Square Circle Spiral

By Phil Plait | August 18, 2009 5:02 pm

One thing I love about having cool friends like psychologist Richard Wiseman: I see all kinds of things I never would have otherwise. On his blog Richard posted one of the best optical illusions I have ever seen:

square circle spiral illusion

Oh baby! Let your eyes roam over it; the squares appear to form a spiral pattern. But then more carefully trace over the pattern — block some of it with your hand to be sure — and you see they are aligned in perfect circles.

Still not sure? Let me prove it: all I did was draw in circles.

Square circles annotated

Even with the circles right on top of them it’s hard to see the squares laid out in anything other than spirals.

Incredible.

I love illusions like this, ones that persist even after you can see the trick. And as always, I like to point out that when someone swears they saw something and then say "Seeing is believing," you can point them to things like this and say, "Not always." Remember: it’s easy to be fooled, especially when you’re not expecting it.

Richard posted a couple of other illusions on his blog, so go look. Also, you can follow him on Twitter!

CATEGORIZED UNDER: Cool stuff, Skepticism

Comments (89)

  1. Ivan

    honestly, ive seen this before. and i saw the circles very clearly. i kind of see the optical illusion i think, but i see the circles more.

  2. Daffy
  3. IVAN3MAN

    Try looking at the illusion while squinting like Clint Eastwood.

  4. YOINK! – That is going into my demonstrations!

  5. That is a really good illusion. This one is even harder to believe, but it’s true: both the blue and green spirals are the same color. http://blog.ted.com/2009/06/amazing_illusio.php

  6. AggieAndrew

    If you blur your vision, you can see the circles. The illusion seems to be caused by the tilt of the squares. If you blur enough so you can’t tell they are titled, the spirals disappear.

  7. dhtroy

    Those are circles?!?! They look like a bucha squares to me …
    :)

  8. FlipC

    I worked at a Quizno’s this summer and this optical illusion is on the bags of our kids meals. Strange coincidence…

  9. AB

    Excellent. I like the way the image appears to shift. Sometimes I can see the circles.
    My 5 year old however only sees it as 4 circles! Not everyone processes visual information in exactly the same way.

  10. I keep forgetting. Is it you or Richard who is the evil twin?

  11. Once the circles are drawn, the illusion totally disappears for me.

    I hate optical illusions…I hope no one ties me down and holds my eyes open making me look at them all day!

  12. Matt T

    Great illusion! For whatever reason, when I scroll this image up and down (on the screen), it even looks like its growing in some parts / shrinking in others. Static confusion layered on top of motion sickness.

  13. @Romeo
    The one with the goatee… d’oh.

  14. Paul M

    I see the circle in the middle, and the rest is just a mess swimming around to me – Evil, now my head hurts.

    Like the vampire poster on Richard’s blog… it’s clever and doesn’t give me a headache

  15. ARJ

    for any who haven’t seen it, my favorite Wiseman illusion is still this old banana gambit:
    http://www.youtube.com/watch?v=QNSbcO86Zag

  16. Roen

    I see the illusion first but very quickly notice the circles. So I pretty much see both at the same time. However, when the circles are drawn in the illusion breaks. I thoroughly enjoy flipping my attention back and forth between them, it’s very cool.

  17. Mike

    Wow, that’s a good one. @_@

  18. Gary Ansorge

    Cool! Square circles, er, I mean round squares, oh frak, never mind.

    Too much confusion here, said the circle to the square but a spiral is the answer, to the upside down stair,,,

    Dang, I WISH that song would quite spiraling round my head.

    I loves illusions but obsessions,,,not so much.

    GAry 7

  19. That’s pretty awesome. Good think I’m not high right now. Wait a second…that’s not good at all.

  20. I can almost see the spiral, but I’m pretty much just seeing the circles, even before you pointed it out…

  21. The Sine

    Good thing your daughter knows how to use Photoshop, right, Phil? ;)

  22. coolstar

    AggieAndrew: nice observation! One of the times when LOWER resolution actually leads to a better answer. If you use a pen to punch a small hole in a sheet of paper and view thru the hole, the illusion disappears (well, at least for me). I’m one of the many who have trouble seeing anything but the circles once they’re drawn on the figure.

  23. Matthew Ota

    I collect optical illusions off of the web. I am also an Escher fan.

    Optical illusions are fascinating because it is a form of psychology, seeing how the eye-brain interface can be confused by the input of such artwork

  24. shannypez

    I saw they were circles of squares right away, but it took me almost a full minute to see the Vampire image. I wonder if that means I’m cracked.

    I also noticed that if you nervously scroll up and down, the circles appear to be moving. Nice.

  25. Fred

    I see the spirals, but if I scroll the page, then they immediately turn into circles. Weird.

  26. Stellar Ash

    To me, it looks like a Fibonacci sequence.

