Whoa.  Dude, that’s trippy.

Is this dancer going clockwise or counter-clockwise?

Check out Dan Harlow’s blog to interpret what you see.  Found via Stumble.

60 thoughts on “Whoa.  Dude, that’s trippy.

  1. At some point when her legs appear together (because she’s facing you or turned away) they switch the leg that is extended and reverse the direction.  It seems like a continuous spin because of the motionand similar general shape at that point in the animation, but there exists a concrete transition.  She moves clockwise when her right leg is extended and counter clockwise when her left leg is extended.  The direction is unmistakable due to her distinct three dimensional nature.  Watch it long enough and you’ll see the transition.  It seems like an optical illusion, but really it just catches you off guard.  I wonder what kind of brain you have to have to realize she’s going both directions at different times and that Mr. Harlow’s entry and Perth Now’s article is crap?

  2. How bizarre.  I can only see her as turning clockwise, no matter how hard I try.  I understand that her dance is symmetrical and not chiral, and that all three-dimensional clues are imposed after I “decide” that she’s moving clockwise, yet I can’t see her differently.

    And no, theocrat, I must beg to differ: the dancer is not “turning” in either direction, or alternating directions, but is rather a symmetrical series of flat images.  It might well be that interpreting how we see it as an indication of whether we are “left-brained” or “right-brained” is crap, but the illusion is real.

  3. I saw her changing direction as well. And besides, it’s impossible to interpret her moving in two different ways. When it looks she’s going clockwise then she is going clockwise.

  4. From the link:
    [M]ost people will see this dancer moving counter-clockwise because they use more of the left side of their brain and tend to be more logical and practical. People who see the dancer moving clockwise (like me) are right brain dominant and tend to be more risk taking and imaginative.’

    That surely is rubbish. Why would the dominance of one brain half over the other have anything to do with it? Also, I’m one of the most rational persons I know and I cannot see the dancer spinning any other way than clockwise.

    In any case, I think that she is spinning clockwise. There’s one visual clue that in particular catches my eye: the outstretched arm. The arm is higher when behind her, at the level of her hip, and comes downwards to the level of her butt when in the front, consistent with clockwise rotation as viewed from this perspective.

  5. Cant see her turning any way but clockwise (and while I am flattered by the creative tag, many of the adjectives listed don’t really apply to me).

    And theocrat, don’t let good old scepticism make you too suspicious. Ceci n’est pas une pipe! This is an optical illusion, and the scientific question is: Does it APPEAR a certain way to you or not? The tricks of how its done do not invalidate the experiment.

  6. I’m with Theocrat (Zilch’s comments taken on board).  My wife claims she switches direction, as does her son. He is Dyspraxic (“spatial dyslexia”). My son (dyspraxic, dyslexic and some mild symptoms of asbergers) only sees clockwise. 

    The biggest clue is the pointing of the foot.

    If you want something that really throws your brain you need to go to the airship hangers at Cardington in Bedfordshire, about 30 miles north of London.  Located on flat terrain, with just a low rise of hills on the horizon, you look at them and go “so what?”.  The best way is to round a corner so you see them from about a mile away without expecting it.  Then your eyes pick up a few clues, such as the house in front.  There is a moment of visual confusion as your brain tries to hold two images simultaneously- hangers ‘close up’, while it struggles with the realisation they are REALLY BIG hangers a long way away. Incidentally in the final scene of ‘Casablanca’ the DC3 in the background is a scale model, with ‘short people’ as the engineers- an early example of ‘forced perspective in movies- see you FotR commentary for more on this.  It works not because film/TV in monocular, but binocular vision is only used within arms reach, close enough for the eyes to get different signals. 

    The brain relies on perspective at anything further.  Remember this next time you fight a Cyclops in D&D;- it shouldn’t get a minus for missile weapons- however it should get a minus in melee.  I have played LRPG, and fighting by firelight is a nightmare in melee- only half the target is illuminated, so binocular vision doesn’t work.  Range is easier as your brain interprets the known height of a human.

