If she’s got breast implants, then they’ve gotten a lot better at making breast implants. She looks like she has breasts, not breast implants (they look completely different).
But never mind that. I find that if I blink when her leg is fully extended (to either side), I find that the leg is always moving towards me after the blink (whichever way it was going before). So I can start off seeing her spinning clockwise. When it gets to the left, I blink, and she’s moving counterclockwise. When it gets to the right, I blink again, and so on, so that she’s always keeping her extended leg towards me.
This effect is not unbiased, however. If I blink at any point when her leg is on the right side of the image, I can switch to clockwise, but I can only switch to counterclockwise when it’s at the very leftmost point of its movement.
And might I add, that she’s got a cute nose, too. So sue me; I’m a face man.
I don’t buy the left-brain vs. right-brain interpretation of this study either. I have to work hard at seeing the illusion in a counter-clockwise rotation, but I consider myself more left-brained.
An interesting note: if you see her as tilting her head to her right shoulder, then you will see her going clockwise, as I usually do. If you imagine her head tilting toward her left shoulder, then she will appear to be rotating counter-clockwise.
I find the counter-clockwise rotation less likely, because you are looking UP at her from underneath. As a taller man, I look down on most people. I wonder if height plays into this illusion?
Like Sapo, the shadow seems to me to break the illusion. The funny thing is, it breaks the illusion for me in the opposite direction than the way it breaks it for her.
The image of the shadow of the raised leg starts low on the right, moves up and toward the left, peaks, then moves down and toward the left, and ends low on the left before disappearing toward the edge of the screen. Neither my reasoning mind nor my perceptual system are able to make this compatible with a clockwise spin.
How could she be spinning clockwise yet causing the raised leg’s shadow to rotate counter-clockwise?
-FrL-
(In fact I’m having a hard time seeing that shadow as accurate at all. Shouldn’t the raised leg’s shadow project further out than the still leg’s shadow?)
Throatwarbler Mangrove, you think it changes directions after a fix number of rotations. You said earlier you hadn’t bothered to count that number exactly. Why don’t you go ahead and do that count, and report back to us. Make sure you counted right: Let it cycle through at least three or four rouds of direction changes. Then tell us exactly how many rotations it took each time for the direction to change.
I’m with you. Took me awhile to get her to move CW, but now i can pretty much do it at will by watching her extended arm and imagining its a sweep second hand.
However, when i look down at the shadow, it immediately sends her spinning CCW again. I think it’s because of the fact that the image is cut off, and if that was her right leg extended, we should see a shadow cast as it passes behind her. Since it’s her left leg extended, as it passes in front of her we don’t see the shadow because it’s cut off of the frame. But as it passes behind her we see the tip of the shadow appear.
I just don’t see how that shadow would be resolvable if she was moving CW.
I’ve finally managed to “make” the shadow “work” in either direction, but when I “make” her rotate clockwise, the shadow’s no longer a shadow but more like a reflection–i.e., as though she were floating on top of a body of water.
And once I started doing that, now the shadow just looks like a reflection in both directions, and the shadow no longer “forces” a counter-clockwise perspective for me!
I don’t know what you mean by saying the leg goes “right to left in front of her.” How does the shadow make you think that’s necessarily the case? The shadow of the lifted leg and the shadow of the standing leg lie (of course) on the same plane, and neither can be said to be “in front of” the other. They just move right “through” each other without one being in front or behind. So ho is it that the shadow indicates to you the lifted leg is moving “in front of her?”
See my previous post as well–it seems to me the movement of the shadow of the lifted leg clearly implies counterclockwise movement. The shadow itself–considered as a two dimensional figure on the two dimensional plane constituting my computer screen–is certainly moving in a counterclockwise fashion.
-FrL-
Also, wouldn’t “right to left in front of her” mean counter-clockwise? If I move my arm from right to left in front of me, my arm is going coutnerclockwise.
Don’t think so. I right-clicked on the picture and saved it to my local hard disk. I opened it in a program (GraphicConverter from Lemke Software) that shows individual frames in an animaged .GIF file. There are 34 frames, always displaying in the same order. I played the animation in my graphics program and with some effort I can see it turning counterclockwise or clockwise.
Yes, I think so. Imagine any crazy 3D shape you like, and suppose that there is a light source infinitely far away on one side, so that its rays are all parallel when they meet the shape. Consider the shadow cast on the opposite wall.
Now remove the first light source, and replace it with one on the exact opposite side of the shape. The shadow it casts is identical to the first shadow. Therefore, if all you could see was the shadow, you couldn’t tell which side the light source was on.
Hey thanks for bringing some actual science to the question of the OP.
Unless there are any better studies out there than the one you cite, the answer to the OP is that there is no evidence a left- or right-brained person (not that such a thing exists anyway; see my and other posts, above) will see the spin differently. Underneath the floofed-up paragraph above, for instance, its just saying that perception flips can occur with internal processing that happens in different locations, even absent external stimulus changes. I think I coulda told 'em that without needing any grant money.
I wish to resolve the comments about the shadow. The shadow of the extended foot is not ambiguous; it is wrong for both rotations, but more wrong for a clockwise rotation.
The dancer is jumping. Her extended foot crosses her silhouette in the straight-on direction twice: once at the height of the jump and once when the axis foot is touching (and the axis foot shadow touches the silhouette axis foot). The axis foot shadow extends most deeply into the picture when the dancer is on the surface, and therefore the extended foot shadow will also extend most deeply into the picture at this point as well.
The light source is behind the dancer (it’s a silhouetted) and above the dancer (the thickness of the axis foot shadow is not elongated. If the light source were close to the horizon the shadow of the axis foot would be much “thicker” i.e. deeper, than the figure foot.
If the dancer is rotating clockwise, the right foot is extended, and she touches the surface with the right leg extended away from the viewer. Because it is extended away, we should see its shadow deeply into the animation since the light source is above and behind the dancer. However in the animation, at the point the axis foot meets its shadow, the extended foot shadow has disappeared. This would not be the case if the extended leg were away from the viewer.
With the dancer rotating counterclockwise, the left foot is extended, and she is at the height of her jump when the extended leg is away from the viewer. This is the point in the animation that we just see the extended leg shadow at the bottom.
Because the extended leg shadow must be at its deepest point in the picture when the dancer is on the surface and the leg is extended away from the viewer, the extended leg shadow is the most wrong when she is rotating clockwise. In the clockwise rotation, the extended right leg is away from the viewer and the dancer is on the surface, but there is no extended leg shadow at all.
At first, I see only clockwise. Then if I focus on the shadow at the bottom, I can force my brain to switch and she’s spinning counter-clockwise. Beautiful illusion.
The “shadow” is indeed wrong for either direction, for the reasons given by Chief Pedant. That means I really got nothing to push for a definitive answer of it spinning one way or another.
I am still unable to see her spinning counterclockwise. To me, she is extending her right leg, which points towards me at the height of the jump.
And props to jovan for the cites. They rescued this thread from IMHOhood.
The windmill in one of the cites, I can easily see spinning one way or another. There is just something about this one that prevents me from seeing it reversed.
This wonderful illusion may not stay forever on the linked-to Herald Sun website. Can anyone download it and stash it somewhere a little more permanent, on a web page to which we can refer other interested parties?
I have tried to do this myself, but I must lack either the know-how or the right software, since all I can scrape off is an isolated GIF image, not the whole animation.
