StarTalk Radio - Physics Freestylin’ with Charles Liu & More

Episode Date: July 19, 2024

What are the physics present at the Olympics? Neil deGrasse Tyson and co-hosts Chuck Nice and Gary O’Reilly with the help of Charles Liu, explore the science in some of the newest additions to the Games with pro-breakdancer RoxRite and freestyle BMX rider Nikita Ducarroz. NOTE: StarTalk+ Patrons can listen to this entire episode commercial-free here: https://startalkmedia.com/show/physics-freestylin-with-charles-liu-more/Thanks to our Patrons Amanda_Mensen, F.X. Flinn, Richard Mylyk, Theresa Anoskey, Jessica O, Cayla Slaughter, Tom Cez, Colin Steifel, John Keller, and Chris Brinkley for supporting us this week. Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.

This is StarTalk Special Edition. Neil deGrasse Tyson here, your personal astrophysicist. I got Gary. Gary O'Reilly, how you doing, man? I'm good, man. It's good to be on again. Very good. And Chuck, of course. Yes. Chuck, nice. Calling in from wherever in the universe you might be at this moment. In my skin. In my skin.

Where I wasn't. I was not in my skin. You were not in your skin. I'm not even aware. That's another conversation that's a new episode so gary you're a resident athlete and a resident professional athlete so i was never paid to be an athlete so what what did you tee up today well we got an olympics coming up fast and it made us think but because it's us we have to think slightly differently start talking we badass when we do stuff today we're going to get into two sports once making its debut in the olympics in paris the other one made its debut in 2021 in tokyo the delayed

olympics one is considered to be an art form and a lifestyle the other one rolls around on wheels so if you haven't guessed it already this is going to be breaking and bmx we're breaking is that what i remember as break dancing is that yes but the dancing has in time disappeared once we've spoken to these two athletes we're going to stick it in a physics blender that we'd like to call the geek in chief charles lu himself and then from that we will explore exactly what's going on in these two sports i'd love with a geek in chief my wingman or when he's on the show i'm his wingman that's how that that's how that goes whichever way you want to play it. Welcome to StarTalk. Your place in the universe where science and pop culture collide.

StarTalk begins right now. We got in the house Roxrite. Roxrite. R-O-X-R-I-T-E. Roxrite, a breakdance legend. Thank you, guys. Thank you for having me. It's a pleasure to be here.

You have 100 victories. So these are like full-up contests with like trophies and things. Is this how that works today? Basically, a tournament of 16, around 16. So you go through the whole tournament, and that's what I count as a victory, the full tournament, not each battle by itself. Oh, the whole tournament victories. Damn, you're like, there can be only one, and it's me.

Yeah, I don't take a victory lap for one battle. I got to take the whole thing. So, Rox, can I call you Rox? Yeah. We're on a first-name basis. Rox, I mean, I'm old enough to remember when this stuff landed right back in the late 70s mid 70s if you're really deep in there what is break dancing's connection back to hip-hop well i mean the connection to hip-hop it's the first hip-hop

dance so when when hip-hop was put together as a cultural, like it's the culture, and they had the elements of hip-hop from DJing, MCs, street art, and then the dance was breaking. So from the very beginning, breakers were there at the parties, and that's where it was discovered. And from there on, they reached different people, and they started developing it and getting it to grow more and more throughout the world. That's how you know it's a real cultural phenomenon because it touches so many people. So what triggered your interest? And you're based in Los Angeles, right? Yeah, yeah. I'm based in Los Angeles,

but I started actually dancing in a small town north of San Francisco in 1995. I just saw a bunch of kids doing it at my school, and I just thought it was the coolest thing I ever saw. And the way that they would spin, it just caught my attention. And right i just started trying it went to my friend's house started breaking on carpet first carpet first first small move yeah that's that's the way you ease your way into it okay so you you're starting to do this thing in the 90s did you ever imagine breaking would become an olympic sport to be honest i never thought i would see it in my lifetime because when i started

i mean in 95 there wasn't so many people doing it it had been considered dead for so many years in the states that only certain people that knew about it or in certain communities they were doing it and they kept it alive to just parties and you know kids that just did it every now and then so for me it was it was something new and when I started at that time there'd be guys from the 80s that still were active in some way in the community and they always talked about breaking being in the olympics they would always mention wow it should have been in the olympics it should have been in the olympics so for me in my lifetime I never thought I would see it so when they told me that it was going to be happening they just blew my mind how do they qualify you for the olympics like are there 10 sets of moves that

you have to be able to do that they judge or is it like x games where you put together a routine and then they just the people who know, you know, the kind of like verbiage of the or the language of the movements? They just say, oh, OK, this is you know, this is how great that was. Or how did how do they judge? of that was as i understand it from my nephew who studies this professionally that some of the break dancing was an art form as a substitute for a gang fight yes wow yeah break battles yeah was it done so battle breaking yeah it's a real deal right right same thing with mcs that's you know instead of fighting mcs will come together and basically lyrically you would battle and you would show that your dominance on the mic was a metaphor or representation for me kicking your ass it's still good if you could kick their ass anyway

you had to be better both so let's let's pick up from Gary's question then. This ascends to the Olympics. Somebody has to make the rules around it so that the world can participate with the same set of expectations. So who set that? I mean, there's a system was developed for judging the dance publicly at the Olympics because people from the community were getting together and creating a format to where you can keep statistics of the rounds that were being scored in tournaments because we wanted to see the results before people would just point and give you their opinion. Now we have statistics where they can keep track of what rounds you were voted for against and

then you can have a better idea of your performance round for round for the olympics this is where they develop a judging system format where they can give you feedback and information as to how you performed as to what you asked about how does somebody pick a winner there's a lot of different moves you don't have a choreographed routine because most of the time you don't know what the bj is going to play he's going to put the song you have to adapt in the moment on the go and adjust your moves as you move some dancers that break uh we choose to have sets which means you choreograph beginning to end what you're going to do or you have people that freestyle movements that they already know how to do right and this is more to the roots of the culture and the dance because it was created as a sporadic form of dance where movements were just done in a sporadic form.

