Get yourself a monitor with livestream (super exciting channel, I'm sure), a bedpan, a comfy chair, and prepare to sit there for 12 years or so. And don't forget to keep the tea kettle within view of that monitor. . .
I was taught that glass was a liquid by my school teachers on a field trip to a glass blowing studio. I was told that a glass bottle would flow into a puddle over time at a measurable rate. I never questioned it. Stuff like this makes me remember the EA tagline "Challenge Everything".
Well, EA kinda borrowed that from Timothy Leary, the 60's bumper sticker slogan, "Question Authority." It was a popular button in my 90's college days.
+Oleum Camino "Actually it's not proven nor disproven yet. " The claim that glass in the windows of cathedrals built during the middle ages "droops" significantly in 500 or 1000 years HAS been disproven and the evidence was even discussed in the video! That it might do the same thing in 1,000,000,000 years is not the point, the claim itself was it does so in significantly shorter timespans and that is just outright wrong.
I'm guessing that is a different experiment? Found some sites saying it dropped 2013 and was caught on film... but this one had last drop 2014... plus if you look at the stream now the drop is pretty big
When I was doing a graphic design degree program, I was taught that glass was installed with the thicker end at the bottom because of a design principle called visual weight. As the principle applies to this situation, glass that is thicker on top looks like it is going to fall over, while glass that is thicker on bottom looks stable.
Thanks for that comment. The video gave an explanation for why we observe the thicker part at the bottom "it was purposefully installed that way", but didn't explain why it was installed that way. Your explanation seems plausible.
that might be the case with stuff like stained glass. old mouthblown panels were made by first blowing it into a bubble, flattening that bubble by rolling it on an incline. blowing some more etc, until you get a roughly 1m long bubble cylinder around 30 cm in diameter. cut the ends off, cut it lengthwise. and then pop it into a straightening kiln. and that is sortof the important part. in the kiln the cylinder is opened up, but as it cools it has a tendency to warp again. thicker heavier parts tend to stay straight while the thinner lighter parts curve up a bit. (that much is what i have been taught, havent actually seen it happen but true or not, the thick parts are straight(er) while the thin parts can be warped) the thick side down is actually about installation. you first put the straight(er) side down, nail it in place with a runner. and then you take the top runner and press the glass straight against the frame with it (glass bends surprisingly much before it shatters, specially thin glass, but its also part of the reason why its common to see corners snapped on older windows). also if you ever remove old mouthblown glass panels, they can still be under tension. always remove the top and sides first, taking care that the top can actually pop out when you do. but the other way around, if you remobe the bottom and sides first leaving the top one last, the bottom of the glass can pop out of the frame as well, and itl fall since its not supported or carried by the frame anymore. another thing that might be behind the glass being liquid myth is the timeline of development. old mouthblown glass has a lot of bubbles, its wavy and looks like its flowing. it was before it cooled down. the next step in the glass evolution was to pull it upright between rollers, which leave a slightly wavy but straight waves kinda pattern, i was instructed to install those pattern upright, its much less disruptive on what you see thu it that way. horizontal warping just looks bad. and the current way of making glass, "float" is the marketing term for it, it is molten glass floating above lead and i forget what else. and the speed its pulled from the furnace defines the thickness of the glass. float is more or less optically perfect without lensing or warping effects.
@@cwell2112 Alternative hypothesis: Take anything with a larger end and a smaller end. See which end is more stable when placed on a surface. This isn't about the _appearance_ of stability, like the OP mentioned. This is about actual stability. Take pyramids, for example, there's a reason the pointy bit is at the top, and it's not the _appearance_ of stability.
@@Mythraen Can't confirm of course, but I think they probably know that, but used 'looks more stable' because the glass is held in place by the frame, so it would not have made a difference. I assume they were trying to say they built it in a way to archive visual stability primarily, while structural stability may have been neglectable in this case. Those two things can occasionally not be the same. For example an object with an externally invisible very high center of mass may look stable, but is not.
