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The Turntable Paradox


Comments • 3 392

  • Steve Mould
    Steve Mould  2 months ago +1605

    I can't believe I didn't make a "how the turntables" joke. That's why I love the comments section!
    Here's a paper with the calculations: m2.askthephysicist.com/Weltner.pdf Note that equations 18 and 19 should have R² terms. That threw me off for longer than I care to admit!

    • joao gomes
      joao gomes Month ago

      Well well well…

    • Preceyese Seyeght
      Preceyese Seyeght Month ago

      Your turntable just hypnotized me, call me Poolboy !!

    • D14
      D14 Month ago


    • A Journey Saved
      A Journey Saved Month ago

      What happens when you change the surface texture. Something, course, or smoother?

    • Mudfossil University
      Mudfossil University Month ago

      Slow it down to .25 and see the TAPE causes the ball to change spin. Lets talk about Fusion??? roger@mudfossils.com

  • Weeeeems
    Weeeeems 2 months ago +5993

    I'm gonna need a 2-dimensional, transparent, liquid filled representation of this.

    • Mihail Milev
      Mihail Milev 11 days ago

      @SAJOWE wym lol

    • robert s
      robert s 28 days ago

      @SAJOWE expectation: ball will fly off. Reality: ball does not fly off.

    • SAJOWE
      SAJOWE 28 days ago

      @robert s hum??

    • robert s
      robert s 29 days ago

      @SAJOWE a dome shape is a hemisphere- at no point was a hemisphere placed on the turntable. If one was placed on the turntable on it's flat base, it would have slid off immediately like the coin. the dome, or firmament is a part of FE because FEers can not understand why air does not get sucked off into the vacuum. The reason a dome is not needed is air is matter, matter has weight. It is held to the earth by gravity (or density if you like). That and vacuums don't suck. Our household 'vacuum cleaners' are not vacuums.

    • SAJOWE
      SAJOWE 29 days ago

      @robert s flat earth theory is like a dome shape

  • Nick Gisburne
    Nick Gisburne Month ago +370

    Watching this video almost 40 years after I dropped out of taking Physics and Maths for A-level, I'm glad I did. The overlying description of what's happening is utterly fascinating, but the calculus, the physics, the number-crunching... it was never going to be for me. I absolutely LOVE the passion you and others have for such things, because I have my own 'things' which give me joy. Glad to be a viewer, amazed to catch of a glimpse of something described in a way I can understand it, knowing that you can do the maths and the physics and I don't have to!

    • Edward Slaughter
      Edward Slaughter Month ago

      @occupyallthethings Why's that? I imagine it pays decently enough. And you don't have to do much heavy lifting or anything. Why the regret?

    • Draven's Cringe Gaming
      Draven's Cringe Gaming Month ago

      @nervousnotebooks science isn't about the money. And if you discover something new, the science community will accept it if it's true regardless how you found it or your qualifications.

    • nervousnotebooks
      nervousnotebooks Month ago

      @Draven's Cringe Gaming That should hold up well on a resume.

    • Draven's Cringe Gaming
      Draven's Cringe Gaming Month ago

      @nervousnotebooks you literally don't. Human interpretation is science. Some of the most ground breaking discoveries were made by ingraduates.
      You don't need college to Google and cognize relevant math formulas, and to look to the stars yourself. See if you'll find anything that'll change school curriculum. Little kids can be scientists (literally). It's the easiest thing to do. And it's hard to think of anything without using the scientific method.

    • nervousnotebooks
      nervousnotebooks Month ago

      @Draven's Cringe Gaming You need to go to college to be a scientist dummy.

  • Eugene Saint
    Eugene Saint Month ago +150

    Wow, this takes me back to the 50;s. We had a record player that didn't work (the audio didn't) but the turntable would spin. We'd put on a 33 LP and put a marble on it. I observed the same results as you did but had no understanding of the physics/math involved. Thanks for the excellent explanation,
    BTW, we would also roll up a paper cone, stick a straight pin through the pointy end, and hold that on a record to listen to our tunes. Way cool.
    Just sane... :^) Saint

    • Matthew M. S., CFP
      Matthew M. S., CFP Month ago

      @Eugene Saint 🤷🏼‍♂️

    • Eugene Saint
      Eugene Saint Month ago +1

      @Matthew M. S., CFP Trust me, Matthew...drugs are not the answer.

    • Matthew M. S., CFP
      Matthew M. S., CFP Month ago

      Record players didn’t exist in the 1950s

    • HexagonalLemon618
      HexagonalLemon618 Month ago

      wtf are you, 90?

    • James Sn
      James Sn Month ago +1

      My little sister and I used to use an empty dog biscuit box and a needle to listen. 😀

  • Harten33
    Harten33 Month ago +3

    Hi Steve, there's lots of fascinating ideas here that would be cool to explore. For example, if the spinning surface was curved like a Euler's disk, how might the motion differ compared to that of the flat or convex surfaces? Here you present flat, and earth is our convex. This harkens back to your "this should slip off but it doesn't" video with spinning concave and convex surfaces and a spinning band. Love the videos and making us foster unique concept connections!

