The Bizarre Behavior of Rotating Bodies, Explained

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Spinning objects have strange instabilities known as The Dzhanibekov Effect or Tennis Racket Theorem - this video offers an intuitive explanation.
Part of this video was sponsored by LastPass, click here to find out more: ve42.co/LP
References:
Prof. Terry Tao's Math Overflow Explanation: ve42.co/Tao
The Twisting Tennis Racket
Ashbaugh, M.S., Chicone, C.C. & Cushman, R.H. J Dyn Diff Equat (1991) 3: 67. doi.org/10.1007/BF01049489
Janibekov’s effect and the laws of mechanics
Petrov, A.G. & Volodin, S.E. Dokl. Phys. (2013) 58: 349. doi.org/10.1134/S1028335813080041
Tumbling Asteroids
Prave et al. doi.org/10.1016/j.icarus.2004.07.021
The Exact Computation of the Free Rigid Body Motion and Its Use in Splitting Methods
SIAM J. Sci. Comput., 30(4), 2084-2112
E. Celledoni, F. Fassò, N. Säfström, and A. Zanna
doi.org/10.1137/070704393
Animations by Iván Tello and Isaac Frame
Special thanks to people who discussed this video with me:
Astronaut Don Pettit
Henry Reich of MinutePhysics
Grant Sanderson of 3blue1brown
Vert Dider (Russian AMtost channel)
Below is a further discussion by Henry Reich that I think helps summarize why axes 1 and 3 are generally stable while axis 2 is not:
In general, you might imagine that because the object can rotate in a bunch of different directions, the components of energy and momentum could be free to change while keeping the total momentum constant.
However, in the case of axis 1, the kinetic energy is the highest possible for a given angular momentum, and in the case of axis 3, the kinetic energy is the lowest possible for a given angular momentum (which can be easily shown from conservation of energy and momentum equations, and is also fairly intuitive from the fact that kinetic energy is proportional to velocity squared, while momentum is proportional to velocity - so in the case of axis 1, the smaller masses will have to be spinning faster for a given momentum, and will thus have more energy, and vice versa for axis 3 where all the masses are spinning: the energy will be lowest). In fact, this is a strict inequality - if the energy is highest possible, there are no other possible combinations of momenta other than L2=L3=0, and vice versa for if the energy is the lowest possible.
Because of this, in the case of axis 1 the energy is so high that there simply aren't any other possible combinations of angular momentum components L1, L2 and L3 - the object would have to lose energy in order to spin differently. And in the case of axis 3, the energy is so low that there likewise is no way for the object to be rotating other than purely around axis 3 - it would have to gain energy. However, there's no such constraint for axis 2, since the energy is somewhere in between the min and max possible. This, together with the centrifugal effects, means that the components of momentum DO change.

Veritasium
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  • John Borden

    John Borden

    2 ժամ առաջ

    Would it be possible for CONTINENTAL DRIFT to change the earth's mass distribution sufficiently to destabilize it?

  • Joseph Chapes

    Joseph Chapes

    12 ժամ առաջ

    C

  • Bolerophon

    Bolerophon

    12 ժամ առաջ

    Feinman was right.

  • Jane

    Jane

    18 ժամ առաջ

    could this explain why gymnasts do the twists in the way they do?

  • matthew harris

    matthew harris

    22 ժամ առաջ

    All Homer Simpson heard was Bla, Bla, Blabla, bla. Oh & me too.

  • mj mia

    mj mia

    Օր առաջ

    love math, good job

  • PimpleJThomas

    PimpleJThomas

    Օր առաջ

    The Earth won't flip... Unless every human being on the planet, and every other living creature, and a bunch of tons and tons of organic and inorganic material, is massively brought up towards one of the poles: that would maybe change the Earth from spinning around the axis of maximum moment of inertia to just around the axis of intermediate moment of inertia, therefore it would flip, and flip again, and again...!

