight is from coms, AC, insulation, monitoring, CO2 scrubbing, oxygen tanks, diapers, etc.
not true. Your skin would be able to hold you together, but the pressure difference would lower the boiling point of your fluids enough that gas bubbles can form in your blood vessels which is generally considered to be a bad thing as they disrupt blood flow. You wouldn't die instantly or freeze over, quite the opposite really, but you wouldn't be fine either. Pressure from the inside out is very different than from the outside.
@Parciwal_Gaming Water at body temperature boils at around 0.05ATM, 5% of our atmospheric pressure. So in a vacuum, blood would boil. But our blood wouldn't be at a vacuum, even if our bodies were. Our bodies maintain a blood pressure of 0.15ATM above ambient pressure. That said, it would be horrible. You would be left bruised everywhere. And some liquids would boil out of your pores and holes (which is why a light rubber layer would be helpful to maintain a 0.05atm compression on you). But there have been brief accidental exposures to vacuums on people. Jim LeBlanc exposed himself by accident while testing a suit and survived. Tests on animals show that you can last for about 30 seconds with no long term effects, and at around 90 seconds you are likely to die or have brain damage. But that's all mostly due to the pressure loss on the ears, nose, eyes, and mouth, as well as your lungs not being able to hold oxygen. But if you had a mask, that would solve those immediate health risks.
@@VPCh. How are you planning to inhale with no pressure difference? I don't think 0.15 ATM is going to let you flow enough oxygen to breath, let along the potential problem of the lungs working in reverse and pulling oxygen *out* of the blood.
@@VPCh. hard vacuum exposure is theoretically survivable. for incredibly brief timespans. the timeframe, is roughly a minute. if you hold your breath, your lungs would burst. (mask or not. a pressure suit is incredibly important), rapid barotrauma for basically most of the body(this might not kill you, but the other things will), your blood will basically stop working, leading to loss of consciousness in around 1-5 seconds. your eyes and ears are likely gone, or badly damaged. and probably lots of internal damage from what could be described as the worst case of decompression sickness you'll ever have. if you have a skinsuit on, or at least pressure over your chest and head, you would live a little longer, I believe(ignoring the fact you're still suffering barotrauma to your limbs). but space doesn't have a lot of stuff out there. if you keep breathing, you're going to start cooking. the human body produces a lot of heat. and we rely on the atmosphere to take that away. space doesn't have much in the way of atmosphere. you won't be able to cool off, and you'll slowly cook(assuming that you don't die from massive barotrauma to the limbs) the large suits are large for a reason. there's a lot of things you need that don't exist in space, and are actively trying to kill you if you're rescued within 1-2 minutes, you could theoretically survive. there's a high chance of brain damage, lung damage, eye damage, tissue damage, etc etc etc etc etc. dogs can do under 2 minutes before expiring. chimps can survive for around 3.5 minutes, we are not chimps or dogs, and most of the depressurization incidents I'm aware of were fatal. if it's sudden, you'll probably die near instantly. the exposure needs to be slow. rapid exposure is incredibly lethal.
1- What if every cloud on Earth was concentrated in one single place/country? How strong would the rain be? A flash flood or something even worse? 2- How heavy can rain get? Can rain become so strong you almost get pinned down by it or is there a limit on how much it can rain on one area per minute?
#2 is a good question. You'd expect the limit to come from water vapour and atmospheric depth - only a certain amount of water can precipitate out of air, and only a certain amount of air can exist vertically in an atmosphere and still be dense enough to hold water vapour. But if you introduce weird, sudden changes in temperature, intuition becomes inadequate. You should email these questions to him.
#2 is easy, all weather models have a parameter called precipitable water. It ranges from less than 1mm over deserts to 75mm (3 inches) in the tropics. That is all the rain you can get in a short period (hours). Persistent wind can bring in more moisture over a longer period (days).
@@gordonrichardson2972 Records from reality appear to disagree with you. 11 inches in 2 hours, for the start of the midwestern (US) flood of 1951, for example.
Lovely to see such a video. Thank you! Piddly points: The taper in the glass will interfere somewhat with the water descending and the glass going up. The air under the glass may be limited to what is already present. There may not be time for more air to flow in and exert pressure. If the tabletop and the base of the glass are both perfectly smooth, there may be no air at all.
That occurred to me too. With a normal tabletop and glass, I would think the minimal air would still be enough to move it (it's still 14.7 PSI) and a bit of movement would give more space for all the necessary air to get under it. Might affect the timetable though when there are that many decimal places in the number, lol
I understand that real surfaces are not perfectly level and real glasses are not perfectly flat, but it is still quite surprising that the small amount of air between the glass and table would be enough to lift the glass. If we imagine there was an airtight fit between the glass and table, would the conservation of momentum from the water being pushed down lift the glass enough for air pressure to kick in? Would this make the process take measurably longer? Very fun and interesting hypothetical!
air pressure is not dependent on the amount of air under the glass. If there was an airtight seal then conservation of momentum would come from the air molecules slowing down not from the glass and it would stay on the table. if there was air inside the airtight seal then the air pressure would break it and lift the glass as normal.
I have a vague recollection that technically the table is also pushing the glass up... At least for the purpose of calculating certain things... Otherwise the table would collapse when you put the glass on it, or something like that. Like I said, vague.
@@laurencefraser That is a good point, normal force from the table is opposing gravity. However, as soon as the glass left the table (assuming there was any air underneath to push it) the normal force would no longer be relevant.
@@jameshulse1642 Yes, this makes sense, thank you. A cylindrical glass that was perfectly flush to the table would not lift. Although, I had another thought. The glasses pictured have angled sides. If the air pressure from the top isn't impacting the glass (since it is pushing on the water, which is not in contact with the bottom of the glass), would the vertical component of the air pressure on the sides of the glass push it up enough for air to get underneath? (sorry for butchering terms) Then again, that small force would still need to counteract the influence of gravity on the glass, which seems implausible.
