The Bizarre Behavior of Rotating Bodies, Explained

  • Published on Sep 19, 2019
  • 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:
    Prof. Terry Tao's Math Overflow Explanation:
    The Twisting Tennis Racket
    Ashbaugh, M.S., Chicone, C.C. & Cushman, R.H. J Dyn Diff Equat (1991) 3: 67.
    Janibekov’s effect and the laws of mechanics
    Petrov, A.G. & Volodin, S.E. Dokl. Phys. (2013) 58: 349.
    Tumbling Asteroids
    Prave et al.
    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
    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 TVclip 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.

Comments • 10 333

  • Konrad Comrade
    Konrad Comrade 19 minutes ago

    so what if: what if the ice-caps on the poles of a hyp.planet are growing, due to rapid climate change. Could such a fast change of moment of inertia overwhelm the energy-dissipation of the viscous, fluid interior or of a fluid equatorial ocean?

  • Leo Stanton Towne
    Leo Stanton Towne 36 minutes ago

    If the earth were to flip over would we notice (other than by reference to the stars)?

  • Bizzaro World
    Bizzaro World 2 hours ago

    All of this to explain a wiggle???

  • Creepy ._. Creeper
    Creepy ._. Creeper 2 hours ago

    Doesn't it work on a spoon?

  • Nairda Charles
    Nairda Charles 3 hours ago

    I watched a girl twirking once, and she suddenly flipped ass over elbows. I thought she was just clumsy.

  • Clyde Kelvin and the Sinners.

    Hi there I find things like this fascinating. I made a little model with a molecular modeling kit that seems to have an odd stability when knocked over, it is a shape based upon the cuboctahedron. I was reading in Buzz Aldrin's book that this shape has interesting stability properties. I have a video of me knocking it over where it lands on one of the three outer weights whilst holding two thirds of the weight up in the air. I would love for you to tell me what you think is happening. If you look on my channel at the playlist labeled Things I do' The videos called Phfizzics Pah! and Physics Pah!
    I would love it if you would take a look and tell me what you think is causing it to have such stability, if you knock it too hard it falls over normally with two thirds of the outer weight down as it is only a plastic model. I hope you will take the time, thank you.

  • ke17h
    ke17h 3 hours ago

    well explained

  • --
    -- 5 hours ago

    Einstein supported Crustal Displacement Theory, but also added the dynamic of melting polar ice, and the impact such redistribution of mass could have on the Earth’s centrifugal forces. Einstein supported it to the extent he penned a rare foreword to “Earth’s Shifting Crust,” published in 1958 and authored by Charles Hapgood. Full text, included. Enjoy.

  • CASPER 12345
    CASPER 12345 5 hours ago

    Ouch..........this video made my head hurt 😫

  • Prateek Panwar
    Prateek Panwar 5 hours ago

    TVclip showed me this thumbnail 1000 thousand times before clicking it

  • magebox
    magebox 7 hours ago

    But what about out huge magnetic earth center? Is this why we have pole shift?

  • nunya bidnezus
    nunya bidnezus 9 hours ago

    how do you know earth spins about the axis of greatest moment of enertia? wheres the proof of that?

  • Flynn1179
    Flynn1179 14 hours ago

    Just a thought.. would the melting of the polar icecaps cause water and hence mass to move towards the equator in accordance with centrifugal forces, resulting in the current axis no longer being that with the largest moment of inertia and hence flip the planet? Or would it make it MORE stable?

  • izzzzzz6
    izzzzzz6 16 hours ago

    V sauce. You missed out on this one!

  • menchelke
    menchelke 18 hours ago

    So, can we say that the earth has never flipped, with life on it? I thought there was evidence that the poles have flipped, and, does the mass and size of the object determine at what point it flips?

  • D Travel
    D Travel 19 hours ago

    Our planet is not alone in the solar system race. So it will not spin. And security systems are asking to change your password every 3o days. Great video, by the way.

  • Shukai Zhang
    Shukai Zhang 20 hours ago

    when KE is dissipated due to movement of liquid, why cant the object simply rotate in a lower speed instead of rotating in the third axis

  • Gotsnakes305
    Gotsnakes305 21 hour ago

    Vortex of the universe..

  • Ty S
    Ty S 21 hour ago

    As cool as it is, it seem like something that wouldnt be over complicated to figure out.