  • Akumuvirus
    Akumuvirus Month ago +58

    I'm so glad you mentioned something about coriolis. That's kinda where my mind went watching the ball go from closer and further to the point of rotation.

    • Akumuvirus
      Akumuvirus Month ago +4

      @Dustin Kirk right about the second part... But the moon does rotate on its axis. Just rotates once a month. Tidal locked with earth and all.

    • Akumuvirus
      Akumuvirus Month ago

      @Feeding Ravens idk... Remember, the center of orbit between moon and earth isn't the center of earth.. so their orbit is a relationship between the two. The reason it's tidal locked with earth is also that reason.
      Adding friction to rotating bodies it completely different than orbital mechanics. As I know of. That ball is experiencing different tangential speeds as it moves closer and further away from the axis. Orbits do have a sling shot kinda effect. But I see that different than this. But I could be wrong.

    • Akumuvirus
      Akumuvirus Month ago

      @truong tran alrighty then

    • truong tran
      truong tran Month ago


    • Dustin Kirk
      Dustin Kirk Month ago +2

      @Feeding Ravens except, the moon isn't rotating on its own axis is it? Planetary satellites orbit their hosts regardless of their own spins. Hmm...

  • Kayasper
    Kayasper Month ago +6

    Fascinating stuff, very well framed in images and clearly explained. Thanks for your video!

  • TINALisa
    TINALisa Month ago +11

    You keep fascinating us as well as entertaining. Thank you for that Steve. And congrats to those, who choose you to promote "THELÄND". Perfect choice. I am from Germany and have seen the clip before. And yes, I believe for tech or science aspiring people, that is a perfect place to go to.

    • Norsilca
      Norsilca 22 days ago +1

      Yeah I loved that his sponsor was a state of Germany!

  • Yass Fuentes
    Yass Fuentes Month ago +18

    As a physicist, this video is pure joy. Thanks for making this video available, Steve ❤️

  • Xvr_Demi_Trees
    Xvr_Demi_Trees Month ago +44

    As a 2,055 year old Carpenter it amazes me that after all these years, we still love playing with balls!

  • Shaharyar Haider
    Shaharyar Haider Month ago +5

    I'm glad to have found you... purely because your videos make me remember my curiosity as a kid. The things you lose when life takes over! Great going!!

  • Juan Ritz
    Juan Ritz Month ago +9

    It would be interesting if you tried the same experiment but with a fabric turntable, to potentially give some cheap insight into how the fabric of spacetime may behave in this spheres in a whirlpool scenario.

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago

      Thanks for 👍☝ liking, watching and commenting on my video's
      Expect more upload soon 🔜
      I really appreciate your effort ✅
      You have been selected among the Xmas giveaway🎉🎁
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  • Beka Emery
    Beka Emery Month ago +3

    This was such an interesting video. I don't remember any of my alevel physics but I do love stuff like this

  • M Pag
    M Pag Month ago +2

    it would be interesting to see the motion of the ball from a relative point of view with a 360 camera mounted in the centre of the turn table.

  • TimeBucks
    TimeBucks 2 months ago +632

    Your videos are simply awesome

  • TinSandwichUK
    TinSandwichUK Month ago

    As the ball gets up to maximum speed, doesn't it take up the inertia properties of a gyroscope especially when you nudge it of axis?

  • John Perkins
    John Perkins 2 months ago

    I would like to see , instead of a ball with the mass concentrated on the outer surface (hollow sphere), a ball with the mass concentrated in the center (large ping pong ball with small metal ball suspended in the center).

  • Kurt Lenser
    Kurt Lenser 2 months ago +1

    Would this work the same on a rotating sphere instead of a rotating disk? Give that the ball was in the center of the sphere where gravity isn't.... how does gravity work in that situation?

  • Bob Adkins
    Bob Adkins Month ago +8

    I imagine the formula for the motion of a slightly elliptical ball would be terrifying.

  • Sam Prince
    Sam Prince Month ago +1

    So going the other way you could work out something about the internal geometry of a ball by spinning it on a turntable, e.g. if it had internal imperfections maybe

  • Legin Sreep
    Legin Sreep Month ago +2

    Reminds me of scientists spinning things in the space station. When things spin in zero gravity they flip every certain number of revolutions. Almost exactly like the pool ball. You are right about gyroscopes, basically the same thing.

    • Nemo1k
      Nemo1k Month ago +1

      You are thinking about the Dzhanibekov Effect: clip-share.net/video/L2o9eBl_Gzw/video.html There are several videos of this effect, including the original footage of Dzhanibekov discovering this effect.

  • Cameron Hoy
    Cameron Hoy Month ago

    I had an amazing realisation about this and have a completely new way of looking at it!
    This situation is perfectly analogous to the case of cyclotron motion in a magnetic field. The rotating tabletop takes the place of the vector potential and would yield an analogous vertical magnetic field. The ball then is like a charged particle.