  7. How the hell can this be going clockwise? Are you smoking crack or something… she’s obviously going counter-clockwise… look at the foot and the shadow… damn.

  8. I must be really fucked up. The first few times I looked at her she was spinning counter-clockwise. Then I focused my attention on her outstretched hand and the next thing I knew she was spinning clockwise. Now I can’t see her spinning counter-clockwise.

  9. How the hell can this be going clockwise? Are you smoking crack or something… she’s obviously going counter-clockwise… look at the foot and the shadow… damn.

    At first I was only seeing it move clockwise.  However, if you keep your eyes on the space between the foot and the shadow, I found that after about a minute of relaxing my focus, the perspective shifted and it started moving counter clockwise.  A little further “practice” and now I can switch back and forth.

    Of course, since it’s an animation, nothing is really moving at all, so that’s the real secret of this illusion.

  10. Double weird. I walked away to get some coffee and when I came back she was spinning counter-clockwise again.

  11. At first I thought; “Counterclockwise, obviously.”  Then I scrolled down to see the explanation and could only see the figure from waist down – and she was going clockwise, no question about it.  Scroll back up, and she keeps going either direction with no apparent moment of change.  Freaky.

    On another level, what Elwed said.

  12. Duckhugger: You’re right. I completely missed the shadow. I naturally assumed that she was oriented upright, but she’s spinning at a slight angle, leaning away from the camera.

    I don’t get what people are saying about switching legs. It’s always the left leg that’s straight down.

  13. Both ways, Close your right eye, then close your left, then close both, Look again and you can almost will the dancer to change directions.

  14. Watch the animation for about five minutes and constantly ask yourself “Which leg does she have extended?”  You will find over the course of that five minutes that the answer changes.  Because she is 3D you can always tell which leg is extended.  Whichever way she’s rotating it doesn’t affect how you determine which leg is extended.  You will notice over time that she does extend different legs and that those legs correspond with different spins.

  15. Watch for the animation start/stop flicker.  You can see it moving around the axis of rotation.  She changes direction after several ticks.  Short enough that you can “concentrate” and see it change directions.  I saw CCW dance and shadow, CW dancer and shadow (shorter amount of ticks), and CW dance and CCW shadow.  CCW shadow and dancer run the longest.  I don’t trust digital animations like this, you can’t be sure if it’s really doing what someone says.  I have seen the mechanical illusions where rotating objects seem to change direction.

    I got a link to a website a while back that supposedly would pick the playing card you were looking at.  It really didn’t, it would show a face card, then pop up other face cards as it’s guess, and fool you into thinking THAT was your card.  Didn’t work if you wrote down exactly what card you picked.

  16. Theocrat: Yes, of course. How stupid of me. When you see her spinning in the clock-wise direction, it appears that her left leg is down, but in the other direction, her facing is opposite, so it’s the right leg.

    I can’t see her changing directions though. But I’ve seen other similar animations, where I’ve seen that effect. If you see her that way, she would, of course, appear to change her stance.

  17. I think the shape of the foot should probably be a dead give away too.  After realizing this, I think it’s rigged, but I’m gonna open it in Image Ready to find out for sure…

  18. I opened the gif up in GIMP to look at it frame by frame.  It’s more elusive than I first realized.  It’s only 34 frames long, but actually it never turns around, it rotates back and forth over 180 degrees.  When it gets to the profile view on each side it switches legs and moves back.  Here’s some stills:
    Left leg forward:
    dancerf2.jpgFrame 2
    dancerf31.jpgFrame 31

    Right leg forward:
    dancerf14.jpgFrame 14
    dancerf20.jpgFrame 20

  19. The image does change on it’s own, I sat down with my wife. We both noticed that at the same exact time. She changes…Rigged…………….

  20. Her body looks clockwise to me but the foot is oscilating – never seeming to make a complete turn.

    I think this has more to do with what part of the body you look at than what side brained you are – I mean if you go to a strip club where do you look?

  21. Her body looks clockwise to me but the foot is oscilating – never seeming to make a complete turn.

      I watched a video of an uneven rectangle rotating that appeared to oscillate until you looked down at it from above.  The thing about the animations is that you don’t know for sure if it’s really turning in one direction or oscillating, since your brain will usually interpret it the same.

    I think this has more to do with what part of the body

    (boobs)

    you look at

    (boobs)

    than what side brained

    (boobs)

    you are – I mean if you go to a strip club

    (boobs)

    where do you look?

    (boobs)

    At their eyes.

  22. I did what Bog Brother suggested, and can get her going anti clockwise.  I am with those who say optical illusion, not right/left brain.

    The brain tends to see what it’s expecting (a la gorilla in a basketball court experiment- GIYF)*.  Humans tend to act first, and rationalise later, as Scott Adams has mentioned regarding hypnotism.

    Clockwise her right foot pointing, anti cw left foot.  I’m guessing that when you first see it the brian makes a snap decision which foot is pointing. Once that is fixed then the rotation of the image is fixed by your knowledge of biology.  The illusion is relying on that as a sillouette each frame could be one of two alignments on a line of symmetry parallel to the viewer- i.e. if she is in the middle of a clock, and you are at 6 o’clock, the ‘mirror’ runs from 9 to 3. So in Frame 14 it is either her left foot pointing to the 2, or her right pointing to 4 o’clock.  If it was posible to set this up with a live model completely in sillouette- flat black, no facing clues- these two poses would appear identical.

    So assuming Theocrat is correct (and I’m sure he is) there are only 34 frames what is happening is
    Frame one- Pointing to “9 o’clock” (ie 270’).
    Frame 34 -p pointing to 3 o’clock/90’ (NB I realise this is different to Theo’s notation- stick wih mine for the moment- westerners think left to right)
    Each frame appears to move the foot approx 5 1/2 degrees. (though the distance moved in pixels will be more around the 6 o’clock position)- this is basic moving picture making a la Hollywood- lots of still images giving the illusion of movement.

    When Frame 34 is reached it plays them backwards in order, back down to 1.  However because the figure has momentum (or at least our brain ‘knows’ it has) we do not see it as a switch in direction, we see a frame ‘35’ which is identical to frame 33.  Whe one is reached it starts back again.

    If can convince the brain the other foot is extended, then it changes direction, because your brain knows to keep the rotation would mean a physically impossible shape.

    *BICBB

  23. ragman – :LOL: I generally scan, for me the whole is more than the sum of the parts, the boobs, face, hips, legs all get looked at when I know I can (not the feet), but I look at the floor when I feel embarassed (in public), and so might notice the feet then

  24. I can change directions at will.  Well, maybe not quite at will, but if I look away for a second when I look back it will have reversed directions, regardless of which way it was going before.

    All of the “left brain right brain you’re crazy no you’re crazy” talk is pretty funny though, for an optical illusion that can be either.

  25. What Theocrat said.  It doesn’t actually do a 360 at all, the 34 frames are too few.  It just oscillates in a 180.  I think Hussar is right that our brains make a snap decision on which foot is extended upon first seeing it, and it has nothing to do with which side of your brain is dominant (I’m sick of hearing about right and left brain dominance, it may be valid in some things, but it gets used way too much to explain parts of human behavior, kinda like Quantum Physics seems to be the answer to all the strange, unexplained stuff in the world.).  If you stare at it long enough, or you change focus then come back, there is a chance your brain will orient on the other foot and see the figure moving in the other direction. 

    It definitely is not rigged though, it’s a .gif file.  If it was a flash file, I’d be more inclined to think it was rigged to randomly change direction, but a 34 frame gif just can’t be made to do that, at least not with the frames that are in this one.  Of course, it really doesn’t have to.

  26. I’ve always considered myself more right-brained than left, but no matter how hard I try, I cannot see the dancer moving in a clockwise direction.

  27. Try this.  Look at the thing head on for a second.  Then, move your focus to off screen, so that you see it with your peripheral vision.  I don’t know if it will happen for anyone else, but I see it moving clockwise while viewing it directly, counterclockwise when viewing it peripherally, and clockwise when I look at it directly again.

  28. It’s pretty strange that my wife and I can tell when it changes at the exact same second…How can that be ? Do it with another person setting beside you…

  29. I’ve now managed to see her turning counterclockwise, briefly, by looking at her feet from well above the screen and slowly moving down.

    And it’s true that it’s not as symmetrical as I thought: because she jumps once per turn, she is seen facing away when on the ground if seen clockwise, and facing front when on the ground if seen counterclockwise.  Her outstretched hand also moves up and down, as flaky pointed out.  These clues may account for some subtle differences in our tendency to see her one way or the other.

    But it’s not rigged- what’s there to rig?  Theocrat’s interpretation of her changing legs and direction is one possible one, but it’s no more “real” than seeing her rotate continuously- I for one can’t see her Theo’s way.  And Theo’s labels of “left” and “right” are dependent upon which direction we see her as facing- the opposite ones are just as “true”.

    All in all, a great illusion.

  30. Paul I think it’s a coincidence that you and your wife are seeing the perceived shift at the same time.  Perhaps it’s a good indicator that you both think a lot alike?

    Anyway, after further analysis of this phenomenon, I’ve come up with the following:

    The dancer image is not 3D at all.  It has no shading, texture or anything at all to really convey depth.  Neither does the shadow.  However, the background is lighted and appears to convey some depth to the figure. This is just an illusion though.  The figure is in front of the background, not in the background as the lighting appears to make it look.  I think the combination of 2D and faux 3D background is where our brains are having trouble.

    I’d like to remove the background and shadow and see if that makes it easier to see the oscillation (I cannot see it oscillating without viewing it frame by frame myself, even though I know it is.)

    This whole thing reminds me of a quote from Jerry Andrus I heard on the Skeptic’s Guide to the Universe:

    “I can fool you because you’re a human,” said Andrus.  “You have a wonderful human mind that works no different from my human mind. Usually when we’re fooled, the mind hasn’t made a mistake. It’s come to the wrong conclusion for the right reason.”

  31. LOL! I bet some asshole is laughing his ass off saying, “Dude look at how many people I got to stare at this picture…”

    The first thing I noticed was a naked lady twirling, then I actually looked to see what the post was about. Then I saw clockwise, nothing else.

    I’m with DOF on this one.

  32. I’m still scratching my head at the rest of you… no matter how I look at it… every time it’s the same… It looks like a 3-D model blacked out into shadow and EVERY feature seems to suggest turning in a clockwise direction.

    Those stills Theocrat posted seem to leave out some parts of the animation… really, looking at her motion in the face, the ponytail, the shadow, the breasts, the arms, the legs, etc… I can’t see any suggestion of clockwise movement at all… she’s always moving counterclockwise for me!

  33. Duckhugger:

    I’m still scratching my head at the rest of you… no matter how I look at it… every time it’s the same… It looks like a 3-D model blacked out into shadow and EVERY feature seems to suggest turning in a clockwise direction.

    I had the same problem, but have seen it counter-clockwise a couple of times by focusing down at her shadow, taking care to ignore her figure in my peripheral vision.  When I convince myself the traveling shadow is going behind the fixed leg, I can get it to change.  Only after much effort and only for a short while.

    BTW, the left-brain, right-brain explanations offered are not convincing.  I’d need to see some citation of reference to understand why they can make this claim.  The only thing I’ve seen about optical dominance having a basis on right-/left-brainedness were not related specifically to the twirling dancer illusion. 

    But WHY is she naked?  Is this a test of the dominance of big-head/little-head thinking?

