The Mathematical Discovery of the X Rays

Abstract

The first to find the new planet beyond Neptune was C. W. Tombaugh, at the Flagstaff Observatory, Arizona. But the world grants the chief honour of this discovery to a man who has been dead fourteen years. Percival Lowell discovered this planet mathematically, determined its mass and plotted its orbit from the perturbations of its nearest neighbour. But he himself never found it in the heavens. Tombaugh, in the same observatory, working with a more powerful instrument, searched the skies with photographic plates where Lowell's calculations had shown that another planet should be found—and found it. That Neptune had been discovered, eighty-four years earlier, by precisely the same process in no way detracts from Lowell's achievement, and emphasises the care with which astronomers give honour where honour is due. This mathematical discovery of a planet preceding its physical discovery has an extraordinary parallel in the discovery of the X rays. Two years before Rontgen found and demonstrated these rays, an...