@@sleepyidiot2010 No, the first drip took 8.1 years. The last drip took 13.4 years. Most of the bump in duration was when they introduced air conditioning. ~13 years is it's new viscosity at A/C temperature. The rest of the slowdown is not because it is continuing to lose heat; after all these years, it has reach an equilibrium with it's environment, but because the weight of the rest of the pitch in the funnel is exerting less force to force out the next drip.
*[Host delivers a pun to the audience and smiles smugly for a few silent seconds]* *Awkwardly delayed response in the back of the audience:* _"...I get it!"_
The closing was so... interesting. "Sometimes the rigid definitions we create for ourselves can introduce misconceptions." I know it's mostly just for puns, but I feel this line resonates far beyond the world of physics.
Glass has been manufactured back at least as far as 3600 years ago in Mesopotamia, but stained glass came some time later. I suspect he meant to say "hundreds" of years.
But yeah gas is a liquid because particles can flow past eachother and it has no definite shape but like liquid isnt a gas because it has a definite volume
+Jeffery Liggett haha I thought about telling more, but I didn't want to reveal any spoilers. I thought about telling you about what happens on page one but it's pretty big... hence 'catastrophic event'
+NerdSync Indeed. I recently heard a good description of how that old glass was made and why it was constructed unevenly (because it was spun). That too might be wrong, but if it is true then it has always been known exactly how the glass formed that way leaving me to wonder how anyone could have come up with that wrong b.s. about it flowing in the first place. That's why figuring stuff out is so hard. Not only is reality tricky, but people lie and maybe just eventually forget that they made something up and come to believe it themselves. And there's no simple way to tell if that's happening or not. (Or doesn't seem to be.)
For my undergraduate capstone some years ago, I did a room temperature viscosity measurement of glass fiberoptic stands under tension with laser interferometry. We could see if there was any flow exhibited down to a change on the order of a picometer. After months of data, no change. We concluded that lead (from established viscosity measurements) would flow into a puddle before glass based on our lower level of detection. I don't recall the timeframe required but it was not realistic in the slightest. Fun times.
With a difference in chemistry of less than one percent glass can have two very slight differences in the coefficient of expansion so Tiffany had to create his colors very carefully. So when two colors were side by side in the same piece of glass Tiffany's best measurements were not 100% accurate and strain developed. Now a one inch long line where the two colors meet would not expand and contract differently such that you could even measure it. If the glass could move at all it would do so over a hundred years, and yet it can and does still crack on occasion after many years due to that strain.
***** Thanks. I liked your joke, too. The only thing I'm not on board with is the "he says pitch is not a liquid" thing. I can only find passages where he says the exact opposite. He of course also says that the distinction is ultimately somewhat academic.
The video touches on volcanic eruptions, but it would be good to hear a discussion on why lava erupts from an otherwise 'solid' crust/mantle. I suspect many viewers are left wondering why.
+Kurt Story From what I recall, earthquakes (and by extension volcanic eruptions) happen due to tension in the tectonic plates. The tension builds up energy and suddenly releases all of it, causing damage and shockwaves. Volcanoes have special ducts that allows the molten rock to flow out as lava. But then again, the whole idea of lava flowing is based on the idea that it is molten. An interesting thought is how there are convection currents within the apparent solid that is the mantle. Perhaps it acts as a non-Newtonian fluid with special properties? Science is weird. :/
+Kurt Story Just to complete the picture (other people here are correct, but not entirely) - there are three ways to melt the rocks of the mantle. 1 - Add heat. This is extremely rare today, as the earth doesn't contain enough heat to do this often. One exception is Hawaii, where a very hot mantle plume is capable of melting near the surface. 2 - Release the pressure. The mantle is only solid at high temperatures if the pressure is also high. At mid-ocean ridges, such as on Iceland, the crust splits apart to expose the mantle. This causes it to melt. 3 - Add water to the mantle. As oceanic crust forms from molten magma, it reacts with sea water to introduce water molecules into the minerals that make up ocean bedrock. When these are subducted under a continent or another piece of oceanic crust, the water molecules lower the melting point of the mantle, allowing it to form magma. Japan is a volcanic island chain created by this process.
