illusion: The same color illusion

[Fu-Kwun Hwang]

http://en.wikipedia.org/wiki/Same_color_illusion
The same color illusion—also known as Adelson's checker shadow illusion, checker shadow illusion and checker shadow—is an optical illusion published by Edward H. Adelson, Professor of Vision Science at MIT in 1995. The image depicts a checkerboard with light and dark squares. The optical illusion is that the area of the image labelled A appears to be a darker color than the area of the image labelled B. However, they are actually exactly the same color.

You can drag the bar at the left and move on top of A and B (or click auto checkbox).
You can also drag the slider to change the color of the bar.

You can hide other blocks if you drag the second slider to highest value.

Those two orange dots are the same color. try to drag one of them to block A, another to block B.
Are they look the same color after being moved?
Enjoy the fun of illusion! Trick your mind!

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.illusion_checkershadow_pkg.illusion_checkershadowApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_illusion_checkershadow.jar' name='illusion_checkershadow7724' id='illusion_checkershadow7724' width='676' height='527' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=7724' target='smfejs'>Run simulation</a>

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.

Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

[lookang]

amazing!
i still see the difference in color between A and B despite the use of a single color at 124 to illustrate that the color is the same.

my eyes and mind are playing tricks on me.

thanks for the new applet!

[Fu-Kwun Hwang]

Click the auto check box.
Did you find the boundary of of two bars with A/B block?
Look at them separately. Did you find diffent color between those two bars and block A/B?

You might think those two blocks are different color if you look at them at the same time.

I just modified the code, you can drag the second slider to hide other blocks,
  and check out if there are the same color.

[lpoennf963]

I have a friend who is falling in love. She honestly claims the sky is bluer. Mozart moves her to tears. -*-