  • Aspect Aviation

    Aspect Aviation

    Օր առաջ

    But in space how do the nut get the «shunt» to start the rotation?

  • Ajay Kumar

    Ajay Kumar

    Օր առաջ

    I am from india

  • Leoni Benedetti

    Leoni Benedetti

    Օր առաջ

    But why would the disk be bumped..? (8 min 27 s) Do we just assume that the small masses arent exactly on the y-axes?And thats why zentrifugal forces also appear there to make it flip...

  • Android480

    Android480

    Օր առաջ

    Intuitive is a stretch, but its damn good.

  • Mike Farmer

    Mike Farmer

    Օր առաջ

    Learned this from a Carpenter back in sixties with a hammer...

  • Robert Boisvert

    Robert Boisvert

    2 օր առաջ

    Very cool. Curious if freezing or damning all the water to a high enough point could impact the Earth enough for a Dzhanibekov effect.

  • Nicco Saur

    Nicco Saur

    2 օր առաջ

    It’s unfortunate that he doesn’t know they are two different effects

  • Jonas Skanning

    Jonas Skanning

    2 օր առաջ

    does that mean before the earth was stabilized it actually flipped?

  • Saivivekh Swaminathan

    Saivivekh Swaminathan

    2 օր առաջ

    uh... you said 'intuitive explanation'... smh...

  • Hank Phillips

    Hank Phillips

    2 օր առաջ

    This explains polar shifting of planetary bodies as they move through space.

  • vikash gupta

    vikash gupta

    2 օր առաջ

    This might explain tilt of uranus

  • Chris Ralph

    Chris Ralph

    2 օր առաջ

    So the theory in the book "Down To A Sunless Sea" is wrong? The story goes that, in a nuclear war, if nuclear warheads detonate at the same point relative to the Earth's orbit, giving a large "nudge" to the Earth, precession will cause the Earth to tilt on its axis.

  • Legazonia

    Legazonia

    2 օր առաջ

    Yo guys, regarding this strange behavior and the earth, check out the declassified document called "The Adam and Eve Story"

  • Douglas Chitwood

    Douglas Chitwood

    3 օր առաջ

    Men!
    Get ready 2 Get Funky.....
    We About to be all one color!
    Tops my day....

  • Rich Garella

    Rich Garella

    3 օր առաջ

    I know I'm out on a limb here, but I don't quite believe that this effect is causing the tennis racket (or phone) flip. The racket or phone flips immediately, every time, even though it is heavier than a wing nut. Well, your typical wing nut. Isn't it more likely that the tennis racket flip just results from our inability to send it up without spinning it a bit? If you try tumbling it with both hands you can make it flip without spinning. It's not easy though.

  • Douglas Chitwood

    Douglas Chitwood

    3 օր առաջ

    NICE! THANKA MON!

  • Jack hammer

    Jack hammer

    3 օր առաջ

    This is all fine and dandy, but, could we please do a follow up, if there already isn't one, that takes into consideration the magnetic fields and there influence

  • Jorge Chávez

    Jorge Chávez

    3 օր առաջ

    But could we put a giant nut at the north pole and it would turn right? lol

  • Michael Kendler

    Michael Kendler

    3 օր առաջ

    Isn’t the same argument with the centrifugal force also true for rotation around the max inertia axis...why is it stable?

  • SomeOne

    SomeOne

    3 օր առաջ

    So an old aged asteroid must spin at its axis of maximum moment of inertia...
    And if it doesn't it must be recently created

  • SomeOne

    SomeOne

    3 օր առաջ

    1:58 I do that every single day yet never noticed it

  • SomeOne

    SomeOne

    3 օր առաջ

    This guy hits millions on every videos

  • Arch Stanton

    Arch Stanton

    3 օր առաջ

    You should flip it mechanically eliminate human imput

  • Jeff Byrer

    Jeff Byrer

    3 օր առաջ

    Why not just use a tennis racket

  • Sana omar

    Sana omar

    3 օր առաջ

    if we build something build or excavate some huge quantities of earth , for mining purposes ,of course . we could achieve such a disaster .