@@Hankathan Calculation time. We are trying to find the lift force at t=0 this is the upwards force from pressure The bits of glass directly under the water with no vacuum in the way will have all the normal pressure interactions and so will not contribute to the lift force. The rim does not contribute to the lift force for the same reason. in the half empty (water on top) glass shown in the video that covers all the bits of glass (the diameter of the base is larger than the diameter of the water at the water vacuum boundary). so lift force is zero. This was a disappointing lack of calculation so I will show the method to work this out with any glass if you are bored. 1) work out the area of the water-vacuum boundary in meters^2 (if it is a circle you can use pi*r^2). this is (1) 2) work out the area of the base in meters^2 . this is (2) 3) do ( (1) - (2) ) * 100000. this the lift force in Newtons to work out if your glass will lift we need to find the weight that is being lifted. I think this is the weight of the glass + the weight of any water touching the glass and the water directly above that water. to find this do ( mass of the full glass (in kg) - (1) * height of the water (in m) * 1000 )*9.8 this is the relevant weight force. if the lift force is larger than the relevant weight force the glass will accelerate upwards at t=0 if it moves up air will move underneath and we will be back at where we were in the video
These two have no idea how lucky they are to survive an xkcd video
they're main characters
Not only that, but in the blog/book, they got a faceful of glass shards
I only really get worried when the black hat dude show up.
It's plot armour
Parallel universes?
- Why do you have this weird glass?
- Ah, survival of the fittest
Why are all your dishes mismatched?
“Darwinism”
"Uh, well, in this case, it's an invasive species. it doesn't do the job of being one of my glasses as well as the others, so it *should* have low fitness, but I can't kill it so the ecosystem has different parameters for fitness now than the ones I wanted when I bought my glasses, and this is really good at them. I should not have introduced this glass."
@@demolisherman1763 as someone with an annoying disability that causes my hands to have a mind of their own sometimes, it's nicer to think of all my broken crockery merely as genetic misfits than expensive and catastrophic disasters
Probably from East Germany.
@@clockworkkirlia7475All his glasses share a single charactaristic which makes them indispensible, which is that they are apparently indestructible under normal circumstances.
He increased their lifespan through science.
For the glass that won't break, install a new shelf labelled "UNBREAKABLE GLASS: DO NOT BREAK".
good idea! surely no cartoon hijinks will occur!
BREAK IN CASE OF EMERGENCY, IF YOU CAN
IN CASE OF GLASS BREAK: EMERGENCY
Superfest probably.
@@DiamondBrickZ oh hi you
After reading xkcd comics for so many years, its amazing how much his voice sounds exactly like it does in my head
I just imaged that he was CGP Grey all along, so my first time hearing his voice threw me off a little.
"In case of uncertainty, break this glass. I dare."
I insist that the glass is twice as large as it needs to be. It's a prime candidate for optimization.
I bestow you the title of fellow software engineer, you can start rewriting systems in Rust and fight on the internet, you also get a JavaScript license to rewrite projects in the newest framework of the moment
The CEO say that the costumers need to get comfortable with the idea of paying full price for half the water due to rising costs of replacing all these broken glasses.
Found the engineer!
Idk about you but I drink exclusively from 800 ml glasses and bottles
Make sure to leave a margin for sloshing.
Optimist: This glass is half full
Pessimist: This glass is half empty
Engineer: This glass is twice as big as it needs to be
Me: This glass cannot possibly be exactly half filled down to the molecule, due to the uncertainty principle.
Young me: “Yeah whatever. Would you like fries with that?”
@@bennyl9228 ̶M̶e̶:̶
Pedants:
Actual Engineer: The glass is at 50% capacity
@@nekoimouto4639 Possibly not true, there's still space between the molecules. You can mix in alcohol into it and watch the volume not conserve
I'm so glad you made a video series of these!
oh wow 2 weeks and no responses
Action Lab is here?! Why does this not have many likes?
My parents asked me about the glass filled halfway with water as a kid and I answered "It's full". They looked at me confused until I said "well half of it is filled with water and the other half air". They were very surprised and when they mentioned it to their friends one suggested to buy me a book by the name of "what if?". To this day it's one of the most visually pleasing, engaging and fun books I've ever read. My only complaint was there wasn't more. I WILL be checking out these other books. I hope your days are filled with the same wonder I had when I first opened your book. Thank you Randall Munroe.
You know its going to be a roller coaster ride when he goes microsecond by microsecond
Last time that happened was the baseball vid and we all know how that one ended.....
I love how there is an XKCD for every situation, including this one: look up XKCD 2553
@@tealtophatvr "hit by pitch"
at least he isn't measuring in shakes (10 nanoseconds)
@@agiar2000and eligible to proceed to first base
Nice to see a What If where no one dies, or is even seriously injured
Did you miss the part about flying shards of glass?
He doesn't mention the injuries inflicted by the glass shrapnel tho. this is basically a low-powered grenade
This video is the censored for kids version -- check the blog for the original ending (spoilers, it's not pretty).
Yeah, since it was only the shards from around the bottom of the glass being ejected and not the entire glass exploding, minor injuries. Maybe someone gets suuuuuuper unlucky and loses an eye, but that'd be the exception.
@@jhouck1969 Optimist: Hey, free shards glass!
About 20 years ago I bought a set of glass cups. Every couple years one would break. One glass remains. Invincible. Unbreakable. Striking fear into the crystal hearts of those who came after. I use it all the time, more than any other glass. Each time I think this will be the time it breaks and I will finally have matching cups... But it never does.
It is the One Cup
I N V I N C I B I L I T Y
Some cups are just built different.
That glass is half full of spite 🤣
The One Cup to rule them all.
Your "unbreakable" glass might be tempered glass (uncommon but not impossible to find), while your others could have been regular glass.
