When mowing the grass, after stopping, it seems like the the world is getting "zoomed out" whereby the tractor and environment seems to be getting stretched and elongated. The closest thing that I can call this is the "vertigo effect" or "Dolly Zoom." As a kid, I always wondered why this happens when in the passenger seat of a car when coming to a stop, where it suddenly looks like the car is going backwards even when completely stopped.
Yeah. I've had this happen when using music visualization software. The first couple of times I used it, I was freaked out thinking "What's wrong with my monitor? Why is everything moving up?" Then, I realized that it was just my eyes playing tricks on me.
+thanrose -- No, I don't think it's anything like that, That problem appears to require a migraine, knock on wood, I don't think I have ever had a migraine. It's not randomly distorted perception, it is a motion exactly opposite of of the motion while mowing. Same effect as the spinning wheel illusion.
Pause at 3:54-55 during the shepards table, and I have a problem with the illusion. You can clearly see that the perceived difference comes from the fact that the slender one if being shown from a specific angle to highlight one of its edges that seem to add to its length. The same thing is being done for the short one, but its angle is shown to highlight the edge on its side, adding to its width.
I have a problem with this illusion too, or maybe it's more with his explanation of it. When he says the table on the left "is much longer than it looks" doesn't he really mean "it looks much longer than it is" ? I think if photos taken from different sides of a real squarish table had been used instead of drawings this trip-up would have been less likely, but also the effect less surprising. Does that coincide with what you're basically saying?
The nearsighted make up around 40% of Americans, so we're not going to be the minority for much longer. :( We already make up the majority in some regions on earth.
I can see the spinning dancer spinning either way if I want to. If I'm not trying, I see her spin clockwise, but I can make her spin counter clockwise (most often by looking at her feet for a moment).
Yep, the dancer was cool. First I wondered how one could see her on her right foot and then the arrows came and she started to move in the other direction. :)
What a great question. I'm gonna guess no, because their 'eyes' don't have cones and rods, but I'm not a scientist. So far, the comments look so stupid...I hope your question isn't lost. Why don't you give yourself a thumb's up on your question and little by little, maybe we can push it upward and someone who can answer, will answer.
SlyPearTree I highly doubt it. As explained in the video illusions are caused by taking advantage of shortcuts in the way our brains perceive the world, along with fatigue as previously mentioned. But with either case it's caused by the brain comparing pieces of visual information and applying existing knowledge about how the world works. Whereas to an artificial eye and brain it's purely quantitative information - pixels and numbers. And it can't suffer from fatigue that would affect it's perception. All information is pure and direct, any comparisons made to existing knowledge is taken at face value, nothing altered to try and make sense of it. Because a computer primarily "thinks" in exact measurements, whereas we think in approximations and generalizations.
I imagine that making them operate with similarly "simple" short cuts as us would effectively improve their day to day ability to process visual information. These illusions are the rarity and acceptable errors when compared to just how quickly and accurately vision can be with animal brains, ours included. Trying to make things perfect would require insane computational power and slow things down to a crawl.
I do not believe there is an advanced enough AI vision system that exists to detect optical illusions much less know what is going on in a video or picture Object detection through pictures is one of the most complex problems in the computer science fields, and as far as I am aware the best method for AI to learn what is in a picture is through large amounts of test data in a neural network meaning it probably won't know what its seeing is an illusion much less an object it is familiar with.
Yes, no and it depends on the case and how you'd define the term "optical illusion". Not in a sense like the optical illusions that the human eye perceive(like the ones in the video) but since camera sensors and especially AI(AI is nothing more than a bunch of algorithms, there is no true AI) have their flaws so you can fool them, technically that would be sort of an optical illusion(just one not intended for humans). Take facial recognition for example, it can be very easily fooled by painting specific pasterns on your face, from the sensor/software perspective that would be an optical illusion.
I'm pretty sure the dots on your shirt are because of the way that plaid works. Also, they're brighter than the lines that intersect to make them rather than darker, making them inconsistent with the illusion you spoke of.
I agree, Hank's shirt actually has more white thread at the intersections, and those intersections are literally brighter than the lines leading to them. Though the individual threads may be the same color. At a minimum, the shirt is not an analogous illusion to the intersecting lines illusion.
your comment shows that you are a misagonistic liar and you propagate patriarchy! thats how lacy would react when you call her out on inconsistencies in her videos
The white squares are there. They are where the white vertical threads cross the white horizontal threads, and there are no black or blue threads present in those places. Through the rest of the white lines, there are darker threads interwoven. Yes, I don't see any "dark" spots there at all.
Huh, I used to be able to flip the spinning dancer at will. Like, it high school when this GIF went around I remember bragging that I could flip it and explaining to friends on one side how the other side perceives it...thing is, I can't anymore. Weird.
Certain optical illusions are harder for the aging eye. I used to be able to perceive and analyze many illusions, but as an old lady it's more challenging, sometimes impossible.
I can flip her but it takes some focus. Like I can't just swap my perception instantly, I have to stare her and think about how I could perceive her going the other way then suddenly she switches.
The spinning dancer, I found the direction of her perceived spin actually depends on which direction you first see her face in profile. Most people I "tested" said if the animation began with her facing to the left they saw her spin counter clockwise, and if the animation was started with her facing right, she spun clockwise! If you start it so you can't see her face and hair, I got the numbers you mention in the vid. I think its cuz people assume her first rotation would bring her face front rather than turning her back first. Now I wonder if that varies by gender, culture, and background?
Same! Maybe it doesn't work in video format, or they sped up the animation so it's harder to change perspective. Either way... That one was bothering me too.
I can switch the dancer to go either way but I don't know how I do it and I can't just switch, I have to kinda be rotating my head ever so slightly in the direction I want her to go and she eventually catches on and rotates the other way. And I don't mean I'm literally rotating my head 360 degrees, I'm just making a little circle rolling my neck. damn that's really hard to explain but so easy to do. Why am I telling you this, persons unknown? because I'm bragging. I can finally do something. I'm one of the chosen ones that can change her direction. When you're as messed up as I am, you've got to hang onto these small victories!
