Man lifts a 40-pound wheel with one hand and no effort because it’s spinning

June 1, 2012 | By Abraham | 34 comments

In this demonstration from 1983, professor Eric Laithwaite shows how a relatively heavy wheel will become virtually weightless if it’s rotating fast enough.

“It’s not a conjuring trick. It’s a fact of science.”

(via Zogotunga)

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34 Comments

  1. Willow Kidd says:

    Was anyone else nervous about his fingers being so close to the spinning wheel? Made me nervous for him. One slip would have been very bad.

    1. Konraden says:

      I was nervous about everyone in that room! Like he said, enough energy to throw itself 200 feet in the air. Imagine if that thing snapped off at the end of the rod, it’ll throw itself over 200 feet through someone’s head. Jeebus H. Superchrist.

  2. Chris Craven says:

    RIP Professor Laithwaite. Your lectures were always fascinating and inspirational. I loved the ones on linear motors and later, rail guns.

  3. Tim Brown says:

    I you take 2 spinning wheels mounted to the inside of a cylinder and then spin the cylinder on it’s central axis – (forced precession) – the entire contraption becomes much lighter. It creates a unidirectional force, or an action without a reaction. Or it creates anti-gravity if the force is aimed opposite of gravity. Try it. But you will not find it in the science books. “Why” is the question.

    1. Lemonade says:

      Why? It isn’t true! Any closeness it has to the truth IS what it actually taught in science books. I don’t know where you got the idea that there is EVER an action without a reaction, but your physics professor sure as hell never said it (maybe there was a misunderstanding?). It’s a bummer this video never explains the physics of what really happens. Both angular momentum and linear momentum are always conserved. What the spinning does do is prevent the wheel from changing its angle with respect to gravity too much(that would change the angular momentum more than the torque of gravity provides). Work against the force of gravity is done over a greater distance, in a similar way to how it could with a corkscrew ramp.

      1. Johnny Steez says:

        theory of relativity is passed its due by date mate get with the times, stop believing what you were taught in science books

    2. Staraj says:

      I believe this principle explains in PART how UFOs defy gravity. But the beings who pilot them know much, much more about how the universe works than do Earth’s best scientists. Consider: Once upon a time, those who thought themselves to be the smartest people on the planet believed it was flat and that the sun was the center of everything.

      Let there be light. And increasingly more of it.

    3. FreeBeer says:

      There wouldn’t have been an explanation less than six month ago – in March 2013, the existence of the Higgs Boson
      and Higgs field was tentatively proved. That means that gravity and mass is caused by a particle that pops into existence whenever it is close to regular atomic particle like protons and neutrons. Perhaps if a large object is rotated rapidly enough it can “shake off” these particles and reduce mass. Or maybe an charged electric or magnetic field can be used to disrupt their connection to regular atoms.

  4. skeptic says:

    I think what he demonstrated was the conservation of angular momentum. He made a comment that there was no centripetal force trying to pull his arm sideways… The energy of the spinning wheel was transferred into torque, it was trying to spin his whole body.
    QUOTE:” At that speed the wheel has enough energy to throw itself 200 feet in the air”…. // Off a ramp maybe //!!

  5. johnnyb says:

    So explain to me in terms that an old farm boy can understand please.
    I understand that there is is an equal and opposite reaction. The reactive force was clearly absorbed by the guy who stored the energy in the flywheel.
    I also understand that a gyroscope does not like to change angles.
    What I don’t understand is why 40 pounds of weight appears to be “lighter”.

    1. HoPpeR says:

      Avoiding trying to explain angular forces of a gyroscope, the force created by the gyroscope creates a corkscrew path where turning the gyro is like pushing it up a spiral ramp. The force necessary to push it up the ramp is less because the path is longer. This is analogous to a lever with an advantage where your force is multiplied but the distance you have to move your end of the lever is also multiplied. Just a rough guess here but it looked like he moved his end of the bar a total of about 400 inches verses a direct lift of the 40lb weight 40 inches. This would give a 10 to 1 advantage, so he had to apply 4lbs of force over 400 inches. Energy is conserved. Think of it another way might help. If he had let go of the gyro, it have fell to the floor, but on it’s way the handle would have spun around several revolutions. You can do this trick with a toy gyro.

      Hope this helps.

      1. ANdrew K says:

        Allow me to disagree. The demonstrator does NOT spend his own energy to lift the wheel, but rather the energy of the rotating wheel. This experiment is based, first of all, on the conservation of angular momentum, which allows the demonstrator to translate the force of gravity into the horizontal precession. The speed of the precession has nothing to do with how high the demonstrator wants to lift the wheel. The conservation of energy kicks in when there is a slight reduction of the wheel rotation to account for the energy spent on raising the wheel.

  6. John says:

    I remember as a young man,17 or 18 years old, Working with Professor Braithwait at Gorton Tank Railway Works, Manchester England.My claim to fame was, I built the first two objects ever moved by a Linear motor,both were angle iron frames.
    Shortly after the initial tests at Gorton,The whole project was moved to Derby or Crew.
    British Rail as far as I know,did not develope the idea any further The next news was that Japan had developed The bullet train,which used the linear motor.
    Professor Braithwait some how upset the establishment,and faded from public view.
    John Heaton

    1. Joey says:

      Only if the plane is spinning.

      Actually, that’s a combination of thrust (by the engine) and the shape (and surface area) of the wings.

  7. george weiner says:

    If I am correct, Dr. Laithwaite’s demonstration would not work with plastic components. My explanation for weightlessness of a gyroscope can be seen at my home page at Weightless Gyroscope.com. My explanation does not use any connection to electromagnetism.
    George Weiner
    703-451-5255

  8. Drew says:

    At no time was he not exerting 40 lbs of force to keep the thing from falling. It was just a lot easier to manage since the angular momentum keeps it stable. I think he may have exaggerated the term “weightless” a bit.

    1. Charles Lloyd says:

      I believe your comment to be incorrect. Dr. Laithwaite has another demonstration in a separate video where he balances a precessing gyro mounted on a board. While the gyro is spinning/precessing, the board can be extended out over the balance point much further than when its not spinning. I believe the effect is the same here.

  9. Robert Smith says:

    It is simply precession. A force applied to a rotating mass reacts 90 degrees in the direction of rotation. If he had turned counter-clockwise the same force would have been applied downward instead.

  10. Charles says:

    Can anyone confirm that the ease with which he lifted it was a function of the length of that shaft? If the shaft had been 6 feet long, it would have been twice as easy to lift? Second question: Does the rpm of the gyro affect the ease of lifting? Or does it only affect the rate at which he lifts it and spins it?

  11. Joseph says:

    Something very similar can be done easily at home with a front bicycle wheel. Hold the end of the axle with the fingers of one hand and then apply a hard spin to the rim with the other hand. Then the spinning wheel can tend to want to hang upright in the air if you just hold one end of the axle.

  12. The Truth says:

    You’re all stupid. Clearly the wheel was trying to get away from the ground because that’s where the devil is.

    Duh.

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