Tricks of Light

Object: Donato Creti, Astronomical Observation: Jupiter. 1711. Pinacoteca Vaticana. Photo: Vatican Museums

From: Lunbeck and Datson, eds., Histories of Scientific Observation, 68 (Chicago: University of Chicago Press, 2011).

The reproduction is dark in the book. For this reason, the contrast between dramatic skyline, textured tree branches, between the people and what they are watching is a little lost to us.

The title of the painting, if not the memory of middle school reading practice for the distinctive stripes on the largest celestial body in our solar system, lets us know that this is Jupiter we are looking at. Next to Jupiter, in beguiling (and fictive?) alignment in the sky are presumably other planets from our solar system. Either the sun has just set or Jupiter can illuminate even the valleys of the mountain ranges that set of the limits of our landed home. As the sky reaches toward Jupiter, it becomes calmer, becomes the perfect night sky to see it. Closer to the ground, to the mountain range, to where we live, there are clouds that look not so much like painted clouds as billowing smoke, energy evaporating toward distance the artist can only represent in denying just how far. In bringing Jupiter close, Creti analogizes not just the desires of anyone who has looked up, but a new way of accounting for the new episteme of observing as opposed to experiment.

At the same time, of the classical poses the two figures in the foreground take, what stands out is their engaged devotion to one another. What’s curious is that neither is looking at Jupiter. Jupiter, instead, oversees their conversation over what we might reasonably presume are astronomical tables. Perhaps it is a debate, given the slightest hesitation in the figure who is standing, and the way that the sitting figure leans in, entreating, but has his back turned to Jupiter. In some ways, it is a perfect illustration of the transition in astronomical practice, the turn away from tables was a turn toward observing the movement of the bodies whose movements had been presumed to be predicted by the tables until the errors in the tables showed themselves too plainly.

The main question the painting asks me is this: where is the light coming from? The way the figures are lit creates the illusion that Jupiter is shining down, as though answering the seeking angles of observation from the two people, from the branches that reach toward it, from the telescope, located just outside the frame, from the mountains, whose lowest valley is illuminated by the answer, as though for all our questions Jupiter had an answer.

On the other hand, the torch of the figure who just turned toward Jupiter could be illuminating the scene and the ground. We name and study the planets but perhaps the light we are most interested in is our own.