Clay Mann I can switch her direction on cue. Naturally I see her spinning counter-clockwise, but if I focus on her feet then I can make her spin clockwise. Fun fact: if you've ever played kingdom hearts, the heart that shows up when the game is loading works like the dancer illusion. I can switch the heart much easier than the dancer. I can even make it switch back and forth to the beat of the background music
Palapa69 Backup yeah I've encountered this before. There's a great train GIF floating around where you can make the train go forward or backward because not enough frames have been captured to really fill in what's happening. Ok I got off my lazy arse and found it. i.imgur.com/TnfzrDD.gif Remember, we are the chosen ones! Our special power? We are able to change the direction of a thing where the recording is too ambiguous to define its direction. Do not abuse this power!
I had an odd fixation with optical illusions when I was in my young teens and I remember sharing at a gif of the Spinning Dancer on Wikipedia for a long time trying to understand the illusion. When I finally got it to flip directions, I was stunned.
During the summer I often choose to sip down my afternoon tea in a chair on the lawn. As I sit there, I sometimes look down onto the grass, and if I focus at one point, the grass straws around that point seem to start swaying slowly back and forth, making this uncanny, but at the same time soothing wave pattern. During the winter, when the sun is shining down on the snow, making it glitter so brightly it almost hurts my eyes, this myriad of little swirly dots, glimmering in blue or purple, appear before my eyes.
Oh i actually changed the way the dancer was moving. At first i thought it was the video but then i went back and saw she was moving counterclockwise but then i looked at my table for a split second and she started rotating clockwise...
The spinning dancer's really cool, it's quite easy to make it go in either direction by initially focusing just below the dancers feet before looking up to the middle of the dancer.
The spinning dancer freaked me out because as soon as he mentioned that people saw it both ways, it switched for me and I couldn't figure out why it happened.
"I might seem like I'm moving around but I'm not. I'm just a series of completely still images flashing quickly before your eyes. Your brain is simply stitching those frames together to create the impression I'm moving around like I would be if I were right in front of you." But wouldn't my brain be doing just the same thing if you were in fact right in front of me?
Thank you for actually explaining how these happen, rather than just showing it and saying it's cool, like pretty much every other time I've been shown these.
Okay, I've been trying to meld these two pieces of information in my head together for a while now, but they just seem to contradict one another: If our eyes only have cells to detect red, greed and blue light, and every other color is a mixture of their respective intensities at any point in time, then does that mean that the visible spectrum of light essentially only contains those three colored wavelengths? Everything I've read about how vision works leads me to believe that there is no such thing as a "purple wavelength" because if there were then how could we see it if our eyes are only sensitive to RGB? But everything I've also read about physics seems to contradict this line of thought, the very concept of UV light for instance depends on the existence of a "violet" for it to be the "ultra" for. So how is it? Does the "purple wavelength" stimulate both red and blue cells so that they both fire up at the same time or something along those lines?
We see with three pigments that don't only see specific colors. They merely have greater sensitivity to certain shades like little hills. The peaks have greatest intensity while the edges only barely activate to those parts of the spectrum. Intense near infrared will activate the "red" pigment weakly, but red will activate it strongly, for example. A specific light hue will invoke them to varying degrees and we interpret that exact balance as a pure single color. We see purple light the same as a mixture of red and blue even if they are composed of different wavelengths of light. That said, there are some oddities of our vision where we see colors that don't really exist as wavelengths of light. Pink is really just low saturation red. Browns are really weak yellows or reds.
Ultimately mapping wavelengths to colors is an exercise of human perception, not pure physics. The visible spectrum is a continual thing and the energy of any given photon is it's wavelength. What that will end up mapping to in a visual system is different for me, you, a gorilla, a sea-slug, etc.
maybe this is an example for ppl seeing color differently. i for example dont see purple on the high frequency end of the visible spectrum. but i have friends who seem to see something they call "purple" for me its just a very dark blue.
+Zetsubou Z. That's a good question, hopefully this graph will help. It shows the ranges of wavelengths each cell is sensitive to: hyperphysics.phy-astr.gsu.edu/hbase/vision/imgvis/colcon.gif As you can see they don't ONLY detect one color at a specific wavelength, rather they each detect a wide range of wavelengths that is centered on different colors. So the red cell will be triggered most strongly at a red wavelength, but will still register colors near it. Hope that helped!
you know, I just started my paetreon subscription and now when you thank us at the end, it feels like I'm apart if this fabulous channel! I'm happy I can help you guys share knowledge to the world!
at first I wasn't sure which way I thought she was spinning (and that direction might have even changed while I was thinking about it), so I started playing it over to see if I could change it, until momentarily it did right at the end. I started writing a comment, then caught hank explain why people think she spins a certain way, and now I can easily change which way I see.
If I skip back a bit and rewatch the spinning dancer it will randomly switch for me. I think it may be going from the first glimpse you have (and the subsequent motion) and your brain continues it from there. I can't switch between the directions while watching one clip (though I am just rewinding and using the same 10s, I didn't find a long loop of the video elsewhere).
Further to this, I think the deciding factor could be the direction of the dancer is A) where on the image your eyes are when you first see it and B) what frame the loop is on when you catch this first glimpse and C) the angle and lighting and other varying factors that influence ones vision. I have a hard time believing that "different types" of people process this information differently. Unless perhaps other cultures tend to look at other parts of an image that when influenced by the language they speak and the conventions they have for print.
I figured out how to see the dancer spinning the other way by focusing on her pony tail. The bobbing up and down makes it so that when she goes away her hair comes back the same way as it came if that makes sense making it easy to notice from the pony tail
TOP 10 mind blowing reasons why scishow is turning into every click-bait RUclips channel ever. (*red arrow pointing to red circle with a mysterious half naked hank making goofy face with a fluorescent background*)
So information is HIGHLY dependent on our perceptions because we aren’t conscious enough or do not have enough attention to examine the environment efficiently. So it relies on memory to put the puzzle pieces together rather than taking the time to analyze it. Very interesting.
i'm the opposite, gesturing is how people talk, people who keep there hands still, like those in commercials(where they have their finger tips touching in front of their stomach) looks weird and unnatural
Yeah, good luck with that. Even if they would make such a video most viewers wouldn't notice it. Same with changing colors of shirts after showing some distraction.
Another case of the Waterfall Effect is when you get out of the car after a particularly long drive, the ground will look like it's retreating slowly away from you.
For Illusion #5: I don't know what effect aging has on perception, but I know that when I was younger, I could easily swap between seeing the dancer rotate in either direction (to the point where I would accidentally swap between the two without trying). Now it takes quite a bit more effort...
number five is truely MIND BLOWING! I can switch between the two, but only by looking at the feet, legs, and hips. I guess I'm naturally clockwise because she spins like that when i'm not really focusing on anythin'. This one's awesome! I gotta share this one!
squarebamboo Embrace the corrections. And help me start a cult that believes that typos are the enemy of life and that everyone must play their role or go to poorly written heel. Don't tell anyone, but I don't believe this. I'm in it to trick people into wearing sarcastic t-shirts. Also that "heel" was intentional if you couldn't tell.
I like to differentiate between visual illusions (those involving brain/neuron processing tricks) and optical illusions (those like your last one which involve physical manipulation of light) when I teach this to my high school students
Just a mild correction but at around 2:00 minutes you say the green cones are firing because you are looking at something green. Counterintuitively the cones ( or any photoreceptor) fires in the absence of the light that it signals for ( be that colored or not ). When they are hit by the light they are sensitive too the photoreceptors hyperpolarize ( I.e become inactive/inhibited). Through a process called disinhibition, bipolar and then retinal ganglion cells fire and relay to the brain that the color the photoreceptor is sensitive to is there. Not a complete explanation here but it is the basic scheme of detecting light/ visual information. This might make for a good sci show episode/ QQ.
Brain.exe has stopped working... rebooting... please wait... Anyway, like I was sayin', shrimp is the fruit of the sea. You can barbecue it, boil it, broil it, bake it, saute it. Dey's uh, shrimp-kabobs, shrimp creole, shrimp gumbo. Pan fried, deep fried, stir-fried. There's pineapple shrimp, lemon shrimp, coconut shrimp, pepper shrimp, shrimp soup, shrimp stew, shrimp salad, shrimp and potatoes, shrimp burger, shrimp sandwich. That- that's about it.
Spinning Dancer has it's "body" shaped like it's moving clockwise, while it's "shadow" is shaped like it's moving in the other direction. If you see her moving clockwise, look at the shadow for some period of time, and you'll see her counter-clockwise.
Changing the direction of the spinning dancer it's pretty easy , just focus a couple of seconds on the foot's shadow or on her arms (depending on your starting direction).
Say Hank, I don't know if you get notified about comments on old videos but I will give it a go. Without going into incredibly tedious detail I once spent two years teaching a computer how to dig images out of very poor images taken under radically different conditions. You could probably make a fascinating video out of how computers are taught to distinquish things like wheels and up rights and .. well you get the idea. In my work I also studied in depth the human eyes response and how it knits together missing information to fin the real thing. Sometime when you have a few years try to knit together the image of someone running through trees in such a way as to be able to distinguish the person correctly LOL. Anyway, as always keep up the great work.
when I first learned about optical illusions in elementary school, I found I could 'flip' the illusion very easily, Magic Eye posters were a great distraction for their time, but I do love a good Olde Fashioned '3rd Screw' or 'Face or Vase'. I guess I'm just a Classicist.
For the spinning dancer to spin in your direction of choosing: To see spin clockwise then cover top half with hand and focus on foot spinning on ground To see anticlockwise then cover bottom half with hand and focus on spinning chest If you are having difficulties then blink a few times and try again.
I see the dancer constantly changing direction, I wish she'd make her mind up and stick to it. I'm not trying to change it, but trying to keep it unchanging, if that makes sense. Hank's checkered shirts have always grooved my eyes!
Fun fact about persistence of vision, your brain can actually retroactively apply what you're looking at now to your memory of the past. This is most noticeable by looking suddenly at a mechanical clock or a stopwatch or timer counting in second increments. During the time it takes to move your gaze from where you're looking before to the clock, your brain receives a blur of nonsensical information that it ignores, and it can fill your memory of that time with the clock you have just started staring at. This is why, if the timing is suitable, it can appear to take longer than a second for the second hand to keep on ticking. At least, that's one idea. There's also theories related to time perception dilation, whereby your brain works faster, effectively slowing your perception of time. But who knows?
If you're having trouble getting the woman to spin the other way, click around the video while she's still on screen. The sudden start of her appearing on screen can reset the illusion, making the rotation appear more prominent depending on what frame of the animation it started on. At the very least it works well for me.
I just googled the spinning dancer and the the first time I saw it, it was spinning counter clockwise. After I typed a comment that I was supposed to post here, I viewed it again and now it's spinning clockwise like how I saw it in this video. Then after I typed this, it's spinning counter clockwise again. Lmao.
I could only see it clockwise, so studied it for a bit and looked at it different ways. Got it counter clockwise, the back for a split second, but now, I'm stuck on counter clockwise. Cant get it back to clock wise! So weird! I love it!
For the spinning dancer, if I cover everything but her legs, it just looks like she’s wobbling instead of spinning. If I uncover her when her foot is moving to the right, I see her moving clockwise, if I uncover her when her foot is moving left, I see her moving counter clockwise. I wonder if that will work for anyone else.
