A big ‘thank you’ to everyone who did the faces experiment yesterday, or who came to my events at the Edinburgh Science Festival – much appreciated!

Today’s offering is very simple…..amazingly, this is not a spiral (and thanks to everyone who sent it to me)….


  1. I put my finger on a line and ran the circle, until with several lines the same thing kept happening: my finger ended where it started. Just for the heck of it I tried the contrasty lines, then the blue, then … argh! The same thing happened every time.

    Fluffy’s observation is cogent: “I know it’s not a spiral so why does my brain insist that it IS?”

    This is one of the BEST visual tricks I’ve seen on RW’s blog yet.

  2. I think it’s because the brain wants to make a perfect black and white pattern, like a chess board. But it isn’t. So the braine moves the pattern and the cirkels with it. This makes them look like a spiral.

  3. I think that it’s affect is stronger because the two outer circles {one blue and one black & white extend out side of the frame. If you want to see an extra treat try scrolling up and down with the photo!

  4. It has to be something to do with the small black and white boxes at each intersection, I’m sure if they were taken out they would just look like rings. Very good though!!

    1. In fact it is!
      Our brain will try to continue a line and the small black/white boxes move the view more in the center than the real circle do, so it seems to be a spiral.

  5. If you squint so the pic is blurry you can just about make out the whole circles, and the image seems to wobble. The squares in the circles, the dark/light blue boxes and the black/white ones, are offset compared to their outside and inside neighbours, giving the appearance of movement

  6. It appears to our brains to be a spiral because the black and white shapes are offset so that they appear to curve out form the center. I’m just as fascinated by the fact that the whole picture jitters!

  7. I saw a spiral at first. Then I put my finger on a line and ran the circle. Now I see a tunnel instead, and I can’t get it to go back to spiral! I wonder what will happen if I come back and look at it tomorrow?

  8. Brilliant. It’s like some kind of torture if you follow the circles. You feel like you ought to be getting somewhere, but you just keep ending up where you started.

  9. Absolutely amazing! Richard constantly gives us examples of how we can not always trust what we think we see.

  10. Does everyone perceive the spiral going in the same direction? I see it going clockwise as it goes from the center to the outside – I can’t “flip” it like you can with those cube drawings and some other optical illusions, so there must be some directional cue in the image itself, right? Probably to do with how the black/white areas are out of line with one another?

    1. Good question I was just thinking the same thing. For me, it seems to go anti-clockwise from the outside to the centre, which is the same sense that you describe. Does anyone see the opposite? Only near the centre, does it seem to be concentric circles.

  11. I’ve loved this on since I was a kid many decades ago. It’s just amazing to me how ones brain can deceive one so easily.

  12. Ok, that is just freaky. I had to actually trace out one of the circles to convince my brain that it wasn’t a spiral. And even in the face of such conclusive evidence, my brain is still managing to trick me into seeing a spiral.

  13. This is pretty cool and it is actually a little difficult to trace the lines in circles without my brain exploding.

  14. This effect is so startling that even after I traced a circle, my brain still refuses to even see it as anything but a spiral!
    Is there a specific name for this effect?

  15. Radial sections are positioned to give the impression that they are curved in the opposite direction of the illusion of the spiral

  16. If you focus completely on the star-like pattern right in the center, you start to see the tunnel of circles instead of the spiral. And the moment you shift your eyes a bit, it turns back into a spiral…

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