+Kurt Story One explanation I've seen in a video about plate tectonics is that subducted crust often traps & drags ocean water down deep where it develops steam under high pressure, causing eruptions where there are breaches near the lava surface.
+SonOfFurzehatt There are other components other than H2O that will decrease melt viscosity as well, say CO2. Though H2O is definitely the best studied and well known component that will depress the liquidus of a melt, especially mafic melts.
+Yaqub Ali it's solid because of the pressure, once it gets to surface the pressure gets to one atmosphere and the temperature causes it to go liquid. they're two forces that counteract each other - hot things flow because the temperature is movement of their molecules, and once the temperature is high enough, the molecule movement is large enough to break the chemical bonds. pressure, on the other hand, prevents the molecules from moving too much. therefore, under high enough pressure, even molecules of very hot materials don't move enough to break the chemical bonds. for similar reason, human blood boils in vacuum without changing its temperature - vacuum is less pressure than normal (no pressure at all, in fact), therefore even the standard, "room" temperature of blood is enough molecule movement to break the bonds keeping blood liquid and start changing it into a gas (which is exactly what "boiling" is, the process when liquids start converting into gas). for the same reason you can make gas into liquid or even solid just by applying enough pressure on them. or without applying pressure, just by cooling them down enough. it's two sides of a swing, the more pressure you have, the more heat you need to keep thing as gas/liquid, and the less heat you have, the less pressure you need to keep that thing solid/liquid. the only "assymetry" is that there's lower limit on the pressure, you can't have lower pressure than vacuum, naturally, and earh's atmosphere isn't that far from vacuum. But as far as I know, there is no (reasonably achievable) upper limit. (There is, kind of, at least for heat, and it's the temperature at which even space itself (not space as Universe, but space as the thing you move through) starts to boil, but it's insanely high, several thousands or milions times higher than the hottest star.)
Window panes were made different in the past. Nowadays we have float glass, where molten glass is poured on molten tin. In the old days I read they had pulled glass. A rod is put in molten glass over it's entire length, and then moved upward carefully. The glass sticks to the rod like soapy water, and gets hard. The bottom gets thicker, because of the glass cooling off fast. (Glass doesn't have a precise melting point) When they put the pane into a window, they would put the thicker part at the bottom, otherwise the thin part would have support most of the weight.
+Ariton Debrliev Depending on it's composition, some glass will melt at temperatures as low as 500 °C (900 °F), others melt at 1650 °C (3180 °F). Depending on it's composition Steel melts at around 1370 degrees C (2500°F) to 1510 degrees C (2750°F). But that's not all, you need to take in acount that steel needs to conduct the heat from the glas in order to melt. So yes, if you have enough molten glas at the right temprature and provided you can pour it on the steel without turning the glas solid, you can melt steel. But it isn't very practical and you would neet allot of molten glass. TLDR: Yes if you have enough, but it wouldn't be usefull in anny way.
I was hoping you were going to bring in mechanical "creep" into discussion. If a solid bends or warps over time, where does that fall in the whole "flowing" and liquid debate?
+MICHAELHICKOXFilms If a material undergoes a deformation over time due to a constant stress and no change in temperature, then it is flowing, however slow it may be. As you may know, this tends to happen to viscoelastic substances like polymer, which behave both like a viscous liquid and an elastic solid. Metals and ceramics don't display this behavior to my knowledge, and so are true elastic solids.
cant you understand the video folks??? he says that some materials that we think that they are solids are actually liquid with extremely high viscosity, he is not saying that all solids are liquids!!!
+MICHAELHICKOXFilms We actually learned about creep this semester in my mechanics of solids class and he talked about old church windows deforming due to temp changes
@@schwarzerritter5724 Well actually, iron can be a liquid though. It can melt and can still be called iron. Glass can melt, but it's not really considered glass anymore since molten sand has the same chemical structure.
