In the 17th century, scientists used physics to explain the miracles described in the Bible. "Late in the autumn of 1680 the good people of Manhattan were overcome with terror at a sight in the heavens such as has seldom greeted human eyes," history tells us. That terrible sight was a comet so bright that it could be seen in daytime. But, like Comet 45P/Honda-Mrkos-Pajdušáková—which is currently relatively close to Earth and may put on its best show this New Year's Eve—the Great Comet of 1680 was not a portend of doom but a scientific blessing. Sir Isaac Newton observed the comet, and his calculations of its trajectory confirmed his universal theory of gravitation. The astronomer Edmund Halley also studied the comet. Newton's equations helped him determine the orbits of 24 other comets and predict when they would reappear in the night sky. The comet of 1680 would likewise inspire one of Newton's closest colleagues and friends: the mathematician William Whiston, whose intricate