The Strange and Unexpected Reason Ice is Slippery

[@besmart]

Disclaimer: My left butt cheek was harmed in the making of this video I'm on Twitter and Instagram at @DrJoeHanson and @okaytobesmart! Tag me if you share the video

[@robbedoeslegrand236]

As long as it's only a butt cheek, you should be OK. ;)

[@sth128]

Put some ice on it

[@alphabeta9425]

Okay

[@Heisenberg612]

Everyone's looking at you weird lmao

[@evandroandrade4909]

"It's the perfect texture for running"

[@veritasium]

Thank you for dealing with this misconception that has been spread by so many science communicators in the past. For the record I admit I was wrong and I linked to a paper in the description of my video. Great work Joe!

[@besmart]

Science is an ever-correcting process! You’re a good sport Derek. High five, my friend 🤓

[@chadistan4790]

Good on you

[@aresorum]

👏

[@lifeofphyraprun7601]

I was swiping for this.

[@user-kx5es4kr4x]

Wow veritusium

[@FNHot]

You have no idea how happy this video made me, I have wondered about this FOREVER. And everyone says friction or pressure, but I've seen BOTH debunked before. My mind can rest on this topic now.

[@zolacnomiko]

SAME.

[@thomasbayer3311]

For now...

[@dreallday07]

Crazy, as part of a Camb medicine interview prep talk, one of the professors had asked this question, we initiated with friction/pressure but came to the conclusion that had to be wrong because you can’t skate on glass and water doesn’t make a difference in how skateable glass is, so we moved onto the structure of ice, and from basic principles ended up on the conclusion stated in the video, we also ended up talking about how the ‘volatility’ - for lack of a better word for the properties - of the surface water molecules allows it to slide similarly to how graphite of a pencil tip would, adding to the theory stated in the video, was fun combining more basic concepts in order to accumulate to a more difficult answer.

[@807pranavghandade8]

You should've just waited till your 12th grade then

[@archie5501]

Same

[@clavierpixelkey650]

- You fell on the ice?? - No, I fell on the non-solid, quasi-liquid layer on the surface of the ice. Those darn free-moving H₂0 molecules…

[@webe3228]

this made my day

[@prodkerstii]

This made me smile

[@brifer6121]

“Solid rock doesn’t float on lava” tektonic plates: “Am I a joke to you?”

[@pjabrony8280]

Tectonic plates float on the mantle, which isn't really liquid.

[@pradyumnbisht4077]

Tectonic plates comes under lithosphere, which made up of crust and upper mantle

[@dhgfhhhghhj]

@@pjabrony8280 the mantle is liquid...

[@Dan0RG]

@@dhgfhhhghhj Quoting Wikipedia: "It is predominantly solid but in geological time it behaves as a viscous fluid".

[@Dan0RG]

@@jacobf_139 ...no.

[@00crashtest]

In university geology class, I learned that the surface state (what you called quasi-liquid) of water occurs between the nucleation (supercooling) and melting points. When ice is cooled to below its nucleation point of around -20 Celsius, the surface stops becoming slippery. I also learned the same applies to other minerals and rocks. When a rock is almost melting but not yet molten, say, at 990 degrees Celsius for a melting point of 1000, its surface also becomes slippery.

[@FacelessOfficial1]

"hey smart people...I just dislocated my shoulder.."

[@bland9876]

My mom said she did something similar to the intro except she broke her wrist

[@FacelessOfficial1]

@@bland9876 ice is dangerous.. almost died in a car accident at some point due to ice..

[@kvonkirk2340]

@@FacelessOfficial1 are you sure its not the cars that are dangerous? they kill people all the time with no ice around.

[@FacelessOfficial1]

@@kvonkirk2340 cars are dangerous if you don't pay attention when you drive (or if someone else doesn't pay attention) or if there's excessive speeding invovled, but ice is an extra parameter....

[@messynate]

This guy at my job dislocated his shoulder by falling on ice the other day 😰

[@TraceDominguez]

When I did a video about curling, they tried to explain ice to me and they FAILED. You succeeded, my friend. 💕

[@besmart]

Thank you friend!

[@garchomowner]

What is this a crossover episode?

[@chestersnap]

Wait this brings up a question I didn't know I had. Why does the brushing thing they do make it more slippery? Is it melting from the friction? Or are they knocking lose more water marblecules to roll on?