  • dh
    dh Month ago

    the hollow and solid, ball, bit would be interesting to see how it would go with multi corded ball, one with a light no weight out side, and a really heavy core, a mini earth as it where? and what number would come out of the math.

  • Frank Humphreys
    Frank Humphreys Month ago +1

    Yes, spinny things! This one is actually one of the easier spinny paradoxes to wrap your noodle around

  • Arthur Wagar
    Arthur Wagar Month ago

    That was interesting. Thanks for sharing. Is there a practical use other than gyroscopes?gyroscope?
    Great comments.

  • Mohamed Mouh
    Mohamed Mouh 2 months ago

    thank you so much. you always come with a beautiful examples and experiments of boring mechanical classe

  • D0S81
    D0S81 Month ago

    would the ball ever fall off if the turnatble was slightly curved like a shallow bowl? also, does this have any applications?

  • William Burroughs
    William Burroughs Month ago +1

    I have noticed a wobble in the turntable. Did you try to minimize that as well?

  • Karmasu L
    Karmasu L Month ago

    After watching half the video my takeaway is this:
    I get the basic idea of whats going on and why the ball is going around in circles.
    But the explanation is making my head spin like the table.

  • Much
    Much Month ago +2

    I saw that freeze frame of the turn table with a crooked line on it and my brain immediately went "ah yes, rolling shutter" and "let's see that line straighten out as it gets closer to horizontal". It's crazy how much arbitrary knowledge I collected while watching those damn internet science channels.

    • Rick the Swift
      Rick the Swift Month ago

      That's incredible, I remember those videos too, but couldn't come up with the term, "rolling shutter". Thanks for reminding me, that may have drove me a little crazy for a while.

  • Vivek Ramanan
    Vivek Ramanan Month ago

    It's interesting how it works, but why does the ball spiral outward until it falls off rather than just keep rotating in a circular orbit

  • Luke James
    Luke James Month ago +2

    What if you gave the turn table one extent-ended end with the entire turn table still 100% stable with the center. So the center of the circle is the same balance point, but there is an extended piece outside of the uniform circle spinning along with it.

    • Luke James
      Luke James Month ago

      Just one half of the circle to start with is extended but evenly balanced with the center point

  • Steve Rose
    Steve Rose Month ago

    You can see the ball rolling faster on the outer ranges of the turntable, and slower in the inner ranges. Pretty cool.

  • So anyways I’ll started blasting

    Watching this after taking physics and this actually makes so much sense. This is actually very similar to rolling an object down a ramp, and that’s where the 7/2 ratio comes from The moment of inertia times the lever arm.

  • Reza Aghideh
    Reza Aghideh Month ago

    Thank you for the informative Video. I'm still wondering how can you explain this in terms of Centrifugal force?

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago

      Thanks for 👍☝ liking, watching and commenting on my video's
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      I really appreciate your effort ✅
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  • MrSkypelessons
    MrSkypelessons 2 months ago +10

    I have always found spinning things and reference frames fascinating, and as an English teacher, I find it fascinating that these very real forces are referred to as fictitious forces and pseudo forces and imaginary forces. I suppose it is to separate them from contact forces and EM forces, but it does seem odd to me. I read that even gravity is a fictitious force. If there's one thing we can be certain of, it's the force sticking our bodies to the floor. Very interesting video and very clearly explained. Thanks.

    • Robert Pruitt
      Robert Pruitt Month ago +1

      And yes, gravity is a pseudo force, or it might be.
      Hard to say I suppose, but Einstein thought so.
      From scientific America
      "General relativity is his theory of gravity, and gravity is certainly the paradigmatic example of a "real" force. The cornerstone of Einstein's theory, however, is the proposition that gravity is itself a fictitious force (or, rather, that it is indistinguishable from a fictitious force)."

    • Robert Pruitt
      Robert Pruitt Month ago +1

      Pseudo forces are indeed real.
      From Texas A&M university.
      "The centrifugal force is very real if you are in a rotating reference frame. It causes objects in a rotating frame of reference to accelerate away from the center of rotation. Washing machines, uranium enrichment centrifuges, and biology lab centrifuges all depend on the reality of the centrifugal force . However, the centrifugal force is an inertial force, meaning that it is caused by the motion of the frame of reference itself and not by any external force. If I stand on the ground and watch children spinning on a playground toy then in my stationary frame of reference their outward acceleration is caused simply by their inertia. In my frame, which is external to the rotating frame, there is no centrifugal force at work. But in the rotating frame of reference of the children, there is a centrifugal force."

    • MrSkypelessons
      MrSkypelessons 2 months ago +2

      @Josh Gordon 'We would not label gravity as a fictitious force' - who is we?
      'This led Albert Einstein to wonder whether gravity was a fictitious force as well. He noted that a freefalling observer in a closed box would not be able to detect the force of gravity; hence, freefalling reference frames are equivalent to an inertial reference frame (the equivalence principle). Following up on this insight, Einstein formulated a theory with gravity as a fictitious force and attributed the apparent acceleration of gravity to the curvature of spacetime. This idea underlies Einstein's theory of general relativity.'