  27. Am I the only one who sees Jesus?

  28. I still prefer the chess board with shadows, with the “these two squares are the same color” illusion. Is this the same guy? I can’t find the URL for the other one.

  29. Trebuchet

    I wanted to vote for the cow! My eye doctor gave me a wallet card of that picture when I was a teenager, a good many years ago, so I recognized it instantly. I suspect it originated as a damaged photograph.

  30. 3. IVAN3MAN Says:

    Try looking at the illusion while squinting like Clint Eastwood.

    Looking lucky, punk?
    ;)

    J/P=?

  31. Papa Surf

    I sometimes look at pictures of planets or the moon and instead of craters I’ll see raised bumps. And while I know they are recessed craters, often I can’t shake the illusion – sometimes I have to download and rotate the image to make it behave.

  32. cory

    anybody else see something like this:

    http://tinyurl.com/ovmlfz

    That’s the closest i can come up with…but i’m not seeing just a spiral, it’s more like interwoven circles.

    I can’t wait till the kids wake up tomorrow and we go look at the rest of the blog!

  33. @kuhnigget
    Am I the only one who sees Jesus?
    Generally or when you look at optical illusions?

  34. jjmcgaffey

    Cory – yes, that’s what I see (not that exactly). Not a clean spiral at all, both sides of each circle seem to be tilted in…now my eyes hurt.

    I saw the vampire so quickly I never saw it as spilled blood – I can’t refocus on it that way.

  35. Torbjörn Larsson, OM

    Illusions are … , well, illusions. (¬_¬) They demonstrate that the mind is embodied, not that we are constantly fooled.

    [But apparently our algorithms will suffer from them as well, as more and more vision routines uses the impressive compression routines evolution have come up with.]

    But they do it well and reveal the specific problems. This one was pretty good even if apparently not perfect.

  36. MadScientist

    OK, that’s another illusion that’s going to be turned into a PostScript file. :)

  37. Sandy L

    TY – that is a very cool illusion! I’m going to share it with my family.

  38. Roen

    Okay, this is interesting… had my wife look at it and I quizzed her.

    She saw the circles first, then the “rosette” (what the rest of us call the spirals) and when she saw the circles drawn in she saw a single long spiral.

    25. shannypez
    … and confirmed when you move the page up and down quickly the circles rotate back and forth.

  39. MadScientist

    OK, I’ve created a PostScript file – where can I post it? :P

    It’s not a 100% copy but anyone can easily tweak the file and fiddle around with what makes the best effect.

  40. @ Shane:

    Only when I’m watching the guy mow my neighbor’s lawn.

    Slap! Ow! Dios mio!

  41. nichole

    blah I don’t see spirals. I see circles, and I get a headache. I always failed those 3d-picture things too. I’m that guy who can’t see the damned sailboat.

    ::jealous::

  42. Stephen

    This is my favourite optical illusion ever
    http://www.michaelbach.de/ot/mot_adapt/index.html

    You can turn off buddha and use it to look at your hand and practically anything in the room.
    The effect is really good

  43. Lupine

    Makes me kind’a dizzy if I stare at it too long.

  44. Michelle

    Argle!!!! I already HAD a headache!

  45. Nemo

    I see two crossing spirals — first counterclockwise, then clockwise. And then my eyes explode.

    I find it impossible to see circles in the first picture, despite knowing they’re there.

  46. Kesstra

    Awesome! But if I close one eye I can see it the way it is, with both eyes open I see the spiral. Weird. Thanks

  47. alfaniner

    I was blown away by this one – The Amazing Color Changing Card Trick
    http://www.youtube.com/watch?v=mNF8AzjC21s

  48. Don

    Aaaahhh!!! My eyes they burn!

    When I try to see the circles I can feel a headache coming, my eyes just can’t focus on the circle.

  49. mike

    decent, but no… takes about 3 seconds to realize what’s going on without reading the description

  50. pat

    Anyone colorblind? Does it still work then?

  51. Buzz Parsec

    GarrrrHHHH!!!

    I had to block out most of it with my hand to keep it from moving. Must be a magic animation that knows to stop when I’m looking at it. Kind of like the angels in Blink. Seriously, I had to scan across it slowly with a piece of paper to prove to myself that it was a static image and not an animated GIF. When I look at the whole thing, I see multiple counter-rotating spirals and get dizzy. Of course, I just watched the U-Tube vid about protein synthesis that someone linked to in one of the “Shine a Light” comments, so maybe I’m getting flashbacks. :-)

  52. Nemo

    Anyone colorblind? Does it still work then?

    Well, it’s greyscale… so…

  53. Alf

    I agree with Ivan. Look at innermost circle and the trick doesn’t vanish but can be seen just with the tail of the eye.

    Alf

  54. Ivan Says:

    Aaahh arent you special, I wish we could all be as special as you.

  55. Scott

    If you close your eyes slightly or view it from a distance the effect disappears. I think it’s when the black blends into the background leaving the white standing out. Up close it’s hard to make the circles out.

    Really cool!

  56. Alvin Raj

    Here’s the same illusion with more squares and rings

    http://people.csail.mit.edu/alvin/pinna/Intersect512.png

    Tilting the squares in every other ring by 90 degrees actually changes the illusion from this weird intersectiony thing into a spiraly illusion

    http://people.csail.mit.edu/alvin/pinna/Spiral512.png

    This particular illusion was created by Pinna and Gregory in 2002, and our lab recently did some research on it!

    And we can make it more dramatic by filtering the image a little:

    http://people.csail.mit.edu/alvin/pinna/Ted512.png

    Here’s an animation I created going between the intersecting-circles illusion to the spiral illusion, the motion is very subtle but your perception of the two illusions switching is pretty dramatic

    http://people.csail.mit.edu/alvin/pinna/pinna.gif

    There is no effect when all the squares are the same color

    http://people.csail.mit.edu/alvin/pinna/White512.png

    the background color of the image actually makes a difference. The effect only appears when the background luminance is between the two colors of the squares.

    http://people.csail.mit.edu/alvin/pinna/greyscalepinna.png
    http://people.csail.mit.edu/alvin/pinna/greyscalepinna_effect.png

    We actually have recently submitted an abstract to VSS that explains (most) of this illusion as a by-product of how we represent visual information. And we can even make images that are guesses of the perception of the illusion using that representation:

    http://people.csail.mit.edu/alvin/pinna/intersectionmongrel.png
    http://people.csail.mit.edu/alvin/pinna/spiralmongrel.png

    (note the spirally-ness or the intertwinyness)

    and for a control:
    http://people.csail.mit.edu/alvin/pinna/whitemongrel.png

    poster download with more details is here: http://people.csail.mit.edu/alvin/pinna/pinna_v7.pdf

  57. John Baxter

    Stephen, I’ve seen the expanding Budda effect when on the rear platform of a high speed (in US terms–pretty slow to those in Europe or Japan) train which comes to a stop after a period at speed.

  58. jabjubi

    for me they moved.

  59. janes'_kid

    When I am moving my head in toward the screen I see the circles clearly but briefly.

    The professionals should probably have some explanation for this.

  60. I see only spirals. Even after the lines are drawn through the circles, my eyes (brain?) still only see spirals.

    My daughter only sees circles. No matter how long she studied the picture she didn’t see the spirals. She could never make out those 3D posters that were so popular a few years ago either, while I could spot the dolphin or hand or whatever right away.

    Interesting.

  61. SanguineMonk

    I don’t know if it’s just me or not, but I see 4 circles, no illusion at all. Am I missing something? Not trying to be a jerk, just really don’t see it at all!

  62. Ryan

    A bit OT: Here’s a report from today where someone claimed they saw a helicopter crashing but it was just a 2′ toy. Kind of blows holes in the “it was x feet across” and “moving y miles per hour” statements UFO sightings bring.

    http://news.yahoo.com/s/ap/20090821/ap_on_fe_st/us_odd_toy_chopper_crash

  63. Galileo Galilei

    E pur si muove!

  64. frank

    All you have to do is squint your eyes and the circles tend to disappear.

  65. DensityDuck

    oh god my brain wants it to be a spiral IT WANTS TO BE A SPIRAL OHHHHHH GAAAAAAAAAAAANNNNNNNN (paf)

  66. Never Say Dice

    Shrink the page and the circles appear.

  67. ZanderArch

    There has to be someway to incorporate this into camouflage for military applications.

  68. I can see the circles if I relax focus, but it’s a persistent illusion. The one with the lines drawn in completely breaks it for me though.

  69. Phil E. Drifter

    Obviously photoshopped. :)

  70. garbarharyarb

    “And as always, I like to point out that when someone swears they saw something and then say “Seeing is believing,” you can point them to things like this and say, “Not always.”"

    Uh, no you can’t.

  71. garbarharyarb

    “There has to be someway to incorporate this into camouflage for military applications.”

    OH MY GOD, YES, THIS MAN MUST BE JESUS

    They already do, you oaf.

  72. Kilian

    Hmm, nope, I can’t see spirals… All I see are circumferences made out of squares. I see the inner ones kind of dislodged from the center when I give them a glance but not spirals, even before I read the ‘trick’ is something wrong with me? =P

  73. scgvlmike

    I scrolled down to see the first image in full, and discovered a secondary illusion: the smaller shapes appear to move around the circumferences of the circles as I scroll– and the interpreted movement looks as if it’s following a spiral, not a circle, even though I can see (with effort) that I’m looking at circles, not spirals.

    Odd one!

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