[@blue_pomeranian]

@@chestersnap probably both, but I'm mainly commenting to give you props on coining the term marblecules.

[@dabeamer42]

@@besmart Hey DrJoe -- how about you tack a wack at the curling question. That is, why does a curling rock curl in the direction it does? Destin S (SED) tried, and found disagreement among PhD's.

[@danecraze903]

That "To be continued" meme made me laugh hard

[@shalice7784]

JOOOOOJO

[@fonsineknshr]

it chortled me

[@lepp522]

@@shalice7784 GOLDEN WIND

[@scotty3739]

lepyrus G I O G I OOO

[@johnnyboi5941]

Joe made a JoeJoe reference😂

[@garyrayr5250]

I am a retired engineer and love your videos. They have so much knowledge packed into them I watch at .75 speed to make sure I keep up. Way back in the day I did my thesis on surface tension flow of melted steel in a weld pool. I think what you have described here is surface tension of a solid. I have not read any papers about this yet and that may be an old idea but thanks for keeping this old brain active.

[@josephinelauren7417]

The thumbnail: NOT SOLID, NOT LIQUID My brain: GAS

[@Purged-f2i]

I was thinking of plasma

[@Abyzzol]

The Unlucky Seagull u were that kid huh

[@thatoneleaf9895]

me, an intellectual: Plasma

[@l00k4tstuff]

A meta-state based on quantum fluctuation at the edge. Duality until observed - or slipped upon. Probably why ice so readily sublimates to gas when it should go through the liquid state.

[@spec_wasted]

I was thinking of jello

[@jamesreid6940]

Just seeing the people in the background looking at him is hilarious 😂

[@doxielain2231]

They're staying curious. Especially the girl in gray.

[@phoenixsspark6150]

Doxie Lain if anyone was wandering. 6:50

[@uniqhnd23]

@@phoenixsspark6150 wondering*

[@uniqhnd23]

@Stellvia Hoenheim F****ing hell you sure about that? This dude did all of this to educate us and you're calling him shameless?! You ever heard of the definition of shameless?!

[@TheMethClub]

ORO 0147 well he has no shame. There’s a negative connotation sure but I feel like in this case it’s less of an insult and more of a fact

[@microska2656]

Normal people: ice skating is so fun Joe: why is ice slippery?

[@knampf9779]

Progress is fun.

[@mr2octavio]

That's the kind of thinking that lets you have a device that fits in your hand and lets you access the whole internet. Because someone asked a 'why is ice slippery' question

[@barbarahouk1983]

@ Swampert D That’s one of the reasons people think me not normal. These kind of questions I was asking in my youth. I was 22 yo when my spouse pointed out to me I had a tendency to “tire people out” bc I would talk about everything that fascinated me. That was in 1977 so there was no internet or KZbin to make videos. Now I am old and tired & ill. So I just enjoy these videos bc I still like this kind of thing. Joe is my kind of nerd.

[@refineKC]

Who's Joe?

[@mrittikamurmu645]

@@refineKC whom you just saw.

[@facetankhank]

Imagine how smart I will look telling this to my children when they start understanding the concept of molecules and atoms.

[@twilaritchey7684]

It’s not liquid, but it’s not solid” Me: it’s jello

[@trollinape2697]

jelly is solid

[@luismijangos7844]

Thanks Dr. Joe for sacrificing your butt for that cool intro!!!!!!!!!!!!!!!!!!!!!!!!!!!

[@besmart]

[@syd.a.m]

@@besmart

[@shambosaha9727]

@@zack7122 Gröss

[@Joetoep]

Just put some on ice on it and you'll be fine

[@Impulse_28]

@@Joetoep but CAN you...? Plays Vsauce intro

[@sheepco]

Me: its because of a thin layer of water Joe: No Me: Oh Joe: But kinda Me: ??

[@annonimooseq1246]

sheepco well no, but actually -no- kinda

[@charliegarrison9688]

Yes, but maybe sorta definitely.

[@PajamaMan44]

Is a single molecule of water considered solid if it’s at -5°C and 1atm?

[@ObjectsInMotion]

Well no, and actually no. Quasi-liquid is not liquid.