  • degustibus
    degustibus 22 hours ago

    Fascinating video, thank you for all the work on it. Please don't mind a couple quibbles/questions. Perhaps you could do a presentation of the equinoxes and gyroscopes (any footage of gryoscopes in space?). In the horrible quake that caused the monster tsunami that hit Japan and Fukushima nuclear plant the force involved actually redistributed enough mass of the earth away from the center to ever so slightly, but detectably, speed the Earth's rotation and shorten the day. Now that was the 4th most power quake recorded with modern instruments, so one does have to wonder what are the plausible upper limits of geological events that could change the planet's motion. Quakes and volcanism are two obvious considerations, but then there is the possibility of a significant mass hitting our moon (increasing its mass or greatly decreasing it) or us directly. Thanks again.

  • David Ville
    David Ville 23 hours ago

    Coming form a computer graphics and 3D background, I find it annoying that they X,Y,Z axis are not colored Red, Green, Blue

  • Mike J
    Mike J 23 hours ago +1

    But the earth is covered in water and filled with liquid magma!?! What if it sloshes about?

  • workski2
    workski2 23 hours ago

    So.......if you pile up two miles of ice over the northern continents during an ice age, how does that change the distribution of weight and does that have the potential of causing the Earth’s crust to slide over the mantle like the skin of an orange sliding over the meat? Well, Charles Hapgood and some dude named Albert Einstein at least thought it was indeed possible. Perhaps that aspect should be looked at more carefully. Food for thought.

  • Billy Sooner
    Billy Sooner Day ago

    For none nerds. Think of the spinning wing nut as an uneven teeter-toter (fulcrum-crowbar) on another, invisible teeter-toter... Capetch?

  • BrokenWishbone
    BrokenWishbone Day ago

    I'd never give all my passwords to any one group, program,company or app of any kind. You're literally turning multiple low value targets into one higher value target.

  • Anas Alamri
    Anas Alamri Day ago

    As Muslims, we do believe that one day, the sun will rise from the west.

  • Shafie Mukhre
    Shafie Mukhre Day ago

    this is such a good explanation, shows that physics has the explanation of all the bizzare things in life

  • ted kaczynski
    ted kaczynski Day ago

    oh, and work on the english pronunciation of 'centrifugal.'

  • ted kaczynski
    ted kaczynski Day ago

    best mathematician alive??

  • Daedalus Young
    Daedalus Young Day ago +2

    I discovered this effect when I dropped a peanut butter sandwich.

  • Rafael Hidalgo
    Rafael Hidalgo Day ago

    So... If I got it right... Is it like this that a large enough meteor can cause a deluge?

  • Ken James Jr
    Ken James Jr Day ago

    11:01 No. The Earth is static and cannot be moved.

  • Antonio Machado
    Antonio Machado Day ago

    Would this phenomenon occur when an object gets spun about it's axis wiyh minimum moment of inertia? Since "the big masses" could be tilted to create the same effect. Why (not) ?

  • Ed Fladung Sr.
    Ed Fladung Sr. Day ago

    I have one problem with the final conclusion. We know, that the center of the earth is a liquid, molten rock. So if the earth contains a liquid, why wouldn't it act like the bottle containing liquid spinning under 0 G's?

  • Rick Scheller
    Rick Scheller Day ago

    I discovered this affect in about 1954 as an 8 year old boy flipping a claw hammer.

  • Manas Bakasov
    Manas Bakasov Day ago

    Hi I like veritasum explanations. I am actually frightened about chinas water dam. It is so huge that can cause so many changes to earh. . Can veritasum make research about this dam. Maybe pyramids were buil to put some arrangement to the earth rotation?

  • Marian Paraschiv
    Marian Paraschiv Day ago +1

    i'm not high enough to watch this. i'll come back in a minute.

    • BW Acuff
      BW Acuff 22 hours ago

      "i'll come back in a minute."
      .................................................nine hours later, Everyone's still waiting for Marian.....who's probably passed out on the couch, with bong water spilled all over the room and half the weed out of the baggy and fallen between the cushions.

      Way to go Marian.......we're just going to watch this without you.

  • Adotsom Adotsom
    Adotsom Adotsom Day ago

    Only one problem with this bogus theory, It's Pseudo Science! The earth does not spin. Re: The demonstrable Michaelson Morley experiment. Oh and btw, the earth is not a globe either. Simply try and prove it and see for yourself. OR DON'T?

  • Hu Arwe
    Hu Arwe Day ago

    Technically no one has been to space. Interesting none the less.

    • Hu Arwe
      Hu Arwe 3 hours ago

      @Pedro Oliveira I believe it's been discovered that the moon is in our atmosphere.