Not truly unbreakable, but a whole lot harder to shatter than normal. When it does go though, tiny shards _everywhere._
Yeah, we had those when I was a child. Supposed to be child friendly because they explode in so small pieces there are no large pieces to step on, but I can't imagine the glass dust was much of an improvement.
I had an indestructible glass cube once. I don't know if it was supposed to be an ornamental ice cube or what the actual purpose was but I saw it at an old ladie's house and she gave it to me because I kept on obsessing over it. Anyway, long story short, in my teens I smashed it with a giant hammer and it made a huge shard that gashed open the side of my foot (I was wearing safety flipflops) and had to get stitches. It did look cool when it exploded, though, and it broke the curse of the indestructible glass cube.
What if the glass was literally half full instead? By "full" I mean all the empty space in and between atoms are filled up with more atoms.
it would basically be the same, very strong rapid decompression
It will either violently explode, killing nearby bystanders since the glass has about a quadrillion times more water in it than what physics should allow. Or, the more fun answer would be that the water collapses into a black hole...
To answer this in What If style, we'd need to address that "empty space" clause -- because it's all quantum fields, which makes it hard to define what that means exactly -- and fill the glass with increasingly dense and exotic materials and see what happens at each stage. My guess is we'd eventually come to a miniaturized version of the "electron moon" situation?
Fuck it, let's fill the glass with the stuff the universe consisted of one Planck time after the Big Bang, with a density of 1 in Planck units.
For an 8 fluid ounce (230mL) glass, this results in a... 2.3×10^92 kg black hole? The Schwarzchild radius of which is 10^39 times larger than the observable universe. Check my math here, but that's what I get.
I think you may have beat Electron Moon's record for the most destructive scenario.
It would make a black hole half as massive as Saturn. A coin-sized black hole would be slightly heavier than earth itself (Thanks, science birds), a glass of water is like 80-90 times as big, and Saturn is 96 times heavier than Earth.
@4:07 the "shwoosh" and "ducks" sounds perfectly combine to hear "shucks" which had me super confused for a second.
what’s the actual word? I only hear “shucks”
WAIT I’m stupid you said it’s “ducks”
@@Juanni it's in the captions, where are manually added on this vid it seems. Good job! 💯!
Well he did say shucks at the end.
@@RedTail1-1 Check the closed captions. The word is "ducks"
Optimist: Glass is half full
Pessimist: Glass is half empty
Alcoholic: Glass is about to be empty
I laughed to hard at this😂
Schizophrenic: Glass is full, why is everyone staring at me?
@@misterms Manic: Glass overspilling full.
Depressed: No glass, no liquid.
Milk, then Cereal, then Bowl: Full under Glass, but Glass empty.
Rain Drinkers: Rain or Clear
Glass Eaters: Full of Glass
@@misterms
Shchizophrenics:
Glass is full
Now it's half empty
It's full again
I try to see the glass as half full
but I'd probably just drink that too!
That exploded less violently than expected for a “What if?”
terraria glitch-master jumpscare
hey look, it's the terraria guy!
i mean it still exploded
why am I not surprised that Doctor Boulder-Laser tunes in to xkcd
They censored the effect. See the original version.
Pessimist: "The glass is half empty"
Optimist: "The glass is half full"
Optometrist: "The glasses are half off"
Salesman: "The glasses are half off!"
Shroedinger: Until someone sees it, it is neither half empty or half full.
Teenager: I was curious right? Can someone call me an ambulance.
Apollo: *_g l a s s k_*
@@KenFullman
It's in a superposition of being half full and half empty at the same time
@@pplesandorangesapollo 3 seconds afterward: *shrock*
The final word of the video sounds more like "shucks" than "ducks".
1:27 AMAZING SFX
regular glass: nothing
vacuum on top: loud bang
vacuum on bottom: *ascended*
Vacuum on side: ?????
@@arahman56 Same as vacuum on top I would assume, as there is an area that the vacuum and air are in contact with. The water is also heavier than the air so it would settle down forcing the vacuum upwards and probably end up like the vacuum on top glass.
That is at least what I think would happen.
@@arahman56 I'd imagine a combination of the two
The top half of is quickly filled by air pressure, while the bottom half is filled by air and water
If the glass survives the uneven vacuum collapse, it may tip over towards or away from the side that was filled with water, jumping a few inches off the table.
The glass with the vacuum on bottom found dad's note (TBoI)
My parents replaced every single piece of glassware in our house as we were growing up, except for these two mugs that, no matter what, NEVER broke.
My guy brought a glass made out of reinforced glass
A reinforced glass made out of reinforced glass?
@@michaelleue7594 a reinforced glass made- 🎇
Could also be one of those rare Superfest glasswares - unlikely, but not impossible.
I wonder if there's a non-destructive way to read its sodium content/distribution.
@@geolykt Sometimes weird Chinese copies of such things find their way into American stores, but it's just as likely it was polycarbonate or some other glass-like polymer.
with a Star Trek transporter you could in theory test this, by beaming out half of the water starting from the bottom of the glass.
Star Trek was never really specific about air travelling with the intended targets. Would expect there to be a large pressure difference between the air being brought into the ship and the ship air already present, so would expect a few nanoseconds of the person being transported either exploding or imploding until pressure equalizes. On the other side should be large pressure wave as a vacuum being left behind gets consumed by the surroundings.
@@davidmcgill1000except it's not an instantaneous transportation.
For some reason I'm disappointed that it didn't result in something that could be described as "an incident".
The specifics matter incident
Not since... the accident.
well
this version omits it for reasons of youtube TOS.
If the glass were larger, at some point the force involved is sufficient that the sound and shockwave could become an incident. You're creating a non-incendiary explosion. All you need for incident purposes is to scale it up.
@@halyoalex8942 The TOS does not say "don't mention people being injured". There are videos on here about natural disasters and industrial accidents.