So that is a style that is in many ways, many people are utilizing today. So then they'll adapt in the moment with the music or they'll adapt their whole round based on what they see. And as you're performing it, there's many things that come into play from execution. How will your moves connect? How will you're taking the opponent out in the battle. The choreography, yeah. Yeah, how well you're battling. So they took all these things into consideration,

and then from there they score it. And as well as the tournament goes on and progresses, repeats, crashes, those things take points away if you start to repeat the moves, the same exact moves you did already. If you start to make small errors, those things matter, and then that can cost you the battle. How did they know it was an error? Maybe you did it on purpose.

Sometimes you can make an error look like a move, right? But if you're not good at that and you don't look comfortable when you fall out of something, it's set out and you can see the errors being made. Somebody had to decide one day, you know, I don't want to dance on my feet. Whose idea was it to dance on your head? B-Boys. This can't be, this was not anybody's mama said

that, okay? I mean, it was just B-Boys and a lot of them from the Bronx, from New York. I mean, for example, we take the Heston. The continuous Heston was innovated by a guy named Kit Freeze. And to think of a continuous Heston without your hands just floating and just spinning for as long as you can.

That idea is just incredible. And to have been somebody that innovated that, I can only imagine his thought process must have been crazy for the time to be able to not see that and then just one day just start doing it i kind of think of it like the balance beam in gymnastics when you look at the old balance beam routines in gymnastics it literally was about keeping your balance and like there were no flips can you not fall off yeah can you not fall off and then as you watch the progression it's like all right well you know what i'm gonna do i'm gonna spin on this little piece of wood and then somebody was like oh okay you're gonna spin i'm gonna jump and spin on this little piece of wood and then it's like you know what i'm gonna do a cartwheel

on this little piece of wood you know what i'm gonna do a backflip on this little piece of wood and then before you know it when you look at the balance beam today, it's like these incredible physical feats that these women are doing. Chuck, you just invented a new Olympic sport, breakdance balance beam. There we go. Yo, that would be so dope. Break dance, Dallas. So, Rox, I come to this sort of from the point of view of physics.

In any physics class, in the first couple of months, you learn all about momentum, linear momentum, angular momentum. You learn about energy. And these are sort of the entry-level ideas that infuse so much of what we understand the physics of the universe to be. So, when you go into these moves, you've got to start out, especially when you spin, you got to start out with a certain sort of beginning angular momentum, right? So that you can keep spinning once you go into that move. So, how much thought goes into your body parts in advance of a move that is the real money move that you're trying to display yeah i mean for some moves you really have to

already know how to do it as you practice it so when you're going into it you really have to have already a center of gravity where you feel you feel very well balanced say like a move where your feet don't touch the ground right we'll take the for example i'm gonna go into a headspin keeping my core in and my center of gravity low to the ground so i'm not throwing myself off balance so i can go straight into it from one one throw and just spin for as long as i want got it got it and also it seems to me we know in sports, especially in football, when you rotate the football, it spins stabilized. So we do this with spacecraft, for example, and some satellites. We have gyros in there. So is it correct that if you stop spinning, it's harder to stay balanced on the top of your head?

So the spinning actually improves while it's acrobatic. In fact, you kind of need to do that to keep your balance is that true uh you'd be surprised some guys can actually just stop on their head with no hands and just from that's crazy oh man that's insane a few people do it but we actually have what we call a freeze so freeze is the sudden stop of momentum so when you're completely spinning full speed and i don't know where you stop that's a freeze the amount of energy that goes into stopping your body from full speed that's a lot that's got to be a lot yeah and just sometimes you do it on one hand you do it on two hands you can stop on your head you can go to your elbow you can catch it in a position where your elbows

on your rib and yours you're just stuck there and to see those posing like you're posing i've seen that yeah man that's that's that's it's very cool so it means you're in full control of all your body parts and all the motion of your body by the way there's something called the law of conservation of momentum linear and angular momentum so there you are spitting and then for you to instantly stop that momentum has to go somewhere so you can only stop if you brace yourself against the earth yeah and so what then happens is you transfer your angular momentum back to the earth the earth doesn't care

earth eats it and it absorbs it but it's still in there in the tiny little bit so this is you interacting back and forth with the earth first to give you the spin to begin with and to have the earth take the spin away once you're done but but there are other ways like what skaters do ice skaters they'll start with their arms extended and then they're spinning at a given rate and we did a whole show on this who was our ice skater sasha cohen sasha cohen sasha cohen right thank you for reminding me but we did that on stage in this. Who was our ice skater? Sasha Cohen. Sasha Cohen. Sasha Cohen, right. Thank you for reminding me. But we did that on stage in front of a live audience.

So, if your arms are outstretched and you start spinning, you'll go whatever rate. And then as you bring your arms in, naturally you will spin up. Yeah. Now, I don't know that I've seen break dancers do that consciously. How much have you thought about bringing your your body parts in close to your rotation the way skaters do to speed up or then to slow down we do that for sure it's called the drill uh so when you're doing for example you take a headspin and you're open so your body's open and then as you lock in the spin starts to speed up faster and faster and you

end up blocking like a pencil drill the skinnier you are the faster you'll spin yes that's that's what we call a drill and then for other type of spin moves that we utilize they have a similar sort of spin and speed is what we call 1990s when you're spinning on one hand and your body's locked in a in a pencil position and you're just drilling wow let me take you back to something you said earlier on You don't know what music the DJ is going to play So that means you're freestyling How are you And how quickly are you adapting your shapes Your flares

And keeping them on beat Because if I wasn't amazed beforehand Once I heard that I am off the chart Because that's ridiculous Yeah So I mean it's just knowing that the rhythm so when you hear the song before you go out usually the

the musical star and just see a standoff where each dancer is waiting to go out usually at that time the dancers are listening to the rhythm of the song and figuring out the the count if they're counting or they're following a certain drum or certain instrument in the song that they want to interpret and they want to highlight for you when they go out so once they figure out who goes first then they just keep adapting to the sound and i mean the ones that are choreographing the rounds or they have their sets from beginning to end for them it's just more like them following the counts and rhythm that they have built in the round where somebody that's freestyling and adapting they're gonna highlight different parts of the round where somebody that's freestyling and adapt them they're going to highlight different parts of the song that somebody that's watching and listening to the music they're

going to start to see the song more so they're visually showing you the music with some other concepts so this is character interpretation so you as your individual character through the music yeah fantastic so rox tell tell us about friction okay and if you're spinning there are two surfaces in contact with each other one is the top of your head the other is whatever the surface may be and that surface is not teflon. Well, first, what is that surface in the Olympics? And I've seen kids spin on their head on the cement sidewalks in the city. They all have male pattern baldness. That's what I'm asking.

You're wearing a Red Bull hat. Are you just completely bald right on the top of your head? Well, man's got a healthy head of hair. Good for him. They're blessed. No, yeah. a healthy head ahead good for him they're blessed no yeah i mean when you're spinning you feel it i mean say i practice for example uh certain moves that i like like an elbow spin so i spin on the on my arm actually but don't even say that don't it hurts for you to say that i spend too much uh if i don't have something on either a callus or you'll burn your hair off

from here uh so when you do head spins or anything related to that you always want to have some sort of protection whether it's a beanie some sort of rag or then we have a spin cap where it has a material for you to help you spin because yeah floors it can vary you can have marley you can have masonite you can have a nice wood gym floor or over polished gym floor where the skin is just burning every time you slide so you have to be you have to be careful now back in the day they used to take their hat off like if you want to spin on your hand i don't know what it's called you put your hand down flat and then your elbow gets tucked in under your torso and then you use that as kind of like a spindle and you just keep spinning around

on it it's a springing action right and back in the day they would take their hat off their head and put it on their hand and then use that to spin yeah that's a hang glide or a hand spin so we still use that today uh but you can't take your hat off because then you have to deal with the hat after you finish your spin so now what people do they'll put their sleeve on their hand as they're dancing so it doesn't take away it doesn't distract as you're watching it because if you see me take my hat off there's a process of taking the hat off put it in my hand spinning then i have to get out of the hand spin and that's a whip move yeah so you spend here and just says you have people doing barehanded oh and and also i've seen in many moves again this is from from i guess decades ago uh you're not so

much spinning it looks like you're spinning but you're actually sort of rolling around oh that's a windmill right so that's a windmill it's a it's a you you are rolling in contact with the ground so there's still very good movement but it's not pure spin on it at a stationary spot what do you call that category of moves they're called power moves anything related to a spin uh where you're defying gravity your feet are off the ground it looks like you're hovering we consider a lot of those power moves um unless you're doing freezes where you're doing sudden stops and you're combining that, then that's considered, we call that stacking. But power moves are basically what you're mentioning right now.

So a windmill would be considered a power move. And that's one of the first power moves that was utilized in breaking that really helped innovate the dance to where it got to in terms of the dynamic side of it. And another quick thing before we end up with Gary's question. dynamic side of it. And another quick thing before we end up with Gary's question, I happen to know in gymnastics, the best gymnasts do not tend to be big people. They tend to be smaller, both men and women, because I guess your body can tuck faster. There's the distance you have to maneuver to get your body to do something is much smaller so in breaking is that also true are there any big like how tall are you for example i'm five five okay so that's that's

like right in there like a gymnast male gymnast or easily five five to five seven tops right do you see any lebron james types out there breaking? No, I did not. There is a few, but the one thing I will say, there's some guys that are maybe 5'8", 5'9", 5'10", that can actually break really well. And when they dance, they stand out way more because their movements are so exaggerated. The way that they attack and the way they connect,

it's really something special to see because it's not so common. Usually we're all 5'5", 5'6 five six within the same height but when you see somebody taller come in and if they can dance and have a really fresh style with the music and be able to mix all the dynamics that the dance has to offer it's really hard to beat people like that because they just they know how to control the floor more let's get to the olympics paris 2024 people watching the olympics and watching breaking would not possibly have no exposure to it maybe have seen it briefly on tv or something so what the whole thing what can we expect what will happen etc well you're gonna see basically

a completely different art form than anybody has seen compared to what we saw in the 80s i mean we've been competing steadily since like early 90s when competitions really started to emerge on a yearly basis. The dance has evolved so much you have so many different styles and breaking now it's not just what we saw back in the day. I think people are really going to be blown away by the moves that people do, the concepts, the way they connect with the music. Just the styles that you will see on stage you will see a good diversity and I'm just really excited for the world to just the styles that you will see on stage, you will see a good diversity. And I'm just really excited for the world

to see the new story of breaking and not what it was and what inspired the world, but it's where it's gone now worldwide. All right, well, we're going to look for this, Rox. Thanks for your time to spend with us. And we'll be cheering you on. And maybe we can follow up, you know, after the Olympics. Well, let's find out first

if rocks is competing oh yeah are you competing no i'm not competing oh but he's invested in in mentoring and coaching so in spirit and soul he's going to be there through people that he works with but possibly not himself busting any moves oh yeah i've worked with a lot of people that are in the process a few of the ones that are already in it i've worked with as well okay sweet okay so your influence will be felt yeah i hope so all right rocks we gotta we gotta uh end it there but thanks for just for being a good sport and for cluing us in to the future the future of hip-hop battle on the world stage yes thank you thanks for having me it's a pleasure no one gets hurt unless you hurt your own damn self exactly exactly

i'm kais from bangladesh and I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson. We have with us Nikita Dukaro. Nikita, welcome to StarTalk. Thank you. Thanks so much for having me. Yeah. Welcome to StarTalk.

Thank you. Thanks so much for having me. Yeah. So you're a freestyle BMX racer in the park discipline, park discipline, a bronze medalist in the 2021 Tokyo Olympics. If I remember correctly, that was delayed from 2020, obviously due to COVID. And a silver medalist. I got your whole resume here. UCI BMX World Championships 2021 and 2022 European Champion 2021.

And so, oh my gosh, we got the right person here to talk about this. So I want to talk about the bicycle, the course design. I don't want to talk about all the physics that might be flowing in and through it. So Nikita, explain, just so we're on the same page, explain BMX. What does the B, bm and the x stand for explain freestyle and explain what park means okay so bmx stands for bicycle motocross and that that originated more with like the racing side when as you said before like they kind of started imitating motocross races on bikes and then you know that evolved into different

areas and disciplines and so now bmx freestyle park is essentially same like small bikes but riding it in skate parks or um which could be cement or wood different materials but it's basically just doing tricks on ramps on small bikes. Like flips and things and twists and all the kinds of things we can imagine? Yep. And one of the surfaces you do this on is cement. I just wanted to know if I heard that correctly. Yes.

Okay. I mean, that's kind of, I think, what it originated with. Right. Yeah. Okay. And tell me about the design of the bicycle. Because I'm guessing originally, if you're just trying to imitate the motorcycle, you're going to get a regular bicycle and try those tricks. But over the years, it looks like the bicycle for your sport has changed.

And I have to presume some engineers got behind it and say, if we make this shorter or this longer, you can do more flips or be more acrobatic or give you more balance. So what do you know, at least in your lifetime, that is infused into the design? Yes. I mean, there's so many different specs of the bike, the geometry, everything that you can get into. personal preference but of course you know every little change of degree or size like you said affects how you can what you can do with a bike if it's easier or harder so these days now with the part bikes um they tend to be a lot shorter um the back end will be a lot shorter because that makes you know rotation spins a lot easier versus like a race bike for example where they're trying to go fast they're not really doing jumps like crazy and they manual

a lot which is basically like a wheelie without pedaling just balancing on the back wheel so they have a longer back end on their bike because it's a lot more stable okay so the bikes are tuned for the for your actions and your activity yes interesting exactly i feel like it really comes down to the bikes because in bmx even just in like specific discipline that i do you will find every single body shape tall short bigger smaller like and it all seems to work. So I think it really kind of comes down to the bike itself and how we run them. When you see a course for the first time, do you immediately know which tricks you're going to bring forward?

Or do you have to, do you get a chance to ride that, feel it and, you know, let it speak to you? It's a bit of a combination. Like a lot of times we'll get the image layout of a course and you can start it speak to you it's a bit of a combination like a lot of times we'll get the image layout of a course and you can start to think about it would be cool to do this here and this there but when you get to a course it's always so different because from a picture you could never tell the distance between the ramps you can't feel how steep steep the ramps are, what the transition, what the radiuses are like. And all of that really affects how easy or hard it is to do certain tricks. And so until you actually get on the course and feel everything, you can't exactly set your routine.

So in the Olympics, how much time do you get to practice on the course that you've never seen before we're never really sure um last olympics we did get a decent amount of time like we had a couple days in a row up maybe like an hour practice because a lot of events we don't get a lot of practice like actual on course time um which makes it kind of hard yeah it makes it pretty difficult um so but the olympics last time around at least we're like generally good about giving us a lot of time to figure things out um because yeah i think it it is a a sport where it's like for example i might know how to do a backflip just to keep things simple simple backflip simple how casual was that yeah okay you start getting into all these crazy combinations

but like doing a trick on one ramp is gonna feel completely different when you move to a different ramp that has a different radius on it because all of a sudden the way you pop off, the speed at which you rotate, everything changes. And so you really have to have time on that new ramp to figure out the little tweaks you have to make. Wow. Are the surfaces only concrete? For most of our competitions these days, it's now wood. So since wood has a certain give to it that concrete doesn't, if you have energy landing on the wood, some of that energy will come back to you in ways that would not have from the concrete. The courses that they build for events are usually temporary courses.

So they'll put up like a scaffolding base and then build the course on top. And so because of that,'s not you know a permanent structure there is a lot more flex everything feels softer so your speed isn't going to be as much you're going to have to really depending on the course either pedal a lot more or pump a lot more to get the speed because yeah everything's kind of soft compared to even compared to a wood park that's like more permanent a permanent structure or it's on top of a concrete base okay so you're saying something beyond what i said because what you're saying is because of that give the wood is actually absorbing energy from you and you have to compensate

by pedaling a little harder or pushing off the turn a little harder it's like a box spring in a mattress the base that you put it on like a box spring and a mattress the base that you put it on like if you have a really nice firm base then you're going to get more return from the wood course if it's squishy it'll just absorb it out yeah yeah okay gary what other questions you have what happens if the ramps are so high how do you then deal with that is it is it advantageous to you and your routine? Or is that just you've got to change the whole thing because the ramps are higher? Does that work?

In fact, don't you want high ramps? Because then you have, if you come off of it, you have more time and distance to do your flips and gymnastics. So it would depend because you could have a high ramp that has a mellower transition or you could have a high ramp that has a steeper transition or vice versa a shorter ramp with a steeper one so i think it's less about the height like we typically ride a lot bigger ramps at competitions and i think they have gotten bigger over time and we don't notice it too much because it's been so gradual but i think it's a lot more about the radius of the takeoff that that affects things because a steep obviously a steeper radius will send you straight up which gives you more time for tricks but also

you will have to push through it a bit to make it over versus just getting shot straight up and coming back down and like not making it to the landing you versus just getting shot straight up and coming back down and like not making it to the landing you don't you don't want to come back down when you started no you got some fore motion there yeah exactly and then like a like a mellower landing or a mellower takeoff sorry is obviously easier to get over the junk but you're gonna stay lower to the ground so you won't have as much time for tricks so there's really like a sweet spot you said you don't get much access pre-competition to the park course but what happens when you come across a fast one does that allow you to go max on the tricks or is it like you know what i really have to control this

better because our courses are just flat like it's not downhill or anything we're not going in a straight line down a set course trail or whatever you know we just have like a square or rectangle tangled surface with different ramps and you can go wherever you want just to be clear unlike snowboarding and unlike skiing, in your sport, you are pumping energy into what you're doing at all times. So you can go against gravity in ways that other people cannot really do so. The gravity vector does not stop what she does because she can pedal against gravity. But you can't just on a ski slope turn around and say, I'm going to ski up slope and do half this course again. You can if you're peekaboo street.

Never mind. Sorry. I'm sorry. Well, yeah. So we're kind of using the transitions again. Everything's about like pumping down the transitions and up to kind of maintain your speed so when you go up and you do a trick you want to land really nicely in that transition and you pump out of it to really get the max speed for the next thing and you can throw pedals in you know here and there as needed but yeah a faster rolling course which

would be a course that maybe is a little more solid on the ground or there's more space in between the ramps that just helps you to, I guess, not have to work as hard to get over things, to jump over, because you won't have to pedal as much. You'll be able to just use the momentum from the ramps to go to the next one. What's more valuable when they're judging you? Because some of the tricks, there's a lot of stopping.

You'll see, they'll come to the top of the ramp, there's a lot of stopping. Like you'll see they'll come to the top of the ramp. They'll come out of it. They'll land on the back tire all by itself. Take a hop, turn around, go back down. Or they'll do the same thing on the front tire and stop. And then there's other tricks where they come out of the ramp and they'll like do something crazy. Like just spin the whole bike around and go right back into the ramp and they'll like do something crazy like just spin the whole bike around and go right back into the ramp what how do judges determine what is more valuable to judge i mean i think with

freestyle bmx it's always been a bit difficult because it is kind of biased like there's no set points for specific tricks or whatever so now like the first thing you said about you know like balancing on the wheel i think that's kind of phasing out a bit from the park competition specifically you'll see that maybe in other disciplines chuck that's old school yeah so now now it is a lot more just like going out of the ramp and doing some crazy spinning thing. So the Olympic model will have to be amended. So faster, higher, stronger, cooler. Like, cool. Now, you stood on the podium last time in Tokyo.

I guess the itch is there to be scratched. You want to be gold. What's it going to take? Man, it's going to take a lot. Since the last Olympics to the next one, there's been a surge of young women joining the sport, which is super awesome because women's BMX was really slow for such a long time, and we've had just this massive explosion.

And with that, the tricks are getting crazier and crazier. I'm now considered like one of the old dogs, which is crazy. I wasn't ready for that. But like we're competing now with kids that are like 16. So wait, have you been mammed yet by one of the younger? I haven't. I don't want that to happen. I haven't been mammed yet.

Thank God. You haven't been mammed yet god I'm told that's a day That's a day I might go home and cry if that happens But yeah it's just going to take A lot of training New tricks are really going to be necessary This time around because

Every girl out there is really pushing The tricks like tricks that Women haven't done in competition yet. The judges really do appreciate like an overall solid run where you're hitting kind of all the criteria, like use of course, the heights, the flow, and obviously like the tricks. And like I said, new tricks,

because there are also judges that have seen us ride in the past. So there is going to always be that bias. And if you bring something new to them and something new to the crowd, you know, the crowd will go crazy. And I think that kind of affects thieves as well. So that's a lot of work. So Nikita, it's been a delight to have you on StarTalk Special Edition.

In our third and final segment, we're going to bring back our geek and chief charles loon up next on star talk all right so we got to make sense out of all of this. And you know who I reach for when I want to make extra sense. I can make some sense, but to make real sense out of the physics of the universe, we bring in StarTalk's geek and chief, Charles Lute. Charles, welcome back. Hey, great to see you, everybody. Neil, Chuck, Gary, you guys are awesome.

These two athletes are amazing. Nikita and Rox. I mean, I love it. And the physics, gotta say, is amazing, too. Can't wait to talk about it with you all. Oh, let's do it. So, there's things that are rotating, if not the body, then wheels. In addition to the wheels rotating, the handlebars, this stuff. So where should we

start here? What's your spin on this, Charles? We went there so soon. You know what? And I'm so ashamed. Now you got no joke left. The word has turned. I'm so ashamed. Oh my gosh. Go ahead. Listen, these two sports are fundamentally about rigid body rotation when you have things that are spinning around other things systems of rotation really right the human body you think of uh say you're doing a head spin or rocks is doing a head spin for example you have your foot hinged to your leg hinged to your hip hinged to your torso hinged to your arms hinged to your leg, hinged to your hip, hinged to your torso, hinged to your arms, hinged to your head. And every one of those has got its own rotational thing going on.

Charles, I have to clarify. You said rigid body rotation. Yeah. Some people are less rigid than others. Oh, yes. When I turn over on the couch, is that rigid body rotation? Surprisingly, perhaps, yes. But it's not that your whole body is rigid.

It's that you have numerous pieces that are rigid that are attached to things. And together, they create this net effect of rotation and motion. Now, in physics, the amount of motion we use loosely could be referred to as momentum, right? That's a term we're all familiar with. Even if we don't know it mathematically, we have an intuitive sense of momentum. Sort of the amount of motion you have. Now, the amount of rotation you have, we kind of call angular momentum. And in the same way that force is a change in ordinary momentum,

torque, like the thing you do on a wrench, right, is the analog when you change rotation. So why don't they call it angular force? They could. It wound up being called torque for some historical reason, which I do not know. Torque sounds much more cool and, you know, I've got to say. It's more superhero. It's a superhero say it's more superhero it's a superhero

like you know what i mean yeah well super villain perhaps i shall torque you ha ha spider-man you know that kind of thing there you go torque is a french word i wonder if it was developed after the newtonian history i don't know neil you know much about this the angular stuff all came after the linear stuff right right so maybe lagrange or legendre had something to do with it well gary you know uh much better than we do as an athlete you're always thinking where your joints are where your arms are your legs are your head is in relation to what you're about to do with the ball you're always setting yourself up for the next event that you're going to execute, whether it be on a bike or whether it be in your choreography. What I found really fascinating when we spoke to Rox was they don't know which piece of music's coming up.

Yes. It's not as if it's, you know, like ice skating where they know it's Ravel's Bolero and they're going to do set certain moves all in a stream these guys are feeling it there's a certain amount of improvisation that's totally so intuitive and they've got to feel what move is about to go down correlates with the music once the music starts they might know this piece of music in which case they can drop a certain move in at a certain time. They've got to get there.

That's the sort of intuitive, athletic ability. That's why if I was the DJ, I would play a waltz. Breaking to three quarters time, I would love to see that. But never minding that, right? Gary, you hit the nail on the head. Yeah. When we are talking about torque, what's really cool is you can generate a tremendous amount of torque with only a little bit of force. And how so?

Well, it has to do with the lever arm. Aha. Right. What we call sometimes a lever arm. Think about when you're trying to stop a door from slamming. Right. Aha. Whether it's your fingertips or your wrists or your elbows or your toes or whatever, you can exchange a tiny bit of force and put it into the system. And bingo, you get a big effect. This is what Archimedes was referencing when he said, Chuck, you surely know this quote. Give me a long enough lever and I shall move the world.

Oh, I thought it was give me a long enough lever and I shall move the world. Oh, I thought it was give me a long enough lever and I will bust a move. Archimedes in the toga, right? Dancing the waltz. No, no, that's Archimedes in the hood. That's a different Archimedes. My goodness. Wait, wait, wait. I thought it was, Charles, instead, give me a place to stand and I can move the world.

Yes, that might be even more accurate. After the show, I'll call him. Yeah, give him your call. He'll find out exactly what he said, yeah. So, he knew that with a long enough lever arm, even someone with the meager strength of a mere human, the torque can very much work in your favor, provided, you know, the physics as he certainly did. That's right. Okay. So, with the bikes.

you know the physics as he certainly did that's right okay so with the bikes oh wait a minute and so when you're talking about levers and you have the point where the lever is the fulcrum whatever is it always you have to have the shorter side which is doing the work and the longer side is where you're pulling like you can't have them be equal right you don't get torqued that way do you you do i'm asking you great question there are three different kinds of levers okay okay and in fact each one of them is useful in a different way so one kind where archimedes is moving the world you're way longer on your side of the fulcrum than the other okay when you have something equal uh that'd be like a pair of scissors right you don't need that much force but you're pushing two wedges together thus creating a cutting motion if it's too long then you don't need that much force, but you're pushing two wedges together, thus creating a cutting motion.