[@rikschaaf]

@@PajamaMan44 Single molecules don't have a phase to my knowledge. That is a property of multiple molecules together.

[@MrC0MPUT3R]

"Solid rock doesn't float on lava" *Laughs in Continent*

[@charliegarrison9688]

It does in movies i seen it

[@ShantanuShinde1]

the crust is not really the solid form of magma though. it is made up of different materials which are lighter than magma.

[@lorrie9462]

🤣🤣🤣

[@pohatunuva3771]

The mantle is solid though, and the asthenosphere is... Funky

[@katastrofygames]

Continents don’t float on lava/magma they float on the mantle which isn’t really liquid. I always thought of the mantle as like thick cookie dough.

[@mepholies]

6:09 The last place I’d expect to find a jojos reference

[@enlightningairieon]

Teacher: There are 3 states of matter, Solid, Liquid, Gas. Student: There are really 4, Plasma as well Me: um, actually...

[@Not.Your.Business]

what about Bose - Einstein condensate?

[@breck1637]

Or Fermionic condensate?

[@Ergo...]

Time crystals?

[@stefansauvageonwhat-a-twis1369]

@@Ergo... thanks, nobody ever mentions them

[@stefansauvageonwhat-a-twis1369]

Hyperliquid?

[@krellend20]

"Something as ordinary as frozen water" belies the fact that water is one of the weirdest molecules in the entire universe, as there is virtually nothing else in all of creation that resembles it.

[@crackedemerald4930]

And it's still amazingly common.

[@12201185234]

@@crackedemerald4930 Because hydrogen and oxygen are incredibly common.

[@kettlebot3610]

I'm gonna need more context to this comment lol, got a youtube video I can check out?

[@sammjust2233]

I'm still annoyed at Veritasium for doing a video on this with the wrong information

[@besmart]

I wasn't gonna name names… LOVE YOU DEREK

[@JayJagpal]

That's fair but I feel we should be tolerant as it's near 8 years old and we're smarterer humans now now.

[@DANGJOS]

Yeah man me too. I actually responded to that video (others did too), at the time, telling Derek that his explanations didn't work. He said to them that he's aware that there's still questions as to how it works, and somehow turned it into him still being sort of right lol. I don't remember how exactly.

[@derekdjay]

Hanson said this was discovered in the last few years. So Derek Muller's video must be older than the discovery itself. He didn't actually give a definitive answer then, only theories.

[@DANGJOS]

@@derekdjay I'll look at his video again. I don't want to be disingenuous.

[@Noneblue39]

5:45 this model using marbles is a good way of explaining it. my gut feeling was it had to do with the x-stal structure at the interface

[@fahrai4983]

Hi! I’m curious, why did you use “x-stal” instead of “crystal”? :)

[@not_dark_lord]

Up next: The actual reason why water is wet.

Water is not wet. Check your facts.

[@ayushsharma9270]

@ water is wet lmao

[@abrams5819]

And bonus episode: is ice wet?

[@bismuthezoid]

My brother and I were arguing about it this morning while having breakfast😂

[@Srahas]

@@FirstNameLastName-rh6zc damn

[@clockworkkirlia7475]

Fascinating! As soon as you mentioned the disconnected polar molecule layer I was thinking about slipping on marbles, super cool to learn about how that can happen!

[@dude-e]

Thank you for using the metric system. I was able to understand things without the need to constantly look up coversions

[@samuelyoung2671]

mhalsari booooo

[@joesterling4299]

Me, on the other hand . . . Luckily, I can convert kg into lb pretty quickly now. (Double it and add 10% of the result--which is just a left-shift of the decimal point of the result.) Getting more practice every day.

[@flytrapYTP]

@@joesterling4299 I still don't understand why anyone thought that keeping the imperial system was a good idea. The conversions are illogical.

[@DANGJOS]

In solid-state physics, this would be known as a surface state.

[@blakelee4555]

Hi solid-state physics.. I'm dad

[@DANGJOS]

@@blakelee4555 Dangit it's supposed to say *"in"!* I freaking hate autocorrect!

[@mr2octavio]

@@DANGJOS oh but now it's not funny anymore

[@LordAJ12345]

@@mr2octavio The fact that the reply doesn't make sense anymore makes it even better. Now you have to piece together what happened.

