Merging Planes Optical Illusion

What is this? An image of a big airplane with a smaller one painted on its side? Or is it some weird project designed to confuse the enemy and maybe even birds? Actually, it's none of the above. This is just an optical illusion, one of the many tricks the brain plays on us.

The brain's complexity is exactly what makes us perceive these illusions, as it makes assumptions based on previous interactions with the surrounding world and is constantly trying to correlate a first time event with information already existing in our "database."

At a closer look, we can rule out the possibility of a paint illusion, since there are two tales and two sets of wheels visible in the picture. What we see are two planes, a Lufthansa 747-400 and a United 757-200 landing at the same time on parallel runways at the San Francisco International Airport.

These two runways are separated by about 225 meters, but it's the size difference and the lack of any additional points of reference that create the illusion. In fact, our brain fails to correctly estimate the difference between the two planes, in addition to the Jumbo being 3 times larger than the 757 and slightly behind.

Therefore, the information gathered by the eye is processed by the brain to give, on the face of it, a percept that does not tally with a physical measurement of the stimulus source. This is only one example of what the brain can do to unintentionally mislead us, with the more complex illusions making us see what is not there at all, like nonexistent geometrical figures and movement in a still picture.

It takes a lot of practice to see behind some illusions and others simply can't be avoided, no matter how hard we try. After all, love hives the illusion of perfection in our partner just to stop looking for others and attempt to mate with him/her.