Dr. Posin's Giants: Hipparchus (1962)

Much of today’s exploration of space would be impossible without the early astronomical discoveries of Hipparchus. According to Dr. Posin, the greatest of these discoveries was that "the tip of the axis of the earth, through the centuries, make a circle in the heavens.” With the help of work done by scientists before him, such as Archimedes, Hipparchus was able to find ways of determining longitudes on earth and in the sky, thereby laying important groundwork for astronomical discoveries through the ages.

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