In theory, the "Flying Dutchman" should appear upside down. Exactly like the sky is "reflected" on the ground in a warm desert, the illusion is reversed by the multi-layered reflection in cold bioms. Was part of my physics exam when in high-school (even tho it was with a good not ol' steel warboat on the illustration^^) so I remember how it works thanks to that.^^
#6: This is colour constancy NOT lateral inhibition. Lateral inhibition is when your brain prioritises resources from the periphery to observe precise details in your central vision (e.g. when you're trying to find something you dropped on the floor, or if you're trying to track a fly)
My personal experience with Motion Aftereffect is from playing Guitar Hero for an hour or so. It used to trip me out I'd play the game and then just watch the wall slowly "move" upward it was kinda cool.
i forced myself to stare at spinning dancer until i was able to see it both ways. i had to, lol. what helped me was concentrating just on the lower foot. imagine what it would look like if the foot was going the other way than the way you're perceiving it now. imagine the shape it would make and overlay it over what you're seeing. then it just snaps into place. once you get the foot right, everything else lines up.
*watching on phone*
*Hank says he's not moving*
*starts rapidly shaking phone*
tell me what's happening now, HANK*
R33KO I want this comment to succeed
+Swampy Mudkipz ^
R33KO *vigorously breathing* oh god!
*breathes harder*
send help!!!!!!!
Hank is not moving, the series of pixels that represent him are.
Sir Francis Lies, I bet he's moving *as we speak*
3:34 The waterfall illusion, AKA, the Guitar Hero illusion, because your TV starts to rise after you pause a game of Guitar Hero.
LimeGreenTeknii damn right \m/
When mowing the grass, after stopping, it seems like the the world is getting "zoomed out" whereby the tractor and environment seems to be getting stretched and elongated. The closest thing that I can call this is the "vertigo effect" or "Dolly Zoom." As a kid, I always wondered why this happens when in the passenger seat of a car when coming to a stop, where it suddenly looks like the car is going backwards even when completely stopped.
Yeah. I've had this happen when using music visualization software. The first couple of times I used it, I was freaked out thinking "What's wrong with my monitor? Why is everything moving up?" Then, I realized that it was just my eyes playing tricks on me.
+Power Max -- Check out Alice in Wonderland Syndrome. It may be the vibrations of the mower that trigger this for you.
+thanrose -- No, I don't think it's anything like that, That problem appears to require a migraine, knock on wood, I don't think I have ever had a migraine. It's not randomly distorted perception, it is a motion exactly opposite of of the motion while mowing. Same effect as the spinning wheel illusion.
I looked at the wall after this vid and saw
Hank Magenta.
Hank's evil twin!
shame. it took me several minutes to get it :/
I was hoping the election results was going to be on this list...
lol
DarxLite Aren't you a Savage
Questionable Cat Questionable cat
+DarxLite - Epic comment, my friend.
wewew salty libtard tears are my fav drink
Didn't blow my mind... my brain is still intact... I call click-bait...
+ExMachina inap
Did it at least give your mind a hand job?
SciShow has people to pay! Lighten up ;)
ExMachina inap
The title is 8 optical illusions. If you didn't learn anything from this you're heading towards brain death.
🤣🤣
Pause at 3:54-55 during the shepards table, and I have a problem with the illusion. You can clearly see that the perceived difference comes from the fact that the slender one if being shown from a specific angle to highlight one of its edges that seem to add to its length. The same thing is being done for the short one, but its angle is shown to highlight the edge on its side, adding to its width.
I have a problem with this illusion too, or maybe it's more with his explanation of it. When he says the table on the left "is much longer than it looks" doesn't he really mean "it looks much longer than it is" ? I think if photos taken from different sides of a real squarish table had been used instead of drawings this trip-up would have been less likely, but also the effect less surprising. Does that coincide with what you're basically saying?
Did you just assume my vision?!
Yocool13's Channel *triggered* I'm triggered!!!!!
no, I'm even MORE triggered, cuz I wear glasses, so I'm vision impaired! it's a minority group! respect my oppression! lmao
*internally oppressed
The nearsighted make up around 40% of Americans, so we're not going to be the minority for much longer. :( We already make up the majority in some regions on earth.
Patrick McCurry evolution doesn't seem to be in yalls favor it seems
Hank looked at his wardrobe and said "Ah, there's the perfect shirt for today's episode."
I can see the spinning dancer spinning either way if I want to. If I'm not trying, I see her spin clockwise, but I can make her spin counter clockwise (most often by looking at her feet for a moment).
One of us! One of us!
MadeofAwesome4ever So unique. Really, just wow!
Péter Kardos 😇
MadeofAwesome4ever Same here
For me, i just have to close my eyes, and imagine her spinning the other way, and it usually works.
I switch between clockwise and counter clockwise with the dancer
haha nice profile pic, only few will get it
Yep, the dancer was cool. First I wondered how one could see her on her right foot and then the arrows came and she started to move in the other direction. :)
If you strip down the jif to single images, she changes rotation for a short bit and then back.
Abdul Malak yknow like peanut butter
Same here. To help switch between clockwise and anti-clockwise, watch her then her shadow.
I love pooping and watching scishow
literally!
Dude your ninja squirtles are epic I love it :D
Hopefully you're sitting on the toilet and not in a chair.
Perfect length vids. Even time for that “just to be sure” push.
😂😂😂
Are there AI vision system that get fooled by optical illusions?
What a great question. I'm gonna guess no, because their 'eyes' don't have cones and rods, but I'm not a scientist. So far, the comments look so stupid...I hope your question isn't lost. Why don't you give yourself a thumb's up on your question and little by little, maybe we can push it upward and someone who can answer, will answer.
