The Controversial Physics of Curling - COLD HARD SCIENCE - Smarter Every Day 111

[@ryanybh]

As a Canadian I felt like it was my duty to watch this.

[@strikernova9]

Ryan Pearsall same

[@jimbobogie8204]

Agreed-it's interesting to see how Americans view the game, although recent international success is leading to more exposure south of the border.

[@NonFiqShun]

I’m American....is there something wrong with me 😱

[@meol0390]

Ryan Pearsall Same, but as a Swede

[@conanichigawa]

**Canadian anthem intensifies**

[@justandy333]

I think its so cool that we've got a relatively simple sport (in concept, Im sure there's a million aspects to the game) thats been played for many many years and people are still debating over how the physics of a curling stone works. Something that appears simple on the surface, but theres a heck of alot more going on when you dig deeper. Gotta love science!

[@MeatBunFul]

@Get on the cross and don’t look back k

[@justandy333]

@Get on the cross and don’t look back - I think you'd find Richard Dawkins work right up your street.

[@BBKing1977]

Canadian here. Curling was my high school sport, so I find this topic fascinating. I remember we would find that a slow rotation worked much better than a fast rotation. In fact, if you wanted to ensure a straight throw (in practice only, you’d never rely on this in competition) you could spin the stone really quickly. To me, this lends credence to the theory of the differential speed of advancement melting the ice more on the left (for in-turn or right for out-turn) edge of the running band. When you spin the stone so quickly, the extra rotation overwhelmed any advantage created by the differential so the frictional lateral forces were negligible. (I think that makes sense, right?) Anyway, not sure why it took me 8 years to watch this video, but thanks!

[@pigman6954]

canadian here = reliable source

[@ludicrous7044]

Does this have anything to do with the direction the water spins in the 🚽 AYE?

[@BBKing1977]

@@ludicrous7044 no

[@andreyromashchenko8967]

1:13 - I got an urge to tell him "don't you dare scratch that coffee table with that rock!"

[@peepz1000]

Ok mom

[@xavierfournier2408]

Ok mom

[@CEOofPancakes17]

Ok mom

[@laurentaylor3221]

Don't scratch the rock with the coffee table

[@docwiz]

Same

[@gordonwaldner9792]

The game has advanced immensely since 2014. There are so many variables to consider. The advances in broom design and ice preparation are big. Sweeping technique and the fitness levels of the sweepers are huge factors. For the average club curler it doesn't matter, just go out and have fun. Next to golf, curling can be the most frustrating game there is. But then, you make a double take out and it's all fun again.

[@chanceadams5157]

2:35 Just watching that makes me want to cry. I can feel the pain in my knee

[@dorothymiles7097]

4:25 I thought friction doesn't depend on the surface area of the contact.

[@projectmagnesium8804]

Totally. Im a hockey player and I can tell you - that was a bad way to fall. He was hurting more than he let on.

[@annyone3293]

The laugh this fall produced is amazing though

[@NoHatJack]

As a hockey player I know how that hurts even with all my hockey gear on

[@jibbircs]

Curling stones are little UFOs with little aliens inside steering them.

[@rL1058-g8g]

+Ryden Swalwell ayy lmao

[@TiegonBerry]

+Ryden Swalwell The men in black will soon erase this comment and your memories.

[@ben-xl7ne]

+TiegonBerry so proof that this is false is the comment is still there and we can remember it. we should us this method to test all conspiracies

[@jimmesc]

joe scrib the govt has known this for years and is still spending millions covering it up

[@Schradermusic]

ben williams, that would mean nothing is true at all.

[@nicoyazawa3428]

I love your videos. You educate without talking to us in a condescending manner.

[@Hopesedge]

Skie Mendacium Makes you wonder why they can't do the same thing in schools.

[@jackflorence6562]

Sean Bevan Passion.And he gets to choose what he makes his videos on, teachers are more or less forced to teach to a certain curriculum and they don't really have a say in what they teach about their subject. That would make me lose a drive for teaching.

[@toddwright2670]

Jack Florence Bingo. I agree that its a passion for what you do. He doesn't see these videos as a "Job". There are teachers out there that have that passion and attitude that do an AMAZING job. Sadly, it seems they are more the exception than the rule, in really any profession. Think of what the world could REALLY be like if EVERYONE was more passionate about what they did. Would be pretty amazing!

[@jackflorence6562]

Todd Wright Oh yeah, I had a few teachers who were so excited to be teaching what they had that day, and they were the ones I learned the most from, but they are few and far between.

[@RockAvernus]

"Interesting facts" and education are two different things.

[@dorothymiles7097]

1:24 I immediately felt my wife yelling at me for one of my friends scratching the table

[@RadagonTheRed]

This is all science friction to me. ;p

[@Cincystone]

I’m guessing you saw the pun on the Seeker video in the recommended section literally an inch from this video ;p

[@Tedula1134]

Puns are super effective against me.

[@Jevans842]

The ending was a bit of a drag,

[@integralmath]

lol

[@Lucianrider]

I see what you did there!! LOL

[@JK-tc2ts]

Wait a minute, so does that mean that whoever invented the curling sport knew of the physics occurring during the stone's travel and the sweeping, or does that mean that explaining the physics occurring is an afterthought and sweeping the stone's path was just a thing to do for fun?