To be fair to the optimist, this scenario isn't nearly as destructive as most other what ifs.
To be fair to the pesimist, this scenario isn't nearly as destructive as most other what ifs.
You should check the comic version.
@@Cudddlefish Electron moon was WILD.
3:30 Perhaps it's "Superfest" glass? It was a glass designed and developed in East Germany and quite a handful of East German bars use them. Quite a lot of material to research I'd assume.
I was just reminded how in school at my friend was bouncing a Dasani water (Coke) bottle lightly with his hand on the table at lunch. One of the bottom things indented and shot a triangle through the cap and the water hit the (admittedly low) ceiling.
This What If hits differently when it's spoken out loud as opposed to read at your own pace.
1:55 "Around this time the glass on the right starts to visibly lift into the air" is the kind of surprising statement that is worth a few seconds of pause to really let that concept sink in. I remember stopping at that point, rereading it to confirm, that yes it just said that, before continuing on. In a video I have to have the reaction time to pause here so I can readjust before continuing.
Granted, I'm at an advantage here because I knew what was coming having read the question before in the book, but still. It's a solid example of how the medium changes the message slightly.
"YOU TWO ARGUING HAS MADE THE GLASS START TO LEVITATE!!!"
Brother if I saw my glass of water start to float, I would start fucking running.
wait are you the rea lquot from the caev story
I had the exact same feeling at the exact same point. That line is actually one of my favourites from the book with how suddenly witchcrafty it sounds amidst the science.
I exactly thought same think whan I saw magnitude 15 video. On last part of it, story said about minus magnitude. I read that part slow and peacefuly but in video narrator said same as other parts.
Optimist: Glass is half Full
Pesimist: Glass is half Empty
Physicist: DUCK AND COVER!
Engineer: Container is twice the size it needs to be. Let's optimize it.
Linguist: Depends if you are filling, or emptying the cup.
Realist: Stop being so melodramatic, it's just a cup of water.
Both wrong, its half empty if its being emptied, half full if its being filled.
technically it's a half-cup of water...
water is water. doesn't matter to me. It's either enough or not enough. keep it simple
Me: **smashes the cup on the ground**
@@petertrudelljrbut if my glass is two cups it's a cup of water
3:56 Let's assume this experiment took place outside. How long would the rising glass be rising for before gravity pushed it back down?
Depens how fast is that glas, he sais a few m/s it shoudn't go too high
The same amount as inside. Or do you think gravity works different inside and outside a house?
@@christianadam2907 nah, dude l. You are absolutly wrong. We don't know how long that glass flied up, cuz it's hit the celling. ( I think He don't want to calculate that too)
@@christianadam2907The glass hit the celling inside in the example.
He asked for an unopposed measurement. This is a valid question.
That would depend on the volume of vacuum, and how much force was imparted onto the glass. It's quite possible the glass would reach escape velocity, and escape the pull of the earth.
The “unbreakable” glass might be Arcoroc. Those accumulate stresses from impacts and like to explode into a shower of glass crumbs at a time of their choosing: Instantly, if flying shards or crumbs of glass hits them, but sometimes days later.
But from the Dollar Store? Did make me wonder though, has China started making East Germany's Unbreakable Glasses?
I really appreciate the effort that Randall must have put in to illustrate realistic looking vibrational modes and shockwaves on the glasses. Excellent work as usual!
This is one of my favorite original What If's. Every time I hear someone talk about half-empty glasses I smile, and ask "which half?". 😎
Thank you for the sound effects. Really helps
“Yeah man it’s half empty.”
“W-what do you mean by that.”
You know, maybe that one oddball glass is just a duralex glass? That sort can take a real beating - up until it hits some until then unknown threshold and explodes into lots of tiny little pieces.
This is great 😁❤
Please do neutron star matter next??? Every astronomy textbook says something inane like "if you had a teaspoon of neuton star matter, it would weigh as much as a mountain."
But... they never state what would HAPPEN if you had a teaspoon of neutron star matter?
Would everything nearby get sucked in by gravity? Would it explode? Would it just radiate beta radiation? If do how much?
Enquiring minds want to know: what would happen if you actually had a teaspoon of neutron star matter???
To better fit the nature of this blog, ask what would happen if you tried to put it in your tea.
He actually has answered this question in his first What If book. The question there is titled:
If a bullet with the density of a neutron star were fired from a handgun (ignoring the how) at the Earth's surface, would the Earth be destroyed?
He actually covers what it would look like if you tried to touch it. It's one of my favorite chapters. Since all of his videos so far have been previously answered in his blog or one of the books, it's likely that the neutron star question will eventually make it to UA-cam, too.
There's no pressure left around it to keep it compressed into its degenerate state, so it's going to expand veeeery rapidly ("explode"), probably resulting in some of those neutrons fusioning with atmospheric gasses along the edge of the wavefront, others decaying into proton/electron pairs again (and some of those fusioning) and just generally being a gigantic space kablooey.
Briefly things would be drawn towards its centre of mass and the top layer of atoms on the teaspoon might start the process of spagettification or tidal disruption, but the explosion is going to make that a bit of a moot point as it fixes the density gradient by distributing everything. Everything in the neutronium, and everything else in the area.
If there's anything coherent left over it might be iron dust, but I don't think so. My money is just on high-speed neutron nonsense.
@@hive_indicator318yes but most of that gravity is gone when you have only a teaspoon of it 😊 there is a lower limit for the mass of a neutron star
You would drop the spoon.
my roommates in college had to demonstrate the point of glass shattering for a project. took them like 1hr of dropping glass cups from a 3rd story balcony to get one to actually break. its weird how glass is sometimes indestructible like that and other times a 1 inch drop will shatter it
Yeah. As kids, my sister and I found our way into a residential construction site - house foundations were as far as they'd gotten but no one was there.
