In the years after Newton published his laws of motion, it was found that the observed positions of the planet Uranus did not match the predictions of Newton's theory. The reason for this turned out to be the
A) perturbing effects of Jupiter and Saturn, whose masses at that time were not accurately known.
B) perturbing effect of Neptune, which at that time had not yet been discovered.
C) perturbing effect of Pluto, which at that time had not yet been discovered.
D) weakening of gravity with increasing distance from the Sun.

Question

Quizplus · Accepted Answer

The observed discrepancies in the orbit of Uranus led to the prediction and subsequent discovery of Neptune. The perturbing effect was due to Neptune's gravitational influence, which had not been accounted for because Neptune had not yet been discovered at the time.

In the Years After Newton Published His Laws of Motion