Chapter 2: Raising (and Lowering) the Roof Summary and Analysis

Early models of the universe were diminutive in scale. The earth was portrayed as motionless and at the center of the universe as the stars and sun orbited them each day, which would have required the stars to travel at tens of thousands of hours a minute. The astronomers were convinced that the earth did not move because the citizens of Athens would have been thrown forward at thousands of miles an hour. These early cosmologists did not fully understand the concept of inertia and it would not be fully comprehended until the days of Galileo and Newton. Once it was theorized that the earth was orbiting the sun and spinning on its axis, the estimation of the size of the cosmos was greatly expanded.

Aristarchus was the first astronomer to...