Optical illusion time!
Here are a couple of examples that have caught my eye recently, the first one you have probably seen before but it's bloody impressive anyway. The two labelled squares are exactly the same colour (check in photoshop if you don't believe me)
The second one is a little more obscure:
The two parallelograms are actually exactly the same size. I still have a hard time believing it. Click here for an interactive demonstration that they are the same. I first stumbled across this second one reading about human perception, here is a short explanation of how it works.
It's quite interesting to note that although our eyes are pretty bad at determining relative brightness (the shadow picture) and relative shape (the table picture), by the time we consciously percieve either one of the images our brain has filtered the input through a kind of 'real life filter' and has made the shadow appear darker and the table appear smaller. It's very interesting to think about exactly how much filtering the brain does, and the lies it can tell us.
p.s. I'm back in Durham as of now so I'll see most of the people who actually read this at work tomorrow. Thanks to the Room311 blog for keeping me up to date with various and sundry going ons in the department during my absence. Look forward to a return to daily (or more) posts in the near future.
Here are a couple of examples that have caught my eye recently, the first one you have probably seen before but it's bloody impressive anyway. The two labelled squares are exactly the same colour (check in photoshop if you don't believe me)
The second one is a little more obscure:
The two parallelograms are actually exactly the same size. I still have a hard time believing it. Click here for an interactive demonstration that they are the same. I first stumbled across this second one reading about human perception, here is a short explanation of how it works.
Objects stretching away from the viewer get foreshortened by projection, and the brain compensates for this, so we tend to see a given distance running up-and-down in the visual field as coming from a longer objectrunning left-to-right. And that makes us see the lengths and widths differently in the turned tables.
--Steven Pinker (in The Blank Slate)It's quite interesting to note that although our eyes are pretty bad at determining relative brightness (the shadow picture) and relative shape (the table picture), by the time we consciously percieve either one of the images our brain has filtered the input through a kind of 'real life filter' and has made the shadow appear darker and the table appear smaller. It's very interesting to think about exactly how much filtering the brain does, and the lies it can tell us.
p.s. I'm back in Durham as of now so I'll see most of the people who actually read this at work tomorrow. Thanks to the Room311 blog for keeping me up to date with various and sundry going ons in the department during my absence. Look forward to a return to daily (or more) posts in the near future.
Labels: opticalillusion
