It's possible to create "impossible" shapes in real life: https://flownet.com/ron/trips/Europe2023/pause/206.html
2D projections of 3D impossible shapes, yes.
Akiyoshi’s Illusion Pages
31–40 of 65 posts
Re: Akiyoshi’s Illusion Pages
#32Some of the movement illusions really pop out if you slowly move your finger across the image and track it with your eyes. Or use a mouse pointer similarly if you're on desktop.
Re: Akiyoshi’s Illusion Pages
#33The second black hole one "Approaching black hole: yesterday" is stunning. I cannot believe it's a still image. http://www.psy.ritsumei.ac.jp/~akitaoka/saishin69e.html
Am I alone in not understanding this black hole one... it's a sequence of three obviously distinct still images in which the black center is larger than the previous image. Meanwhile, each image on its own is offering no kind of perceptive illusion to me...
I don't intuitively understand any illusion. I don't have conscious introspection into what the layers of neurons are doing between the retina and conscious visual perception. The layers of neurons use certain indirect cues in order to detect size, depth and movement. Those cues do their job in most circumstances, but test cases can be constructed which falsely trigger those cues. That's just an intellectual generality that doesn't explain anything specific.
Re: Akiyoshi’s Illusion Pages
#34I was really happy about the first one, "spontaneously", including the quotes, this is such an apt description!
Alas, for me it seems to occur mostly on eye movement/focus change.. which happens to happen... spontaneously
Re: Akiyoshi’s Illusion Pages
#35Earlier quoted context omitted.
Am I alone in not understanding this black hole one... it's a sequence of three obviously distinct still images in which the black center is larger than the previous image. Meanwhile, each image on its own is offering no kind of perceptive illusion to me...
I don't intuitively understand any illusion. I don't have conscious introspection into what the layers of neurons are doing between the retina and conscious visual perception. The layers of neurons use certain indirect cues in order to detect size, depth and movement. Those cues do their job in most circumstances, but test cases can be constructed which falsely trigger those cues. That's just an intellectual generali…
You should add shadow to the list of important cues. Something light in shadow can be the same color as something white in direct light. You can see that optical illusion in https://en.wikipedia.org/wiki/Checker_shadow_illusion.
My favorite example of where shadow matters is "the dress". As https://slate.com/technology/2017/04/heres-why-people-saw-th... explains, those whose brains assumed it was in shadow saw it as white and gold. Those whose brains thought it was in light saw it as blue and black. (It was actually a blue and black dress, in light. But the photo was taken in such a way that most people thought it was in shadow.)
Re: Akiyoshi’s Illusion Pages
#36I used to have a high quality printout of the rotating snakes illusion by my desk.
I had people who refused to be at my desk because it creeped them out that they absolutely knew the paper couldn't be moving, but their brains kept seeing the snakes rotate.
Re: Akiyoshi’s Illusion Pages
#37I can never see these illusions :/
Only the bulge works. Movement I can’t see at all.
Am I supposed to look at it a certain way? I tried at different distances. I’ve tried using larger screens. Nothing..
Re: Akiyoshi’s Illusion Pages
#38I can never see these illusions :/ Only the bulge works. Movement I can’t see at all. Am I supposed to look at it a certain way? I tried at different distances. I’ve tried using larger screens. Nothing..
A lot of the movement ones are more noticeable with actual movement so scrolling a little bit could help. I notice them popping more when I scroll through his twitter feed.
Re: Akiyoshi’s Illusion Pages
#39I used to have a high quality printout of the rotating snakes illusion by my desk. I had people who refused to be at my desk because it creeped them out that they absolutely knew the paper couldn't be moving, but their brains kept seeing the snakes rotate.
What a great filter that must be!
Re: Akiyoshi’s Illusion Pages
#40One of Akiyoshi Kitaoka's recent work that I found absolutely stunning is the following illusion where a ring of one colour appears to be either in front of or behind two rings of another colour:
https://twitter.com/AkiyoshiKitaoka/status/16812686184854568...
https://nitter.net/AkiyoshiKitaoka/status/168126861848545689...
To my perception, the blue ring appears to float above the red rings. It feels a bit like an autostereogram where a 3-dimensional image emerges out of a 2-dimensional image. However, there is no autostereogram in this image and there is no crossing of eyes involved. The 3-dimensional image arises out of an otherwise plain image of differently coloured rings on a dark background.
An analysis of this illusion is available here: http://www.psy.ritsumei.ac.jp/~akitaoka/Kitaoka2015_Referenc...