Square Circle Spiral

The entire universe in blog form
Aug. 18 2009 5:02 PM

Square Circle Spiral


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:

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

Advertisement

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!

TODAY IN SLATE

Politics

Don’t Worry, Obama Isn’t Sending U.S. Troops to Fight ISIS

But the next president might. 

The Extraordinary Amicus Brief That Attempts to Explain the Wu-Tang Clan to the Supreme Court Justices

Amazon Is Officially a Gadget Company. Here Are Its Six New Devices.

The Human Need to Find Connections in Everything

It’s the source of creativity and delusions. It can harm us more than it helps us.

How Much Should You Loathe NFL Commissioner Roger Goodell?

Here are the facts.

Altered State

The Plight of the Pre-Legalization Marijuana Offender

What should happen to weed users and dealers busted before the stuff was legal?

Surprise! The Women Hired to Fix the NFL Think the NFL Is Just Great.

You Shouldn’t Spank Anyone but Your Consensual Sex Partner

Moneybox
Sept. 17 2014 5:10 PM The Most Awkward Scenario in Which a Man Can Hold a Door for a Woman
  News & Politics
Altered State
Sept. 17 2014 11:51 PM The Plight of the Pre-Legalization Marijuana Offender What should happen to weed users and dealers busted before the stuff was legal?
  Business
Business Insider
Sept. 17 2014 1:36 PM Nate Silver Versus Princeton Professor: Who Has the Right Models?
  Life
Outward
Sept. 17 2014 6:53 PM LGBTQ Luminaries Honored With MacArthur “Genius” Fellowships
  Double X
The XX Factor
Sept. 17 2014 6:14 PM Today in Gender Gaps: Biking
  Slate Plus
Slate Fare
Sept. 17 2014 9:37 AM Is Slate Too Liberal?  A members-only open thread.
  Arts
Brow Beat
Sept. 17 2014 8:25 PM A New Song and Music Video From Angel Olsen, Indie’s Next Big Thing
  Technology
Future Tense
Sept. 17 2014 9:00 PM Amazon Is Now a Gadget Company
  Health & Science
Medical Examiner
Sept. 17 2014 11:48 PM Spanking Is Great for Sex Which is why it’s grotesque for parenting.
  Sports
Sports Nut
Sept. 17 2014 3:51 PM NFL Jerk Watch: Roger Goodell How much should you loathe the pro football commissioner?