We found an empty beer bottle and tossed it down onto the concrete and it just bounced around! We couldn't believe it.
the wonders of hard materials, glass isn't that weak, but it's very prone to fracturing.
The engineer has put half his water in a backup glass.
Optimist: The glass is half full!
Pessimist: The glass is half empty!
Physicist: Everyone, get under the table.
Great video!! I think it would be interesting to see if the glass was literally half full in the sense that there are no gaps between the water molecules.
"This isn't my glass! My glass was full! And bigger!" (with apologies to Terry Pratchett :D )
Thank you for saying water is nearly incompressible. So many people affirm that water is completely incompressible.
Back in my chemlab days, I had some access to high pressure equipment. Water compressibility is noticeable if you put around 1000 atm of pressure on it, but even then it's only around 5% more dense than water at atmospheric pressure
Speed of sound would be infinite in an incompressible medium since a disruption to one part would force instant reshuffle of the molecules everywhere.
But to be fair, a lot of hydrodynamics assume water completely incompressible just to make calculations actually solvable.
Why does the water pressure increase as you go further down unto the ocean then?
@@ashtongiertz8728is this a real question?
@@anastasiao4036 yes, but I'm pretty sure it was intended for the person above me. seems like a problematic assumption to make when designing submarines, for example.
I never ever though about "what half is empty". You really know how to think out of the box. I'm impressed!
In this case, it is how to think out of the glass.
What if the glass itself is half empty? (like, in its walls) That's a thermal mug!
we're never looking at a glass of water the same after this
UA-cam having 2 likes moment
bro fell off
Having 40 mln subscribers but still having 7 likes
Well, that definitely humbled the social media manager at UA-cam xd
Lets ratio UA-cam (aka more comments than likes)
I like that there is a normal air-water glass because every experiment needs a control
That one unbreakable glass reminds me of „Superfest“ a Glass company from the former GDR that made chemically hardened glasses in a similar process as Corning make their Gorilla Glass.
Iirc east Germany had the problem that didn’t have the manufacturing capability to resupply all the bars and restaurants in the country, so the government paid scientists to develop a new kind of glass that was next to unbreakable and they were successful.
Some say it wasn’t widely adopted as the drinking glass companies rely on steady income from replacing broken glasses…
Yeah the problem was they needed to expand their market past cups and use the stronger glass in other places. That or... close up shop which they did.
Superfest was significantly more expensive to produce. And the companies that sold drinking glasses did not see a market in it.
besides normal glass is not expensive at all.
Notice that Gorilla glass basically only produce phone screens and not drinking glasses.
I hear very similar arguments all the time were misinformed people yap about how the space pen is proof of how stupid the americans are, or that light bulbs are designed to fail to make the consumers buy more bulbs.
I think this is the first time I’ve ever heard someone else acknowledge my argument for the glass, being what was described as the linguists argument
It's a terrible argument because it assumes a glass is either always being filled or always being emptied.
@@maskettaman1488 not necessarily, it just depends on whatever was last being done to the glass, being filled or emptied
@dexis9412 Exactly, like if you're drinking from it or refilling it. I think the problem is when you just stumble upon half a glass out in the wild, you don't know if it's being emptied or filled. Strange thing is, in my language, we almost always say half a glass or half full glass, so I never really think about half empty glasses.
@@dexis9412 No, a glass that was filled to 50% an hour ago is not still being filled. If someone new shows up who has no idea if the glass was last filled or emptied they would still need a way to describe it at rest.
This isn't tricky to understand
@@maskettaman1488 yes but it was in the process of being filled. Just because construction workers weren’t working overnight doesn’t mean the building isn’t half built when they aren’t there. If you half fill the glass then leave, it’s still half full.
However yes, sponge brought up an interesting point. A half glass in the wild would still need to be described, so I’d probably opt to say it’s half empty as evaporation would be slowly emptying it at all times unless it’s 100% humidity.
So in conclusion, if you don’t know what was last being done to the glass, wether or not the glass is half full or half empty depends on the humidity.
99.99% of matter is empty space between the nucleus and electrons of atoms, so i’d argue that the glass is very empty.
Now create a scenario where the subatomic particles of water in the cup are so clumped together, making it truly half full. (And a black hole may or may not obliterate our existence)
1:40 are you sure the glass wouldn't break?
Yes
Yes, I think he is
About that one glass:
"Superfest, also called CV-Glas[1] or Ceverit[2] until 1980, was a brand of drinking glasses in the GDR. Due to being made of chemically strengthened glass, they were notably strong. The Superfest glasses were produced between 1980 and 1990 in what was then state-owned Sachsenglas Schwepnitz." Wikipedia
It was developed as a export product, but nobody wanted to buy it.
Because you could never sell replacements.
It was also significantly more expensive. Gorilla glass which is basically the same thing have their niche in phone screens for a reason.
@@tobi4036 supposedly, Corning copied the formula after the patent expired.
Optimist: The glass is half-full.
Pessimist: The glass is half-empty.
Chemist: The glass contains 50% H2O, 39% N2, 10.5% O2, 0.4% Ar and 0.1% CO2.
It is a bit unusual for Chemist to use volume when talking about ratios.
Actually that's assuming the water is pure, however it is likely it is normal drinking water which has impurities to make it safe to drink.
-A chemist
Alchemist: The glass contains 65% oxygen, 18% carbon, 10% hydrogen, 3% nitrogen, 1.3% calcium, 0.6% phosphorus, 0.3% sulfur, and trace amounts of 15 other elements. This mixture can be turned into a living being via Human Transmutation, but _what could equal the value of a human soul???_
And then the chemist would write a 5 page essay about it
@@blueyoshi8517 The amount of impurities like salt ions in typical fresh water is less than 0.1%, so the actual value for water here is >49.95%, which rounds up to 50%. Same goes for traces of other gases that are typically present in the air.
- Another chemist
Watched a guy repeatedly slapping the lid-side of a Frappucino bottle in a convenience store. Was not disappointed.
