If you take a reel of movie film and unwind it, you'll find that it consists of hundreds and thousands of still pictures. The whole magic of the cinema is based on a peculiarity of the human brain. When presented with separate images in rapid succession, the brain ceases to discern them as separate images, rather it links them all together. This is called the "persistence of vision." The result is the illusion of movement - motion pictures. Your eye and brain retain a visual impression for about 1/30th of a second (the exact time depends on the brightness of the image).

Persistence of vision accounts for our failure to notice that a motion picture screen is dark about half the time, and that a video image is just one bright, fast, little dot sweeping the screen. Motion pictures show one new frame every 1/24th of a second. Each frame is shown three times during this period. The eye retains the image of each frame long enough to give us the illusion of smooth motion.

Thus, the reality of the film exists in one place only: in the mind of the beholder. It exists in the human brain that connects all these separate realities into one flowing existence.

What's the difference between a young child and a grown person?

To a young child, every moment is a different world, a different existence. Things have no direction, no assembly leading toward an overall reality. First this moment happens, then this moment, then this. That's the nature of someone who is small. In Hebrew the word for "small" is katan. Katan and the word katua both come from the same root, kut, which has the same meaning in English - "cut." For someone young, katan, every second is a separate reality, katua. There is no connection between them. Thus, a child has no sense of direction in his life.

When a person gets a little bit bigger, he has a direction, but it's not straight. It twists this way and that. He is easily swayed from his path by distraction and irrelevance.

The definition of maturity is that our entire life is focused on a single direction. We take all the disparate events of life - all its byways - and we unify them into a single cogent direction. Every frame of existence is joined together into the film of our life.

A child is impatient because nothing seems to be going anywhere. Every moment is katua, cut and separated from the next. His attention span is measured in seconds. The minimum definition of adulthood is the ability to weld all of these snapshots of reality into one single cinematic flow.

The Hebrew word for "adult," gadol, is connected to the Hebrew name Gad. "Gad is a marching troop?" (Bereishit 49:19). The essence of a marching troop is that it continues forward; the beginning connects to the end. An adult - a gadol - perceives life as a single system, a single route-map, a single film. He puts all of life's individual moments together and makes them into a continuous whole. Being an adult means having persistence of vision.

The planet connected to the month of Tevet is Saturn, or, as it is called in Hebrew, Shabbtai. Shabbtai, as its name suggests, is connected to Shabbat.

In our weekday morning prayers we say to God, "How many are Your actions?" On Shabbat we say, "How great [gadol] are Your actions?" Shabbat is not a pitstop before we plunge back into the mle of the week - the reverse is true: Shabbat is the climax of the film, its purpose and its resolution. God created a world of six days that lead to Shabbat. Shabbat takes the "many" - the sum of all the weekdays - and joins it into one system. Shabbat makes the week "great."

Similarly, one of the names the Torah uses for tzitzit (the woven threads that hang from a fourcornered garment) is gedilim. Gedilim is from the same root as gadol. The purpose of the tzitzit is to raise our eyes to that Greatness which is without end.

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