• Question: how does ilusions work?

    Asked by alisa26x to Ed, Sam, Steve on 23 Jun 2011.
    • Photo: Edward Morrison

      Edward Morrison answered on 23 Jun 2011:

      Illusions are fascinating.

      When we see the world, we don’t just passively receive an image like a video camera. Instead, our brain makes assuptpions about how the world should be. Visual illusions work by violating those assumptions, causing us to see things that aren’t there, or fail to see things that are there. Scientists can use illusions to understand how the brain works.

      Illusions aren’t just limited to the eyes, the ears can be fooled too. Here is my favourite illusion, called the McGurk effect: http://www.youtube.com/watch?v=ypd5txtGdGw.

      There are also some cool visual illusions here: http://www.echalk.co.uk/amusements/opticalillusions/illusions.aspx

    • Photo: Steven Daly

      Steven Daly answered on 23 Jun 2011:

      I agree, illusions are fantastically amazing. My favourite one is actually to do with the sense of touch. What you do is your cross your first two fingers, close your eyes and then stroke your nose with the gap where the fingers are crossed over. After a while it will feel like you have two noses!

    • Photo: Sam Tazzyman

      Sam Tazzyman answered on 23 Jun 2011:

      This I absolutely love: