3
" What moral to draw, then, of the nonexistence of an innermost planet and the universal triumph of general relativity? At least this: Science is unique among human ways of knowing because it is self-correcting. Every claim is provisional, which is to say each is incomplete in some small or, occasionally, truly consequential way. But in the midst of the fray, it is impossible to be sure what any gap between knowledge and nature might mean. We know now that Vulcan could never have existed; Einstein has shown us so. But no route to such certainty existed for Le Verrier, nor for any of his successors over the next half century. They lacked not facts, but a framework, some alternate way of seeing through which Vulcan's absence could be understood. "
― , The Hunt for Vulcan: ...And How Albert Einstein Destroyed a Planet, Discovered Relativity, and Deciphered the Universe
4
" This Saturday, Galle and a volunteer assistant, Heinrich Ludwig d’Arrest, command the main telescope. Galle stands at the eyepiece and guides the instrument, pointing toward Capricorn. As each star comes into view, he calls out its brightness and position. D’Arrest pores over a sky map, ticking off each candidate as it reveals itself as a familiar object. So it goes until, sometime between midnight and 1 A.M., Galle reels out the numbers for one more mote of light invisible to the naked eye: right ascension 21 h, 53 min, 25.84 seconds. D’Arrest glances down at the chart, then yelps: “that star is not on the map!” The younger man runs to fetch the observatory’s director, who earlier that day had only reluctantly given his permission to attempt what he seems to have thought a fool’s errand. Together, the trio continue to watch the new object until it sets at around 2:30 in the morning. True stars remain mere points in even the most powerful telescopes. This does not, showing instead an unmistakable disk, a full 3.2 arcseconds across—just as Le Verrier had told them to expect. That visible circle can mean just one thing: Galle has just become the first man to see what he knows to be a previously undiscovered planet, one that would come to be called Neptune, just about exactly where Urbain-Jean-Joseph Le Verrier told him to look. — "
― , The Hunt for Vulcan: ...And How Albert Einstein Destroyed a Planet, Discovered Relativity, and Deciphered the Universe
5
" Vulcan is long gone, almost completely forgotten. It may seem today to be merely a curiosity, just another mistake our ancestors made, about which we now know better. But the issue of what to do with failure in science was tricky right at the start of the Scientific Revolution, and it remains so now. We may—we do—know more than the folks back then. But we are not thus somehow immune to the habits of mind, the leaps of imagination, or the capacity for error that they possessed. Vulcan’s biography is one of the human capacity to both discover and self-deceive. It offers a glimpse of how hard it is to make sense of the natural world, and how difficult it is for any of us to unlearn the things we think are so, but aren’t. "
― , The Hunt for Vulcan: ...And How Albert Einstein Destroyed a Planet, Discovered Relativity, and Deciphered the Universe