[@peterbills4129]

The Scots invented Curling. I'm guessing it was invented, as many sports are, as a social event involving drinking, competition, and camaraderie. How did brooms get on the ice? Women. Why? Speculation. Once the brooms were left on the ice the boys were left up to experimentation and observation with those brooms. Thank women for Curling. Without the brooms they left on the ice, Curling would have never evolved into the sport it is today. Edit: Add: Yeah, physics has nothing to do with Curling

[@R4IDFTW]

@@peterbills4129 Thank women for something men did, great

[@peterbills4129]

@@The_Arctic_Kiwi So I was trying to make a joke, but I guess I was too subtle. My apologies. Yes, horse hair is used in curling brooms today. At the time curling was being developed and refined they used old fashioned brooms. Ones that look like what witches fly around on. Evidence of this can be found in the emblems of many curling clubs and pins awarded at bonspiels. The club my parents were members of literally had old brooms of this type hanging on the walls. What I was suggesting was the women, angry that their men were spending too much time having fun and drinking it up while curling, went down to the river or lake with brooms to chase their men home. If you search for "woman chases man with broom" and look at images, you will see what I'm getting at. It's a relic "meme" of the past.

[@cupguin]

It's not that strange, lots of sports and activities have complex physics at work. A lot of advances predates understanding the physics that underpins them. People who do something over and over tend to experiment, or do things by mistake. You don't need the full scientific method to start to figure out what works and what doesn't work. After generations of ad hoc experimentation the best way to do something can end up being counterintuitive, like how to curl a stone. And as to why people are interested, that's the wonderful and infuriating truth about science. No one knows what is going to turn out to be an important discovery. If it's a profession then understanding the underpinning science can lead to faster breakthroughs. Those breakthroughs mean cash. If I figured out a better way to curl a stone you better believe I'm going to open my own curling business. But again, since science, figuring this out might have massive reprecussions. This is ice and friction. Maybe whoever cracks this will mean others applying what they've learnt to new areas. It might make the lives of people in cold climates safer or could change how we deal with friction in everyday life. Or it could just help Canada or Sweden in a bonspiel.

[@anndalynnketellapper8296]

Peter Bills very rarely are horse hair brooms used anymore. In fact, I would be really surprised if anyone was using them for other than sliding. Covered brushes are used now, and they don’t leave any debris on the ice for rocks to pick. My skip still uses the rink rat for sweeping!

[@snalrus]

little did he know that only 1 year later, subbable would be acquired by patreon.

[@arklowrockz]

And that Patreon would start getting trigger happy banning content creators it doesnt like

[@JonatasAdoM]

@@arklowrockz Just lile ye Old tube

[@JonatasAdoM]

So that's why I have never heard of them anymore

[@nenelevy9925]

what?

[@crieverytim]

that's a shame. we need another platform that doesn't cater to the cancel crybabies and that somehow doesn't get overridden with deplorables either.

[@ianthomas1560]

When I began curling 12 years ago (I'm only 20 so it's been a big part of my life), I originally thought it was the same thing as the guy from BC said. I'm also Canadian, so maybe that's just how we think. The scratch theory that the Swedish man talked about is what we used for so-called Directional Sweeping. If a sweeper starts their broom in front of the centre of the rock and sweeps on a slight angle towards the other side of the rock, they will create scratches on the ice like the Swedish experiment with the sandpaper. This will cause the rock to tend towards that direction. Before 2010, sweeping was mainly to make the rock go further, and also to make it curl less. Now, when I say curl less, there's an important distinction to be made. The rock is not actually curling less. If you throw two rocks 100% exactly the same, one swept and one not, the two rocks will line up perfectly, just one past the other. The rock doesn't curl less, but more it delays its "breaking point" when it really starts to curl, due to it not losing as much speed because of the sweeping. Before the 2010 Vancouver Olympics, we in Canada did a study on sweeping and figured out all this stuff about directional sweeping, but it wasn't really used. In 2013 and 2014, we had what would later be called the "Broom-ha-ha." Horsehair brooms, as can be seen at 4:22 with the guy on the right in the video, are extremely efficient at this directional sweeping, because the individual hairs scratch the ice a ton, and therefore make the rock move a ton. An interesting video on it can be found here: kzbin.info/www/bejne/npKopq1qZ752mq8 The scratches in the ice make the rock tend towards a direction, but I don't think the rock causes the scratches enough to make it curl. I believe that it's the difference in velocities on the sides of the running band that cause it to curl.

[@blueberry1c2]

flashback to the ridiculous (now illegal) broom with the waterproof coating and plastic insert that can literally change a rocks direction

[@GregConquest]

As I watched this video, I kept thinking these stones curl the same as a spinning baseball. Maybe the mechanism of the curve/curl has more than just a superficial parallel. If they are deeply equivalent, then the differential speed of the advancing side over the retreating/more slowly advancing side would be the cause on both cases. ... In baseball, the advancing side builds up more pressure on that side of the ball and pushes it the opposite way (the ball curves toward the way the front of the ball is spinning). The effect is more pronounced with a textured surface (the seams on a baseball and the dimples on a golf ball). So, if my hypothesized parallel is true, then, by moving faster over the ice, the "advancing" side of these stones would be pressing down on the same spot on the ice for less time thereby causing less melting there. There would be more resistance to forward motion there. ... Is that it? Or does that not duplicate the equivalent of air pressure in this thought experiment?