[@thearmyofiron]

@@LordAJ12345 pretty easy to piece, only needed to read 2 replies

[@jalphototecture]

I know the rink this was filmed at! Chaparral in Austin, Texas!

[@besmart]

Bingo!

[@masonsilvers6789]

*TEXAS INTENSIFIES*

[@kevinpham8693]

Haha I’ve been here a couple of times!

[@danieljensen2626]

Lol, I've been there but I was just thinking a lot of ice skating rinks look pretty similar.

[@Liv-dh6tn]

*yee haw people have entered the chat* (including me!)

[@AshenElk]

Committee: "Why would you like money?" Scientist: "To find out why ice is slippery." Committee: "Um…"

[@herrrausragend850]

Oh man. I got to know ur channel from my girlfriend and what can I say? I've learned a lot from you and it's always getting more and better. But the best part of your videos is that you don't take yourself too seriously. There's always the small piece of humor that makes your videos sooo special! I love it!

[@ninjanerdstudent6937]

Joe: I am going to make an episode about ice. Also Joe: Okay, I need to learn to ice skate before that episode.

[@robertsteel3563]

IOTBS: *falls* Guy in the background: What happened?

[@resonance-cascade]

Just say Joe....his name is Joe

[@robertsteel3563]

@@resonance-cascade I, for some reason, did not know that! *EDIT:* but i am gonna leave it :P

[@resonance-cascade]

@@robertsteel3563 i said it just for you to know... ;)

[@robertsteel3563]

​@@resonance-cascade​thnx! :)

[@aizenreeve9435]

6:10 okay, you caught me off guard on this one 😂 lmao

[@BasementRuthie]

This actually makes so much sense!! I love that we never stop learning!!

[@FreakyRufus]

So my question now is about the experiment of holding two ice cubes together. Are you exerting enough pressure to make them melt a little and then refreeze? Or, are they sticking together because all the molecules on the surface form additional hydrogen bonds?

[@vyor8837]

Melt and refreeze

[@alakario]

We do know more about the moon than water and food.

[@fabiolatouwole7588]

Yep that's right and sad 😅

[@alakario]

@@maya_yaser wow

[@longleaf1217]

its true, we also don't know why melted ice tastes the way it does. I mean its like the most common thing and yet it still holds so many mysteries.

[@liligman]

Brandon Woodyard All the Melted ice I’ve come across tastes like the water before it froze...am I missing something here? 😂

[@chestersnap]

It's because a hunk of spherical-ish space rock in a near vaccuum is about as simple as physics gets but the way the human body interacts with _all_ of the chemicals that make up food is pretty complicated _especially_ considering chemicals will also interact with each other so you have to know how the human body will interact with all chemical combinations potentially found in food and not just individual chemicals. _And_ every human body is different and each of those bodies are dynamic systems that don't stay the same. _And_ it's real easy to get into ethical issues when performing experiments on how certain foods interact with people. _And_ - do I really need to go on or can we accept that maybe life being more complicated than a large rock should be understandable?

[@stefansauvageonwhat-a-twis1369]

I read in a journal that this question is one of the few not understood questions of science. Thanks!

[@stefansauvageonwhat-a-twis1369]

🤣

[@btdpro752]

If a scientist asks you to trust them because they are a scientist, don't trust them. That's why they publish their research and others check their results.

[@freakdeath1020]

6:09, Literally, Jojo Memes are taking the internet.

[@ALLANX7]

fixed: JoJo memes have taken the internet.

[@kpi7757]

@Gurnaj Virk Yes it is. if you have ever watched the show, even the first part, you would know

[@anaksamanananggal3940]

But still. I still wanna call them *MEEEMMMEEESSS*

[@Abyzzol]

Gurnaj Virk dude the to be continued meme is from jojo

[@JesuszillaS]

JoJo memes have been around since the early days of the Internet, dude. MUDAH.swf is old af

[@peetiegonzalez1845]

Great explanation. Can you also explain how it's possible to cut ice, slowly, with a relatively low amount of force, like a weight suspended on a thread. I've heard this explained by the same pressure phase diagram argument, that doesn't really make sense due to the high pressure needed.

[@einsteinwasright1044]

Properly sharpened skates have a slight concave curve between the two sides, and the skater alternates between the two edges when skating. Thus the pressure from the blade is much greater than the simplistic calculation that you used when you assumed that the entire blade width was in contact with the ice. Also only part of the blade is in contact with the ice from front-to-back, not the entire length of the blade. Even if the blade is flat, the skater still alternates between the two edges.

[@DogeTrump]

6:08 Quality meme 😂👍

[@shalice7784]

6:09

[@mr2octavio]

@@shalice7784 6:08 is better, it allows time for the joke to happen.

[@sreejasrivaram8250]

A daily dose of JoJo memes makes my day..

[@kseriousr]

The joke didn't quite land.

[@hadi-bx1xo]

KZbin: Hey you wanna see a video about why ice is slippery? Me: Yeah sure why not.

[@kjellenproductions7349]

The slipperiness must be the work of an enemy stand!

[@teddyzawseome]

Ho so you're stepping on me ? Even tho you're grandfather told you how slippery I am.

[@azuregriffin1116]

*JOJO INTENSIFIES*

[@JX1JoJo]

Ah yes, Jojo...

[@madison8818]

SOFTO ENDO WETTO

[@Skeloperch]

@@madison8818 Your comment was disliked by beetle enthusiasts world round

[@ForestOokami]

Honestly this came at the best time. Everything where I live is currently under a pretty thick coat of ice, so now I know exactly what to blame for how sore I am from falling while trying to clear it off!

[@kentjohnduga6833]

We should have known. At engineering school, when we were taught that water in any of its three phases do something weird (solid less dense than liquid, autoionization of water, six-side crystalline structure of ice, etc.), this is always attributed to its capability to H-bond. And indeed, H-bonding did something weird again! Thanks Joe!

[@Gumby518]

6:08 WAS THAT A JOJO REFERENCE??

[@benjaminmeusburger4254]

YES!

[@kjellenproductions7349]

MASAKA! *ORAORAORAORAORAORAORA*

[@thepotatogamingkr]

Yare yare daze😑

[@xanderberg3653]

Is that the seinfeld bass music playing?

[@HyLee98_aka_KingAyam]

If they make something scientific about jjba universe, things like kars trap in space forever

[@coleworld8265]

6:06 never thought I'd live to see the day there would be a Jojo reference in a PBS video

[@krovek]

Now we need to see a Za Warudo time freeze in an episode of Space Time

[@Z3DT]

Every time you skip forward in a video is a Jojo reference. You're using King Crimson.

[@verify6329]

Everything is a jojo reference

[@unknownpotato4140]

i can't be the only one who stopped when that happened scrolled down jsut to see this

[@bjmoreno043]

Yes

[@shadowsfromolliesgraveyard6577]

So it's like how graphite gone 1D has really weird properties, so does Ice.

[@rpierrelouis071]

Kieron George 🤔 you might be on to something

[@nickeman132]

If y'all discovered smth just say it imma just leave a reply here

[@GATORBUBS]

The amount of extremely detailed and easy to understand visuals on this channel is amazing

[@IamGhede]

This makes sense. Being a delivery driver I have had my fun with ice and snow and nothing is as slippery as black ice when stepped on with a snow covered boot.

[@blue_pomeranian]

I've been obsessed with the science of ice ever since 4th or 5th grade (when I learned atoms get closer together to be solid, except water). That question on why water expands yet becomes solid haunted me until 11th grade when I took chemistry. It was so satisfying to learn that it was due to the charges on hydrogen and oxygen aligning the molecules so perfectly to create hydrogen bonds, with a ton of empty space in between from the hexagonal angles. You sir have just satisfied my other deep curiosity of water. In elementary school I had a book stating the thin layer of water theory was the cause of slipperiness, but I never fully accepted that theory as water on another flat surface did not produce the same effect. Having surface solid molecules constantly bonding and breaking due to not being enveloped by structural bonds makes much more sense.

[@ericbrunet7474]

No it doesn't make much more sense. Firstly, that layer is so infinitesimally small it can hardly be that relevant to our physical bodies. Secondly, what about all the rocks that also have the same sort of molecular arrangements?!?! Why aren't they slippery?!

[@M4rtingale]

That animation of Joe slipping on marbles made my day 🤣

[@bbbbob757]

need more Jojo references in awesome vids like these

[@MrBej]

This just makes me love science even more

[@doubleirishdutchsandwich4740]

Feynman talked about how on the surface of liquid water, there is constantly an exchange of more highly charged h20 molecules in the water with less highly charged h20 molecules in the air. When the flow is out of balance, the water evaporates.

