Explain this illusion!

by Matthew Cobb

Here’s a great illusion, known as the Mephisto Spiral. How does it work? Answers in the comments, please. And no peeking or googling! I’ll post the answer later on today.

23 Comments

  1. GBJames
    Posted October 26, 2017 at 10:06 am | Permalink

    Very clever! (I watched the original youtube which gives it away.)

    • ploubere
      Posted October 26, 2017 at 10:11 am | Permalink

      Some hand technique involved which he doesn’t explain, but yeah.

      • Posted October 26, 2017 at 11:43 am | Permalink

        I’d guess the technique is to grip very loosely and simply let the wires spin in your fingers as you pull your hands away from each other.

        • infiniteimprobabilit
          Posted October 26, 2017 at 6:29 pm | Permalink

          That’s what occurred to me second BUT – no matter how loosely the spirals are held in the fingers – they would move with the hands. Unless they were somehow restrained longitudinally and I can’t see how.

          (First thought was that the hands were twisting the spirals but they’re visibly NOT doing that).

          What is noticeable – looking at the shadows – is that the left-hand spiral comes much further off the paper than the right-hand one, which must be somewhat flattened.

          This doesn’t help.

          Only other possibility is that the spirals are in fact much longer than appears, and their ends are hidden behind a cut in the paper. Doesn’t seem very likely.

          I do note that, as he pulls one spiral away, so the other one ‘lengthens’ to stay with it. This must be a clue but I can’t solve it.

          I remain completely baffled.

          cr

          • Posted October 26, 2017 at 9:15 pm | Permalink

            The two wires are spot welded together at the tips.

  2. Posted October 26, 2017 at 10:35 am | Permalink

    Without googling it looks to me like he’s taking advantage of the angle of light and using the shadow of the coil for the illusion.

    I’ll google it. I will not be surprised to find out I’m wrong. I usually am. About everything.

    • Posted October 26, 2017 at 10:36 am | Permalink

      Note in proof and before the googles; part of the coil is painted white. Which helps.

      • BJ
        Posted October 26, 2017 at 11:03 am | Permalink

        Ah, so they’re connected. I thought he was just very skilled with keeping two separate wires together while spinning them.

  3. Steve Zeoli
    Posted October 26, 2017 at 10:50 am | Permalink

    Twist the wires instead of pull them?

    • BJ
      Posted October 26, 2017 at 11:02 am | Permalink

      Exactly what I’m thinking. Spinning the wires in place would give the illusion of being pulled apart/pushed together.

  4. Geoff Toscano
    Posted October 26, 2017 at 11:20 am | Permalink

    Something to do with shadows and he’s just moving his hands up and down the spirals? I really can’t figure it.

  5. Sshort
    Posted October 26, 2017 at 11:53 am | Permalink

    He is turning a single connected coil in half steps (the white helps for positioning the fingers). The overlap of 3 peaks and valleys stays exactly the same with each “pull” (twist).

    The movement of the hands enforces the illusion, especially because the frame does not let us see coil extending with each movement on the right and left.

    I think that’s pretty much it. But even with that knowledge, maddeningly effective. My monkey mind is still losing money on the bet.

  6. Jake Sevins
    Posted October 26, 2017 at 12:02 pm | Permalink

    The two wires are attached and he’s just spinning them to create the illusion that they’re coming apart. You can see this by watching the wire opposite to his moving hand because it seems to “grow” as the hand moves away… but it’s not growing (of course), but rather the join-point is re-centering.

    I had to watch the video about 10 times to unfool my eyes… it’s very effective!

    • Posted October 26, 2017 at 12:08 pm | Permalink

      I think that did it for me. Thanks to your clue about what to look for.

  7. Gareth Price
    Posted October 26, 2017 at 12:54 pm | Permalink

    I think there are two wires and he is twisting them. The wires are like corkscrews: as he moves his hand to the right, he twists the wire which screws it towards the left, so the wire doesn’t translate in either direction.

    • Gareth Price
      Posted October 26, 2017 at 12:57 pm | Permalink

      And, I meant to add, vice versa for the left hand.

      • Gareth Price
        Posted October 26, 2017 at 1:07 pm | Permalink

        Also, I think the area of overlap is moving slightly left to right and back again. So when he moves his hand to the right, he screws the right hand wire towards the left. However, screwing the wire to the left doesn’t quite compensate for the movement of his hand, so the wire translates slightly to the right. At the same time, he screws the the wire in his left hand towards the right but without moving his hand. This keeps the same overlap between the wires although the overlap moves slightly to the right. Then it is all repeated the other way. Possibly! Perhaps!

  8. ThyroidPlanet
    Posted October 26, 2017 at 1:30 pm | Permalink

    Now THAT is another good illusion hand-picked by Mr. Cobb

    • ThyroidPlanet
      Posted October 26, 2017 at 1:31 pm | Permalink

      Oops – sub

  9. Posted October 26, 2017 at 1:39 pm | Permalink

    Reblogged this on The Logical Place.

  10. infiniteimprobabilit
    Posted October 26, 2017 at 6:37 pm | Permalink

    Arrgh! I just followed to the next Youtube video where it is explained and all I can say is, I’m amazed by the complication of the explanations given by commenters above (including notably me) when the answer is so simple and obvious. We’re all assuming one vital fact which is, in fact, incorrect.

    I won’t say what it is here, I’ll leave it for PCC to reveal all in his next post.

    cr

  11. Bob Barber
    Posted October 27, 2017 at 9:01 am | Permalink

    If you really want to understand, look up your local International Brotherhood of Magicians ring or Society of American Magicians group and attend a meeting.


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