SlyPearTree I highly doubt it. As explained in the video illusions are caused by taking advantage of shortcuts in the way our brains perceive the world, along with fatigue as previously mentioned. But with either case it's caused by the brain comparing pieces of visual information and applying existing knowledge about how the world works. Whereas to an artificial eye and brain it's purely quantitative information - pixels and numbers. And it can't suffer from fatigue that would affect it's perception. All information is pure and direct, any comparisons made to existing knowledge is taken at face value, nothing altered to try and make sense of it. Because a computer primarily "thinks" in exact measurements, whereas we think in approximations and generalizations.
I imagine that making them operate with similarly "simple" short cuts as us would effectively improve their day to day ability to process visual information. These illusions are the rarity and acceptable errors when compared to just how quickly and accurately vision can be with animal brains, ours included. Trying to make things perfect would require insane computational power and slow things down to a crawl.
I do not believe there is an advanced enough AI vision system that exists to detect optical illusions much less know what is going on in a video or picture Object detection through pictures is one of the most complex problems in the computer science fields, and as far as I am aware the best method for AI to learn what is in a picture is through large amounts of test data in a neural network meaning it probably won't know what its seeing is an illusion much less an object it is familiar with.
Yes, no and it depends on the case and how you'd define the term "optical illusion". Not in a sense like the optical illusions that the human eye perceive(like the ones in the video) but since camera sensors and especially AI(AI is nothing more than a bunch of algorithms, there is no true AI) have their flaws so you can fool them, technically that would be sort of an optical illusion(just one not intended for humans). Take facial recognition for example, it can be very easily fooled by painting specific pasterns on your face, from the sensor/software perspective that would be an optical illusion.
I saw the spinning lady change colour.
Just an optical illusion right? Ha.. Ha.. *sweating profusely*
wrg, no sweax, anxiex etc for suchx, anyx
Hanks shirt looks normal to me 6:40
Hank Magenta, also known as Hank Green xDxdxD
Hank Aftergreen.
Maximiliano Britez badum tss
The waterfall effect happens when you just stare at the road as a passenger. That gives a nice warp drive effect when you are stopped.
That drives me freaking crazy when I'm in the car (no pun intended).
I like propellers and ceiling fans. Used to try to "catch each blade" as it rotated to a specific point and count them properly as a kid.
I'm pretty sure the dots on your shirt are because of the way that plaid works. Also, they're brighter than the lines that intersect to make them rather than darker, making them inconsistent with the illusion you spoke of.
I agree, Hank's shirt actually has more white thread at the intersections, and those intersections are literally brighter than the lines leading to them. Though the individual threads may be the same color. At a minimum, the shirt is not an analogous illusion to the intersecting lines illusion.
your comment shows that you are a misagonistic liar and you propagate patriarchy!
thats how lacy would react when you call her out on inconsistencies in her videos
That would be expected, since the background is inverted, light on dark.
Not saying you're wrong. I can't tell if the squares are really there or not.
The white squares are there. They are where the white vertical threads cross the white horizontal threads, and there are no black or blue threads present in those places. Through the rest of the white lines, there are darker threads interwoven.
Yes, I don't see any "dark" spots there at all.
Huh, I used to be able to flip the spinning dancer at will. Like, it high school when this GIF went around I remember bragging that I could flip it and explaining to friends on one side how the other side perceives it...thing is, I can't anymore. Weird.
Atticus Lee same
Atticus Lee Being able to "flip the spinning dancer at will" sounds like mind controlled hard-ons.
Certain optical illusions are harder for the aging eye. I used to be able to perceive and analyze many illusions, but as an old lady it's more challenging, sometimes impossible.
look at where the legs cross for a long time
I can flip her but it takes some focus. Like I can't just swap my perception instantly, I have to stare her and think about how I could perceive her going the other way then suddenly she switches.
I saw her spinning counterclockwise at first but then it switched and now I can't change it back.
After a while it just started switching directions randomly.
The spinning dancer, I found the direction of her perceived spin actually depends on which direction you first see her face in profile. Most people I "tested" said if the animation began with her facing to the left they saw her spin counter clockwise, and if the animation was started with her facing right, she spun clockwise!
If you start it so you can't see her face and hair, I got the numbers you mention in the vid.
I think its cuz people assume her first rotation would bring her face front rather than turning her back first. Now I wonder if that varies by gender, culture, and background?
I usually have no problem turning the spinning dancer around but right now I just can't and it bothers me quite a bit.
Todesnuss You've become dumber. sorry
Todesnuss having the same issue haha
Same! Maybe it doesn't work in video format, or they sped up the animation so it's harder to change perspective. Either way... That one was bothering me too.
I looked up a gif of it online and couldn't figure it out either. Very odd.
Albert Einstein Thanks for the advice. I shall go visit a hair doctor first thing in the morning.
I can switch the dancer to go either way but I don't know how I do it and I can't just switch, I have to kinda be rotating my head ever so slightly in the direction I want her to go and she eventually catches on and rotates the other way. And I don't mean I'm literally rotating my head 360 degrees, I'm just making a little circle rolling my neck. damn that's really hard to explain but so easy to do.
Why am I telling you this, persons unknown? because I'm bragging. I can finally do something. I'm one of the chosen ones that can change her direction. When you're as messed up as I am, you've got to hang onto these small victories!
Clay Mann I can switch her direction on cue. Naturally I see her spinning counter-clockwise, but if I focus on her feet then I can make her spin clockwise.
Fun fact: if you've ever played kingdom hearts, the heart that shows up when the game is loading works like the dancer illusion. I can switch the heart much easier than the dancer. I can even make it switch back and forth to the beat of the background music
Clay Mann me too
Palapa69 Backup
yeah I've encountered this before. There's a great train GIF floating around where you can make the train go forward or backward because not enough frames have been captured to really fill in what's happening.
Ok I got off my lazy arse and found it.
i.imgur.com/TnfzrDD.gif
Remember, we are the chosen ones! Our special power? We are able to change the direction of a thing where the recording is too ambiguous to define its direction. Do not abuse this power!
Lucy zhang I see you have the gift, be careful who you share this knowledge with. There are those who seek to steal our power!
I didn't see dots on Hank's shirt... now I can unsee them.
I can too
The spinning dancer one is so much fun once it switches. All you do is pause it and then think of the way you want it to go. IT'S SO COOL!!!!
You mean to tell me that the Flying Dutchman isn't just from Spongebob? lol
you have got to be kidding me.....
Did your head explode when you learned that Bikini Atoll exists and was the site of massive atomic testing leaving some parts uninhabitable by humans?
Thank you Hank, and all others invovled in making science even more enjoyable here on youtube for YEARS!! Awesome work guys. Greetings from Sweden!
The spiral didn't work for me... even if I tried extending the video of the spiral by going back.
same effect as when you get off the car after a long ride. the world seems to be moving away from you for a little while
I think it's because their spiral is so wonky. They didn't bother to make smooth. They were too busy coming up with click bait titles.
I had an odd fixation with optical illusions when I was in my young teens and I remember sharing at a gif of the Spinning Dancer on Wikipedia for a long time trying to understand the illusion. When I finally got it to flip directions, I was stunned.
Wow! So that's why after skiing all day with orange goggles everything looks weird that evening
It's amazing how the way our brains process visual information and the way digital video compression works is quite similar
5. I'm able to switch between the two, but I have to pause the video and concentrate very hard on what I'm expecting to see.
During the summer I often choose to sip down my afternoon tea in a chair on the lawn. As I sit there, I sometimes look down onto the grass, and if I focus at one point, the grass straws around that point seem to start swaying slowly back and forth, making this uncanny, but at the same time soothing wave pattern.
During the winter, when the sun is shining down on the snow, making it glitter so brightly it almost hurts my eyes, this myriad of little swirly dots, glimmering in blue or purple, appear before my eyes.
Oh i actually changed the way the dancer was moving. At first i thought it was the video but then i went back and saw she was moving counterclockwise but then i looked at my table for a split second and she started rotating clockwise...
I like that this actually explains how illusions work rather than just saying "PSYCH THEY'RE ACTUALLY THE SAME SIZE" or something.
I can switch perceptions with the dancer. I feel special.
Right foot by default.
The spinning dancer's really cool, it's quite easy to make it go in either direction by initially focusing just below the dancers feet before looking up to the middle of the dancer.
4:24 Adolf Thicc
legend has it he had a thicc booty
Eddy Is Ready adolf fick
So motion aftereffect is probably why my vision gets all wavy after I play guitar hero or rockband for a long time
BUT WAS THE DRESS WHITE AND GOLD OR BLACK AND BLUE?
BLACK AND BLUE
Steve Cheetah White and Blue
Steve Cheetah A. All of the above
Am i the only one who were able switch from seeing gold and white to black and blue?
The spinning dancer freaked me out because as soon as he mentioned that people saw it both ways, it switched for me and I couldn't figure out why it happened.
Freaking Dutch people and their magic ships...
"I might seem like I'm moving around but I'm not. I'm just a series of completely still images flashing quickly before your eyes. Your brain is simply stitching those frames together to create the impression I'm moving around like I would be if I were right in front of you." But wouldn't my brain be doing just the same thing if you were in fact right in front of me?
4:25 Adolf Fick? thats quite the interesting name if you're german.
well back then they didnt have tech like today so they had to do the next best thing.
( ͡° ͜ʖ ͡° )
The name Adolf has really died out for some reason.
Max Brockie no idea why that happened it was probably just a culture shift
Thank you for actually explaining how these happen, rather than just showing it and saying it's cool, like pretty much every other time I've been shown these.
Okay, I've been trying to meld these two pieces of information in my head together for a while now, but they just seem to contradict one another: If our eyes only have cells to detect red, greed and blue light, and every other color is a mixture of their respective intensities at any point in time, then does that mean that the visible spectrum of light essentially only contains those three colored wavelengths? Everything I've read about how vision works leads me to believe that there is no such thing as a "purple wavelength" because if there were then how could we see it if our eyes are only sensitive to RGB? But everything I've also read about physics seems to contradict this line of thought, the very concept of UV light for instance depends on the existence of a "violet" for it to be the "ultra" for.
So how is it? Does the "purple wavelength" stimulate both red and blue cells so that they both fire up at the same time or something along those lines?
We see with three pigments that don't only see specific colors. They merely have greater sensitivity to certain shades like little hills. The peaks have greatest intensity while the edges only barely activate to those parts of the spectrum. Intense near infrared will activate the "red" pigment weakly, but red will activate it strongly, for example.
A specific light hue will invoke them to varying degrees and we interpret that exact balance as a pure single color. We see purple light the same as a mixture of red and blue even if they are composed of different wavelengths of light.
That said, there are some oddities of our vision where we see colors that don't really exist as wavelengths of light. Pink is really just low saturation red. Browns are really weak yellows or reds.
Ultimately mapping wavelengths to colors is an exercise of human perception, not pure physics. The visible spectrum is a continual thing and the energy of any given photon is it's wavelength. What that will end up mapping to in a visual system is different for me, you, a gorilla, a sea-slug, etc.
maybe this is an example for ppl seeing color differently. i for example dont see purple on the high frequency end of the visible spectrum. but i have friends who seem to see something they call "purple"
for me its just a very dark blue.
+Zetsubou Z. That's a good question, hopefully this graph will help. It shows the ranges of wavelengths each cell is sensitive to:
hyperphysics.phy-astr.gsu.edu/hbase/vision/imgvis/colcon.gif
As you can see they don't ONLY detect one color at a specific wavelength, rather they each detect a wide range of wavelengths that is centered on different colors. So the red cell will be triggered most strongly at a red wavelength, but will still register colors near it. Hope that helped!
Thank you guys for your explanations! I think I have a better notion of how it works now.
love the dancer one, its fun making her spin in different directions
you know, I just started my paetreon subscription and now when you thank us at the end, it feels like I'm apart if this fabulous channel! I'm happy I can help you guys share knowledge to the world!
at first I wasn't sure which way I thought she was spinning (and that direction might have even changed while I was thinking about it), so I started playing it over to see if I could change it, until momentarily it did right at the end. I started writing a comment, then caught hank explain why people think she spins a certain way, and now I can easily change which way I see.
Why can't cameras focus great on black and white stripes?
it looks like the stripes are moving
Plusle OPTICAL ILLUSIOOOOON
If I skip back a bit and rewatch the spinning dancer it will randomly switch for me. I think it may be going from the first glimpse you have (and the subsequent motion) and your brain continues it from there. I can't switch between the directions while watching one clip (though I am just rewinding and using the same 10s, I didn't find a long loop of the video elsewhere).
Further to this, I think the deciding factor could be the direction of the dancer is A) where on the image your eyes are when you first see it and B) what frame the loop is on when you catch this first glimpse and C) the angle and lighting and other varying factors that influence ones vision.
I have a hard time believing that "different types" of people process this information differently. Unless perhaps other cultures tend to look at other parts of an image that when influenced by the language they speak and the conventions they have for print.
Can any Optical actually cause harm to your eyes?
Nayib Noyola obviously not
Nayib Noyola the maccoulough effect causes changes in your eyes that can last months, I did it like 5 months ago and still see it sometimes
nathaniel holland-pass I somewhat feel like trying this. Thanks
Nayib Noyola it's pretty subtle, I rarely notice it anymore, if you want more information I think the modern rogue did a video on it I'll check
I figured out how to see the dancer spinning the other way by focusing on her pony tail. The bobbing up and down makes it so that when she goes away her hair comes back the same way as it came if that makes sense making it easy to notice from the pony tail
Nevermind i cant do it anymore
TOP 10 mind blowing reasons why scishow is turning into every click-bait RUclips channel ever. (*red arrow pointing to red circle with a mysterious half naked hank making goofy face with a fluorescent background*)
The video itself is good quality and not like the others thank you.
.... what?
The thumbnail was a spiral. o_o
Throttle Kitty I'm intentionally going overboard with my comparison to illustrate that the thumbnails are becoming more clickbaity
So information is HIGHLY dependent on our perceptions because we aren’t conscious enough or do not have enough attention to examine the environment efficiently. So it relies on memory to put the puzzle pieces together rather than taking the time to analyze it. Very interesting.
Here's a challenge: make an entire video without gesticulating.
I'd like to see this done as well. It looks stupid when people just wave their hands all over the place when talking.
i'm the opposite, gesturing is how people talk, people who keep there hands still, like those in commercials(where they have their finger tips touching in front of their stomach) looks weird and unnatural
Yeah, good luck with that. Even if they would make such a video most viewers wouldn't notice it. Same with changing colors of shirts after showing some distraction.
thats a stupid idea
Why would he?
For 2, I experienced this today! We were doing a survey on this bright pink paper, and when I looked away, everything was... green.
Hello, i see your reading the comments. Have a great day!
Another case of the Waterfall Effect is when you get out of the car after a particularly long drive, the ground will look like it's retreating slowly away from you.
You won't believe how clickb8 our clickbait is! #5 will shock you!!
For Illusion #5: I don't know what effect aging has on perception, but I know that when I was younger, I could easily swap between seeing the dancer rotate in either direction (to the point where I would accidentally swap between the two without trying). Now it takes quite a bit more effort...
Don't go down the same path as WatchMojo SciShow, don't do it.
number five is truely MIND BLOWING! I can switch between the two, but only by looking at the feet, legs, and hips. I guess I'm naturally clockwise because she spins like that when i'm not really focusing on anythin'. This one's awesome! I gotta share this one!
Sorry to be THAT person but there's a typo in the description box XD
squarebamboo want to have a go chap
it got fixed by the way
squarebamboo Embrace the corrections. And help me start a cult that believes that typos are the enemy of life and that everyone must play their role or go to poorly written heel.
Don't tell anyone, but I don't believe this. I'm in it to trick people into wearing sarcastic t-shirts. Also that "heel" was intentional if you couldn't tell.
Or maybe it was an optical illusion! *knee slap*
I like to differentiate between visual illusions (those involving brain/neuron processing tricks) and optical illusions (those like your last one which involve physical manipulation of light) when I teach this to my high school students
Top 8 ways Scishow used clickbait to get me to unsubscribe. You won't believe number 1!
his head didn't blowup
The Minkers www.quora.com/What-are-the-most-commonly-used-words-in-clickbait-titles
TRIGGERED
"Local Man Discovers Method of Screening RUclips Channels to Guarantee Quality Content! RUclipsrs and Advertisers Hate Him!"
Just a mild correction but at around 2:00 minutes you say the green cones are firing because you are looking at something green. Counterintuitively the cones ( or any photoreceptor) fires in the absence of the light that it signals for ( be that colored or not ). When they are hit by the light they are sensitive too the photoreceptors hyperpolarize ( I.e become inactive/inhibited). Through a process called disinhibition, bipolar and then retinal ganglion cells fire and relay to the brain that the color the photoreceptor is sensitive to is there. Not a complete explanation here but it is the basic scheme of detecting light/ visual information. This might make for a good sci show episode/ QQ.
Brain.exe has stopped working... rebooting... please wait...
Anyway, like I was sayin', shrimp is the fruit of the sea.
You can barbecue it, boil it, broil it, bake it, saute it. Dey's uh, shrimp-kabobs, shrimp creole, shrimp gumbo. Pan fried, deep fried, stir-fried. There's pineapple shrimp, lemon shrimp, coconut shrimp, pepper shrimp, shrimp soup, shrimp stew, shrimp salad, shrimp and potatoes, shrimp burger, shrimp sandwich. That- that's about it.