    • Josh Gordon
      Josh Gordon 2 months ago +1

      @MrSkypelessons don't conflate the force that might injure someone (e.g. the contact force as they slam into the door of the car) with the perceived force that attracted them towards the door in the first place.
      We would not label gravity as a fictitious force. However, yes, in a very thereotical sense gravity is not a force like a push or a pull. However this has to do with General Relativity and advanced ideas in physics. For your (and my) every day life experiences, gravity is very much a force that pulls massive object towards one another.

    • John Thompson
      John Thompson 2 months ago +1

      The difference between fundamental and fictitious forces is that if you change your perspective on a fictitious force, you can make it go away (in the sense that they’re no longer terms in any equation), and things like electromagnetism will exist in every reference frame.
      From an English major point of view - picture something like Fight Club. Tyler Durden was very real for some of the characters’ perspectives and even produced real outcomes for them, but was still not real.

  • Siggy Retburns
    Siggy Retburns Month ago

    Im pretty sure googles spying on me. I was watching a video of some guy spinning a heavy top. It was on a flat surface, bit like tops do, it eventually made its way off the edge. So he made the surface slightly concave. And I was thinking thats going to make it worse. I used to think making it concave would keep it towards the center. But now i dont think it does. If it was convex, it would stay closer to the center.
    Kinda like a skateboard on a 6ft diameter pipe in contrast to being in the pipe. You would think that if you are in the pipe, the board would be drawn towards the center. And if on top, you tend to roll off. Its the opposite. The way a skateboard steers is in reaction to whichever way the rider leans. So if youre on top, the board steers to the center because the board turns in the direction of whichever side has the front and back wheels closer together and closer to the board. The side you start to roll off of has the wheels farthest apart and from the board, not because youre leaning. But because the board changed its perspective the same way as if you were leaning. Inside the pipe is the opposite. Trying to stay centered is harder. The more it veers off the more itsforced to veer off.

  • AlexSnchz
    AlexSnchz Month ago

    can you test on a flexible table?
    similar to what’s used to explain gravity in universe

  • Richie5903
    Richie5903 Month ago +2

    Somewhere in the back of my mind I seemed to remember something about the moons around planets having orbital resonances with each other which seemed remarkably similar to the ball and table.
    Example IO has a 4 to 1 ratio with Ganymede.
    I know it's not caused by the same thing but still amazing

    • U.V. S.
      U.V. S. Month ago

      This is much more amazing due to the fact that there are these weird fixed ratios 7:2 (!) and 5:2. The orbital resonances are much more arbitrary

  • Darrin Lalla
    Darrin Lalla Month ago +2

    This was so nicely presented. Great video.

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago

      Thanks for 👍☝ liking, watching and commenting on my video's
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  • In the Public Domain

    Loved your video. Where can we buy an inexpensive turntable? Would an old record player work, or would it be a problem because of the metal rod in the center of the recordplayer???

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago

      Thanks for 👍☝ liking, watching and commenting on my video's
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  • Tom Oman
    Tom Oman Month ago +1

    You’ve done a great job of contributing something for all of our benefit.

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago

      Thanks for 👍☝ liking, watching and commenting on my video's
      Expect more upload soon 🔜
      I really appreciate your effort ✅
      You have been selected among the Xmas giveaway🎉🎁
      Quickly send a direct message to me above ☝☝☝..

  • Richi42
    Richi42 Month ago +1

    Le gars qui a eu l'idée de faire tourner sa crêpière n'a sûrement pas mis tout le rhum dans la pate a crêpes 🤔🍺 belle expérience/démonstration 👍🏼

  • Jack ThaKlown
    Jack ThaKlown Month ago

    I wonder how the ball would act if it was spinning in the same direction as the turntable before letting go?

    HELIFY NOE Month ago

    And, if you stop the spinning table, and allow the mini ball to sit still anywhere on the table, both are still moving with the exact same magnitude of motion as they were during any of the previous experiments performed. The "Absolute" motion vector for the ball (and the table), is vector "c". This motion vector can not be changed, other than change the direction in space-time, of which it is pointing. Now if you analyze the outcome of this 4D motion vector that is applied to everything, you end up with the following equations. The Lorentz-Fitzgerald length contraction equation, the Time dilation equation, the Velocity addition equations, and the Lorentz transformation equations.

  • Phillip Paul Watkins

    Fun Fact: this trick was famously used by The Steve Miller Band for their "Abracadabra" music video, using a spinning cymbal for the turntable.

  • Space_Debris
    Space_Debris Month ago

    It's work making an argument that _'the turntable'_ isn't well represented in explaining the accurate workings of the universe! I appreciate Steve Mould's excellent efforts in helping me make the innards of my head spin grinning! 😀 Thank you Sir!