0:12 YES! Beret Guy!
i salute your commitment to beret guy
And a cameo from Black Hat. Have those two ever faced off? I feel Like they’ve shown up in the same comic, but I don’t think they’ve ever really interacted with each other that much.
@@korok2619 Thank you. I spent a long time on my analysis video.
@@Cudddlefish No, Black Hat and Beret Guy been in the same comic 14 times, but the two of them have never interacted before. I go into much more detail in the video on my channel. At 1:31:29 I discuss Black Hat and Beret Guy interactions. I tried to link my video, but that comment got taken down.
To summarize the segment: Beret Guy has 105 appearances (as of the making of that video, that number has since increased to 106) and Black Hat was at 174 appearances (also increased since), they have been in the same comic 14 times, they have been close enough to interact 3 times, and they have interacted 0 times.
Hon hon hon
AS USUAL.... AWESOME!!!! THANK YOU!
Love that my thought process about when to say half empty and half full was actually a real thing
Did you actually specify liquid water? Using ice (solid water) the first and second glasses would be about the same, but the third glass would have an ice plug suddenly rammed into the glass. If the fit was perfect, this would stay static until the ice starts to melt or sublimate into the bottom half. If not a perfect fit, air will leak past the ice plug to fill the vacuum.
Hell, why constrain ourselves to water? Instead we could use thorium!
Or... the ice smashes into the glass again.
@@Roach18 Why not use quark-gluon plasma or a black hole? That sounds way more fun!
This is a language question. When someone says water, noone assumes it to be ice unless there is some context. By saying Water, he specified liquid water. You can't just say it could mean ice within reason here.
@@neaneoneunuo9651 I personally assume it to be superionic black ice, the most common form water takes in the universe
For a fraction of a microsecond, when the water hits the bottom of the vacuum on bottom glass, small bubbles of water vapor will be symmetrically compressed (due to extremely high surface tension at the micro scale) and the vapor will be converted to a white hot plasma of perhaps 10,000 K, and produce a shock wave audible as a sharp ping in the glass. You can see this elsewhere here in a demonstration the germans call "der wasserhammer rohr" or just "wasserhammer". Briefly, in the mid 2000s it was thought the temperatures could reach millions of K and achieve fusion in deuterated solvents, but this was a fraud.
You may already know this, but General Fusion in Canada is developing an inertial compression fusion reactor that uses fluids to compress plasma enough to get fusion. It's not water, of course. The fluid is lithium, and the fuel is deuterium and tritium. The impetus comes from high speed piston drivers striking the sides of a cylindrical vessel with melted lithium being spun at a high enough velocity to leave a very low pressure hollow in the centre that plasma can be injected into. The timing is tricky, but according to modeling and testing, it looks plausible. The heat and other products of fusion are largely absorbed by the lithium, and can be drawn off to supply heat to a conventional steam turbine for electricity generation, and breed tritium for fuel.
@@seabream I am, I've been casually following their work for 2 decades now. It's a form of magneto-inertial confinement rather than pure inertial, because the plasma collapsed at the core of the machine is a magnetically confined spherical tokamak configuration. My interest has progressively waned over the intervening years because they still haven't shown any neutron production, but there's nothing in the physics that fundamentally rules out the scheme. I believe Commonwealth Fusion, with its far more conventional tokamak using high temperature superconductors in the US and Tokamak Energy doing a similar thing in the UK now have the best chance at breakeven and burn in the MFE world. I come from the laser ICF world. We hit breakeven at the capsule level and tn burn a few years ago as you know, but it's not going to produce net power to a grid anytime soon. Just pure science for a while.
This comment and its replies feel like a joke but I'm not educated enough to tell lol.
@@Muhammed_English314 me neither but it's real :p
the physicist records everything, the pragmatist ducks. 😊
Hearing absurd scenarios described via the clinical and dispassionate language of physics is always delightful.
Water hammers are no joke. When a nearby zoo would clean its polar bear tank, they'd partly empty and refill the tank, and when it was done filling they'd shut off the water supply quickly enough to cause a water hammer that kept breaking water mains in a neighboring town. They had to start closing the supply more gradually to reduce the effect, but I still hear it in our pipes when they do it, and I'm more than a mile away.
What the hell is the diameter of their pipe???
I am upset that they weren't wearing proper PPE for this experiment.
As opposed to the other What Ifs... :D
man this channel is so good, literally the most satisfying thing for my adhd brain that i've seen in a while, keep up the good work man
My answer to the question "is the glass half empty or full?" has always been "which half, and full of what?" so this makes me very happy
1:54 "Around this time the glass on the right starts to visibly lift into the air" is one of my favourite "What if?" lines ever, hands down. Timing is everything, and even the written answer delivers it at exactly the right time. :mwa: chef's kiss.
my question is:
if the glas is standing there, where does the air pressure from below come from?
I mean it depends on the surface of course, but lets say it stands in a flat metal sheet while having a flat bottom.
When you said "the pessimist is probably more right than the optimist" at the beginning, I was expecting a city-leveling blast. A smashed glass and some water damage on your shirt is far more optimistic than anything I was guessing at the beginning of the video. lol
Lol true.
I'm guessing the optimist and pessimist in this cartoon were not aware they were in an XKCD scenario, or they would both have been pessimists 😄
Sounds like you were overly optimistic for the level of destruction this video would contain. The pessimist wins again!
Just watch out for broken glass
Tbh several glass shards propelled at your upper half body with speed greater than 10m/s at less than a meter of distance seems like a pretty bad day to me
I like this one. There's not enough energy involved to cause unthinkable cataclysmic mayhem yet enough energy to cause an interesting thought experiment.
The world needs more of this. This is the kind of thing that makes physics fun and approachable to regular people. Regular people getting more interested in and reverent of Science is the only way we persist as a species.
This is one of my absolute favorite "what if" pieces.
