[HN Gopher] Mind-Bending Perceptual Illusions (2018) ___________________________________________________________________ Mind-Bending Perceptual Illusions (2018) Author : robertwiblin Score : 73 points Date : 2021-08-25 19:04 UTC (3 hours ago) (HTM) web link (nautil.us) (TXT) w3m dump (nautil.us) | cymon wrote: | Number 12 is quite something, it works with anything you look at | after staring the center of the top image. I looked at my food | and I could see it moving in a very odd manner, went back to | image for 15 seconds and looked at the walls, same effect and | repeated the same with other stuff and after 10 minutes I feel | motion sickness like the one you get after spinning and losing | your balance (not everyone gets this I think) | gpas wrote: | It's amazing how well it reproduces how some psychedelics warp | vision. Those act on the brain, this tricks the eyes, similar | result. | | I experience something similar while cycling on trails. If I | watch only the road rolling under me for some time and then | look at some static object, like a big cloud, it appears to | move towards me (or away, can't remember right now). | the_arun wrote: | Very nice collection. All the illusions are due to natural | intelligence in the days of artificial intelligence. Brainpower | is always a mystery to me. | cwkoss wrote: | I wonder how many of these illusions work in 3D. Might have to | take a crack at modelling the rice wave illusion or the cafe wall | illusion for 3d printing. | causality0 wrote: | Number 8 has not been created correctly. The line segments | actually are being lengthened and shortened because the black | segments overlap part of the colored line when they're convex and | do not when they're concave. You can see this if you lay the tip | of your mouse pointer over them. | dredmorbius wrote: | One of may favourite instances of an optical illusion ever is | this short video of a cat pouncing on a sheet of paper on which | shows an apparent-motions spirals illusion. | | https://yewtu.be/watch?v=S4IHB3qK1KU | | It reveals that at least _this_ aspect of feline and human visual | perception appears to be similar. | | As a means of getting inside a cat's head, it's never failed to | fascinate me. | | There's another ... _perceptual phenomenon_ is probably a better | description than _illusion_ ... contained in an episode of the | You Are Not So Smart podcast. In it, a short snippet of noise is | played. It sounds completely random. After a cue is heard ... the | noise resolves to a comprehensible message. | | In my case, I'd started listening to the podcast whilst falling | asleep. I don't recall consciously hearing the cue ... but ... | when I replayed the podcast the next day, _I could understand the | audio clip on the first play_. I 'd "crossed over to the other | side* without even consciously hearing the cue. | | (I've looked for the episode in the archives listing. I cannot | find it though I think it may turn up.) | | https://youarenotsosmart.com/all-posts/ | tobr wrote: | > 3. Confetti | | > The illusion is a vivid demonstration of the fact that we don't | directly perceive the colors of objects in the world. Instead, | the perceptual system takes an educated "guess," based on the | objects' surroundings. | | I disagree. E.g. the circles overlapped with green and blue lines | look greenish to me, and the circles overlapped with purple and | blue look pinkish. If the apparent difference was due to | perceiving the lines as a neutral surrounding, the effect should | be the opposite: a circle overlapped with green should come | across as _less_ green, not more. | | I'm pretty sure the effect just comes from half-toning. | carl_dr wrote: | Agreed, I experience exactly the same, and is the weakest | (read: most easily understood) example shown. | | The others are all very good, I really like that I can | understand why I am perceiving them the why I do, but despite | of that can't "fix" that perception. | croes wrote: | >If the apparent difference was due to perceiving the lines as | a neutral surrounding | | That's not how it works. | | https://www.livescience.com/confetti-munker-white-optical-il... | | Another example | | https://www.sciencealert.com/crazy-optical-illusion-makes-yo... | matsemann wrote: | Check out http://illusionoftheyear.com/ | | It's a yearly contest with people coming up with various stuff. | Normally one finds Kokichi Sugihara in the top. I'm a big fan of | him after meeting him at a conference (FUN With Algorithms), and | made my own attempts on some of his concepts: | https://github.com/Matsemann/impossible-objects | codeulike wrote: | https://github.com/Matsemann/impossible-objects | | holy crap those gifs with the mirror are completely doing my | head in | JabavuAdams wrote: | Wow, that means we really can't trust our eyes / senses for a lot | of things! Some people should figure out a way for us to figure | out what's true or not, even though we can't see what's true or | not. /sarcasm | dylan604 wrote: | That's why eye witnesses aren't as reliable as one might think | niccl wrote: | I've often wondered if there are perceptual illusions for blind | people: Maybe a physical cafe wall would feel like the rows | weren't parallel. | john579 wrote: | I seem to be immune from most of these illusions. I am not color | blind and both my eyes can see fine. It must be something inside | my head that's different. I have to read the explanation to | understand what other people are seeing. ___________________________________________________________________ (page generated 2021-08-25 23:00 UTC)