    • piru talreja
      piru talreja Month ago

      hey can you provide me its explanation

  • Terry
    Terry Month ago +1

    Gosh how I missed science class, this was delightfully entertaining, you're doing an awesome job, thank you for it!
    liked subscribed and commented :)

  • RECK Adventures
    RECK Adventures Month ago +1

    This is super fascinating! I wonder how we can take advantage of this 🤔

  • Bonkoodle
    Bonkoodle Month ago

    Isn't whether a ball is solid or hollow dependent on what percentage of it is hollow? Surely it's a continuous spectrum dependent on how much of the inside it missing.
    Would the ratio be somewhere between 7:2 and 5:2 depending on what proportion is removed?

  • Ben Harvey
    Ben Harvey Month ago

    Your 'paradox' videos are my favourite ones, Steve

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago

      Thanks for 👍☝ liking, watching and commenting on my video's
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      I really appreciate your effort ✅
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  • anamul pathan
    anamul pathan Month ago

    Your videos are awesome and scientific

  • Олег Крым
    Олег Крым Month ago +1

    Добрый день Стив, я когда начал смотреть модель физического опыта вашего почему то подумал про гирокомпас которые были на кораблях ,раньше были два типа Спэрри и Анштюц , к сожалению я не знаю английский язык но видео посмотрел до конца ,я в школе очень любил физику и объяснение её законов

  • Tsuyochie
    Tsuyochie 2 months ago +1

    as someone from Baden-Württemberg the new name "The Länd" is laughable and embarrassing, not to mention the whole Cyber Valley thing.

  • Kevin Elyard
    Kevin Elyard 2 months ago

    The part with tilting the turntable and the gyro makes me think about the helicopter series on Smarter Every Day where they talk about gyroscopic precession. You can feel this force with a fidget spinner if you spin it up then tilt it back and forth.
    Link to the episode:
    Skip to 1:07

  • Eclectician
    Eclectician Month ago +1

    2:14 "The ball only knows about that one point of contact."
    Steve: "Excuse me, Miss, where might the sentient billiards balls be located? I want to trick my viewers."
    Miss: "Straight down this aisle next to the crystal balls and the Magic Eight Balls."
    Steve: "Of course! How silly of me not to have realized that!

  • illegitimate0
    illegitimate0 Month ago

    This feels like one of the problems I would have gotten wrong on my dynamics class in school.

  • Jim Mulholland
    Jim Mulholland Month ago

    The fact that Earth doesn't get flung out of the solar system, we're the ball, the sun is the center of the turntable, and the turntable is our solar system? I'd like to see a demonstration with more than 1 ball on the turntable. Different size balls, different distances from the center, opposite "sides" of the turntable.

  • EdP IV
    EdP IV Month ago

    What happened was exactly what I thought would happen. I only watch the beginning of the video because I thought the ball was going to stay on the turn table.

  • Alex_Z
    Alex_Z Month ago +1

    Physics is just amazing. I wish I would studying more in highschool

  • Thomas Shaddox
    Thomas Shaddox 2 months ago +413

    Would be cool to mount the top-down camera to the turntable so it rotates with it. When you mentioned the non-inertial reference frame stuff I was hoping to see the ball’s path from that reference frame.

      REMIND ME SOMETIME 2 months ago

      Or better yet attach a gopro to the ball

    • SpydersByte
      SpydersByte 2 months ago

      @MrDaraghkinch haha my initial thought as well :D that was a fun toy

    • ivan D
      ivan D 2 months ago +1

      @Thomas, here you can see something similar - clip-share.net/video/OAs_1ysRHW0/video.html

    • BibiBosh
      BibiBosh 2 months ago +1

      I think we are missing alot of footage. We need part 2 despite already having part 1.
      We need more videos like this !!!!

    • Josias Lourenço
      Josias Lourenço 2 months ago +1

      12:14 Make every effort to live in peace with all men and to be holy; without holiness no one will see the Lord.
      3:19 Repent, then, and turn to God, so that your sins may be wiped out, that times of refreshing may come from the Lord,
      James 2:24,26
      Ye see then how that by works a man is justified, and not by faith only. For as the body without the spirit is dead, so faith without works is dead also.

  • Keith Lyons
    Keith Lyons Month ago

    What would happen if the ball was spinning in one spot and you suddenly stopped the turntable by grabbing it. Would the ball travel at a tangent of 60 degrees in a straight line off the turntable? Please try this and let me know. I am sure this is what would happen.

  • erg0centric
    erg0centric Month ago

    Tilted turntable is similar to gyroscopic precession of a helicopter rotor disk. I would imagine this is well documented in helicopter control systems.

  • Michael Purcell
    Michael Purcell Month ago

    Try adding a magnet at the center of the table and one in the center of the ball. Hence, the creation of gravity vs inertia mimicking the movement of solar systems and the universe 😉

  • Siggy Retburns
    Siggy Retburns Month ago

    Hokey smokes, dude. I'm gonna be trippin out on that for a few years. I thought for sure the ball would just roll on the table, slightly getting behind while all the time rolling out to the edge.

  • mattastic wild life

    @SteveMould what happens if you use a magnetic ball?? Maybe on a spinning copper turn table??

  • Pengurrito
    Pengurrito Month ago +1

    I wonder what happens if the disc was slightly concave to counter the "slippage" effect where it eventually rolls off the table.

    • Jose Peixoto
      Jose Peixoto Month ago

      Try convex also: pulleys are CONVEX to prevent the belts (leather belts in the old days) from flying off.

    GOKUL CHANDRAN Month ago

    very informative and interesting

  • Tony Johnson
    Tony Johnson Month ago

    That British humor gets me every time (@55 secs) those gigantic hands with that pool ball 😆

  • Jared Arnell
    Jared Arnell 2 months ago +309

    Love the video! Wanted to say, I did my master's thesis on how students conceptualize the Coriolis force, and I'd recommend avoiding terms like "fictitious" when describing it. It gives students the impression that it's 'made up' or 'doesn't exist', which conflicts with their bodily perceptions which have experienced the force first-hand. Also, it makes it sound like it shouldn't be trusted (let alone, used), rather than emphasizing how helpful (and necessary) the Coriolis force is when viewing things from a non-inertial frame. Personally, I try to call it an "apparent" force, because it 'appears' when you change your perspective to the non-inertial frame. It's all about clarifying the contexts in which the Coriolis force is productive.

    • Jimmy2Hertz
      Jimmy2Hertz 2 months ago

      @scose Emergent at it's core means consequence/resultant, therefore it's just and outcome of interaction rather than a core property, no recursion or complication required.

    • surfcello
      surfcello 2 months ago +1

      @Steve Mould "Apparent" is also inline with the "apparent wind" that sailors talk about, a term which you may also have used in your video discussing sailing downwind faster than the wind. So that would be consistent. (Although, in the case of sailing, the boat usually _is_ an inertial frame of reference (for practical purposes), and so one might not want to use the same word after all.)
      Come to think of it, Newton's force of gravity is an "apparent" force, too, and we are in a non-inertial frame here on earth. But that doesn't help anyone who isn't interested in relativistic phenomena.

    • Tony Splodge
      Tony Splodge 2 months ago

      @ReverseEngineered Good point. Optics makes use of Real and Virtual for images but I prefer Apparent (from my electrical engineering course, all those decades ago)

    • Ryan McCampbell
      Ryan McCampbell 2 months ago

      @Steve Jones The important thing in science is whether you can use a model to produce useful predictions. As long as you understand the assumptions and limitations, you can use "fictitious" forces to make useful and accurate calculations, so there's not much use being pedantic over definitions. From the point of view of a person on a roundabout, the ball will absolutely appear to accelerate away from them, and using centrifugal force simplifies the picture so you don't have to transform your frame of reference.

    • Ryan McCampbell
      Ryan McCampbell 2 months ago

      @Patrick Jordan Gravity and centrifugal force are "forces" only depending on what model of the world you use. Physics is all models; if you really dig into quantum mechanics then the idea of forces themself get pretty murky, when you really have probabilistic exchanges of virtual photons between charged particles (or something like that). But that doesn't mean it's not useful or valid to simplify those interactions into a "normal force" between two surfaces in contact, for example. By the same reasoning we simplify the picture of gravity by treating it as a force so we don't have have to deal with time dilation and whatnot, and we simplify descriptions of rotating frames by treating inertia as a force so we don't have to transform everything into an inertial frame.

  • OneAwesomeGamer007
    OneAwesomeGamer007 Month ago

    Have you tried a hollow ball with a liquid inside?

  • Shardul Swarup
    Shardul Swarup Month ago

    The answer is Moment of Inertia (I) =MK^2
    Where K is radius of gyration.
    Class 12 CBSE

  • Erik Da'Raven
    Erik Da'Raven Month ago

    Have you tried a magnetic table and a steal ball?

  • Jakub Kochaniecki
    Jakub Kochaniecki Month ago

    I love calculating the mass of the balls

  • Jeremy Solan
    Jeremy Solan Month ago

    the yellow vector arrow should really be green, since it represents the sum of the other two. made that a bit confusing, half of my brain wanted to see the green arrow as the sum of the yellow and blue

  • SankyP Vids
    SankyP Vids Month ago

    Physics is magic, never fails to amaze me!

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago +1

      Thanks for 👍☝ liking, watching and commenting on my video's
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  • Ori Ray Kai
    Ori Ray Kai Month ago

    Interesting how it nutated around in a little circle, independent of the different speeds of the turntable at each point. The spin of the ball exactly cancels the centripetal force of the table spin. I wonder if there's a geometric proof of that?

  • DHH L
    DHH L Month ago

    Can this mechanism be used on high speed trains? As trains have to find ways to cancel out centrifugal force when then are turning a sharp corner.