If it's too long, then you don't gain any advantage. Gotcha. Now, then the third kind of lever, which is super cool, is where you actually have the fulcrum closer to you than to what you're doing. That's when you actually produce more force, but you want to spread it out more. An example is like a broom. more force but you want to spread it out more an example is like a broom if you want to sweep something say a whole bunch of dust off of the ground you don't need a lot of force but you need area so you use the lever in such a way the broom where the fulcrum is you're holding it up in the corner right the pushing starts way up top right nobody brews with their hand down near

the sweeper because then you don't get any any motion you don't get the advantage so you're literally improving the sweeping effect by having that weird kind of lever that you don't think of when you're trying to move the world that was archimedes the janitor right okay so so charles are we looking at multiple axes of rotation here for either of these guys absolutely that's where the beauty and the athleticism come along right nikita was talking about this amazing trick being worked on right where you are back flipping with the bicycle which is one axis of rotation and throwing a handlebars which is the other axis of rotation at the same time they actually affect each other in ways that are so complicated that she can't calculate them she has to try it and try it and try it until it works by

falling into the foam pit right this is true in our physics as well as soon as you throw in a second and a third rotational axis things start getting very complicated i heard a story once uh one of my colleagues uh senior colleagues was working with the chandra x-ray observatory and what he said was the hardest thing for the flight engineers and the aeronautic engineers to work on is actually measuring things like the roll pitch and yaw of the telescope as it's orbiting the Earth while it's orbiting in this highly elliptical orbit, while it's doing this and that and spinning, actually to point it at the place you want it to point for seconds or minutes or hours at a time.

And to stay pointed to the thing. That's right. It's very, very complicated. And so, doing it on this human microcosmic scale with no computer other than your brain you're just simulating you're redoing you're practicing over and over again to get these kinds of things lined up you're literally calculating things like the tennis racket theorem and the moments of inertia in real time what's the tennis racket theorem oh oh yes that's

right we should talk about this. But you can't just drop that on us and walk away. All of you are interested. Go read about moments of inertia. Okay. Think about momentum. When you are creating a momentum in physics, it's the mass times your velocity, right? Mass is like the amount of stuff that is moving when you're calculating momentum so moment of inertia is the thing that allows you to figure out like the characteristic of your object or your bodily system with many parts that will react to rotation, what we call angular velocity, in the same way. So angular momentum is angular velocity times the moment of inertia. Okay, so that's the technical phrase.

But just to clarify, what we're saying here is we have mass that we have an intuitive understanding of. The mass equivalent in rotation is the moment of inertia well said okay that's right so conversationally speaking we are always looking at objects with different strange shapes okay they may be oblong they may be multi-part things like that if you can calculate its moment of inertia in the same way that you can weigh an object and figure out its mass, then you will know how it will react or how that part of your system will react when it gets spun. And so, the tennis racket theorem is one of four really cool theorems about spinning and moments of inertia. You should try it yourself sometime. Take a tennis racket and if you try to spin it in three different

ways you throw it up in the air in one axis it just comes right back to where it was no problem you spin it in another axis it also comes right back to where it was no problem this i did this with chuck yes chuck didn't i demonstrate this to you with a book that's right i didn't know i didn't know there's a tennis racket well you could call it the book theorem if you want. It's technically called the intermediate axis theorem. But basically, you spin it in the third direction, in that intermediate direction, and it will always do a flip. Charles, this blew my mind when we first did it in physics class when I was in high school. Yeah, isn't it cool? So, let me give a gander at it.

So, if you have an object that has three different axes of rotation okay so let's take a just take a book or like you said a tennis rag i think a book because they're like they're flat and they're flat thank you each axis has its own moment of inertia exactly so you can spin it horizontally that's easy right you could spin it vertically that's easy but if you want to spin it vertically. That's easy. But if you want to spin it top to front, that moment of inertia, the value of that moment of inertia is lower than one of the values and higher than the other.

And the system is unstable rotating around that axis. And it goes to the other axis all by itself that's right it's mind-blowing so we'll always flip no yes always flip oh yes you could by the way you could do with your cell phone but you might drop it yeah i'm saying do it over a foam pit so charles we have these athletes so you're giving me much more appreciation of what they're doing yeah yeah by in the way you describe it i'm thinking what a sprinter only has to move one leg in front of the other kind of yeah really like that's all you say paul is doing the athlete is not just doing singular direction of motion but the body as a whole moves in the singular direction

that's the key when we're judging the bmx or we're judging the braking you are judging motion in multiple dimensions which makes it more complicated in soccer gary the obvious analog about rotating multiple times and trying to get something to move is the bicycle kick yeah right and when every time i see a bicycle kick i'm i'm just going there's some moment of inertia change going on there when you connect with it and it goes in that's like the hundredth time you've tried it because generally it's more likely that you miss but right honestly it's true but are you speaking for yourself of course yeah have you ever done a bicycle kick gary yeah yeah so and i've connected but the thing is you hi even a bicycle kick, Gary? Yeah, yeah. And I've connected, but the thing is,

even a blind dog can find a bone. Wait, Gary, is there video of you connecting? Of course not, no. Oh, man. Well, in that case, I remember when I did a bicycle kick. Exactly. When we talk about muscle memory in athletes, right, you practice, you practice, you practice, you memory. Here's another neurological imprint.

