Black and White Optical Illusions

Today I will be posting some black and white optical illusions!  (Yes, I know that really doesn't have to do with black and white at all.... but the pictures are in black and white!).  Also i wont be posting next Tuesday or Thursday because my school is AWESOME and we have Wilderness Week (where we all go on different awesome trips into the wilderness to bond with each other).  Have fun with these illusions though!(:

 This is the Chubb Illusion.  The two smaller circles are in fact the exact same image, though they seem to have different contrasts.  This shows the difference images seem to have in different contrast backgrounds.  The left circle image seems to have a higher contrast, while the right one seems to have a lower contrast (more blurry).

This is the Blivet Illusion.  It is an impossible shape; see how the left side of the shape seems to have three cylindrical prongs coming out, while the right side ends in two rectangular prongs.  This kind of impossible shape is also know as a poiuyt, which relatively means an undecipherable figure.

This is called the Cafe Wall Illustration.  Although the parallel straight horizontal lines (between the black and whit checker lines) appear to be bent, they are in fact all straight and parallel.  It is the skewed placement of the black and white squares that creates this illusion.  To check the straightness and parallel-ness of the lines, simply put our fingers or a piece of paper to to cover all but one of the checkered rows.  You will see that the greyish lines on either side are parallel and straight.

Last but certainly not least, here is the Fraser Spiral Illusion!  This is my favorite because it really stumped me.  See all those big windy spirals?  Well they're actually not spirals, they're circles!  The black and white twisted looking ropes paired with the background design creates the illusion of many spirals, where there are only concentrated circles.  To test this (because I know you don't believe it either) you can simply trace one of the "spirals" with your finger (or a pencil or other object) and see that it just meets itself and keeps going around in a circle. !!!

Have an awesome rest of the week (I will be enjoying myself floating down the Rogue River)!!(: