The Blue and the Green

The entire universe in blog form
June 24 2009 10:34 AM

The Blue and the Green


Via my evil twin Richard Wiseman comes one of the best color optical illusions I have ever seen. The original was apparently posted on Buzzhunt Akiyoshi Kitaoka's incredible optical illusion website:

Advertisement

Blue green spiral illusion

You see embedded spirals, right, of green, pinkish-orange, and blue? Incredibly, the green and the blue spirals are the same color. At first I thought Richard was pulling our collective legs, being a trickster of high magnitude. So I loaded the image in Photoshop and examined the two spirals. In the two squares displayed below, the one on the left is colored using the same color from the blue spiral, and on the right using the green spiral.

green and blue squares

Like I said, incredible! For pedantry sake, the RGB colors in both spirals are 0, 255, 150. So they are mostly green with a solid splash of blue.

The reason they look different colors is because our brain judges the color of an object by comparing it to surrounding colors. In this case, the stripes are not continuous as they appear at first glance. The orange stripes don't go through the "blue" spiral, and the magenta ones don't go through the "green" one. Here's a zoom to make this more clear:

Blue green spirals zoom

See? The orange stripes go through the "green" spiral but not the "blue" one. So without us even knowing it, our brains compare that spiral to the orange stripes, forcing it to think the spiral is green. The magenta stripes make the other part of the spiral look blue, even though they are exactly the same color. If you still don't believe me, concentrate on the edges of the colored spirals. Where the green hits the magenta it looks bluer to me, and where the blue hits the orange it looks greener. Amazing.

The overall pattern is a spiral shape because our brain likes to fill in missing bits to a pattern. Even though the stripes are not the same color all the way around the spiral , the overlapping spirals makes our brain think they are. The very fact that you have to examine the picture closely to figure out any of this at all shows just how easily we can be fooled.

This is why I tell people over and over again: you cannot trust what you see even with your own eyes. Your eyes are not cameras faithfully taking pictures of absolute truth of all that surrounds you. They have filters, and your brain has to interpret the jangled mess it gets fed. Colors are not what they appear, shapes are not what they appear (that zoomed image above is square, believe it or not), objects are not what they appear.

So the next time someone swears they saw Jesus, or a UFO, or a ghost, show them this picture. What you see in life is absolutely and provably not what you get.

Edit to add: if you like this illusion, then you might want to check out this audio illusion, and this one of a spinning woman's sillhouette which is one of my all-time favorites.

TODAY IN SLATE

Politics

Talking White

Black people’s disdain for “proper English” and academic achievement is a myth.

Hong Kong’s Protesters Are Ridiculously Polite. That’s What Scares Beijing So Much.

The One Fact About Ebola That Should Calm You: It Spreads Slowly

Natasha Lyonne Is Coming to the Live Culture Gabfest. Are You?

A Jaw-Dropping Political Ad Aimed at Young Women, Apparently

The XX Factor
Oct. 1 2014 4:05 PM Today in GOP Outreach to Women: You Broads Like Wedding Dresses, Right?
Crime

Operation Backbone

How White Boy Rick, a legendary Detroit cocaine dealer, helped the FBI uncover brazen police corruption.

Music

How Even an Old Hipster Can Age Gracefully

On their new albums, Leonard Cohen, Robert Plant, and Loudon Wainwright III show three ways.

How Tattoo Parlors Became the Barber Shops of Hipster Neighborhoods

This Gargantuan Wind Farm in Wyoming Would Be the Hoover Dam of the 21st Century

Moneybox
Oct. 1 2014 8:34 AM This Gargantuan Wind Farm in Wyoming Would Be the Hoover Dam of the 21st Century To undertake a massively ambitious energy project, you don’t need the government anymore.
Behold
Oct. 1 2014 6:59 PM EU’s Next Digital Honcho Says Celebs Who Keep Nude Photos in the Cloud Are “Stupid”
  News & Politics
Politics
Oct. 1 2014 7:26 PM Talking White Black people’s disdain for “proper English” and academic achievement is a myth.
  Business
Moneybox
Oct. 2 2014 9:19 AM Alibaba’s Founder on Why His Company Is Killing It in China
  Life
Atlas Obscura
Oct. 2 2014 10:42 AM The Hanging Coffins of Sagada
  Double X
The XX Factor
Oct. 1 2014 5:11 PM Celebrity Feminist Identification Has Reached Peak Meaninglessness
  Slate Plus
Behind the Scenes
Oct. 1 2014 3:24 PM Revelry (and Business) at Mohonk Photos and highlights from Slate’s annual retreat.
  Arts
Brow Beat
Oct. 2 2014 10:36 AM How Bad Will Adam Sandler’s Netflix Movies Be?
  Technology
Future Tense
Oct. 1 2014 6:59 PM EU’s Next Digital Commissioner Thinks Keeping Nude Celeb Photos in the Cloud Is “Stupid”
  Health & Science
Medical Examiner
Oct. 2 2014 9:49 AM In Medicine We Trust Should we worry that so many of the doctors treating Ebola in Africa are missionaries?
  Sports
Sports Nut
Oct. 1 2014 5:19 PM Bunt-a-Palooza! How bad was the Kansas City Royals’ bunt-all-the-time strategy in the American League wild-card game?