retrograde motion
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Dark Matter: How Do We Know?
In theoretical physics, there are countless theories as to what dark matter is. But how do we know it’s not a wild goose chase? Technically speaking, we don’t. But fortunately for us, this question comes back to one of the…
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The Copernican Revolution
Nicolaus Copernicus lived from 1473-1543, a time when rebellion against the Church was at its height. And unfortunately for the astronomy of the time, it had gotten inextricably tied up with Christian teachings. In that time, heaven and hell weren’t…
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The Ptolemaic Universe
Claudius Ptolemy lived about five centuries after the Greek philosopher Aristotle’s time. Aristotle’s model for the universe — the first geocentric model, with Earth at the center — was still widely accepted, and Ptolemy sought to improve it. Ptolemy was one…
