tag:blogger.com,1999:blog-8627322010786735293.post8204206315475913264..comments2023-10-01T09:35:35.894+02:00Comments on Antipodes: Explanation of the spinning woman demoWilliam Skyvingtonhttp://www.blogger.com/profile/10052367756561555096noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-8627322010786735293.post-86243738288553364282009-05-26T19:44:33.928+02:002009-05-26T19:44:33.928+02:00I find it amazing that innocent observers are stil...I find it amazing that innocent observers are still commenting upon this illusion, of zero interest. It's a cunningly-designed animated GIF. That's all there is to say. As they say in France, we should not seek midday when it's already two'clock in the afternoon... I repeat: This animated GIF of a spinning woman is a totally uninteresting illusion. I end up regretting that I ever joked about this gadget.William Skyvingtonhttps://www.blogger.com/profile/10052367756561555096noreply@blogger.comtag:blogger.com,1999:blog-8627322010786735293.post-26818486802025297782009-05-26T16:11:04.739+02:002009-05-26T16:11:04.739+02:00I agree that the spinning is in the animation. I'...I agree that the spinning is in the animation. I'm not a computer scientist, animation expert, or Ph.d; but if you scroll your screen up and look just at the animation the shadow of her feet, you can tell it's programed. The shadow of her lifted foot either passes to the front or the rear of her body showing the circular motion. Without the spinning body in sight, you can plainly see when she changes direction!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8627322010786735293.post-16587072852370218292008-08-10T07:44:00.000+02:002008-08-10T07:44:00.000+02:00I disagree with the above explanation. It's a ver...I disagree with the above explanation. It's a very simple and effective, yet well thought out, illusion. The direction of spinning is actually ambiguous - in other words you can either interpret it to be clockwise or counter-clockwise at any point in the animation. So yes, the direction of her spinning does depend on your interpretation of the image.<BR/><BR/>To understand how this illusion works, you could imagine a simple square rotating such like the silhouette. The first still animation of this rotating square would just simply look like a square. With each subsequent frame of the animation this square will shrink width wise ever so slightly until it is a mere line. At this stage of the animation the square would have rotated 90 degrees. As the square continues to rotate, it will expand width wise until it is back to its original square shape. So the square has now rotated half a cycle as the back of the square is now facing you.<BR/><BR/>Either the square rotated clockwise or counter clockwise, whichever way your brain interpreted it. The direction is ambiguous because the element of depth has been left out here. In real life, as the square rotates, the side that has come closer to you would have appeared to become larger. But in this case, the square only shrinks width wise so that the direction of rotation is unknown.<BR/><BR/>If you look at the individual stills, in each of them, the leg that is lifted can either be her left or her right. Infact with a bit of brain control, you really can make her "rotate" in the other direction at will.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8627322010786735293.post-34603729599055962492008-02-09T14:48:00.000+01:002008-02-09T14:48:00.000+01:00But why two people seeing the gif at the same time...But why two people seeing the gif at the same time perceive the change in rotation at different times?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8627322010786735293.post-41988921995131144152007-10-21T12:49:00.000+02:002007-10-21T12:49:00.000+02:00Neither was my comment - it was supposed to be a j...Neither was my comment - it was supposed to be a joke as well!<BR/><BR/>Thank you for your explanation, at least now I understand how it works.<BR/>It's a great animation.cmhttps://www.blogger.com/profile/13628012646010636255noreply@blogger.com