[@BigSh00tsie]

6:09 - Roundabout. Immediately subbed when i heard that.

[@Velocity1357]

Anyone else notice the “As dense as you?” In the background at like 2:18 ish

[@TerribleTonyShow]

6:08 I know that meme is dead, but I laughed really hard.

[@spambots235]

@200 ok im not jojo fans but I often see that meme

[@miketacos9034]

"We should abolish ICE." Ice caps continue to melt. "No not like that."

[@littleloser8072]

I always thought that the moment it came out the freezer it begins to melt so that's how it creates that thin layer of water and if you look at it it also feels a bit dry for the moment after. what I didn't understand is why things stick to ice

[@veldawells2839]

I find your research and programme delivery so enlightening. You make science so interesting and engaging, and I can't help but watch one video a day to learn facts - staying curious. Love the water surface molecule analysis quasi liquid layer. Hope you recovered from your icy slip.

[@Cnidarian64]

If H2S was cooled to below it’s melting point would it be slippery? The hydrogen bonds in H2S are slightly weaker

[@besmart]

I was wondering this exact question while making the video. I was not able to find an answer. Maybe someone else can.

[@micahbirdlover8152]

@@besmart I Love your videos 🥰

[@Aaron-ub1qw]

"As dense as you? " Bruhhhhhh

[@evans3636]

2:17 Oof that burn. was that from the editor? yipes. xD (Words under the picture in the background)

[@gibbeldon]

I'm not so good on ice but I love skiing. Snow behaves completely different yet again even though it is the same molecule. You can create slippery ice by compressing snow, but on its own snow isn't slippery at all. On the contrary: it really helps when fighting the slipperiness of ice. Until it begins to form compact ice underneath... fascinating.

[@plentyofpaper]

I was explaining to one of my employees that ice is slippery because pressure causes the top layer to melt. Then part way through explaining, I realized you can easily slide light-weight flat things that exert very little pressure across ice easily. I then told my employee that this is what I've been told, but it could be wrong, or a half-truth or something, and I wasn't really sure, so take it with a grain of salt.

[@DavidLaFerney]

Sawdust on my smooth shop floor makes it very slippery - because it prevents cohesion between floor and shoe. Same thing? Kinda?

[@RobBCactive]

Any loose boundary layer will generally be slipperier than fixed solid, it reduces static friction which is greater than dynamic, in effect it's a lubricant like graphite

[@kjellenproductions7349]

The title should be: "The Actual Reason Why Vanilla Ice is Slippery"

[@lukek.5773]

nice

[@mosessmith8485]

nice

[@THESTEIN325]

nice

[@sreejasrivaram8250]

Iggy! Get out of here!.! Oh god!

[@MSR_47]

Yea he was so slippery that polnareff slipped and almost died

[@SimranjeetSingh-qo8ph]

Fun fact: Quasi is an Italian word that translates to almost in english.

[@frikativos]

It is actually Old Italian, AKA "Latin".

[@THeDoMeTB]

it is also a german word

[@valkyriewave9591]

i mean.. it's also an English word that means almost

[@THeDoMeTB]

@@valkyriewave9591 I've never heared someone use quasi in english, except in scientific context

[@ehma7960]

@@frikativos I'm pretty sure it's used in modern Italian as well

[@Richard_Nickerson]

I let this sit in my watch later for 2 days because I thought I knew the answer already. Thanks for teaching me something!

[@TravisR1982]

This is a great 7 minutes. Thanks Joe, for finally debunking the pressure melting that I learned about once.

[@glow15]

"we'll always be uncovering new mysteries" is the most comforting AND terrifying truth of our decade😵😂

[@chronovore7234]

“Solid rocks don’t float on lava” The island floating in the middle of Kilauea volcano would beg to differ

[@doms6741]

"Solid rocks don't float on larva" Earth's crust on the mantle.

[@g3tsiak547]

Indeed you are correct. Solid rocks don't float on "larva"... They just crush them flat. All that insect larva never had a chance.

[@zonzaykay]

@@g3tsiak547 oof

[@photonicpizza1466]

The mantle isn't liquid, it's solid. The immense pressures just make it act fluid-like in geological time.

