Drew
Level 8 question
Student

My name is Drew and I am an 8th grader in Glastonbury, Connecticut. My question is this: Why do the numbers of quadrants in a graph increase in a counter clockwise pattern? Why aren't they numbered increasingly in a clockwise pattern?

Hi Drew,

The decision that a circle should be labelled counterclockwise was made by the ancient Babylonians long before any surviving mathematical works, so nobody really knows why it was made. There are only guesses. My guess: when the earth is taken to be fixed, the sun revolves about the earth approximately one degree per day in the positive (= counterclockwise) direction. (Not quite one degree since it takes the sun approximately 365 days to "revolve about the earth".)

On the other hand shadows (of a sundial, for example) move in the CLOCKWISE direction. Consequently, it makes sense to design clocks to run in the "negative" (=clockwise) direction.

In the model of the planets favored by ancient astronomers (and in use until about 500 years ago), when viewed from a vantage point above the north pole the sun, moon, and the objects we call planets all move about the fixed earth in the "positive" (= counterclockwise) direction.

I hope this helps,
Chris
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