  • Grgazola

    Grgazola

    3 օր առաջ

    Shouldn't the explanation include the cause of small imbalances, the same as with the butterfly effect or other seemingly chaotic movements such as convection?

  • Michael Mills

    Michael Mills

    3 օր առաջ

    The Earth may BE STABLE, but you sir , are not...

  • Michael Mills

    Michael Mills

    3 օր առաջ

    I hate ppl who pronounce it " cent re "fuge" al' force! Aside from spelling its PRONOUNCED ' CENT TRIF I CAL' FORCE. EVERY AMERICAN AGREES.

  • Lucas Kman

    Lucas Kman

    4 օր առաջ

    Best Mathematician alive? You've not seen my maths teacher I guess.

  • Justin Credible

    Justin Credible

    4 օր առաջ

    BUT.... that's cgi... ;-)

  • Jishnu Rajeev

    Jishnu Rajeev

    4 օր առաջ

    I want earth to fcuking flip... Boring blue ball of water has done nothing cool yet

  • MARIN

    MARIN

    4 օր առաջ

    Finally the Earth will remain stable. Gosh! – I was so worried about that.

  • Joseph Caldwell

    Joseph Caldwell

    4 օր առաջ

    So in theory, if nothing ever "bumps" the object off the Y axis, this effect would not happen?

  • Emmanuel Lehuu

    Emmanuel Lehuu

    4 օր առաջ

    And if it never flips, thats proof the earth is round (more or less, my point being it isnt flat) so show this video to flat earthers ;)

  • Tatu Race 150

    Tatu Race 150

    4 օր առաջ

    this disk has more 8 years, you video here
    https://www.youtube.com/watch?v=tDr26U49_VA

  • Lerogi Z

    Lerogi Z

    5 օր առաջ

    Okay, okay. I’m finally watching it.

  • Daniel Loiselle

    Daniel Loiselle

    5 օր առաջ

    We’ll literally all flip out if global warming melts the ice caps..

  • Dre Mack

    Dre Mack

    5 օր առաջ

    All I could see was Booker T doing the Spinnerooni.

  • Roman Romero

    Roman Romero

    5 օր առաջ

    i wish my girlfriend wouldn't flip too 😂

  • Brad Cornwell

    Brad Cornwell

    5 օր առաջ

    Sooooooooo, does this mean that Arthur C Clarke's "Rama" wouldn't be possible?

  • Meow Milev

    Meow Milev

    5 օր առաջ

    Hmmmm i might introduce these to my new sling shot coaster!

  • Awreccan

    Awreccan

    5 օր առաջ

    8:24 but what causes the initial "bumping" of the disc that causes the small masses to lose alignment with the y axis?

  • DubDanTV

    DubDanTV

    5 օր առաջ

    0:48 Name of the movie?

  • Alethea Black

    Alethea Black

    5 օր առաջ

    Does anyone think that the wing nut, while attached to the screw, is *actually* magically flipping back and forth? This is a vivid testament to EMERGENCE THEORY; it supports the ground-breaking work of scientists such as Donald Hoffman and Klee Irwin, who argue for the brain's active involvement in *composing* what we see.

  • Jean Albus Persévérance

    Jean Albus Persévérance

    6 օր առաջ

    Exactly what I thought but much better verbalized, thanks for your explanation. :-)

  • Scott P

    Scott P

    6 օր առաջ

    Easy to see in real life. Flip a hammer. Done.

  • Konstantin Askinadze

    Konstantin Askinadze

    6 օր առաջ

    how would a tetraeder behave?

  • leohobb leohobb

    leohobb leohobb

    6 օր առաջ

    I think it is stupid and naive to trust passwords to a server company or web service.Last pass promoting is stupidity on nitro in my opinion.The rest of your video was ok with smart teori explained.