Imagine Nikita's doing her double axis flip and all the rest of it to be able to practice knowing where her head should be, knowing everything in the landscape around us and learning and learning and learning, just like you would strengthen muscles to achieve certain performances. That's right. What I want to bring from what Charles said into this is, when you do a bicycle kick, not only is your body rotating, but when you are in the proper position, your leg not only moves forward, you then pivot at your knee so that you get like three times the extra force on the ball the rotation of your body the movement up in your ball joint of your hip and the movement of your

knee joint am i right here charles i think i'm right there it's a series of levers that's right yeah each lever adds to the ultimate amount of acceleration you provide to the ball when you strike it it's amazing it's so amazing how quickly the ball comes off the foot in a bicycle get faster than if you just ran up to the ball and kicked it because you got all this rotation going behind it usually yes but it doesn't always have to happen that way right it also depends uh like ronaldo had an amazing kick just right off the ground because he is tall and lanky and he was able to snap those levers those pieces of his body in such a way as to provide tremendous energy you have to make a really clean contact as well on the ball if you only get a grazing blow on it then that kind of theory goes away and then it's embarrassing and you don't make

the highlight reel right no you don't no no espn for you okay so so all their body parts are moving in all different ways that they're in control of and we watch this in awe that's right again now i'm not impressed with with usain. Oh, you ruined the Olympic. No, no, no, no. Usain is amazing. No, please. Just remember that this is three-dimensional motion, right? It's the difference between enjoying watching something linearly and watching something going in all directions.

I mean, you were talking about rocks being able to adapt instantaneously to the music that's available yeah let's say let's say chuck puts on that waltz right and rocks has got to break to the waltz he already has in his brain the muscle memory to do certain things in three-quarter time right and what do you do to make all those things come together? In the end, it's that beautiful artistry of body parts moving in concert, in sync, together with what you have in your brain, what you've learned to do, what your muscles know how to do instinctively. That creates these amazing routines and amazing athletic activity. Now that you mention this, I think we've been primed to receive this because of what we've already come to love in gymnastics. The body's twisting, turning, tumbling. The body's doing things more than one thing at a time.

And so now you take the time-honored displays in gymnastics and apply it to these two new new to the olympics and i now i'm looking forward to it because i was like indifferent at first but no no no and think about skiing aerials or the skateboarding where you're in the pipe and you're doing rotations and moving at the same time think about diving where you're being accelerated constantly in one direction while you're twisting your body back and forth and back and forth it's all there we just never really think about it that much on the greek statues right they're only one directional most of the time so let me ask you this what is keeping you from the drift so what is it about this motion that's keeping you on the line of your gravity you're just falling straight down but you don't see the person they jump off but they don't keep

going to the left out out out into the pool they go straight down even though there's twisting and turning and twisting and turning when they do the same thing in gymnastics the same thing in gymnastics, the same thing in breakdancing. What is keeping you in place? Gravity. Your launch. Gravity. Gravity. Your initial launch, if the diver jumps outward too far, they will go in a parabolic path. Okay.

The diver must know how to jump pretty much exactly straight up and straight down. Yeah. Right? Also, if there's a wind they will drift right it's as little lateral movement as possible is what you have to incorporate in order to get that's right something else unlike golf where you can slice or what's the other one you slice or hook hook hook or hook that's because there's a spin on the ball interacting with the air that's right now the gymnasts are not spinning that fast or moving through the air that fast.

That'd be a 10. They got to worry about a spin deflection through the air. That's right. That would impress the Russian judges. That's for sure. Finally. I don't think there'll be Russian judges in this one. Oh, that's right.

There won't be Russian judges this year. No. So, Charles, encapsulate this. What's the physics we should pay attention to? When you're looking at the BMX and the braking sports, look for the combinations that show the most rotation in the most numbers of axes. Right. Watch for the breaker's body as they are rotating,

maybe on their head in this direction clockwise counterclockwise meanwhile their other parts their hips for example may be rotating in a different angle and meanwhile they're doing all these things together the complexity of what they can do in different axes is what's going to matter similarly in the bmx especially in the tricks see if they are doing the combination of the backflip with some other twist. Are they doing another turn? The complexity, the more you put in, the cooler it is. And the physics just pops out in this sort of beautiful display. For BMX, I might be looking for a Swiss gold.

Okay. Let me just say, I just might. Oh, look at you. Okay. But how about breaking? You know, I'm from the Bronx, you know. You're going to tell me, like, no. We all must love the art form.

But just like you said, Neil, if you're thinking about the culture expanding, wouldn't it be amazing if a Swedish or a French or a Korean athlete won a breaking gold. No. Right? The hell are you talking about? No, it would not. It'd be good if they won silver, but not gold. Okay.

Silver is fine. Imagine if it's gotten to that point, right? That means that America has overall, once again, been able to influence the world in a positive way. Let me say that another way here. So, Chuck, if America loses to a Scandinavian nation, America still wins because our influence has spread far and wide. Now, I want to double win. I don't care about none of that.

Stop. That's America, man. America. I don't want no doggone, what you call it? A moral victory. A moral victory. We don't need that. No, no, man. Mark, I don't want no doggone, what do you call it? A moral victory. A moral victory. We don't need that. We're not here to touch the world. We're here to win.

Alright, we got to end it there. Charles, it's a delight always to bring you in on these conversations. You ratchet it up with torque to another level every time you participate. Thank you so much. What a pleasure. And let me just end with a quick cosmic perspective.

You know, I'm an Olympics purist. I kind of only want like the sports that ever appeared on the Grecian urns, but I can be warmed to other human exploits. You know, the whole world is not just the javelin and the discus. It's how the inventiveness of people, cultures, places, things come together and reach for the aspirational goals established by the Olympics faster, higher, stronger. And I've been softened in this conversation and in others I've had for those who want to see the growth in all the ways people can express their own talents of mind and a

body on a world stage. And that's a cosmic perspective. Again, Charles, good to have you. Uh, and Gary, Chuck,

until next time, uh, Neil deGrasse Tyson, as always, keep looking up.