This is one of my favorite questions ever answered by XKCD.
It would most likely contain approximately as much non-water as it would water.
But air is up to 4% water so it doesn't really
How much is any amount of nothing?
This was a very good place to use the word "approximately".
One of the more tame videos
yea i half expected those glass shards to draw blood
@@alveolate They did in the original. I liked the 'Hey, free glass!' line.
@@alveolate pretty sure they did in the original, i was waiting for that to show up in the video but ig they're keeping it more pg?? idk way more deadly situations have been covered in the past
When I heard ”literally half full” I thought of the water occupying exactly half of the glass’s volume, to infinite precision (though I guess it is up to the resolution of one water molecule).
This turned out to be interstingly more detailed than I first expected.
I want to believe that this is how MC Water Hammer got his name.
can't touch this... because it's a vacuum (for a very short time)
Always get a laugh out of these, loved the first "What If?" book and will definitely check the new one out too!
Old joke: The optimist says the glass is half full. The pessimist says the glass is half empty. The engineer says the glass is twice as large as it needs to be.
This was always one of my alltime favorites! So glad this one got adapted for the UA-cam channel!
Ah, this ep is less bloody than the article I see. One caveat is there's no "hey, free glass!"
So, what's the case result as shown in the glass on the left at 0:40 where the vacuum is on the side of the glass?
Probably similar to the vacuum-on-top scenario, but it also slides a bit towards the side that had the vacuum.
Good question. My guess is, as above, a lot like the vacuum-on-top one since the air has direct access to it. But, the air can only get in through that narrow opening...
Yeah, I can't picture it 🤷🏻♂️
I imagine it will be much less impactful, though more chaotic. Not only will the vacuum fill with air quickly, but water will also fall down a bit, so there will be much less energy. Still, once the mass of water get's going into the vacuum, it won't stop just because there is some air in the way. Then at some point you have water smashing the side and half of bottom of the glass, you have boiling water mixed with air, hard to guess how much splash there would be and if the glass survives. But definitely much less "destruction" than bottom vacuum case.
same as the vaccuum on top bc the water doesnt form a seal
02:55 It looks like the bottom level of the glass (on the "inside") is half the height of the vacuum/water. It is like that only if the weight of the glass and water are the same. Otherwise the lift is proportionally to the weight ratio of water to glass
I would have said the lift is proportional to the square of the weight ratio. But I could be wrong...
This youtube channel reminds me a lot of oldschool youtube science videos, like the guys who would do science questions like this on whiteboards. Middle school me would have LOVED this channel, luckily I get to enjoy it now as a college student. :)
"Yea, but what if the other half was *actually* empty?"
Physicist: *1,000 yd stare*
...and the engineer says: "It's twice the size it needs to be"
Nah, the engineer says it's got a high safety factor against sloshing. :)
Silly engineers
Finally caught one of these the moment it was uploaded, had a copy of the original book and I miss it to this day
Buy another? I don't understand why you wouldn't get another copy.
I think this is the least destructive What If video I’ve seen
That was such a cool video. Like minute physics but better. Subbed
this one is my all-time favorite what if!!!! i'm so glad it's been adopted to video format :)
People always overestimate the pressure difference between our atmosphere and a vacuum. It's not really all that much. About the same difference as scuba diving 10m deep.
You could probably survive a vacuum for a while if you had a mask (0.2atm, pure oxygen) that let you breathe normally and prevented your mucus membranes/eyes from drying out. And a rubber second skin suit would be nice, to keep your skin from drying too fast.
It's not even cold, since you are only losing heat through black body radiation.
Our bulky space suits are mostly just to prevent the sun from burning us, since there's no air to protect us from the full heat. The majority of the weight is from coms, AC, insulation, monitoring, CO2 scrubbing, oxygen tanks, diapers, etc.
not true.
Your skin would be able to hold you together, but the pressure difference would lower the boiling point of your fluids enough that gas bubbles can form in your blood vessels which is generally considered to be a bad thing as they disrupt blood flow.
You wouldn't die instantly or freeze over, quite the opposite really, but you wouldn't be fine either.
Pressure from the inside out is very different than from the outside.
@Parciwal_Gaming Water at body temperature boils at around 0.05ATM, 5% of our atmospheric pressure. So in a vacuum, blood would boil.
But our blood wouldn't be at a vacuum, even if our bodies were. Our bodies maintain a blood pressure of 0.15ATM above ambient pressure.
That said, it would be horrible. You would be left bruised everywhere. And some liquids would boil out of your pores and holes (which is why a light rubber layer would be helpful to maintain a 0.05atm compression on you).
But there have been brief accidental exposures to vacuums on people. Jim LeBlanc exposed himself by accident while testing a suit and survived. Tests on animals show that you can last for about 30 seconds with no long term effects, and at around 90 seconds you are likely to die or have brain damage. But that's all mostly due to the pressure loss on the ears, nose, eyes, and mouth, as well as your lungs not being able to hold oxygen. But if you had a mask, that would solve those immediate health risks.
@@VPCh. How are you planning to inhale with no pressure difference? I don't think 0.15 ATM is going to let you flow enough oxygen to breath, let along the potential problem of the lungs working in reverse and pulling oxygen *out* of the blood.
