Optical Illusion: Which Way is She Spinning?

If you watch long enough, it will change direction of rotation.

Wow.

Clockwise when I first look at it and the same phenomenon as the poster's happen: look away and eventually, she appears to go counter-clockwise. Then as long as I remain focus on the upper body, no problem. As soon as I look at the foot closest to the floor though, the rotation reverses to clockwise !! Very interesting....

I'm not seeing it, it looks more to me like the 'dancer' is passing wind and waving the smell away...

You mean not turning at all?!? (gotta go thru the link for that)

My bad, my vote CW. It doesnt seem to change but obviously only half of my brain is working today

That's alright. I have to look at the text beside it and somewhat concentrate on making it turn the other way for it to happen but it does work. Reminds me of the damn 3D puzzles; sometimes, you get it right away, sometimes, you feel your brain is gonna pop out of your skull !!

I found it easier to concentrate on the one foot on the floor and could convince myself that it was changing direction.

I get exactly the opposite - seems CCW if concentrating, but CW in peripheral vision.

It's not an optical illusion, it's a trick. Notice that sometimes she's standing on her left leg and spinning clockwise, but when she seems to be spinning counter-clockwise, she's on her right leg. The video changes. There's no trick to knowing which way she spins when one breast appears and then the next. The trick is that the change is imperceptible, people think they're looking at an optical illusion. Where did this come from?

No its real. My friend and I were staring at it the same time. It was CCW for me and CW for him at the same time. The first time I went to the website it was rotating CW but I was able to switch (after a little practice) by staring at the feet. Much easier for me to change CCW to CW than CW to CCW. Also, if it was going CCW and I read anything it reversed. Definitely fun.

I agree with Roger - no trick. I downloaded the image (.gif) file from

http://www.news.com.au/common/imagedata/0,,5675247,00.gif

and pulled it into ImageReady. It's a 34 frame animation, played at 30ms per frame, then just looping. There's nothing in the source code for the web page to suggest it could be played backwards. Also, you can view it on its own in e.g. Windows Picture & Fax Viewer, & get the same effect.

Odd thing is, if you scroll the filmstrip back & forward (in ImageReady), it looks (to me) as if she's going CW when scrolling back, & CCW when forward.

Hope I'm not treading on too many copyrights here!

Thanks for posting the picture - our blocker at work wouldn't let me go to the site. Unfortunately, I can't make it look like she is doing anything except spinning CCW. I've tried all of the tricks indicated by others so far. Maybe I'm just trying too hard?

The heck with that...where can I meet her?

Yeah I would have to say, at least for the males, it is an optical distraction. Do we really care which way she is spinning? Can I get her phone number?

It depends on where you look. If you focus on the feet you can make it look like it is just going back and forth. Normally we don't attend to where our gaze is and it wonders around some. So as your focus moves from point to point it changes your perspective. if you focus on certain features you can get it to spin in only one direction. But looking at the feet makes it much more unstable.

After 9 years of classical ballet training and about the same in TaeKwonDo I have had a lot of experience watching human bodies spinning.

Great illususion, I appear to be able to change her rotation at will just by thinking about it. Spencer.

It is an illusion of the eye/mind.

If one concentrates on seeing only the upper foot, in relation to
the rest of the body, the figure only oscillates to the left and right.

That is, the mind "fills in the blanks" when seeing the overall shape.

If the upper foot, at the time, is oscillating to the left (clockwise)
the mind "understands" the figure is rotating clockwise. Conversely
if the upper foot is oscillating to the right, the mind "considers" the
shape to be rotating anti-clockwise.

This can be shown by masking the shape above the knee of the upper leg;
where, now with an open mind, the upper leg (bum) does not pass "around"
the back of the figure; the leg only to oscillate to the left and to the right.
Now, remove the mask and the figure will rotate in your chosen direction.

The mind has filled in the blanks, to "understand" and complete the motion.

jt.

No kidding - 10 million to be won on http://www.mfnb.at

I'm now pretty sure that (for me) it has something to do with concentration (& ability to concentrate). I've been up for about 20hrs & had about 5 pints - my eyes are starting to wobble. I can only see CW now!

(ref. my #8: ... seems CCW if concentrating, but CW in peripheral vision.)

I perceive her as spinning clockwise only -- I tried without any success to see her going the other direction. Maybe I am a hopeless right-brainer. I will try again. I don't like the idea of being half-brained or hemisphere prejudiced.

Try scrolling this page till you see only the legs from the knees down. Then it is easier to make it go either way. Just when the foot gets to one side, imagine it coming around to the front... or back.

Ken, I tried your suggestion, and it worked immediately. Once I saw the counter-clockwise motion of the feet, I gradually uncovered the remainder of the image as was able maintain the CCW spin. Focusing on the least detailed part of the image apparently facilitated the change of direction. I guess the top part of this image has stronger visual cues that trigger the left/right hemisphere perceptual bias. Very interesting optical illusion.

Does that mean the sun will eventually rise in the west?

Hi PWSlack, Be frightened, very frightened. Otherwise, I seem to make the figure revolve any way I wish just by looking at it and willing it with my mind, am I some sort of psycic? Spencer.

Scapolie- Are you talking about the spinning globe? That would be scary but I don't think it is psycic. It may in fact start with the same four letters but it is a different work I am thinking of. Are you able to morph other objects at will?

No I'm only joking. Spencer.

Actually, you might be physic.

Hi vermin, Yes you are right because I just knew that you would add to this post sooner or later. Spencer.

Well, actually I was looking for a post on ontological empiricism, but this intellectual challenge was just too much to pass up!