44 thoughts on “This will seriously mess with your head, man!”

    1. If you are interested to delve more into this issue, I can highly recommend Christopher Chabris and Daniel Simons book, “The Invisible Gorilla: How Our Intuitions Deceive Us”

      I think Neil deGrasse Tyson usually state that, eyewitness testimony is, among ‘the lowest form of evidence there is’ 🙂

    2. Yes, it works just fine if you build a hollowed-out half cube like the one in the animation. It doesn’t even need to be that big or elaborate.

      It helps at first to only look at it with one eye. With a bit of practice, though, you can not only make it work with both eyes, you can make, for example, a Rubik’s Cube do the same thing.

      Cheers,

      b&

      1. How would a Rubix cube do this, seeing as it is already an actual 3D cube? Or are you saying that you can “trick” your eyes into perceiving it as an “inverted half-cube” (i.e. you can make yourself perceive the rubix cube as if it were something like the construction in the video)?

        I would think that live with 2-eyes you would need to be far enough away for stereoscopic depth perception to be insignificant. Although I suppose that the cues from shading & motion parallax might be strong enough in this case to override stereo depth.

        1. Yes, and yes. You can trick yourself into thinking that the Rubik’s Cube is inverted, and you can even do it with both eyes at a normal distance.

          b&

  8. The weird thing is, usually once you see what the optical illusion actually is, you can flip back and forth. Not with this one though, I can’t see the cube inverted even though I know it is.

  9. That is so cool. It’s like the hollow-mask illusion that Richard Dawkins talks about in his books.

    1. By focusing on the bottom corner I was able to keep the checkerboard pattern on the outside, even after he flipped the board.

  12. This and other ‘optical’ illusions are really mental illusions.

    There only minor differences in the light reaching the eye between this convex part cube, and an actual solid cube. It’s a similar illusion to the rotating mask that looks convex when it is concave.

    That these are illusions only becomes apparent to the subject when the perspective changes sufficiently to give other clues about the actual geometry.

    But when the geometry, the POV, is such that the illusion in the brain occurs, it really does *feel* like we’re seeing what we are not seeing.

    And this last point is significant when it comes to … wait for it … the mental illusion of free will. The difference is that for the free will illusion we don’t get to change the perspective; our POV is always from the inside. We always *feel* that our willed actions are uncaused. We are dualists by nature. It is only the intellectual consideration of what is actually required for *free* (uncaused) will that makes it implausible.

    Then compatibilists say, everything is physical, it’s all physical interaction of brain and environment, but we still have free will, “Look, I can raise my hand. I could have done otherwise”. It’s as if in this case they are saying, “Look, it really is a cube. When the POV shows it isn’t I of course know it’s a fake cube. But when the POV is right, it really is a cube, it’s not an illusion!”

    1. Since you’re taking this off topic and ending your comment with a straw man that I don’t most of the compatibilists here have ever propounded, let me respond.

      Briefly, I don’t think that knowledge of how brains function at the molecular scale necessarily negates or renders “illusory” a description of the results of brain function from our own or others’ POV. While the molecular scale knowledge can inform our evaluation of what brains are doing at the “human scale”, the human scale evaluation usually adds to the molecular scale description, even – if we’re careful – when we know the human scale description is faulty.

      I think it is possible to consistently reject my opinion on this. However, I have yet to hear an adequate explanation of how in doing so, one can avoid describing all the results of brain function as nothing more than “illusion”. Do you also classify every thing that emerged from the minds of Newton, Einstein, Mozart, Beethoven, Da Vinci, Picasso, and every other human being as equally “illusory”? How do you avoid complete nihilism?

        1. A movie is reducible to still frames running through the projector. So all movies are illusions. I’m sure that you could go through Dead Man frame by frame and get the story, but miss the point until you mentally ran the frames together when you were done. Being an illusion doesn’t mean something isn’t real; it is just a real illusion :). There is still a useful distinction to be made between the movie and the set of still frames, even though there is complete identity from an analytic standpoint. Same for mind and brain.
          Visual illusions are a beautiful example of this. The illusion is created from an appallingly small amount of actual data from the retina, superimposed on an immense mental landscape, made, of course, from the record of previous brain processes. The illusion changes as the visual data flits across that landscape, driven by small changes in the momentary information – the mind ‘choosing’ where the information fits best in the narrative. The information actually fits just where it does – completely deterministic, but so what? You might as well worry that if your copy of Dead Man is missing three frames, it is not the real movie. That is also true.

    2. Excellent Ron.
      I always use “optical” illusions as an analogy when explaining the illusion of freewill, especially to drive home the point that the illusion-of-freewill is actually something. You’re not just dismissing freewill, you’re putting the illusion-of-freewill in its place.

      I’ve generally used the checker board illusion as my analogy. The two squares are not different colours (there is no freewill…), but the two squares really do look as if they are the same colour (…but the illusion-of-freewill is real).

  13. I immediately saw it as it really is, but I’m already familiar with the convex Jesus faces long sold that, when similarly misperceived as convex, seem to follow you around the room.

  16. It’s an old trick, known at least to people from the era in which death masks were all the rage. One of my favorite incarnations is Jerry Andrus’ dragon. Jerry was an incredible close-up magician and optical illusions were a hobby if his.

Comments are closed.