The Optical Illusion Thread

[ziggysego]

I get a pain in my head when I look at any of these optical illiusions below.






Thankfully they are not real and have only been made up on Photoshop.

Very good Kerry Mike 

[Orior]

This is my favourite.

Count the people in the picture.
Wait until the picture changes, then count the number of people again.
Is it the same number?

[supersub]

The red triangle has a bit of its shape in 17 squares but the second red trianlgle only covers 16

[muppet]

The red triangle has a bit of its shape in 17 squares but the second red trianlgle only covers 16

If the grid was made of perfect squares then the red and green triangle would have slightly different angles (in the bottom left angle as you look at them). In that case the hypotenuse of the big triangle wouldn't be perfectly straight and should change slightly when you move the sectors around.

The fact that it doesn't must mean that the grid isn't made up of perfect squares? Or am I missing something?

[Orior]

Those are perfect squares chief. Come on, chop chop.

[el_cuervo_fc]

Those are perfect squares chief. Come on, chop chop.

The angles in both triangles differ.  In the first shape, the angle outside of where the triangles meet is slightly less than 180 degrees.  When the roles are reversed the angle is slightly more than 180 degrees.  this difference accommodates the extra square

[Square Ball]

That is doing my feckin head in

Same here. Can't figure it out at all.

If you follow the slope, the bottom triangle has a less sharp slope than the top one, therefore more space to spare.
The 2 two triangles do not occupy the same area.
Thats the limit of my observation

Thats it, The hypotenuse isnt a straight line but is in fact two seperate lines with different angles to the x axis

somebody cant count is the answer, looked at this, then looked some more and no effing idea 

[Hardy]

Those are perfect squares chief. Come on, chop chop.

The angles in both triangles differ.  In the first shape, the angle outside of where the triangles meet is slightly less than 180 degrees.  When the roles are reversed the angle is slightly more than 180 degrees.  this difference accommodates the extra square

I agree. The clue is in the title - this is the optical illusion thread. The big "triangle" is not a triangle, just a drawing of something that looks very like a triangle.

The green triangle and the red triangle have different proportions. The sides of the green triangle that form the right angle are are 2 and 5. The sides of the red triangle that form the right angle are 3 and 8 (i.e. the tans of the acute angles are different). 3/8 is not equal to 2/5. Therefore, when you line them up with their vertical and horizontal sides parallel, their hypotenuses will not be parallel. Therefore the hypotenuse of the big "triangle" is not a straight line.

On the other hand, it could be magic.

[bcarrier]

Thats it I can see it now .

The top roof has a bit of a "belly" in it and the bottom one has the the opposite effect.

Good thread.