I seem to be constructing several posts that use historical case studies as evidence in favor of the argument Andy Clark makes in Natural-Born Cyborgs. I suppose this might be cited as an example of the collaborative power of ad hoc networks, of the ability of the Internet to serve as a multiplier of intelligence. Though it occurs to me that that phenomenon might just as easily be seen as an example of what academics do all the time: pick up a thread from a book and pull on it, tie it to other threads, and see what new things you can do with it. (The notion is inspired by Susan’s comment on an earlier post.) One of the admirable (or perhaps “sensible” is the better term) things about Natural-Born Cyborgs is its attitude towards technology: it’s broad enough to include things like writing (i.e., writing instruments, paper, and written texts) and– though the book doesn’t mention it– drawing. Drawing is one of those skills that for a long time was appreciated for the mental and visual discipline it was thought to impart (in addition to its utility in the pre-photographic age); it’s also one in which materials, and training matter profoundly in shaping how sight works– how a person looks at a subject, what they focus on, what they select for. Or as Victorian critic Philip Gilbert Hamerton put it,

Every drawing is in a substance and on a substance. Every substance used in drawing has its own special and peculiar relations both to nature and to the human mind.

In the history of science, one of the great examples of artistic training influencing perception– and through perception, our view of the universe– is Galileo Galilei’s observations of the Moon. Williams College art historian Samuel Edgerton uncovered the relationship between Galileo’s artistic training and his studies of the lunar surface, and explored them in a series of articles and The Heritage of Giotto’s Geometry, published in 1991. Galileo’s lunar studies, Edgerton claims, provides “a clear case of cause and effect between the practice of Italian Renaissance art and the development of modern experimental science.” [“Galileo, Florentine ‘Disegno,’ and the ‘Strange Spottedness of the Moon’,” Art Journal (Fall 1984), 225-232.] For my purposes, Edgerton’s work is interesting because it provides an example of how our interaction with media can reshape the way we look at the world. I discuss it at greater length in the extended entry.

It won’t do justice to the argument to present it without copious illustrations, but here goes anyway. And forget looking on Edgerton’s Web site: he’s not much for the Web, it seems. Edgerton argues that Galileo’s Florentine artistic training, with its deep concern for representing chiaroscuro, linear perspective, and reflection of light between objects, “contributed crucially” to his discovery of “the true physical appearance of the surface of the moon.” Edgerton reviews drawing manuals and the kinds of problems they presented to students, and finds that they were filled with exercises in which students were supposed to draw the shadows of raised surfaces on spheres– really complex patterns cast by overlapping stelae, geometrical figures, etc.. (This is the kind of thing you’ve got to see for yourself to appreciate; Heritage of Giotto’s Geometry has some great plates. These exercises, Edgerton argues, gave Galileo “an eyesight educated to see the unsmooth sphere of the moon illuminated by the sun’s raking light.” Edgerton then examines Galileo’s wash drawings of the waxing and waning Moon made in November and December 1609. They show that Galileo

still regarded the Moon somewhat in the old medieval watery spirit. With the deft brushstrokes of a practiced watercolorist, he laid on a half-dozen grades of washes, imparting to his images an attractive soft and luminescent quality. Remarkable indeed was Galileo’s command of the baroque painter’s convention for contrasting lighted surfaces and his ability to marshal darks and lights to increase their mutual intensities…. [In one corner] he set down a little practice patch of dark and light washes surrounded by a white area, probably to help his engraver realize the form of the lunar crater as it took shape in the waxing light. With artistic economy worthy of Tiepolo, Galileo indicated the concave hollow with a single stroke of dark, leaving a sliver of exposed white paper to represent the crater’s glowing brim.

Galileo’s familiarity with the way light plays on complicated surfaces is obvious in these drawings, and it makes it possible for him to conclude in The Starry Messenger that “the surface of the Moon is not smooth, uniform, and precisely spherical… but is uneven, rough, and full of cavities and prominences, being not unlike the face of the Earth, relieved by chains of mountains and deep valleys.” Edgerton provides three additional piece of evidence to back up his reading. First, on the same folio with the drawings, Galileo performed a small calculation of the height of a lunar mountain peak based on its distance from the terminator and the size of the shadow it cast; the exercise, which involves using some basic trigonometry. could have been taken out of a contemporary geometry or drawing manual. Second, Galileo notes that part of the darkened Moon is faintly illuminated by light reflected from the Earth. “How was Galileo able to make such a discovery? What led him to raise this issue in the first place?” Edgerton asks. “The fact is… the ability to depict reflected light was one of the outstanding achievements of Renaissance painting,” and every good art student was taught to look for it. Galileo, trained as he was in Florence and connected to its prestigious Accademia del Disegno, “was able to paint reflected light with considerable competence,” and to notice such reflections even when looking through a telescope. Finally, Edgerton compares Galileo’s drawings with those made by Englishman Thomas Harriot, who was working at exactly the same time and with a similar telescope, but knew nothing of Renaissance drawing techniques. His drawing shows a ragged terminator and dark blotches on the lunar surface, but no sense that what he sees is a play of light and shadow on a complex surface. A few months after reading Starry messenger, though, Harriot produces a second drawing more like Galileo’s. All in all, the piece is a gem of historical detective-work and argument. I very highly recommend it. A few years ago, I came across another, but far less dramatic, example from the history of astronomy about how choice of materials in astronomical drawing encoded ideas about how astronomers should observe their subjects:

As an example, consider the 1846 article “On astronomical drawing” which helped establish the reputation of young Charles Piazzi Smyth. (He became Scottish Astronomer Royal a few years later.) Not only did he make a strong case for the critical importance of “painstaking, accurate and detailed” drawing for astronomical research; he offered detailed instructions about materials and methods. He recommended India ink and brush as “abundantly sufficient” for most purposes, as it is “very refined, expeditious, and permanent,” but also allows for “alteration and correction to a certain extent.” Why India ink? Hamerton was full of praise for material: it allows the artist to both render small details accurately, but also requires him to render “broad washes over considerable spaces… with rapidity and decision.” It also produces a vast number of tones, from deep black to a nearly transparent gray; this range of tonal gradation, and the ability to create a perfectly black background for astronomical drawings, would have been a plus. But there was a subtler reason for the choice. India ink has to be applied to the page when wet, and when moving from dry media like pencil to monochrome washes– the standard progression in art manuals, and a move Smyth assumed his readers would make, as he cautions them that “this mode [i.e., India ink] may at first prove somewhat difficult”– artists have to learn to see in a different way, to develop new methods of organizing perception. As Hamerton explained it, newcomers to washes have to “abandon the mental habits which are concerned with the line, and to acquire the habit seeing nature in spaces… divided into many smaller spaces of differing degrees of [light and] darkness.” Spaces of differing degrees of light and dark: it would be hard to come up with a better description of what a nebula looks like through a telescope. India ink and brush were ideally suited to astronomical drawing, I would argue, not only because it allowed users to record fine detail, but because it forced astronomers to think and see in terms of spaces and relations between spaces, rather than lines and discrete objects.