Simply Impossible

By Carl Zimmer | May 11, 2010 11:19 am

Here’s the newly anointed best visual illusion of 2010. No fancy computer graphics. Just cardboard, glue, and some wooden balls. Fabulous.

[Update: Thanks to Sam Mackrill for directing us to the inventor’s web site, which includes building instructions.]


Comments (23)

  1. That’s almost as amazing as effin’ magnets — how do they work?

  2. fasteddie

    Great stuff. The only clue all is not as it seems is the travel time for the ball on the ramp at the top of the screen. It’s slightly less than for a ball on the ramp at the bottom of the screen. I only noticed that after the 3rd viewing.

  3. CWorthington

    Niiiice. I envy those people who have a grasp of perspective. Like Julian Beever and his chalk drawings. Some fantastic stuff. Thanks for sharing!!

  4. Shane

    forced perspective. Used in movies quite a bit back in the day

  5. I’d really like the plans to make one of these.

  6. Sam

    Awesome video!

    I don’t understand how some of you can say you watched this video 3 times and don’t understand how it works… The camera moves at about 30 seconds into the movie and shows you how the illusion was created…

    Anyways though, cool stuff!

  7. Simorgh Dinatale

    @Scott: I had no idea you were a Juggalo…. I’m so disillusioned now!

  8. Ben Mann

    This is amazing.

  9. Comanche

    @Shane: Yeah, the Lord of the Rings movies used it quite a lot to get the hobbits looking smaller than Gandalf. Sneaky, but awesomely clever.

  10. johnk

    Neat illusion. To me it seems similar to the Ames room illusion. In the Ames room illusion, a room is constructed such that, from one view it looks like a normal room, but from any other viewpoint its clear that the walls are distorted and the floor is slanted. The important thing in both the Ames room illusion and the magnetic ball illusion is that, from the start view perspective, the illusory view is a possible correct interpretation of the visual input, but the visual data are ambiguous. Rotating the perspective shows that the visual system made the wrong guess. Real Ames rooms are neat and have been constructed in several museums.

    I looked for a link and found this video of Ramachandarun explaining the Ames room:

    Actually, I don’t really like Ramachandran’s explanation. The magnet balls and Ames room illusion are due to the visual system trying to create a 3D representation of the word from 2D data (the flat retina). Ramachanran’s explanation of the expectation of parallel walls mostly misses the boat. Our visual system uses inferences from linear perspective, such as that lines whose projections converge at the horizon are parallel. Parallel walls may play a role but are secondary.

    I’m trying to guess what mistakes the visual system is making in the magnetic balls illusion. Is it that the alleys are equal length? That the platform is in the center? that the pillars holding the alleys are vertical? Are equal height? Equal width? All of the above? My guess is that only 1 or a few of the mis-guesses of visual perception are the core of the illusion. Putting them all together makes it very compelling — and makes the construction of the illusion brilliant.

  11. Sam Mackrill

    Plans can be found on inventor’s (Koukichi Sugihara) website:

  12. Ow wow, this is superb!

  13. Ginger Yellow

    “The only clue all is not as it seems is the travel time for the ball on the ramp at the top of the screen.”

    The rolling uphill thing is a bit of a clue as well…

  14. Roger Pedersen

    Just wonderful.. Brilliant.. EFFING GENIOUS:D

    Btw.. What’s the music that’s playe in the video called? Anybody know?

  15. confusionist

    I’ve seen the possible. Therefore, that cannot be the IMpossible, because I am…. and therfore, I is, and so be it.

  16. Thats Crazy….I love it, it had me fooled for a min.


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

The Loom

A blog about life, past and future. Written by DISCOVER contributing editor and columnist Carl Zimmer.

About Carl Zimmer

Carl Zimmer writes about science regularly for The New York Times and magazines such as DISCOVER, which also hosts his blog, The LoomHe is the author of 12 books, the most recent of which is Science Ink: Tattoos of the Science Obsessed.


See More

Collapse bottom bar