+Mohogany Guy 1869 hmm or is it? as you add more material to the liquid it becomes more viscous so is quick sand a solid or a liquid? you can run on quick sand (or this case quick tea) but if you stand still you will sink.
One fascinating thing is that it can be far more helpful when working with building foundations to consider the ground to be liquid, like honey, just a really really thick liquid...and if you are studying liquefaction, a not so thick liquid. Now generally speaking, it's not a liquid, but unless you go deep you aren't usually dealing with solid rock, and the particles of dirt, or clay, or sand, slide past each other somewhat like the atoms in a bucket of water. By extension, designing good foundations can feel very much like designing a boat. There's even an analogous force to buoyancy, soil heave!
There's also this clay structure which is like three dimensional house of cards filled with water. It is solid if you press it down, but sideways motion can cause huge landslides if the formation is on incline. There have been building collapse catastrophes when this happened because no-one knew about this type of clay.
Actually lava (even basalt), diverges greatly from the composition of the mantle, the mantle is mostly olivine and pyroxenes, who are very hard to melt, so when something melts it's the minerals that require a lower temperature to do so, plagioclase and clinopyroxene. When we do see parts of the mantle is when magma brings up xenoliths made up of olivine and pyroxenes, completely solid because even the hotter lavas can't melt them.
+L Delivery Guy now we're getting to the heart of the matter. It's tough to get everyone onto the same definition of when a liquid is viscous enough to be a solid but 10^13 P seems to be a reasonable cutoff and glass is around 10^22 P
+Veritasium Wouldn't it work better to define liquid/ solid in terms of phase transitions? At ~1500 celcius glass needs to overcome the latent heat of fusion so that is the point the solid/liquid transition occurs.
@@Ronit1302 "a rose by any other name would smell as sweet". An object, or an object's behavior, doesn't change based on what we call it, or how we categorize it. An object's behavior _would_ change if you could somehow change the math involved with it. In a way, regardless of what name or qualities we assign to objects, the math _is_ the object.
Perhaps this info is in a more fun form than hearing it from a boring teacher?! When one seeks out the information willingly, it will surely stick much better than being force fed. imho
Triple259772 On the video, near the start, it shows a time lapse of the experiment. If you look at the small green clock, you can see the second hand turning anti-clockwise.
Older stained glass was mouth-blown and very difficult to make in sheets of uniform thickness. Some stained glass is still made this way. It can vary from 5/16" to 1/16" within a small sheet of glass. The pieces weren't necessarily turned with the thickest part at the bottom. Pieces that vary in thickness can also vary in tone with the thicker parts being darker. They were arranged for aesthetic reasons as much as structural reasons.
fun fact: the word trolling was first used in a, like, common misconceptions themes usenet community. people would "troll for newbs" by posting things that everyone knew were false, but only the new people would react to because they were the only ones who didn't know the person was trolling. trolling like fishing, not trolling like angry men under bridges. the fact that they used most often: that glass is liquid.
@Engineer_guy _1461 Dude, I'm pretty sure that Jack Gammon was making a sarcastic joke. No one is really dumb enough to believe that evolution is a myth and creationism is fact. Well, maybe americans, but there are some smart americans, too and I suspect that he's one of them (and that he was making a joke).
@Engineer_guy _1461 I weep for humanity. I dream of a world where everyone dumb and/ or delusional enough to believe in a magical-sky-wizard (and all the pants-shittingly crazy nonsense that goes with it), goes to live in america, leaving the rest of the world for those of us who wish to live our lives free of delusions. Oh what a wonderful world that would be (though I expect it'd really SUCK to live in that america)...
Is I Isi The 'study' he referred to was a physics thesis which has been since proven fallacious. Stained glass made by hand has a very variable thickness which the artist exploited as a means of controlling the transmittance... the brightness of the areas of the picture. They discovered that by reducing the thickness of the glass used at the top, both the orientation of the piece and the mean thickness of the glass pieces in the image it caused the observer's eye to track upward to follow the increase in brightness... So... an effect created deliberately to inspire an emotional feeling of uplifting. Your teacher missed the memo.