  • Caleb Cain

    Caleb Cain

    6 օր առաջ

    I have two questions about this, and maybe you, or somebody else reading these comments, would be able to answer them.
    1. Out of curiosity, hypothetically, if the planet did flip, given the information you've explained, and the time it takes to complete one rotation along the normal axis of rotation (one day, of course.) how long would it take to flip?
    2. What changes to the inertial points of the earth would occur if, let's somewhat less hypothetically say, we go from having a large mass of ice at each end to having a landmass at one end and ocean at the other with the ice distributed over the planet in the form of water?
    I'll be honest, I'd love to tease out these questions myself, but I'm notoriously incompetent with higher math, and whatever I came up with would probably not be reliably accurate, even if I did manage to find an answer, so I thought I'd throw this out and see if anybody is more up to the task than I am.

    • Caleb Cain

      Caleb Cain

      6 օր առաջ

      SIde-note: I love your channel. Keep up the great work.

  • Alethea Black

    Alethea Black

    6 օր առաջ

    And here is the quote that describes it, by Lawrence M. Krauss: "But when you look at CMB map, you also see that the structure that is observed, is in fact, in a weird way, correlated with the plane of the earth around the sun. Is this Copernicus coming back to haunt us? That's crazy. We're looking out at the whole universe. There's no way there should be a correlation of structure with our motion of the earth around the sun - the plane of the earth around the sun - the ecliptic. That would say we are truly the center of the universe. The new results are either telling us that all of science is wrong and we're the center of the universe, or maybe the data is (s)imply incorrect, or maybe it's telling us there's something weird about the microwave background results and that maybe, maybe there's something wrong with our theories on the larger scales.”

  • Alethea Black

    Alethea Black

    6 օր առաջ

    The earth, the universe, indeed the multiverse routinely "flip." It is our perspective that is flipping. Here is the image of the Cosmic Microwave Background (CMB): https://arstechnica.com/science/2014/03/is-the-universe-lopsided/2/

  • Alethea Black

    Alethea Black

    6 օր առաջ

    This is brilliant. Thank you, Derek Muller. Whether the earth were to "actually flip" is a question inseparable from an observer. Indeed, there is substantial evidence from the Sloan Digital Sky Survey (SDSS) that the entire universe "flips" routinely along the ecliptic; see the alternating hot-and-cold pattern of the Cosmic Microwave Background (CMB), sometimes referred to as the "axis of evil" (because its implications could force us to rethink everything we believe we know about physics). Could centripetal and centrifugal forces, and the role of "an observer" have anything to do with human health? I explore this and more in my recent presentation (23-min) at the Science of Consciousness Conference. https://www.youtube.com/watch?v=dws-3gNzyZ4

  • Food Farm

    Food Farm

    6 օր առաջ

    Ok time to add more mass to the north pole

  • Matthew28 Apologetics

    Matthew28 Apologetics

    6 օր առաջ

    So what about an airplane propeller and its effect

  • Dennis G

    Dennis G

    6 օր առաջ

    I have seen this same effect with a kicked field goal (American football), look at the rotation and flip in slow motion, the laces rotate end over end as well....

  • Mans Ativo

    Mans Ativo

    6 օր առաջ

    Oh my i've been doing that on my phone cause it was cool. Flipping it then when I catch it, it faces backwards.

  • Chris Tashik

    Chris Tashik

    6 օր առաջ

    Very interesting. The Earth flipping idea reminds me of a spinning bowling ball. The internal core of a bowling ball is meant to make the ball “wobble” which allows for a different surface to contact the lane with each revolution. As someone who use to drill bowling balls for a living I know that with some lines and math this can be overcome and the ball can be drilled so that a specific user can roll it and the ball will rotate around only one axis. (Creating more or less hook)

  • SuperSupermario24

    SuperSupermario24

    6 օր առաջ

    I would have appreciated it if you covered the other axes of rotation in the same way, showing why the same centrifugal forces wouldn't have been present in the other scenarios.

  • Achim Kandler

    Achim Kandler

    6 օր առաջ

    Hi, about the earth possibly being able to flip, your explanation that it behaves like an ateroid is not convincing. Look at the examples with the bottles filled with liquid. In the case of the earth it is also filled with liquid. And it has an atmosphere attached to it. With all these things together it looks to me it could flip. And we might already be in the very middle of it. The axis of the earth is tilted which is the reason we have seasons. Now this might or might not be connected. But I think it's too early to void the possibility it's happening to earth :-)

  • ameer hanani

    ameer hanani

    7 օր առաջ

    prophet muhammad said : "The Hour (the judgment day ) will not be established until the sun rises from the West. (6.158). Sahih al-Bukhari.

  • eppie design

    eppie design

    7 օր առաջ

    In balance !!

  • pkgfx.

    pkgfx.

    7 օր առաջ

    Who else just started flipping their phones??

    • Thomas Johnston

      Thomas Johnston

      2 օր առաջ

      Grabbed a book instead

  • Christopher Franko

    Christopher Franko

    7 օր առաջ

    He concludes the video with "the earth is spinning at its maximum moment of inertia which is stable" but.. the earth is changing. Ice caps are melting, land masses are moving.. couldnt the conditions change in a way that causes the flip one day?

  • Christopher Franko

    Christopher Franko

    7 օր առաջ

    As soon as I saw the object flipping i immediately thought "is earth going to do this one day?" and then my fears were allayed. 10/10 would watch again.

  • Ashwni Kumar

    Ashwni Kumar

    7 օր առաջ

    very interesting video

  • Pedro Viana

    Pedro Viana

    7 օր առաջ

    I wonder how much mass would need to be moved from the equator to the poles so as to change the axis with the maximum moment of inertia.

  • giuseppe d

    giuseppe d

    7 օր առաջ

    which tools have you used for animations?

  • DAY S

    DAY S

    8 օր առաջ

    In the quran 1400 yeats ago allah say the sun will rise from the sunset that time it doesn't matter if u become believer it's done

  • jalbert222

    jalbert222

    8 օր առաջ

    I had to stop listening half way through. Cen tri FU gal forces? It is pronounced Cen TRI fi gal. Geeez.

    • jalbert222

      jalbert222

      6 օր առաջ

      Good point and G'day :)

    • Stephen Parkinson

      Stephen Parkinson

      8 օր առաջ

      Not here matey. Two nations divided by a common language ;-)

  • Henry Henchion

    Henry Henchion

    8 օր առաջ

    So earth won’t flip bc it already flipped

  • Archangel Raphael

    Archangel Raphael

    8 օր առաջ

    so is the intermediate axis theorem an explanation for the *tippe top* that befuddled physicists like Pauli and Bohr?
    https://kachina2012.wordpress.com/2008/04/14/chess-the-game-of-life-and-the-tippee-top/

  • Archangel Raphael

    Archangel Raphael

    8 օր առաջ

    AHA an anomaly that involves invoking centrifugal forces ... nice

  • Lorenzo Carelli apd

    Lorenzo Carelli apd

    8 օր առաջ

    This is the 4th time I am watching this, and finally I understand it

  • christopher welsh

    christopher welsh

    8 օր առաջ

    Years ago, I did once flip a tennis racket without it making that 1/2 turn. Once.

  • diecast jam

    diecast jam

    8 օր առաջ

    It could be called the remote control effect too. When I sit in bed watching TV I have a habit of flipping the remote control, and it always does this half rotation too, it's always intrigued me in a minor sort of way. I will try my best to not let it rotate by flipping it different ways, but no it still does the half rotation thing. Funny when I noticed it flipping the remote, I don't think it was that novel, I'm pretty sure it's something I have witnessed before in other things, probably the tennis racket.

  • cj valverde

    cj valverde

    8 օր առաջ

    This something stupid you would learn in school that has 0% help later in life

  • S Grim

    S Grim

    8 օր առաջ

    So earth, being partially liquid, will flip something approaching 90 degrees then.. (when the next ice-age puts enough ice-masses at the poles to force a flip towards the equator)

  • Jibran Saleem

    Jibran Saleem

    8 օր առաջ

    what if there was no disturbance at all in the intermediate axis as if it was spinning properly

  • Alex Ford

    Alex Ford

    8 օր առաջ

    Great video. I like intuitive answers rather than mathematic equations, etc., which I really do not trust regardless of how sophisticated their proofs. I love the intermediate, maximum moment and minimum moments of inertia. For some reason, this reminds me of Tesla, and I don't know why. AF

  • Thomas Kolb

    Thomas Kolb

    8 օր առաջ

    Hm, so this phenomenon is actually caused by the rotation not being perfectly aligned, but slightly bumped out of alignment. If the rotation was perfect (like mathematically perfect) it actually wouldn't happen. But in the real world, even the smallest (and I mean on a microscopic scale) misalignment will slowly accumulate and at some time (say, like after a million rotations) suddenly flip over to rotate yet another million rotations until the next flip... Interesting.

  • Justin Erickson

    Justin Erickson

    8 օր առաջ

    I learned two things that only bring on more questions. 1. Learned that spinning things in space are not necessarily stable. 2. Most people pronounce "centrifugal" force differently than this obviously very smart guy. Mind blown.

  • No Username

    No Username

    8 օր առաջ

    Is this why earth’s poles are moving?

  • Sergio Ontiveros

    Sergio Ontiveros

    8 օր առաջ

    Would it even matter if the earth flipped over? I mean would we even notice such an event? Or would the centrifugal force send anyone near the north and south pole flying into the sky? The reason i ask is because if i understand correctly, as the earth spins the surface can move at roughly 1600kmph and we dont seem to feel that, so if the earth suddenly flipped would we even notice it?

  • tiger12506

    tiger12506

    8 օր առաջ

    Fascinating. So now I understand those toy tops that flip over when you spin them, or my phone which spins ok, but then violently wobbles, or why I am forced to anticipate the tennis racket flip. Really good video.

  • Dick Hansen

    Dick Hansen

    8 օր առաջ

    Love the way he explained this. So easy to understand.

  • BOBXFILES2374a

    BOBXFILES2374a

    8 օր առաջ

    Thank you, Professor Proton!!

  • BOBXFILES2374a

    BOBXFILES2374a

    8 օր առաջ

    This video keeps coming up i the sidebar. Much more interesting than I expected. The math, however, is nothing but meaningless squiggles to me!

  • Ls Sl

    Ls Sl

    9 օր առաջ

    How does that work with earth spinning

  • Nick Naccarato

    Nick Naccarato

    9 օր առաջ

    This video terrified me for a hot minute

  • raulsgomes

    raulsgomes

    9 օր առաջ

    Earth isnt going to flip if nothing interfers with its axis of inertia. But if something with a very big mass passes by.....
    This is mass, but what about the change of the magnetosphere? Why does it happen?

  • Slim ben frej

    Slim ben frej

    9 օր առաջ

    In coran god tel . It s same day the sun rises in the west
    Think you god for this religion
    Dans le coran . Dieu dit . Que un jour la soleil se lève de l ouest
    Merci dieux pou cette religion .
    Peace for the humanity
    La paix pour l humanité.

  • federico casabona

    federico casabona

    9 օր առաջ

    @veritasium, if humans decided to finally build the famous space elevator, so tall that would exit the orbit of the earth, would this elevator dissipate energy and eventually turn earth like happened with Explorer 1?

  • Tungsten Kid

    Tungsten Kid

    9 օր առաջ

    Did he explain why the wingnut flipped or did i miss it?