Spinning Dancer has it's "body" shaped like it's moving clockwise, while it's "shadow" is shaped like it's moving in the other direction. If you see her moving clockwise, look at the shadow for some period of time, and you'll see her counter-clockwise.
Changing the direction of the spinning dancer it's pretty easy , just focus a couple of seconds on the foot's shadow or on her arms (depending on your starting direction).
Say Hank, I don't know if you get notified about comments on old videos but I will give it a go. Without going into incredibly tedious detail I once spent two years teaching a computer how to dig images out of very poor images taken under radically different conditions. You could probably make a fascinating video out of how computers are taught to distinquish things like wheels and up rights and .. well you get the idea. In my work I also studied in depth the human eyes response and how it knits together missing information to fin the real thing. Sometime when you have a few years try to knit together the image of someone running through trees in such a way as to be able to distinguish the person correctly LOL. Anyway, as always keep up the great work.
when I first learned about optical illusions in elementary school, I found I could 'flip' the illusion very easily, Magic Eye posters were a great distraction for their time, but I do love a good Olde Fashioned '3rd Screw' or 'Face or Vase'. I guess I'm just a Classicist.
For me the dancer was going clockwise the first time you showed it, then counter clockwise the second time.
Should've covered the McCollough effect, it is probably one of the coolest illusions around.
For the spinning dancer to spin in your direction of choosing:
To see spin clockwise then cover top half with hand and focus on foot spinning on ground
To see anticlockwise then cover bottom half with hand and focus on spinning chest
If you are having difficulties then blink a few times and try again.
I see the dancer constantly changing direction, I wish she'd make her mind up and stick to it. I'm not trying to change it, but trying to keep it unchanging, if that makes sense. Hank's checkered shirts have always grooved my eyes!
Fun fact about persistence of vision, your brain can actually retroactively apply what you're looking at now to your memory of the past. This is most noticeable by looking suddenly at a mechanical clock or a stopwatch or timer counting in second increments. During the time it takes to move your gaze from where you're looking before to the clock, your brain receives a blur of nonsensical information that it ignores, and it can fill your memory of that time with the clock you have just started staring at. This is why, if the timing is suitable, it can appear to take longer than a second for the second hand to keep on ticking. At least, that's one idea. There's also theories related to time perception dilation, whereby your brain works faster, effectively slowing your perception of time. But who knows?
If you're having trouble getting the woman to spin the other way, click around the video while she's still on screen. The sudden start of her appearing on screen can reset the illusion, making the rotation appear more prominent depending on what frame of the animation it started on. At the very least it works well for me.
I just googled the spinning dancer and the the first time I saw it, it was spinning counter clockwise. After I typed a comment that I was supposed to post here, I viewed it again and now it's spinning clockwise like how I saw it in this video. Then after I typed this, it's spinning counter clockwise again. Lmao.
At first I thought the dancer was going clockwise, and then I stared at it for like a minute, and it started going counterclockwise *mind blown*
watched that several times to try and see the dancer go the other way. Finally I saw it, then couldn't switch back!
Love all the arm-waving. It makes him look so much brighter ... another optical illusion.
chackered square was very good example for me thx SciShow
I could only see it clockwise, so studied it for a bit and looked at it different ways. Got it counter clockwise, the back for a split second, but now, I'm stuck on counter clockwise. Cant get it back to clock wise! So weird! I love it!
a cool illusion: if you're on pc, while hank is talking touch the screen with your fingertips and be amazed.
you now have a dirty screen.
I've had the experience of seeing one of these illusions one way, then when finally seeing it the other way, I could no longer see it the first way...
I knew about all of these and the causes of them too. Fresh material please.
I like that you explain why the illusion happens it’s so interesting
I saw the dancer rotating anticlockwise for the 1st few rotations, changing to clockwise when her outstretched leg was to the right.
I feel like if I think about how hard my brain works, it's going to get tired and stop trying or break.
The spinning dancer is trippy.. Sometimes I see it switch the way it's spinning...
Dogs: yes yes you are. Can you move faster.
For the spinning dancer, if I cover everything but her legs, it just looks like she’s wobbling instead of spinning. If I uncover her when her foot is moving to the right, I see her moving clockwise, if I uncover her when her foot is moving left, I see her moving counter clockwise. I wonder if that will work for anyone else.
Woah! I was able to see the dancer spin both ways!!!
In theory, the "Flying Dutchman" should appear upside down. Exactly like the sky is "reflected" on the ground in a warm desert, the illusion is reversed by the multi-layered reflection in cold bioms. Was part of my physics exam when in high-school (even tho it was with a good not ol' steel warboat on the illustration^^) so I remember how it works thanks to that.^^
#6: This is colour constancy NOT lateral inhibition. Lateral inhibition is when your brain prioritises resources from the periphery to observe precise details in your central vision (e.g. when you're trying to find something you dropped on the floor, or if you're trying to track a fly)
Anyone else so bored in quarantine they're listening to videos about illusions?
My personal experience with Motion Aftereffect is from playing Guitar Hero for an hour or so. It used to trip me out I'd play the game and then just watch the wall slowly "move" upward it was kinda cool.
This will give so many people ‘hope’
already 20 likes on a 10 minute video only uploaded 60 secs ago...
It's really impressive.
And there are already 4 "around my anus" comments, too.
da Sharpman
Those are the best.
***** good point...
+Pro Haggis
Are there really? Or is it an illusion?
i forced myself to stare at spinning dancer until i was able to see it both ways. i had to, lol. what helped me was concentrating just on the lower foot. imagine what it would look like if the foot was going the other way than the way you're perceiving it now. imagine the shape it would make and overlay it over what you're seeing. then it just snaps into place. once you get the foot right, everything else lines up.