1:04 I never realized the pitch drip setup was so small before!! I've watched the livestream a few times before and I always pictured it being much bigger than that, but I guess I hadn't seen a person next to it for scale before now. Go figure!
One point that I wish you would've covered in this video is why glass warps over time, it's that warping that makes people think that glass is a liquid.
Glass doesn't warp over time, and optics in telescopes are a proof of that. It's just the technology used to create glass was flawed and it was making irregular pieces that are bigger on the bottom (I guess mostly because they allowed glass to cool down in vertical position). EDIT: Or I'm misunderstanding word "warp".
I've seen images of glass bottles that have been warped under their own weight from just being out in the Sun for many years. At least that's the explanation that I've gotten, is that the Sun produced enough heat to the glass bottles that the bottles would very slowly collapse in on themselves, which is the argument that's I've heard for glass being a liquid, but also many things have a solid, liquid, and gaseous state depending on temperature. For example, there's what's called a Demon class or Hell class planet where the environment is so hot that iron acts like water, having a solid state when the temperature is cool enough, a liquid state as the iron warms up, and a gaseous state when it's too hot. On a Demon/Hell class planet it literally rains molten iron as the gaseous state of the iron cools in the atmosphere rains down in liquid form. And we know, watching glass blowers that glass has a liquid state, but at what point does the glass stop being solid and act as a liquid as the images of warped bottles indicate that just having the glass set out in the heat of the Arizona desert over many years show that the glass has enough flow to collapse in on itself. Just do an image search for, "warped glass bottles," and you'll see what I'm talking about, though some of the images are of artificially warped pieces, but there are some found in the desert warp supposedly just from the heat of the Sun.
No glass doesn't warp, I'm a glassblower and have worked with glass for many years, you need to warm glass to around 550˚ to even start it warping and up to 850˚ to really manipulate it. In answer to POLISH COOKING, glass wasn't cooled in a vertical position, It was spun on a blowing iron like a large flat plate and the glass near the iron was thicker than the glass at the edge of the plate. When it was cracked off the iron, you were left with a messy piece in the centre where the iron used to be but because it was so expensive to make they still used that centre piece as small window glass known as the bullseye. you still see it as decorative glass today in front doors as a rippled circular "bullseye"
Then explain this please - old window (like 50 years old) held in place by a wooden frame is now loose at the top but still tightly held at the bottom and it's clearly thicker at the bottom. Maybe it was a bit thicker to start with but the people who made that window wouldn't leave it loose like that at the top. You can say the because the lower part of the frame was subjected to more moisture (rain or whatever) it swollen more than the top part but why would the top part shrink ? Btw - when doing a maintenance on old windows is it advised to flip the glass upside down if you want to keep using it, just that says much.
About glass - In the attic of an old house I found a pane of glass roughly 18" square that had been leaned against a wall and it had a significant bend with the top being a good 4" out of plane. This was an uninsulated attic, in Silverton 9,700' elevation, the glass had been subjected to extreme regular temperature change so I believe that helped it along. It was truly amazing - I heard a chemist describe it as an 'infinitely slow moving liquid' once.
@@citizenschallengeYT So I'm gonna call this myth busted. Glass is not liquid - it is a solid at room temperature. When exposed to excessive sunlight and desert temperatures, it loses rigidity and becomes malleable, just like household plastics. Glass left in a desert attic with a tin roof will behave much the same way as a plastic green toy army man left out on the porch on a hot summers day lol. I'm really glad I found this comment, it's kinda helps round out the points made in this video.