@@VPCh. hard vacuum exposure is theoretically survivable. for incredibly brief timespans. the timeframe, is roughly a minute. if you hold your breath, your lungs would burst. (mask or not. a pressure suit is incredibly important), rapid barotrauma for basically most of the body(this might not kill you, but the other things will), your blood will basically stop working, leading to loss of consciousness in around 1-5 seconds. your eyes and ears are likely gone, or badly damaged. and probably lots of internal damage from what could be described as the worst case of decompression sickness you'll ever have.
if you have a skinsuit on, or at least pressure over your chest and head, you would live a little longer, I believe(ignoring the fact you're still suffering barotrauma to your limbs). but space doesn't have a lot of stuff out there. if you keep breathing, you're going to start cooking. the human body produces a lot of heat. and we rely on the atmosphere to take that away. space doesn't have much in the way of atmosphere. you won't be able to cool off, and you'll slowly cook(assuming that you don't die from massive barotrauma to the limbs)
the large suits are large for a reason. there's a lot of things you need that don't exist in space, and are actively trying to kill you
if you're rescued within 1-2 minutes, you could theoretically survive. there's a high chance of brain damage, lung damage, eye damage, tissue damage, etc etc etc etc etc. dogs can do under 2 minutes before expiring. chimps can survive for around 3.5 minutes, we are not chimps or dogs, and most of the depressurization incidents I'm aware of were fatal.
if it's sudden, you'll probably die near instantly. the exposure needs to be slow. rapid exposure is incredibly lethal.
1- What if every cloud on Earth was concentrated in one single place/country? How strong would the rain be? A flash flood or something even worse?
2- How heavy can rain get? Can rain become so strong you almost get pinned down by it or is there a limit on how much it can rain on one area per minute?
#2 is a good question. You'd expect the limit to come from water vapour and atmospheric depth - only a certain amount of water can precipitate out of air, and only a certain amount of air can exist vertically in an atmosphere and still be dense enough to hold water vapour. But if you introduce weird, sudden changes in temperature, intuition becomes inadequate. You should email these questions to him.
This is an excellent stump the meteorologist question. You should also send it in to your local stations. 🌧️
#2 is easy, all weather models have a parameter called precipitable water. It ranges from less than 1mm over deserts to 75mm (3 inches) in the tropics. That is all the rain you can get in a short period (hours). Persistent wind can bring in more moisture over a longer period (days).
#1 xkcd whatif raindrop?
@@gordonrichardson2972 Records from reality appear to disagree with you. 11 inches in 2 hours, for the start of the midwestern (US) flood of 1951, for example.
Old Soviet joke I heard my grandparents tell: The optimist studies English, the pessimist studies Chinese, and the realist studies physics.
This! Is SOO very True... Today. RuZZian woman better start getting used to the idea their future husbands will be Chinese Men.
So you are optimist, nice)
This is my new favourite channel
Video recommendation, what if I crushed a gold bar with the weight of the world
Lovely to see such a video. Thank you!
Piddly points: The taper in the glass will interfere somewhat with the water descending and the glass going up.
The air under the glass may be limited to what is already present. There may not be time for more air to flow in and exert pressure. If the tabletop and the base of the glass are both perfectly smooth, there may be no air at all.
That occurred to me too. With a normal tabletop and glass, I would think the minimal air would still be enough to move it (it's still 14.7 PSI) and a bit of movement would give more space for all the necessary air to get under it.
Might affect the timetable though when there are that many decimal places in the number, lol
Great video! Still, hits different, given the current investigative hearings on the Titan submersible....
I'm so glad to finally see someone mention that half empty and half full are relative to whether they are being drained or added to.
I glad you turned down the shatter effect in animation and make the ceiling fall not a shower of sharp bits.
I understand that real surfaces are not perfectly level and real glasses are not perfectly flat, but it is still quite surprising that the small amount of air between the glass and table would be enough to lift the glass. If we imagine there was an airtight fit between the glass and table, would the conservation of momentum from the water being pushed down lift the glass enough for air pressure to kick in? Would this make the process take measurably longer?
Very fun and interesting hypothetical!
air pressure is not dependent on the amount of air under the glass. If there was an airtight seal then conservation of momentum would come from the air molecules slowing down not from the glass and it would stay on the table. if there was air inside the airtight seal then the air pressure would break it and lift the glass as normal.
I have a vague recollection that technically the table is also pushing the glass up... At least for the purpose of calculating certain things... Otherwise the table would collapse when you put the glass on it, or something like that. Like I said, vague.
@@laurencefraser That is a good point, normal force from the table is opposing gravity. However, as soon as the glass left the table (assuming there was any air underneath to push it) the normal force would no longer be relevant.
@@jameshulse1642 Yes, this makes sense, thank you. A cylindrical glass that was perfectly flush to the table would not lift. Although, I had another thought. The glasses pictured have angled sides. If the air pressure from the top isn't impacting the glass (since it is pushing on the water, which is not in contact with the bottom of the glass), would the vertical component of the air pressure on the sides of the glass push it up enough for air to get underneath? (sorry for butchering terms)
Then again, that small force would still need to counteract the influence of gravity on the glass, which seems implausible.
@@Hankathan Calculation time.
We are trying to find the lift force at t=0
this is the upwards force from pressure
The bits of glass directly under the water with no vacuum in the way will have all the normal pressure interactions and so will not contribute to the lift force.
The rim does not contribute to the lift force for the same reason.
in the half empty (water on top) glass shown in the video that covers all the bits of glass (the diameter of the base is larger than the diameter of the water at the water vacuum boundary).
so lift force is zero.
This was a disappointing lack of calculation so I will show the method to work this out with any glass if you are bored.
1) work out the area of the water-vacuum boundary in meters^2 (if it is a circle you can use pi*r^2). this is (1)
2) work out the area of the base in meters^2 . this is (2)
3) do ( (1) - (2) ) * 100000. this the lift force in Newtons
to work out if your glass will lift we need to find the weight that is being lifted. I think this is the weight of the glass + the weight of any water touching the glass and the water directly above that water.
to find this do ( mass of the full glass (in kg) - (1) * height of the water (in m) * 1000 )*9.8
this is the relevant weight force.
if the lift force is larger than the relevant weight force the glass will accelerate upwards at t=0
if it moves up air will move underneath and we will be back at where we were in the video
What would be really terrifying is if by "half full/empty" it meant in the full half even the vast empty space between atoms had been filled.
Or if the "empty" was totally free of virtual particle pairs...