    • Pedro Oliveira
      Pedro Oliveira 4 hours ago +1

      Hu Arwe ?

  • Nofer Trunions
    Nofer Trunions Day ago

    Because it is NOT POSSIBLE to make an object where the MOI between any pair of axes is EQUAL due to MANUFACTURING TOLERANCES.
    EXAMPLE: MOI of 1.00002, 1.00001, and 1.00000 for a precision "sphere."
    HYPOTHESIS: Is it that every object does behave this way, it's just that it takes so long for the flip to occur that it is never realized - or observed but considered of little interest since probably due to some weak interaction with the rotation of the earth and Coriolis or some such?

  • Blue Eyes White Teddy

    So if i understand it correctly the only reason why this effect happens is because the things never spin perfectly around the axis?

  • Justin Fuhri
    Justin Fuhri Day ago

    Does/can this happen to planets

    MAJESTIC1 Day ago

    Jesus it was unbalanced! LOL

  • Chris Vargas
    Chris Vargas Day ago

    The theory is based off quantifiable physics but in actuality the earth experienced 1000's of pole shifts in its 5.4 billion years of of existence. Its written in the stone.

  • C R Sant
    C R Sant Day ago

    Veritasium: Thanks for this video. However go to see section 142 Quote: " In this time they said that the sun had moved four times from his accustomed place of rising, and where he now sets he had thence twice had his rising, and in the place from whence he now rises he had twice had his setting;"
    Maybe Profs Terry Tao can look into this.

  • The Impaler
    The Impaler Day ago +3

    When I was 17yrs old, I verified this principle using a 1969 Dodge Charger, high speed, and an inclined embankment.

  • lilmacc 19
    lilmacc 19 Day ago

    Ok wait, say that one more time...?

  • Rafael Pelayo
    Rafael Pelayo Day ago

    Do not try to throw the tennis racket without flipping, that's impossible. Instead, only try to realize the truth... there is no tennis racket. Then you'll see that it is not the racket that flips, it is only yourself.

  • Brett Dawson
    Brett Dawson 2 days ago

    The Russians have Dzhanibekov but we have negroes!!

  • Scott McCollum
    Scott McCollum 2 days ago

    Besides having a concern for the earth flipping over, I would bet that the real secrecy the Soviets had about this phenomenon was that if they could understand it, then they could weaponize it somehow. So if we didn't pay attention to this behavior or give it consideration, then we wouldn't also be trying to understand the behavior of the "spinning flip". Build a weapon with behavior we don't understand, and they would have it first. That was their ongoing passion.

  • Tito151
    Tito151 2 days ago

    I know it's your sponsor, but LastPass is a terribly overpriced service ever since they were bought out by LogMeIn. BitWarden is a MUCH better service.

  • ومضات من نور

    The movement of the key due to its impact by double forces, the first gravitational force of the Earth and the second gravitational force free of space and thus see this effect clearly

  • Cuthbert Milligen
    Cuthbert Milligen 2 days ago

    Sorry, but you did not explain why the wingnut rotated about its longitudinal axis for a stable amount of time then 'suddenly' flipped. I learnt about the precession phenomenon in university classical mechanics (Euler's Equations? I forget...) But that was continuous, not discrete. Please explain further...

  • Moth Man
    Moth Man 2 days ago

    DOES this explain global walming?

  • Raivo
    Raivo 2 days ago

    Did not Victor Shauberger try to explain the same forces to us? Tornado in a tea cup?

  • bi to
    bi to 2 days ago +1

    eventually the Earth is going to flip, as the prophecy of Mohamed PBUH

  • Chris Harrison
    Chris Harrison 2 days ago +1

    The real flaw in this video is at the very end - "with LastPass you never have to remember a password ever again".
    "Honey, what's our password into LastPass?"
    "I forgot"

  • St Wayne
    St Wayne 2 days ago

    I have witnessed this before, but it never occurred to me to get excited about it as I assumed it to be just "one of those things." As for why I thought this, you can thank my dad. He always told me that if I thought about it, that it was for sure that someone much smarter than I has already figured it out. And he was right. Question: could this be why UFO's start to wobble, and then crash?

  • Harvey Dude-o
    Harvey Dude-o 2 days ago

    So what effect is there to Earths spin/kinetic energy due too all the oil being pulled out!

  • Oliver Von arx
    Oliver Von arx 2 days ago

    So utterly fascinating!!! 😯🤯👌