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Chapter 1: Is Earth the Center of the Un... > From the Geocentric Theory to the He... - Pg. 50

From the Geocentric Theory to the Heliocentric Theory The mysterious behavior of planets puzzled people for a long time, as evi- denced by the fact that etymologically, the word planet comes from the Greek word for wandering star. People thought that the planets wandered around and changed their locations, while the other stars--that is, the so-called fixed stars*--revolved while maintaining the same positional relationships on the celestial sphere. Oh yeah, I heard that explanation at the planetar- ium once. Yeah, I bet the name planetarium comes from the word planet. You sure know a lot of things, That's because I went to school in America.