Explaining Optical Illusions: Part 2 - The famous checkerboard illusion

Why do optical illusions work? Well, in this video we will be looking at another optical illusion. Just one this time, though it is a famous and very strange one, and I’ve added some animations so we can better see what’s happening. So let’s get going.

So this illusion is the famous checkerboard illusion, first published by Edward Adelson in 1995. This is the famous Adelson checkerboard illusion. In this video I will explain why we see the 2 squares A and B as different colours and not the same as they actually are.

[RichardM-kvuu]

If i squint and blur my vision I can just about see that they're the same value. I do a bit of art, and this is actually a great example of how hard it can be to choose the right values to use!

[XavierPil]

So what colors are the adjacent square B?

[gmodiscool]

if i focus hard enough, i can see they are the same color. its almost as if the color is changing, and im fighting my brain to see the real color.

another time, i was able to see almost 8 dots on the phantom dot illusion or whatever, even though the video said i was supposed to see 2 or 4.

[spritemasters]

But what I don’t get is the two squares still look different even before the shadow is placed.

[ElLenadorLA]

Great stuff, I can’t see the truth of it no matter how hard I try but if I squint really hard I can see they’re the same color

[fannytorres]

I see it now. Thank you so much:) Great video

[alexandrumacedon]

well at the end the text isnt moving but that was a pretty good explanation. good job keep it up
i see im actually subscribed, it seems it isnt the first time i consider u did a nice video. cheers. :)

[lostn]

can you show the checkerboard without the light being cast?

[doji-san]

Why in the beginning is A also light shaded?

[Dr.Z.Moravcik-inventor-of-AGI]

Are you sure the explanation why it works is the shadow? I can mask the other part of the image except the shadow area with my fingers (so that my brain has no idea it's a shadow) and I still can see quite different shade. Shadow is not the explanation.
Wait for my video where I will explain it.

[DrunkJester]

Green on the left grey on the right...🤔 it's probably my biased perception. 😅 i have no idea but cool nonetheless. ✌️❤

[robertwhiteley-yvsy]

The left and the right hemisphere perceive reality differently. The left has a habit of quick and dirty thinking and is more than happy to create illusions to satisfy itself. The left hemisphere is algorithmic to the point where it will create an algorithmic pattern where one does not exist. The right hemisphere appreciates the gestalt view of reality because that is actually how the world is. If you want an experiment. Ask your child to copy a drawing of their favourite superhero. Then ask them to draw another but turn the drawing they are copying upside down. You will find that the upside down drawing is a lot better. The reason is because if you turn the drawing upside down the left hemisphere cannot use its quick and dirty thinking so it checks out and the right hemisphere that is much more attentive will take up the job creating a better drawing.