[@DaMoniable]

This really feels like one of those 'well duh, why didnt i think of that' moments, and really shows that simple questions sometimes have really really simple answers.

[@johnclarke4701]

So yesterday I watched a KZbin video of the BBC's program QI (Quite Interesting) episode 09 of season 17 related to Christmas in 2019. One of the items was why is ice slippery? (@18:41) and they talked about the same issues including the idea that the pressure of stepping on the ice causes it to melt, the reference to elephants in high heels, the crystal structure of ice where the surface molecules cannot bond with three other molecules. Don't know if they were watching this channel or had found the same reference study, but there you go.

[@jasonakers6538]

Nice JoJo's reference *slipped* in there. Heh...

[@masonsilvers6789]

I-its not... It's a meme from some years ago.

[@Commander-Ledi]

@@masonsilvers6789 Pick an episode from somewhere in middle of the 2012 jojo anime, and skip to near the end a bit before the credits start rolling and watch. You can do this few times with different episodes just to reinforce some facts for yourself. After that, come back and apologize.

[@pieloloon]

dude. it was a meme back then, he doesn’t have to know jojo to make the meme.

[@arrpee7468]

Jason Akers I’m glad that you mentioned it

[@koro7921]

Is that Jojo reference?

[@rokonda507]

ROUNDABOUT ON THIS VIDEO MADE IT 10 TIMES BETTER

[@mysticvitriol]

when he entered i thought yuri on ice... am i weird?

[@deathdog148]

Epic

[@emegrande]

@@mysticvitriol no ure big cool

[@Porkey_Minch]

It's not a Jojo reference, it's a _motherfucking_ Jojo reference

[@yasurikressh8325]

Wait aren’t there astronomical objects who have ice that is formed through pressure even though its temperature is way above the melting point of water ?

[@ramsey_ajr1702]

I'm not scientist but perhaps the pressure is so great it forces the molecules together creating ice even at a extremely high temperature.

[@Limpatome]

Water has several forms of ice, at very very high pressures you can form those ices. Look for the phase diagram of water on google.

[@BainesMkII]

The video has the simple Phase Diagram for water, fit for normal daily life. It gets a bit more complicated when you push it to further extremes. It is also more complicated in that there isn't just a single version of ice, but rather something like 18+ known versions (and some more that are still only theoretical?) produced at different extremes with different structures and properties.

[@photonicpizza1466]

That's a different kind of ice, such as ice VI, ice VII, or ice X. Different arrangements of the water molecules either to different crystal lattices, or no crystal lattice at all (amorphous ice). The ice we normally interact with, ice I, melts under higher pressure, but once the pressure gets high enough, it can reform as a solid with a different structure. Water is very, _very_ weird.

[@DANGJOS]

@Yasuri Kressh I'm not aware of any astronomical objects with that kind of ice, but yes, it is possible. If you extend the phase diagram to even higher pressures, the ice takes on a different structure (I think it may be cubic, instead of the familiar hexagonal ice). This cubic ice is *more dense* than not just regular ice, but also more dense than normal liquid water! So it would actually sink.

[@tetonpal19511]

You should talk to the curlers at your ice rink about this. I saw the house painted in so there is definitely a club there. There are all kinds of physics involved in the sport and this quasi layer makes a big impact.

[@crow2989]

6:00 I had made a guess at the start of the video that the explanation was individual water molecules acting like marbles, jokingly. Color me surprised with the analogy.

[@Q_20]

VPNs offer additional security only over a public network. Otherwise, it's just a proxy.

[@Zomakoguy]

But an encrypted proxy, right?

[@elllqslaz]

@@Zomakoguy nope

[@fghsgh]

@@Zomakoguy kzbin.info/www/bejne/jYengnilmpuNjbs

[@noinformationavailable4114]

Not necessarilly, proxy traffic is just forwarding specific data to point b and then outwards, a vpn typically will have more security and will encrypt everything outbound of a network for a specific device.

[@fghsgh]

Another advantage of a VPN is that it is a proxy for all kinds of connections, while a "proxy" proxy is just for HTTP. Also, it lets you connect multiple devices to one virtual LAN network, but maybe some VPN services don't allow that.

[@raulvanhoorde1215]

But then why are not all crystaline structures slippery? Salt?