[@Badaskin7392]

as i watched this video i imagined people would come up with crazy lies like your story

[@Fishingboatsalaska]

Greg Conquest. I believe the baseball curves due to lowered pressure rather than increased pressure. According to Bernoulli principle when air speed increases, pressure must decrease Otherwise interesting theory !

[@jdel1538]

Too long

[@jcortese3300]

Curling is what happens when you live near the Arctic Circle, it's February, you haven't seen the sun in months, and you need to invent a way to pass the time before you go completely out of your mind. You go out to the toolshed and there, you find a rock and a broom, and g/d it, you are GOING to make a sport out of them. We can only thank our lucky stars that the inventor of curling didn't find a dead moose and a carton of gunpowder in the toolshed, or else "curling" would be a significantly gorier sport.

[@Lopez.Victor]

Your comment made me laugh pretty hard, so thanks for that.

[@the1derpface]

There is a sport in central asia which involves people riding on horses while attempting to put a goat carcass in a goal.

[@spencerwalton9051]

Janis Cortese. HA! I curl and that made me laugh so hard.

[@trecou]

2:35 Should have used his Phantom camera for that one

[@Colonel_Overkill]

Press F to pay respects.....

[@lewismuriungi1023]

I'm here for the laugh in slow mo

[@robofan3226]

We know how to fly and land rockets on mars, but we still don't understand how a simple curling game works. Waaaat

[@Chartranos]

we still don't know how cats purr......

[@CrunkNuts]

A cat's purr begins in its brain. A repetitive neural oscillator sends messages to the laryngeal muscles, causing them to twitch at a rate of 25 to 150 vibrations per second. This causes the vocal cords to separate when the cat inhales and exhales, producing a purr. But not all cats can purr.

[@ltsam5815]

Cats can also mimic the decibel of sound given off by other creatures with their meow and purr. For instance when cats interact with humans they tend to give off the same frequencies as human infants. Curious.

[@AcessDBpro]

Before we can understand how a simple curling game works, we have to understand the reason that curling even exists as a thing in the first place.

[@c_h_r_i_s_t_c_o_r_e]

when have we landed a rocket on mars🤔

[@SvobodovaEva]

I started playing curling a few weeks ago, thank you for these videos. As a former student of Physics, I appreciate them so much.

[@rafaeltrinidad6165]

so hot

[@macfady2181]

In addition to all that is outlined here, brush head materials etc also play a big role. In more recent years, there is even directional sweeping being used. It used to be thought that sweeping simply increased distance while lessening curl and visa versa, but it turns out the direction the sweeper closest to the stone is "pushing" while sweeping can also increase or decrease curl, even while simultaneously increasing distance.

[@vernonhuffman3595]

2 things no one ever thought would be mentioned in Alabama. Curling and physics.

[@jfbeam]

Physics is mentioned a lot in AL. NASA has facilities there. Curling? Yeah. I'm surprised anyone in the South knows it exists.

[@vernonhuffman3595]

Oh I know brotha I wasn't trolling. Just failing at humor.

[@carcademy]

+Vernon Huffman Your last reply is my entire life lmao

[@soorma01]

We know you were talking about the general population lol.

[@TS_Mind_Swept]

I’m no one

[@bahbcat]

It's comforting to know the experts aren't sure.

[@charlesballiet7074]

seems ridiculous that musk has rockets landing on there toes from orbit yet we cant explain how curing works

[@mushkamusic]

Destin, I watched this video years ago when it came out. I've just watched it again, and I'm sat here wondering if you might be able to learn more by creating an experiment with a high speed camera, shooting from underneath, recording the interactions between a curling stone on a sheet of polyurethane which has been prepared with a thin coating of pebbled ice. It'd be incredibly cool to even find out if you could see any friction melting happening through the lens. Just a thought.

[@markszyszkiewicz]

Or an optically clear curling stone

[@santividal9387]

But there must be ice on the top of the polyurethane to make the "curling rock" slice, and that would disturb the video... (Am I saying something stupid? Yeah, probably I am...)

[@mikemoloney6448]

@@markszyszkiewicz hi mark they make small rocks for kids out of cement that weigh 18 pounds and 25 pounds and they don't curl the same as a granite rock . so i think it would be unlikely that your idea would work. there is come chemistry in affect with the special granite from Elsa Craig island in Scotland where all currant curling stones are quarried.

[@ivanrybkin9384]

@@mikemoloney6448 maybe it uses Earths magnetic field as well))))

[@AqeroEdits]

I never thought I would watch a 10 minute long video about curling and actually be entertained! great video! :)

[@BobHolowenko]

As a Canadian Curling fan I am serious in saying that I appreciate all the hard work and research that went into this. Kudos. +1 for mentioning UNBC.

[@drewwatson835]

Go UBC!!!

[@opencabinets]

The graphics on these videos are always so well done and easy to understand truly quality content

[@MyStonerMind420]

I watched curling for a few hours today and I must say I found it very boring. Plus the women kept giving me funny looks through the hairdressers window.

