Thread: Favorite optical illusion?

  1. #1
    Banned ಠ_ಠ's Avatar
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    Favorite optical illusion?

    Post your favorite optical illusion here

    http://i694.photobucket.com/albums/v...5526610548.gif
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  2. #2
    spurious conceit MK27's Avatar
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    Wow. After you see it the first time, you can hold the color "in your mind" the 2nd time and slowly perceive what I guess is an after image "fading" (otherwise I tend to refocus too quickly). Rods and cones! If your pupils and time sense were severely dilated, I bet the effect would seem to take a forever

    A little while ago I heard 5-10% of your rods are predictive, ie, they will fire in advance of a regularly moving object, which is part of what enables you to catch a ball and shoot pidgeons. Hopefully someone out there has a good illusion playing on that...
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

  3. #3
    Banned ಠ_ಠ's Avatar
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    Quote Originally Posted by MK27 View Post
    Wow. After you see it the first time, you can hold the color "in your mind" the 2nd time and slowly perceive what I guess is an after image "fading" (otherwise I tend to refocus too quickly). Rods and cones! If your pupils and time sense were severely dilated, I bet the effect would seem to take a forever

    A little while ago I heard 5-10% of your rods are predictive, ie, they will fire in advance of a regularly moving object, which is part of what enables you to catch a ball and shoot pidgeons. Hopefully someone out there has a good illusion playing on that...
    that reminds me of

    http://mahboubian.googlepages.com/3d-Dinosaur.gif
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    I've always liked the moon, actually... it appears bigger on the horizon, but isn't. But the thing that really gets me is that if you take a picture of a 'bigger' moon sitting on a horizon with a camera, the moon will look 'smaller' / 'normal' in the photo.
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  5. #5
    Guest Sebastiani's Avatar
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    ಠ_ಠ, that is a pretty cool illusion.

    How about this one?
    Last edited by Sebastiani; 06-20-2009 at 06:30 PM. Reason: pruned

  6. #6
    Guest Sebastiani's Avatar
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    This one's pretty good, but you have to adjust your eyes in order to see the animation.
    Last edited by Sebastiani; 06-20-2009 at 06:29 PM. Reason: whoops, wrong post
    Code:
    #include <cmath>
    #include <complex>
    bool euler_flip(bool value)
    {
        return std::pow
        (
            std::complex<float>(std::exp(1.0)), 
            std::complex<float>(0, 1) 
            * std::complex<float>(std::atan(1.0)
            *(1 << (value + 2)))
        ).real() < 0;
    }

  7. #7
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    Quote Originally Posted by Sebastiani View Post
    This one's pretty good, but you have to adjust your eyes in order to see the animation.
    wow, reminds me of the tuning fork and strobe light experiment we did in physics

    (the thumb tip thing didn't help)
    Last edited by ಠ_ಠ; 06-20-2009 at 06:29 PM.
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    spurious conceit MK27's Avatar
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    Quote Originally Posted by Sebastiani View Post
    This one's pretty good, but you have to adjust your eyes in order to see the animation.
    I could not get this one to work at all for me, but maybe it is based on the fact that the center of your eye is blind*. Five minutes and I feel like a sucker. Nothing. Where is the shark???

    * close one eye, hold your thumb straight in front of you, and move it very slowly back and forth horizontally but *do not follow it*, keep your eye still and relaxed. There is a very distinct point (maybe 6-8" from center toward the outside, and 1-2" wide) where your thumb "disappears" because it is in the blind area. It is not "out of focus", if you concentrate you can see part of your hand is simply not in the picture. Gone. I showed everybody I met this for a week after it was shown to me; I could just not believe I had been walking around the whole time blind in the center of my eye like everyone else

    [edit, okay I think I found it -- more like a killer whale, and facing left?]
    Last edited by MK27; 06-20-2009 at 07:10 PM.
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

  9. #9
    Guest Sebastiani's Avatar
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    Interesting. I've never noticed that effect before. I know that some can't see stereograms due to certain visual impairments, but quite often they just don't understand the technique. Do you wear glasses?
    Code:
    #include <cmath>
    #include <complex>
    bool euler_flip(bool value)
    {
        return std::pow
        (
            std::complex<float>(std::exp(1.0)), 
            std::complex<float>(0, 1) 
            * std::complex<float>(std::atan(1.0)
            *(1 << (value + 2)))
        ).real() < 0;
    }

  10. #10
    spurious conceit MK27's Avatar
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    Quote Originally Posted by Sebastiani View Post
    Interesting. I've never noticed that effect before. I know that some can't see stereograms due to certain visual impairments, but quite often they just don't understand the technique. Do you wear glasses?
    No; last time I was tested I had "better than 20/20", so this is probably a previous psychedelic brain injury. I think I found it tho -- facing left and sort of waggling? Of course, I imagine I could find my mother in there if I tried hard enough...
    Last edited by MK27; 06-20-2009 at 07:20 PM.
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

  11. #11
    Guest Sebastiani's Avatar
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    >> I think I found it tho -- facing left and sort of waggling?

    That's it. Once you latch onto it, relax your eyes, and the animation just sort of pops out at you.
    Code:
    #include <cmath>
    #include <complex>
    bool euler_flip(bool value)
    {
        return std::pow
        (
            std::complex<float>(std::exp(1.0)), 
            std::complex<float>(0, 1) 
            * std::complex<float>(std::atan(1.0)
            *(1 << (value + 2)))
        ).real() < 0;
    }

  12. #12
    spurious conceit MK27's Avatar
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    Quote Originally Posted by Sebastiani View Post
    >> I think I found it tho -- facing left and sort of waggling?

    That's it. Once you latch onto it, relax your eyes, and the animation just sort of pops out at you.
    I think that thing is somewhat unsafe.
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

  13. #13
    Banned ಠ_ಠ's Avatar
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    Quote Originally Posted by MK27 View Post
    I think that thing is somewhat unsafe.
    don't worry, it's just a shark, whats the worst that could happen?
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  14. #14
    Registered User carrotcake1029's Avatar
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    I think this page is interesting:
    The Right Brain vs Left Brain test | PerthNow

  15. #15
    Guest Sebastiani's Avatar
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    Interesting. It's definitely turning clockwise for me - but then the position of the body even indicates that. Does anyone here really see it going counter-clockwise?

    EDIT: OK, I did get it going the other way now, but the natural tendency is definitely clockwise, for me.
    Last edited by Sebastiani; 06-21-2009 at 12:03 AM.
    Code:
    #include <cmath>
    #include <complex>
    bool euler_flip(bool value)
    {
        return std::pow
        (
            std::complex<float>(std::exp(1.0)), 
            std::complex<float>(0, 1) 
            * std::complex<float>(std::atan(1.0)
            *(1 << (value + 2)))
        ).real() < 0;
    }

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