Quote Originally Posted by Bertrand View Post
you realize the existence of the outer planets was inferred based off behavior, as was the validity of certain calculations when they were later discovered via direct observation, right?
Actually, the existence of Uranus was predicted by perturbations in the orbits of Jupiter and Saturn, and after Uranus was discovered, a further prediction was made for the position of an additional planet, Neptune. Weirdly enough, Neptune was found fairly far from where it was predicted to be. When the calculations were checked, it was found that gross errors had been made in the gravitational calculations. The errors were large enough to basically negate any validity they may have had and reduced the predictions to garbage, but they gave the impetus to look, and a planet was found.