[@datboithatyeets4558]

My Stoner Mind what, you watch these videos

[@andyandtracy]

My Stoner Mind jjjjmkmo

[@Grimace_Integ420]

very clevar

[@markpointer2967]

Hahah! Oh my aching sides! 👍🙂

[@travelwell8098]

Hahaha... dude... thanks for the laugh!!

[@KennyCiseroJunior]

I love how the people who invented the sport most likely didn't understand a fraction of these explanations of the strategies they developed just by playing the game.

[@peglor]

If you go into enough depth into anything you get to the point where nobody understands it. Luckily, the laws of physics don't have to be understood to tune a neural net to respond in the correct way to a set of inputs, so nature simply sidestepped the problem and got on with it until humans showed up and started asking questions :-D.

[@OmGoit]

All kinds of people drive cars but most of the don’t understand internal combustion engine.

[@johnglennie4282]

@@OmGoit What? I have two cars, and neither one has an internal combustion engine. Ohmmmmmmm

[@absolutium]

@@johnglennie4282 Power Wheels arent cars.

[@VICTORdoomm]

what is deionized water reverse osmosis, where I work uses it, but my job isn't to under stand it, I have looked at our control screen so many times trying to figure it out. when I first seen this video back in 2014 those words didn't mean anything to me, but now it does and I want to be smarter every day

[@VICTORdoomm]

I still want that clock, and I cant find it

[@NubetubeRob]

This is the ultimate its 3am and I haven't started my essay yet video...

[@Zipoqs]

You're a very smart man! Love your channel and your content! The true way to continue growing as a being is through education!

[@herculesmclovin]

I've very much enjoyed this series and I love it when questions are hanging in the air!

[@tron-8140]

Curling looks so boring but its actually really fun. And as Destin found out, a bit harder to throw aswell :P

[@darkfusionz1782]

that's what I always say.

[@UNSTABLE111]

It's boring for me if it's not close.. or a shut out..but I do appreciate the skill involved in curling

[@RamatiKat]

Throwing is not hard if you have a broom.

[@Xalexalexale]

@Current Batches honestly i think the hardest thing in curling is the granite stone

[@JoeHanson]

I propose that the competing labs face off in a science curling battle to decide whose idea will emerge victorious. Two theories enter, one theory leaves, everyone has a beer. Great stuff SmarterEveryDay

[@RichardHayes]

I'm for the 2nd (and obviously superior Canadian theory) with the different frictions due to different forward and reverse velocities of the spinning rock. That's the way they explained it on Murdoch Mysteries so it must be correct.

[@stephenfowler4115]

The rate of spin of the curling stones is so small I wouldn't think it would have a measurable effect on the stones motion. In the video you showed the stones didn't make even half a complete rotation before they stopped.

[@billswingle2672]

Excellent! Both the topic selection AND video.

[@SamChaneyProductions]

I love your channel but as a woodworker, 1:25 made me cringe

[@mysjackson88]

The cat said the same thing at 3:02. The cat was like..."F@#$ that, I'm out"

[@epicspacetroll1399]

lol I'm not a woodworker but I was also like "is he really doing that to the table?"

[@Ceelvain]

I'm just careful with my suff, and I was like: "you're gonna scratch the table!"

[@Feligresa]

Who cares? A table gets scratches at some point no matter what anyways. Even more so considering he has a cat.

[@baannaannaa9580]

Sam Chaney him on ice made me cringe

[@chadstewart8624]

A lot has changed in the curling world in 7 years. (Even at the club level, but especially at the pro level) This video deserves a follow up video!

[@docforest4851]

Agree. The various ways that directional sweeping are done and how angles of sweeping are changed depending on speed and rotation is cutting edge science

[@janelin6083]

A curling controversy! I love it! I really like curling, it's chess-like strategy, remarkable precision and funny calls. I really had no idea that there was so much scientific mystery to the curl. Awesome!

[@hassnur497]

3:04 Me: "where are you going" Cat: "YES"

[@TheArmyKnifeNut]

Oh look! The KZbin algorithm is recommended this Smarter Everyday video that suddenly becomes relevant every four years!

[@MrUltraDreamz]

Be my science Teacher please.

[@TransAm20000Wr]

he reaching out to more people this way tho

[@Ceelvain]

An actual teaching would be much less entertaining that those videos, unfortunately. If you really want to have a useful deep understanding of the mechanics of things, you can't escape the math. And math is hard.

[@Libelibel]

math is hard, but if you look at it like a challenge, you will -still- considering them entertaining.

[@allendeguzman2108]

Nuxxy

[@unfa00]

Destin's master class?

[@morganahoff2242]

I'm so glad you covered this. I was actually excited when I saw the thumbnail: "Oh! Destin's done a video on curling!" But it's interesting you talk about the leading and trailing edges; I always thought it was about differences in the left and right sides. Like a helicopter rotor (you have a video on that) when it's moving (translating?) one side is moving through the air faster than the other. I know a Frisbee does this, and it's responsible for why Ultimate players release a forehand throw with the disc tilted down -- if they don't it will flip itself over. You need to do a companion video on the physics of Frisbees! The difference between the glass on the coffee table, and the stone on the ice sheet is something to do with weight and melting. Ice skates work by concentrating weight onto a blade edge, such that the pressure is so great the icy actually melts. Does the stone do this? More exploration required...