[@syndicatepro8174]

No H bonds, NaCl = trigonal planar Salt BP/MP different.

[@bemusedbandersnatch2069]

@@syndicatepro8174 Actually what else is there out there that's like H-bonds in water really? H-bonds are weird.

[@plaguex5z011]

@@bemusedbandersnatch2069 I could be wrong but I’m pretty sure water is such a unique molecule due it’s hydrogen bonds being entirely unique.

[@ninjanerdstudent6937]

This is what he was talking about at Tedx.

[@loupe500]

Great video, but I still have some questions that I don't think was answerd. For example, if the fact that ice is a crystal and the surface can't be as organized as the rest just because it doesn't have anymore molecules to connect, than why this isn't true for every crystal? If that was the case, diamonds would have to be slippery as well. Crystals are just a bunch of very organized molecules, Ice is no exception, but why is the surfice of ice so special even compared to other crystals? Because I never heard of Quasi-Liquid Ametyst or something like that (I may be wrong on that one but I honestly never heard of any other crystal having a similar property). Anyways, as I said, great video. Love the channel and the way you explain science in a easier way, so everybody can be as interested in learning as possible.

[@blackmber]

I watched this video when it came out and was reminded this winter when skating at -30°C. The ice was obviously not wet. Also snow is slippery at those temperatures even when it forms a rough surface on the road (though wet snow is much worse for driving). But I couldn’t remember why. I guess memories about ice are slippery, too.

[@besser-nicht]

Short: gravitation sucks Long: pressure + gravitation sucks even more

[@keitatsutsumi]

5:17 that escalated quickly

[@epser5842]

No one: Editors: *aS dEnSe As YoU?*

[@nahlia_marv_music]

We just learned this in physics lesson today! Thanks for making this, now i understand it much better.

[@HayTatsuko]

What an interesting, well-presented video! My new thing has been learned, for today! Love the shout-out at 6:08, too.

[@joroc]

So solids don't exist because you can scratch them. Wow

[@Phyto.]

What?

[@hollanderson]

Note to self: Why is ice slippery? Previous theories: - There is a thing layer of water around ice Created by contact When 2 pieces of ice are placed together, they stick. The air is warmer than the ice, so there is a constant layer of water. Created by pressure Ice has a lower density than water. But... On skates 88kg human exerted on 900^2 mm only lowers the melting point by a fraction of 1 degree c. And... with normal shoes it lowers it even less. It would only work on elephants with heels. Created by friction Skating on the ice creates friction, which melts it. But it seems like you can slip even when "standing still". Water on ice is way more slippery than water on a smooth floor. New theory: - The thin slippery layer is not liquid water, or solid ice Created by quasi-liquid layer Water is a polar molecule, uses hydrogen bonding. In liquid state, there are less bonds than in solid state. On the surface of ice though, the molecule may only have 1 bond, hence "tumble around in disorder", detaching and reattaching itself to the ice and each other.. Problem: It's very hard to determine the properties of quasi-liquids, as the boarder between quasi-liquid state and solid state are very difficult to pinpoint. Where is the boarder? How to we categorise it? How thick even is it? Summary: Ice is slippery partially because of melting and fiction, mainly because of the H2Os coming loose on the ice's quasi-liquid layer.

[@ntnwwnet]

Obligatory NordVPN warning: do some research before giving them your money.

[@FauzanARB]

I thought this was answered in a video made almost a decade ago,but looks like we learned something. Thanks!

[@thealantam]

That explanation brings me into another question: how does the surface of all the other (non-slippery) solids look like, i.e. what makes those surface molecules not slide around like a quasi-liquid?

[@savageissb850]

Jojo reference 6:10

[@ewwahuman2318]

So in layman’s terms, Ice is broken like literally everything else in existence?

[@JayFreely]

How is anything in existence broken?

[@JayFreely]

Like what else?

[@Anderson-f4t6c]

I hate ice it cold , slippery and forms everywhere.

[@veganchaatparty]

wow!!! Never knew this would be so super interesting.....amazing!!! No doubt I love ice so much....wow this blew my mind....really super science here...super thanks for sharing Joe!! You're super ultra awesome!!

[@nw2kr8bc3t]

this makes me think about the weird and magical properties other materials could have if you put them in specific situations