    Big-head thinking:  I wonder why this illusion means I’m right-brained. You know, maybe she’s not naked, maybe she’s just like that changling Mystique character from the X-men or maybe she’s wearing body paint… 

    Little-head thinking:  Damn! Can you imagine the three-way with her and her sister from them mudflaps?

  34. But WHY is she naked?

    Or, perhaps, why aren’t most people naked most of the time? – in hot countries at least it’d make sense. Maybe in a few centuries time it’d be normal

    I was born naked and I’m gonna die naked!  gulp

  35. Now that I look at it, sometimes it looks like its going clockwise and sometimes counterclockwise, I think depending on which motion she is in during the animation when I begin to move my eyes up away from her legs and towards her head.  The moving away from the legs and towards the head seems to solidify whatever direction I thought she was rotating in when i last saw her and she continues in that direction until I take another determined look at her legs again.  Now that I’ve seen it frame by frame I can sometimes also see the actual sweeping motion of it going back and forth over the 180 degrees instead of any kind of actual spin, but when I cease to concentrate on what’s happening it begins to appear to spin again.

  36. With a little effort I can get it to change what direction she seems to be twirling. But there is something about the animation that looks a tad off though. It seems to help to look away briefly and look back when trying to get it to change direction.

    When I look about an inch or two below the picture so I’m only looking at her with peripheral vision, she just bounces back and forth. She won’t turn in a full circle. The illusion of her turning is completely negated for me.

    I have always wondered about the right-brain, left brain stuff. It sounds awefully suspicious to me. Dunno.

  37. I have always wondered about the right-brain, left brain stuff. It sounds awefully suspicious to me. Dunno.

    I certainly question the methods of measurement (there is more to inteligence than what things like IQ tests measure), particularly for the subjective and unquantifiable, and without reliable data it crumbles.

    I certainly think emotional intelligence has a part, and appears to correlate loosely with the ability to rationalise (look at trolls as the contrast), but it’s bound to be misinterpreted and have judgements passed on people from the results of tests that continue the misinterpretation

  38. I’m surprised at how much attention this picture has gotten. It just so happens that the Ulead PhotoImpact (the poor man’s Photoshop) program I use to make the graphics for SEB comes with a gif animation editor. So I opened the file up in that to take a look.

    As it turns out the file isn’t rigged and it is, indeed, an optical illusion. There’s a couple of key frames where I noticed my eye had a hard time determining which leg was extended and it’s entirely because the image is flat, not 3D as everyone seems to think it is. Therein lies the trick. Take another look at the sample frames Theocrat posted and you’ll see that the image is completely flat with no highlighting to suggest it’s 3D. It’s our brains trying to fill in the missing details that gives it the 3D effect.

    So when we reach frames where it’s ambigious as to which leg is forward, for me it’s Frames 1, 17, and 33, our brain guesses and it affects the rest of our perception of the animation loop. As it turns out, I’m not alone in that assessment. I found an entry at I Fought The Law Blog that also makes this point and provides a visual aid to show how it works. It all depends on which leg you “think” she has raised. It still works even if you slow it down. The original animation had a 0.03 delay on each frame. Saving it with a .5 delay gives you this:

    The effect remains even at a slower speed. Incidentally, the 34 frames is more than enough for her to make a complete circle as the starting and ending frames are exactly what you’d expect if the animation were continuous.

  39. At this slower speed, I can switch her at will and keep her from ever doing a complete 360, but rather just going back and forth.

  40. Ragman you need to improve your subliminal messsages – I could still see the fnords wink

  41. I didn’t mention the fact that its 2D as I took it as read- there are no 3D images on the web, films etc, unless you include the one by the artoo unit with no memory, in which case I’m off to Alderbarren

  42. Technically no 3D images in that they don’t have have any depth, but you can have faux 3D images, just look at a stereoscopic photo or any CGI movie.  The animation that has us all agitated though obviously doesn’t even have that though.

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