  • Chrismofer
    Chrismofer 2 months ago +556

    This helps me visualize how a Lagrangian orbit can be somewhat stable despite all the forces being apparently unblanced.

    • Chrismofer
      Chrismofer Month ago

      @Hidden Object it's a real shame how many people can't handle a basic technical discussion and have to invoke god to feel like they contributed.

    • Hidden Object
      Hidden Object Month ago +1

      @Tlaloc_Temporal yeah I figured something like that, its just why though? There's really no benefit for such things. I'll never understand such thinking lol

    • Tlaloc_Temporal
      Tlaloc_Temporal Month ago +1

      @Hidden Object -- You'll see theology trolls and proselytizers in most popular science channels. Physics channels also get fringe science spammers, for things like Electric Universe and Quantum Woo.
      I think it's a mix of people trying to recruit open-minded people to their group, and people trying to retain people already part of their group who are exploring other ideas.
      Most of them are bots, some of which are pointed to certain channels, and some of which might be given certain topics to post on. Others must be real people (or advanced bots) because they'll have whole arguments with you, but those ones tend to write entire rambling novels, so beware.

    • Hidden Object
      Hidden Object Month ago +2

      For an insightful comment, what's up with the flat earth person and bible quotes in the replies? Seems odd to me since this channel is all about explaining scientific concepts in an easy to understand format.

    • memespace
      memespace 2 months ago +1

      It's strange I just saw another video that made me think of the JWST maintaining stability and L2.

  • John Gavel
    John Gavel Month ago +1

    What about different accelerations? A slow acceptation and a fast acceleration?.. then what about a cyclical speed? Increasing then decreasing speed? Would the ball stay on longer then?

  • Speeddymon
    Speeddymon Month ago

    I'm curious what happens if you nudge the ball inward while allowing it to spin up? I can't be the only one thinking that the direction of the "equator" changing also has something to do with the movement of the ball post-nudge

    • Speeddymon
      Speeddymon Month ago

      Also what happens with a hollow ball that has been half filled with a liquid? Not water but something equally as dense as the surface of the ball?

  • David Seed
    David Seed Month ago

    at 4:19 the turntable velocity vector as shown in blue surely should be perpendicular to the black radial lines

  • Col kri
    Col kri Month ago +1

    if you make a giant sized version of this, wouldnt this be good energy?

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago

      Thanks for 👍☝ liking, watching and commenting on my video's
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  • Jörg Reinhardt
    Jörg Reinhardt 2 months ago +671

    'discs behave wiredly on turntables'... that sums up my entire experience of the 90's quite nicely

      iAMPREACHERMAN Month ago

      Put the needle on the Record.

    • Own Lee Tugenda
      Own Lee Tugenda 2 months ago

      @Jörg Reinhardt I say that because his mention of vinyl records wich were widely available at the time. Some records were said to repeat hidden messages if played backwards (they can't play that way you have to manually drag the record in reverse). That's what I meant by saying he spun them the wrong way.

    • Jörg Reinhardt
      Jörg Reinhardt 2 months ago +2

      ​@fluffigverbimmelt you probably do.... unless you guessed that I am a sloppy typist and not a natural English speaker.

    • Jörg Reinhardt
      Jörg Reinhardt 2 months ago +1

      @Own Lee Tugenda ...is what I assumed, when I encountering techno music for the first time... but it turned out it's supposed to sound like that... which seemed totally legit, once turned on, tuned in dropped out appropriately.

    • Josias Lourenço
      Josias Lourenço 2 months ago +1

      12:14 Make every effort to live in peace with all men and to be holy; without holiness no one will see the Lord.
      3:19 Repent, then, and turn to God, so that your sins may be wiped out, that times of refreshing may come from the Lord,
      James 2:24,26
      Ye see then how that by works a man is justified, and not by faith only. For as the body without the spirit is dead, so faith without works is dead also.

  • bumpstart
    bumpstart Month ago

    stunned my uncle who poses this one as part of the hire process in the big firm he worked at . the one about same mass same size same colour but one is hollow. how to tell apart? . took me about 10 seconds to ponder and i got it right in one go.. spin them

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago

      Thanks for 👍☝ liking, watching and commenting on my video's
      Expect more upload soon 🔜
      I really appreciate your effort ✅
      You have been selected among the Xmas giveaway🎉🎁
      Quickly send a direct message to me above ☝☝☝.

  • Jeff Zlatkin
    Jeff Zlatkin Month ago

    How does the resistance (surface area, etc) of the white stripe on the turn-table factor in? Or is it like 'paint' like the 'paint' on the ball?

  • Bill Keith Channel
    Bill Keith Channel Month ago

    Great job. You just proved the earth is a flat stationary disc, not a spinning, moving sphere.

  • moncorp1 Inc
    moncorp1 Inc Month ago

    Phew! I'm glad he explained. For a second I thought he had giant hands!

