Probably the world’s best optical illusions

IMHO, the world’s best natural optical illusion is this picture of 2 planes which seem to be colliding in mid-air, but are in fact a safe distance from each other.

Apparently, it’s a Lufthansa 747-400 and a United Airlines 757-200 that were on simultaneous approaches to 2 separate runways at San Francisco Airport. The separation requirement for flying in parallel and doing simultaneous approaches is more than 200 meters. Therefore, these 2 planes are actually more than 200m apart!

How did the picture turn out to be like that? Timing and position of the photographer is one thing. Another, and possibly most important is: The fact that the Lufthansa plane is 3 times larger than the other plane and it being positioned slightly behind, gives us this amazing optical illusion.

Impressed? Check out this other optical illusion. The squares marked A and B are the same shade of gray, yet they appear different. I bet everybody, even after several glances, would be stumped by this one.

After the jump.

You can test it yourself: run Photoshop’s colour picker over A and B, or even better, join A and B using two vertical stripes of the same shade of gray, which would reveal that both are of the same colour: