God was intently looking into the book in his hand. Science peeped over his shoulder to see a pencil sketch of a family with a kid. Sensing the presence of Science over his shoulder, the Lord said:
God: Do you know what this is?
Science: Well! It looks like a drawing by some child depicting his family.
God: It is! And it is also quite famous on earth. This is the flip book used in the Indian film Taare Zameen par. Know what is a flip book?
Science: Oh yes! It is a series of sequential drawings placed one after another to form a book in such a manner that when you flip the pages of the book rapidly, it gives the impression of movement. This particular book was used to show the little boy moving away from his family…
God flipped the book and indeed the stick figure representing the little boy kept moving away from the family.
God: (Murmurs) Wonder how it works…
Science: Flip books are essentially a primitive form of animation, Lord. Like motion pictures, they rely on persistence of vision to create the illusion that continuous motion is being seen rather than a series of discontinuous images being exchanged in succession. The ability of the eye to retain the impression of an image for a short time after the image has disappeared is called persistence of vision. Rather than “reading” left to right, a viewer simply stares at the same location of the pictures in the flip book as the pages turn. The book must also be flipped with enough speed for the illusion to work, so the standard way to “read” a flip book is to hold the book with one hand and flip through its pages with the thumb of the other hand… like this (so saying Science took the book from the Lord and flipped it)
God: So basically it is an optical illusion – that is a perceived image that differs from reality, right?
Science: Yes Father! In fact all forms of animation are optical illusions. The information gathered by the eye is processed in the brain to give an impression that does not tally with a physical measurement of the stimulus source. There are three main types of optical illusions – literal optical illusions that create images that are different from the objects that make them, physiological ones that are the effects on the eyes and brain of excessive stimulation of a specific type (brightness, tilt, color, movement), and cognitive illusions where the eye and brain make unconscious inferences.
God: Do you know why these illusions occur?
Science: My research children feel that optical illusions are due to a neural lag which most humans experience while awake. When light hits the retina of the eye, about one-tenth of a second goes by before the brain translates the signal into a visual perception of the world. Scientists have known of the lag, yet they have debated over how humans compensate, with some proposing that the motor system somehow modifies the movements to offset the delay. Some scientists feel that the human visual system has evolved to compensate for neural delays, generating images of what will occur one-tenth of a second into the future. This foresight enables humans to react to events in the present. This allows humans to perform reflexive acts like catching a flying ball and to maneuver smoothly through a crowd. Illusions occur when the brain’s attempt to perceive the future don’t match reality.
God: So in the case of the flip book or rather the Flick book as some call it, persistence of vision or the phenomenon of the eye by which an after image is thought to persist for approximately one twenty-fifth of a second on the retina, is the reason man perceives motion, eh?
Science: Well in the beginning man did believe that the perception of motion (which is Brain centered) is the result of persistence of vision (Eye centered). But in 1912, this myth was debunked for he understood that the eye is not a camera. In other words vision is not as simple as light passing through a lens, since the brain has to make sense of the visual data the eye provides and construct a coherent picture of reality. But in the realm of cinema, we still accept that the persistence of vision is the key to this phenomenon.
God: So in a motion picture or say an animation, nothing really moves. Just an illusion of movement is created, correct?
Science: Yes Father! Animation is the rapid display of a sequence of images of 2-D artwork (two dimension), or 3-D model (three dimension), positioned in order to create an illusion of movement. Early popular animation devices were the flip book and the Chinese zoetrope which means ‘wheel of life’. The zoetrope consists of a cylinder with slits cut vertically in the sides. Beneath the slits on the inner surface of the cylinder is a band which has a set of sequenced drawings. As the cylinder spins the user looks through the slits at the drawings on the opposite side of the cylinder’s interior. The scanning of the slits keeps the pictures from simply blurring together so that the user sees a rapid succession of images producing the illusion of motion, the equivalent of a motion picture.
God: Hmmm… what do you mean by sequence?
Science: If I want a flip book to show the movement of say Suryanamaskar in yoga, the first image should be Pranamasan, followed sequentially by Urdhvasan, Uttanasan, Eka Pada Prasarnasan, Chaturang dandasan, Shastanga pranipatasang, Urdhwamukh shwanasan, Adhomukh shwanasan, Eka Pada Prasarnasan, Uttanasan. Now images leading from one posture to the next have to be incorporated and placed sequentially.
God: What happens if the images are not sequential? I mean what if the order is muddled and you get Uttanasan then Adhomukh shwanasan followed by Charurang dandasan and so on…
Science: It will begin to resemble viewing a dancer under a strobe light. That is, the movement of the moving object is viewed by a series of short samples and not as a continuous view. Then there is no link in what is being viewed.
God: Do you realize what this means?
Science looked on puzzled.
God: Every individual drawing or frame has an independent reality of existence. However its implication is derived only by sequencing it in the right order. By itself maybe every minute of human life has its own worth. But life is not merely a series of freeze frames viewed in isolation. Their significance is based on the entire sequence.
Science: Yes Lord! I do understand! Most often, people view life with a strobe effect and see only a small sampling and decide it is bad or not worthwhile. Also they begin to hold on only to their limited sampling forgetting all the in between portions that make it complete. They end up asking ‘why me?’
God: The reverse is also true my child. Isolated incidents of grace and greatness also do not make smooth viewing. Here again there is no stability. For a perfect motion picture view, every individual frame should be beautiful, continuous and also the entire sequence meaningful and coherent. Same is the case with life. Every moment of life should be complete and beautiful in itself. But equally true, they have to fall in line with a larger purpose, a greater cause, a higher vision. Every moment of life should be filled with that superior purpose otherwise life will be like living under a strobe light!
Written by Gita Krishna Raj | Published in infinithoughts in February 2010
When Science met God… | Segment Six: Lost in Time | Chapter Two: The Flip Book