[@joshuatree9358]

Is that lack of downward turn why my flick is so bad?

[@ThisIsReMarkable]

@Joshua Tree Maybe, but probably not. A disk that is thrown with no wind, completely flat, with the right handed backhand, it will eventually fade to the left, from the thrower's perspective. If the disk doesn't have enough spin, it's not stable. Try to give it more wrist flick and imagine your disk is running across a table as you're throwing. (This is just a guess, having not seen you throw 😄) Good luck! Source: 10 years of Ultimate and disc golf 😁

[@robertherzog9294]

Destin, I just ran across this old video... I'm an ice hockey player, but I got invited to play in a curling league for a year or so and won a number of championship games while doing so. It's a very complicated sport and we luckily had one of the best strategic skips leading our team. I enjoy engineering and physics and that's really what made me want to try this sport out.

[@petrocksgarage]

I don't know if this has been brought up or not, but around 10:32 there is a typo. Its Club, not Clug, in Milwaukee Curling Club. :-) And no, I'm not a member of that clug. I wouldn't join a clug that would have me as a member. :-)

[@nerys71]

Patreon is also monthly - keep up the great videos. I work 120 hours a week and have limited time for youtube and you are one of the few I always watch!

[@nerys71]

Maroonedinred sounds about right 5 to 6 hours sleep a night. How? No clue and that scares me even more than the workload.

[@TheTransforcer]

Nerys what do you do that takes up such time commitment?!

[@nerys71]

TheTransforcer three full-time jobs trying to take care of my pups family in the dead he left me when he died :-) yeah it's fun

[@justsean6199]

I hope you enjoy working, You'd never catch me doing 120 hours at "work" to give myself the life I require..... I don't undersell myself, maybe you don't either but live in a system that leaves you with no option to do so. GET OUT! The world is a big place and there are opportunities everywhere, you just have to willing to put yourself first.

[@nerys71]

i hate it. but I have few choices. again if it was just me I would have been out a year ago. but its not just me. I have siblings I am morally responsible for to at least some degree. My sister in particular is mentally retarded. while functional she would not survive on her own at all. these responsibilities complicate things greatly and have me kind of "stuck" if I can manage to get a mortgage to secure a new home then options open up for me. I can sell this house erase all my debt and have a chance at a fresh start in a location with a cost of living about 1/10th what it costs to live here.

[@GaryLane080157]

Curling rock and baseball turn against the direction of the front of the ball and rock. You would think a baseball would bite into the wind and steer the way of the rotation... but it doesnt. So we know about the magnus effect. When you try to drive a car on Ice you don't hit the accelerator because you'll just sit and spin. Better to start out slow and let the tires grip. The faster side of the Rock slips more and the slower side grabs more creating a pull in that direction. Slingshot effect...

[@Volound]

the same thing happens with footballers when they impart spin. look at the roberto carlos free kick of 1997.

[@guppo26]

Though balls in the air clearly don't have friction with a solid surface. And balls rotating on a solid surface have 3 dimension of rotation, which would probably factor into a lot.

[@JohnSmith-vu3hx]

guppo26 Its essentially the same thing but with air friction. As the ball flies through the air with a spin, it pushes on the air with a greater force on the side that is spinning forward than the side that is spinning backwards. This creates a high pressure area on one side of the ball that pushes it to the opposite side.

[@deker48]

It's a completely different mechanism, no comparison..

[@Volound]

Derek Corbett in both cases, intuition is wrong because of emergent physical phenomena. absolutely a comparison.

[@DipanGhosh]

John Smith You're right. That's known as Magnas effect, Veritasium has made a video in this, you can find it. However, I think the mechanism in this case is very different.

[@ruylereax94]

3:06 Cup: teachers knowledge Cat: me

[@godzillasauris]

Lol

[@raymondmgba7183]

watching you fall on ice was the funniest thing ive watched in awhile...and love that you had fun during lmao

[@ChrisVejl]

Did you try rotating the glass on ice? Could be interesting to see if it responds the same way as the curling stone.

[@steveheist6426]

Could also be interesting to try the *stone* on other rough surfaces. Textured drywall, pressboard, what have you.

[@devonopdendries7722]

Cool video. I always imagined the curl had to do with asymetric friction melting, so it's interesting to see the other theories. For the curling haters out there, one could say the same "It's boring" comment to any other sport out there when you haven't tried it and you don't understand it. An experience is never at the mercy of an argument.

[@francisschweitzer8431]

ANY SMARTER EVERY DAY IS A MUST WATCH …. Even if it is 7 years old. ( it’s 2/22 )

[@onehitwarrior1708]

10:00 "i just broke it, dont tell on me", momma is always in charge 😂😂😂

[@gavinfleck1315]

Wow! What a video. As an avid and competitive curler I found this very interesting. It turns out that the "scratch theory" regarding the rocks curl is more correct. Nowadays we use "directional sweeping" to control how much or little a rock can curl. We do this by sweeping on a certain side of the rock and scratching a path with the broom allowing for more or less curl.

[@BoxcarWilly284]

Doesnt the coefficient of friction of regular ice decrease as velocity increases? My theory is that the "side" of the stone spinning with the direction of travel should be traveling at a higher velocity relative to the ice and therefore have a lower friction.

[@oisiaa]

And this all started when I made Destin's chicken camera video popular on Digg quite a few years ago.

[@bobt250]

I was convinced that they spin the stone to make it go STRAIGHT like a bullet leaving a rifled barrel. Apparently I'm wrong but not so fast! Would it be fair to say that a stone with no spin would have an unpredictable path while spinning it creates a predictable path albeit curved??

[@montyziebell1077]

Yes, that is correct.

[@NonTwinBrothers]

Woah! 8:30 THE first SmarterEveryDay that mentions Patreon! Crazy that his page has been going for more than 8 years at this point

[@this_mfr]

I would think that angular momentum would have some impact on the direction of each object, no? The glass spins very quickly, relative to its diameter. The stone, however, has a contact surface much smaller in diameter than the diameter of the object and it is spinning much, much slower. Sometimes not even one full rotation before it stops. So, then, wouldn't the forward momentum overpower the angular momentum's effect? If forward momentum is not perfectly straight, than as it overpowers the effect of angular momentum it will move in the direction the stone was pushed, regardless of spin. Notice with the glass that it doesn't really start to curve off course until its forward momentum slows, while the angular momentum stays fairly constant. It isn't until its forward momentum is less than the effect of the rotation that it begins to move off course. I theorize that it moves opposite of the spin because the angular momentum overpowers the forward momentum. As for the curling stone, forward momentum is maintained all the way through and appears to always be greater than its angular momentum, even right before it stops. I'm curious to see what would happen if you spun that stone as fast as you could while pushing it forward relatively slowly. Perhaps then the angular momentum would overpower the forward momentum and we'd see it move just like the glass does due to friction at the front being greater than at the rear.

[@nhschleicher]

+Chris Snyder I'm quite late to the conversation, but as a long time curler I would like to add a few observations. Spinning the stone faster (thus increasing your angular momentum) actually causes the stone to curl less. For maximum curl you usually want to deliver the stone such that it completes around 2 turns before it comes to rest. Actually it seems that the slower it spins the more it curls, but if there are any defects in the ice you're delivering the stone on it can reverse direction/curl if you don't impart enough spin. That's why people like to stick with the 2 turn rule of thumb. Throwing a stone without any spin can make it behave like a knuckle ball, and more frequent than not it'll "piick up" a spin and curl that direction.

[@udipta21]

Wow, I had no idea there was so much technicality behind this seemingly simple sport.

[@katefriesen]

Curling is the opposite of simple...

[@dan4c0d3]

It's the hardest sport I've ever tried. Don't underestimate curling until you try it.

[@vananderson2895]

There is a reason why they call curling "chess on ice". It is anything but simple.

[@bermudezk12345]

Was watching the Winter Olympics in 2022 and saw curling and was so interested in how it worked and here I find this video!

[@ianmacfarlane1241]

Could have mentioned that until recent years ALL of the curling stones in the UK came from the Ailsa Craig in Scotland - due to it being considered the perfect granite.

[@djcowss]

3:02 Looks like your cat doesn't like physics

[@coachcastle666]

Excellent video, as someone who loves physics and grew up next to canada I salute you and your hard work

[@umakariharu8035]

There is a lot more to this sport than I thought lol. I wanna learn it now

[@TheDaynenmc]

Destin, I'm no scientist. I'm a truck driver, so I work with what I know. I awoke this morning thinking about this. Which is kind of strange in itself. #1: The sweepers heat up the ice in front of the stone to create a layer of water. (So if a vehicle is driving along and hits some water it starts hydroplaning. Almost no friction on the front tires now and most of the friction on the back tires) #2: So the spinning would be the reverse of your glass cup example because most of the friction is now on the back instead of the front. If they stop sweeping then the stone slows it's spin and curving? So the theory with the scratches doesn't make sense when the water gets involved. The water negates most, if not all, of the friction on the front. Am I way off base here?

[@markomus1]

I was thinking the same thing and think you're mostly spot on. The sweepers aren't needed, though, to create the initial ice heat--not for the physics of the spin, anyway; that's provided by the weight pressure and friction heat of the stone itself. The sweepers simply "season" the ice a little so the stone can go further. Not sure why this is such a big mystery. :D

[@campkohler9131]

This work is a great contribution on the way to a wonderful solution to a non-problem that is not worth solving.

[@kimghanson]

I think the Canadian's theory is closer to what I had always assumed. I thought the side of the stone rotating back toward the launch point had more frictional "grab" by virtue of it moving slower relative to the ice under it. You can often see something similar when a stone comes to rest. One point on the stone will reach 0 speed and stone will pivot about that point. That point has maximum friction. Yes, that thin layer of lubricating water refreezes that fast. So without the lubricatiing layer at that small point, there is enough friction to spin the entire rock, much like a death spiral in figure skating. Also, as a rock slows, it curls more. I think that supports the Canadian theory a little better than the Swedish.

[@vananderson2895]

I feel like the Canadian theory also better reflects that stones take some time coming down the ice before they start to "catch".

[@chadpunte1731]

Put something colder than the ice on the ice and see if that affects the rotation?

[@zestoslife]

That is a clever idea. I wonder if you put a stone in liquid nitrogen until it equalized if this would behave differently. My gut feel is that it would just freeze to the ice though!

[@chadpunte1731]

That's a very good point. I suppose I didn't consider that.

[@JoQeZzZ]

Ice is slippery because of the 'aquaplaning' of the melting ice. If you throw a stone which is colder than the ice, it would freeze to the ice much quicker and the effects would be even less notable.

[@stackman120]

The rocks are left on the ice 24/7 so they are equal temperatures, though Destin’s rock was likely warmer when he pushed it on the hockey rink. It’s actually a problem to get new rocks onto ice as they need to be left in the same conditions as the ice but not on it because they will melt it until the equalize. The ice is kept near 28°F so that friction melting can occur, ice that is colder does not play as reliably.

[@minaragy5131]

That's smart. You can make ice from salty water instead (add some ions) that would decrease it's melting point and affect its specific heat (heat capacity)

[@Moist_yet_Crispy]

I love all your video Destin! I'll be contributing! So much love for this channel.

[@cheatingthesystem21]

10:03 blew my mind O.o

[@FE3DBAK]

yeah same here

[@bakintoast]

That was a wollop, to be certain. I actually laughed out loud at it, because it was so awesome and made so much sense.

[@svp-3015]

Mee Too

[@One-im8nw]

what about it

[@jacobmelanson3210]

Canada dominates curling with 35 golds to 7 for Sweden.

[@TransAm20000Wr]

canada ftw

[@erdvilla]

Mexico rules with our Curling captain Consuela; no no no no!

[@elvineagle476]

Mexicos second best player is Carlos Juan Martinez lopes Rodrigues of Guadalupe. He's also Donald trumps butler/slave. His second favorite sport is cross country.

[@snaglinegaming6097]

Elvineagle what does trump have to do with curling?

[@jimmesc]

@@snaglinegaming6097 Nothing, thank God

[@A_Name76]

So if you spin the stone to the right and push it forward, the right side is moving slower relative to the ice. It's almost pulling itself in the direction of the rotation, while the opposite is being prevented by the the momentum of the curling stone and the low friction level on the ice. The velocity of the stone is very important as well. Does this sound at all accurate?

[@flashcre8or]

I want to listen to Destin's slowmo laugh on repeat forever

[@sonicrising6614]

Leave it to the Scottish to invent a game that cant be explained by science....yet.

[@MattH-wg7ou]

I feel like the secondary explanation makes more sense to me, the one at 6:55 or 7:23 more accurately, it reminds me of the helicopter speed limit...differential lift based on movement relative to the overall motion. Thr overlapping scratch theory had me thinking it would curl in the opposite direction than it does.

[@ExDementia666]

My question is why it also works on the cup on the dry surface of his table

[@95TurboSol]

Dang Destin is making 6,300+ bucks per video from patreon!! That's not counting the several hundred per video of ad revenue! That's awesome, if there is anyone that not only deserves it but will use it well it's Destin!

[@AbhayKumar-cm2kh]

+95TurboSol he spends waay more than that on making some videos, travelling expenses and such...

[@95TurboSol]

Abhay Kumar I doubt he spends quite that much, maybe on a rare video like the amazon one or that one with the panorama shot of that ancient abandoned city, you can take an all inclusive tour of the amazon for under 4k, includes lodging, all meals, drinks, tour on a boat with tour guide, then all you have is the plane ticket to get there and back which is just over 1k each way so you are looking at about 6k, even if he spent the extra 300 on souvenirs and such he would still profit about 1k bucks from youtube ad revenue (pay is roughly 100 dollars per 100k views, he makes around 1 million views on most videos). He is doing well, and should, he makes great content. (P.S He is now making 6,700 per video on patreon).

[@Tacixa]

+95TurboSol from memory destin said most if not all of the profits from these videos go into his childrens college funds, i thought that was amazing

[@95TurboSol]

MrTacixa College would be payed for in like 1 year!

[@LvcianoN]

I think I read he no longer will use the money to pay for college but he will put it towards making more videos. Can't remember where I read it so i might be wrong. Anyhow I feel happy for him, he provides excellent videos and content. He is one of the best video creators in KZbin in my opinion, he deserves what he makes.

[@LSPD1909]

Curling is amazingly fun and I recommend everyone to try it! Go Canada !

[@arthyualagao8279]

@2:02 i thought you were about to launch that cup across the room😂

[@leebarker539]

Meaty, delightful, head-scratchingly curious, artfully edited, and the highest and best use of KZbin. Destin is Topmost Superior.

[@MrLuc85]

People always say curling is boring but they've never tried it! It's really fun and insanely friendly and social

[@quenjankosky7348]

Insanly friendly? What?

[@MrLuc85]

Im guessing youve never curled before :P

[@quenjankosky7348]

yeah, is it fun?

[@dan4c0d3]

Quentin Jankosky It's really fun and extremely hard.

[@atomsmasher101]

I don't think people are saying it's boring to play. I think people are saying it's boring to watch, kinda like baseball. haha

[@veo16]

Good information but probably useless to me unless I find myself in a life or death situation where my only option to live would be to answer a random question about the physics of Curling.

[@SquashBox]

The beauty of science is learning about how things work and turning mysteries into progress. It may not be useful for you but that's not the point. There are people trying to figure this out, and Destin wanted to make this research accessible to us. Which is Fantastic!

[@davidedbrooke9324]

Having just won a gold and sliver at this at the Winter Olympics this was a good watch, 🇬🇧 The effect is a similar result when motorcycling and have to counter steer, ie push one grip away to turn that way, push left the bike will lean and turn left.

[@CorneliusSneedley]

Hmm. Scratched table, scratched floor, broken drinking glass... your wife made you mention the patreon vs Subbable thing, right? :)

[@montgomerybojangles8644]

Now we know the closest Curling club to Alabama, turns out its just over in Wisconsin.

[@sitbone3]

What about gyroscopic motion causing the stone to curve ?

[@rileylorenz1396]

8:40 is that a Rocket ship in the background?

[@Nexfero]

its a model of the Saturn V in Huntsville AL

[@RonJohn63]

Nexfero Which is... a rocket ship.

[@TwoVera]

Watching this episode made me only recall the curling scene of consuela from family guy.

[@EnxzVFXz]

no no no no no

[@michaelhetu390]

You're not alone, child.

[@slep1654]

Me too XD

[@bagussuryolaksono9963]

im here coz of that

[@DylanDaPickle]

harken same

[@danballarin]

Honestly, doesn't ice friction reduces with more speed, and is stickier when moving slow, so doesnt the rotation do the opposite

[@argoth83]

3:05 "Science? RUN!"

[@PseudoTactics]

Actually the best curlers in Canada are CRAZY strong. They lift bro, things much heavier then rocks. Buff as hell. It's true you don't need to be extremely strong to be a good curler. But it gives the best Canadian curlers an edge over their competition because of how much more they can heat the ice up and therefor have more control over shots. This means that the one throwing the rock has more room for error and can throw a little lighter while trusting in the ability of their sweepers to fine tune the shot. This equates to a HUGE advantage over teams that don't have as much control over the rock when it's let go, especially since each rock curls differently, and each sheet of ice also has weird spots that act differently everyday, meaning you can't just rely on your experience or muscle memory of throwing the same shot every time.

[@OO11OO11OOO]

My fav sport when I am at the pub. It's so calming. And up here in Canada, we have a lot of those on TV.

[@junito1008]

1:49 I have the same Coca Cola Cup !!

[@potatoman7895]

i have an idea. try curling with the same type of cup you used at your house and push it in the same way, except on ice.

[@jimdevilbiss9125]

Your presentation is excellent as always. However if I put a curling stone on a table in my house and pushed it it would probably be the last video I ever made. Of course I haven’t made any videos either.

[@emulsion_]

And people say curling is boring.

[@cambroe]

As a sport, yeah. It's like watching a shoutcast for an ant walking across a parking lot. It'd have to be humorous. As a science it is fascinating, I'll admit it.

[@emulsion_]

Nice...

[@srcoolguy]

Tucker Morrent you're not gonna win the argument dude, just because you and a handful of other nerds find it fascinating doesn't make it exciting. hope you have dealt with your hormonal imbalance.

[@srcoolguy]

Tucker Morrent oh yeah my bad for the late comment... the problem was is that after I made my comment in August I sat down and watched a game of curling... it was so boring i fell asleep for 6 months, that's what took me so long to reply. Again, my apologies. I'm perfectly chilled out btw, don't look now but i think you're the one who needs to relax.

[@dan4c0d3]

Don't judge curling before you try it. Until you actually understand the game, which is best done playing it, it might seem boring but in reality, it is one the hardest games I've ever played. It has also became one of my favourite sport over time.

[@Arrslicker]

Hey, you are awesome. Hope your day is amazing (A student viewer who may one day have money to give you the appropriate love)

[@ludiwang1172]

Yes, this is what I say to all the good channels asking for help, or the nonprofits that ask for my donation. "I'd help you if I could!"

[@stevenewsom3269]

That was a nice comment you left but I have to admit reading your user name afterwords made it very funny lol

[@anthonysanders532]

Love your work. Keep it up. I’ve seen every video you have made and always anticipate new arrivals. Thank you for the knowledge

[@seanmaloney6342]

3:06 Cup: teachers knowledge Cat: me

[@hsmoscout]

3:30 dat focus pull tho

[@segrimsjinn]

I always thought it was like the "gears" principle you have the glass and the table is only 2 gears so it rotates away from input. But on ice you now have the water melt creating a 3rd gear so now you have stone water ice. So it goes into the rotation. I hope that makes sense.

[@stephenstruble5064]

I'm glad that you go so in depth. I've noticed that a lot of people seem to fool themselves into believing that they understabd something. (I am guilty of this as well.) Friction combined with circular motion can be a bit complicated. Should do some more experiments with materials that have a similar coefficient of friction.

[@mohyla103]

Those bloody Coca-Cola glasses break SO EASILY

[@swedneck]

+mohyla103 it's like they want you to buy more of them..

[@stefandenhoedt]

+Tim Stahel (Moustached Viking) consumerism

[@swedneck]

Stefan H. more like higher-ups wanting more money regardless of how it's achieved.