  • trustnoone81
    trustnoone81 2 months ago +196

    I started chuckling to myself the second I saw the equation for the moment of inertia of a ball. This was so cool! It's nice to see some interesting physics can still be done with closed form equations.

    • Dynoids
      Dynoids 2 months ago

      @Josias Lourenço hmmmm

    • Josias Lourenço
      Josias Lourenço 2 months ago

      12:14 Make every effort to live in peace with all men and to be holy; without holiness no one will see the Lord.
      3:19 Repent, then, and turn to God, so that your sins may be wiped out, that times of refreshing may come from the Lord,
      James 2:24,26
      Ye see then how that by works a man is justified, and not by faith only. For as the body without the spirit is dead, so faith without works is dead also.

    • JordanPeterson SucksMonkeyButt
      JordanPeterson SucksMonkeyButt 2 months ago +1

      @pineapplepenumbra haha, thanks!

    • pineapplepenumbra
      pineapplepenumbra 2 months ago +1

      @JordanPeterson SucksMonkeyButt It helps that your post was good, but I thumbed you up before I read it, just because your name deserves it.

    • JordanPeterson SucksMonkeyButt
      JordanPeterson SucksMonkeyButt 2 months ago +10

      @Luke Downes Luke Downes by closed form equations they mean that the equation can be solved analytically which generally leads a nice solution. Otherwise you have to solve it numerically.

  • Simon Bendix Borregaard

    I would love to see an investigation of this motion in relation to birkland currents in the galactic fillaments. Stars in interior bands of galaxies has been seen to move in opposite direction of the general rotation. I wonder if the strong nuclear force can be analogous to the dimension of surface tension, meaning incredibly stable wobbly orbits..

  • Dan Miller
    Dan Miller Month ago

    I once did an experiment on a turntable with a radial slot attached and a steel ball fastened at the center. When the ball is released it accelerates radially outward. Yet the classical mechanics text (Den Hartog) says the ball rolls out at a constant velocity after slipping along a tangent (Newton). No it continues to roll out faster and faster. I photographed it but didn't need that to hear the ball roll faster and faster radially out. It's A.P. French in his Newtonian Mechanics that says the "particle" slips along a tangent at the start.

  • Greg Smith
    Greg Smith Month ago

    The '"T" in the Space Shuttle Experiment -- Where it is unscrewed and continues spinning in the same direction and then "flips" and turns the other way for a few spins and then flips back and does the same thing over and over and over and over and over...
    Can you do and explain that one? -- PLEASE!

  • Lou F
    Lou F Month ago

    Wouldn't have thought it would do that, wouldn't think solid or shelled would be different.

  • Blaise
    Blaise 2 months ago +4020

    I can't be the only one that initially thought it was pi rotations rather than 7/2 when you counted them

    • Mihail Milev
      Mihail Milev 11 days ago

      @Sacher Khoudari ikr, now that I think abt it

    • Mihail Milev
      Mihail Milev 11 days ago

      @Isaac M oh what did they say?

    • Mihail Milev
      Mihail Milev 11 days ago

      @Mike Lumer lol

    • Mihail Milev
      Mihail Milev 11 days ago

      @David Smith same lol. But I haven't had breakfast yet. I'm gonna go eat now. Lol

    • King Charles III
      King Charles III 16 days ago

      @moumous I agree. It's not Pi. I suspect people are seeing 7/2 and somewhere in their memory Pi involves those two numbers (22/7), so they're satisfied that _they_ must be right and Steve, who's gone to the trouble of producing this demonstration with its clear explanation, must be ever so slightly wrong!

  • Peter Smythe
    Peter Smythe 2 months ago

    Well, if I ever live on a rotating spacecraft, I will make sure to abuse this information to the maximum extent possible.

  • pablojrl123
    pablojrl123 Month ago

    It'so so hypnotizing watching the ball roll like that :p

  • REKIK Saifeddine
    REKIK Saifeddine Month ago

    the same think happens to helicopter. you are actually moving right to go forward (gyroscope)

  • Gregg Roberts
    Gregg Roberts Month ago

    I could force the ball off the table in less than 2 seconds. It's all about the amperage.

  • Lui Zucchetto
    Lui Zucchetto 2 months ago +95

    Your videos are simply awesome! I am a rerired Physics Teacher and could have used your videos to engage and challenge my students while I was teaching. I never miss your videos and thank you for keeping my love of Physics alive and I hope inspiring a whole new generation of young students to take up the challenge of physics and science in general.

    • Aze
      Aze 2 months ago +1

      your videos

  • Jayden Chan
    Jayden Chan Month ago

    It'll be cool if we can watch the experience with the turntables reference frame

    • Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official
      Reàch mè on Nicègràm 👉Pastor_E_A_Adeboye_Official Month ago

      Thanks for 👍☝ liking, watching and commenting on my video's
      Expect more upload soon 🔜
      I really appreciate your effort ✅
      You have been selected among the Xmas giveaway🎉🎁
      Quickly send a direct message to me above ☝☝☝..