Do you know that every Christmas you witness the phi phenomenon? In fact, the entire neighborhood is celebrating the phi phenomenon during the Holiday season. Phi phenomenon is an illusion, which can be seen in homes a few weeks, sometimes even months before Christmas. How? The blinking lights that adorn every house are a testament to this phenomenon; by blinking on and off in succession they create an illusion that tricks viewers into believing they are in motion.
Max Wertheimer—the Introducer
In 1910, Max Wertheimer, the founding father of Gestalt psychology, hinted on the idea of the existence of phi phenomenon as an optical illusion which is caused by alternating light movements.
If you were to witness this phenomenon, your eyes would perceive the lights moving in a series of sequence as one. However, the lights are stationary, unmoving, but your brain is tricked into believing otherwise. Wertheimer indentified this phenomenon along with persistence of vision in 1912.
Persistence of Vision
Persistence of vision, a theory, provides people with the insight on how a human brain combines a series of images into a complete picture. For instance, close one eye and look through a tube holding it vertically. When you don’t move the tube, you only see one image, but upon moving it, your brain combines the images as one to show you a complete picture of your surroundings. However, persistence of vision isn’t responsible for motion illusions in fields such movies and cartoons, phi phenomenon is. Researchers were quick to conduct an experiment to study the human perception.
The Experiment Researchers studying this phenomenon asked a few people to come in for a screening of images on the TV. The researcher showed the viewers two images in a series, the first picture was of a line situated on the frame’s left with the other one on the right. After seeing the two images quickly, the viewers described what they saw to researchers.
Majority of viewers said that they saw the picture as one, filling up the spaces between the two images especially when the speed was increased. However, people confuse this phenomenon with beta movement, which is similar in nature, yet very different as well.
The Difference between Beta Movement and Phi Phenomenon
The similarity between the two forms is that lights are repeatedly turned on and off creating an effect of an illusion of two things moving as one. The difference is that in beta, lights are in different locations whereas in phi phenomenon, the lights are either different in color or found in one location.
Next Christmas, when you look at the flashing lights, phi phenomenon will come to mind instantly. Instead of being oblivious to how the magic happens, you will know the secret behind it.