@@Mygg_Jeager fair enough, though it was dark attic, heat, plus at 9700 elevation huge daily temperature swings up in there summer and winter. Slough and Sag happens. :-)
Our experiences of glass warping are just anecdotal, so we’re idiots and the science guys are always right. Control the verbiage and control the truth.
maybe the reason the old stained glass is thicker towards the bottom is over those many centuries, they have been exposed to enough heat to slowly return a few molecules of the glass to a liquid state here and there. (just like how water doesn't have to reach boiling point to have some evaporate, just needs enough energy in a handful of molecules for it to break away from the rest of the liquid and turn into a gas). particularly with the high lead volume in old stained glass, a nearby fire (like a bonfire or the like) could potentially cause a miniscule shift towards liquid state from the heat, and over centuries having even that tiny amount melt, slide down a bit before rehardening, over and over, could cause it to build up towards the bottom. The telescopes are probably more likely to be away from high heat sources, plus the glass used in telescope lenses is very likely a different composition of materials (there are a number of types of glass from different chemicals, and even the same base types made from silica primarily can have other impurities added in)
While on a field trip we were taught that glass is a liquid by a glass blowing EXPERT while he was doing a live demonstration of glassblowing. Until now, I never questioned him.
That black liquid that takes 10 years to make a drop? It's encased in a glass cylinder, poured in a glass funnel and dripping into a glass tumbler. Given the length of the experiment, you can over time measure for any change in any of these glass artifacts used in it to find out if glass is liquid at room temperature. Two birds, one stone.
The glass used for this experiment is most likely borosilicate glass, which behaves much different from soda lime glass used for windows. A common misconception people have about glasses is that it's a name for a single compound. It's not. It's a type of material, i.e. glass does not refer to the components it's made of, but only to the disordered state they're in. You can make a glass of almost anything, including metals!
@@IOffspringI didnt know this, thanks chief. seems obvious now that you mentioned it as i knew how glass was made, but never thought of what it was made of.
When making glass for windows, they blow "a dish", and cut it into squares. The "dish" is thickest at the middel. The middle of it with the broken off bottom of the stem is sometimes used in a middle window in a door.
This again clarifies an old theory I’ve learned. That materials cannot be classified as solid, liquid and air; rather the material can be defined by the four governing properties of it. It’s rigidity, viscosity, temperature and the gaps inside ( empty space). It’s written in my language as පඨවි, ආපෝ, තේජෝ , වායෝ
Alien 1: "Let's liquify this poor man with the lasers installed on our ship!" Alien 2: "Nah bro, let's wait thousands of years and he will liquify himself." That was bad because my brain can't get enough molecules FLOWING into it. Guess I'll go with the FLOW and stop.
@The Lenny Show well it's been 2-3 years since I wrote that comment and now I think they're both bad. Perhaps we shall agree to disagree. Just please calm it down with the "I'm sure you stole it". Stealing comments is against my principles because I, like many other sane people, believe le Internet points are kinda - um - meaningless (gasp). The only way I might've "stolen" the joke would be if I got heavy inspiration from another comment without realizing it. And I doubt that since I can't find a funny in my joke.
It is not simply that it is difficult to make a plate of glass with a consistent thickness, so one end is randomly thicker. Instead, old glassworks would intentionally make one end thicker, as that is the easiest way to control *where* the thick part winds up. If you try, and fail, to make glass consistently thick, you can end up with a thick spot in the middle, which is much more obvious to the viewer.
So if solid, liquid and gas are just different states of the same matter, why is there such a sharp drop off between the two? Why under heat does solid ice seem to transition directly to water, as opposed to slowly going from ice to firm sludge to mid sludge to loose sludge to water?
Because the states are easy to distinguish. Imagine you are with your friend : either you are holding his hand, or not. There is no middle ground. The same thing is happening with matter : either elements are bounded, or not.
+DataSlam One reason is that substances that drop from a [solid --> liquid] instantly as opposed to [solid --> runny sludge --> liquid] depends on the lewis structure of the chemical. Long chain chemicals tend to stick to one another much better than molecules like water that have no chain structure due to the increased surface "rubbing" area they possess.
thermodynamics dude.... thermodynamics.... for a change of state to happen you need all the mass at the same temperature so as the outer mass losses t faster than the inner you observe different phases.... hope I helped you
+DataSlam You will see that sort of behavior in melting metal. But in ice, a structure that is considered solid only because it stays in a perfect crystal structure, breaks apart as soon as the water molecules get enough kenetic energy (heat) to lossen up from the hard bonds that held them in the structure. You know that party trick where 4 people rest their head on eachother's lap in a circle and balance themselves on one another? Like a crystal, if something will disrupt the balance (for example, kicking one of the people), the structure will collaps, no middle ground.
Philip Madden What are you sayin' Phil? Huh? You sayin' I'm not calm? YOU SAYIN' I'M NOT CALM?! You chill Phil. I'm clearly what is referred to as an "Internet troll"
Glorious Potato That pun made me want to strangle kittens, but I'm gonna be honest, I've never seen a potato put on glasses before, so I'll let you off
Well I remember reading a school book definition of fluid, or rather a paragraph about it:- "Fluids are substances that can flow. All liquids and gases and some solids can flow, and hence are fluids." I don't have italic option on my moblie keyboard, but now I understand the "some solids".
We like to categorise things, pigeon-hole them. As satisfying and as useful as this is in general, we need to remember that things are often not so black-and-white and that reality does not conform to our attempts at describing it.
+Chris Weeks (Trombone Guy) I'd assume it's the amount of time for a certain volume of something to drip vertically some exact distance. That's just a guess, though.
+Chris Weeks (Trombone Guy) Resistance to flow is measured by how fast something moves due to gravity, a known force. Volume through a measured opening x time. Pour liquids through a funnel and time it. Temperature is included in factoring viscosity. Ex: Motor oil shows a number for viscosity: a higher number will flow more freely in cold temperatures (50W) and in hot climates, a slow moving oil (10W) will take longer to overheat. A hybrid oil (10-40W) is used for multi-season driving.
+Chris Weeks (Trombone Guy) You put the liquid into a container and then drop other things (like a lead ball) into it and see how long it takes to fall a set distance. www.teachengineering.org/view_activity.php?url=collection/cub_/activities/cub_surg/cub_surg_lesson03_activity1.xml
+L4Vo5 Yes, the Earth is broken into a few layers; the solid crust, the solid but plastic-like mantle (which can also be broken up further using rheologic and mineralogical properties), a liquid iron shell, and a solid iron core. Fun fact - If there wasn't a liquid shell around the core, the Earth wouldn't have magnetic fields.
+Nicholas Tan It does come from melted mantle, which happens when it gets hydrated, heated or has a "quick" depressurize from the surrounding, or by magma originated in hotspots in the mantle-core boundary. You have to think of these processes in a geological time scale :D
Sooo... I'm American, I was taught in school that the mantle is molten rock, flowing like a thick soup underneath our feet. It's obvious now that this is incorrect, and I feel like I have a right to be angry about being taught incorrect information. Is it just the US educational system that is doing this, or does this happen elsewhere?
They don't teach you that the mantle is liquid. The mantle is described as "plastic", which means that it moves a little bit over long periods. It is a solid, that is correct, but it still flows. Really, look it up in an online science textbook. Just because you *think* you were taught *one* wrong thing doesn't mean the american school system is broken.
Just because you can find the correct answer on Google doesn't mean that people are (or were) being taught correctly. I was in school before Google was a thing. I didn't get my first cell phone till my senior year of high school and it was a flip phone that didn't even have a color screen.
I don't know. The big cathedral in Frankfort Germany has glass that's almost an inch thick at the bottom and about 1/4 at the top. Are you sure it's not just the type of glass? On an unrelated note, I was a surveyor in the Army in the 80s and I also noted the survey control point outside the church was 15 inches lower than the original data which had been taken in the 1600s or 1700s. I forget. It's been a few years. The cross on top of the church, also an SCP, was dead on.
Could you please make a video about Rapa Nui? I've just watched a documentary about it and it was so interesting. And if you could do a video about it, it would litterly make my whole life :D
