On September 25, Mario Biagioli, a specialist of Galileo, early modern science, and the relationship between science, spectacle, and art, gave the lecture "Moving Images for Unstable Objects: Galileo's Pictorial Engagement with Change."
This lecture was a part of the monthly open research seminars at the Department of Art History, and it was the department's dean Ilia Doronchenkov who introduced the lecturer listing his numerous academic degrees and titles. Mario Biagioli had a PhD in history of science from UC Berkeley; this discipline is the main field of his scientific interests. Although, he also studied computer science, photography, and museum studies.
Mario Biagioli taught history of science at Harvard for fifteen years, was a Guggenheim fellow and a founding member of the International Society for the Theory and History of Intellectual Property (ISTHIP). He also taught at UCLA, Stanford, the Ecole des Hautes Etudes in Science Sociales (Paris), and the University of Aberdeen (Scotland). Starting in 2010, he has been teaching at UC Davis and since this academic year Mario Biagioli is part of European University's community, where he is directing a research project on the history of Russian computer science with a grant from the government of Russian Federation.
Images as Scientific Arguments
Mario Biagioli started the lecture with a "teaser;" he showed an animation made of Galileo's scientific drawings representing sunspots. This way, Mario Biagioli underlined that the main theme of the lecture was the relationship between art and science, and, more precisely, the role of images in Galileo's discoveries.
Galileo used images to present astronomical objects discovered with a telescope between 1610 and 1612; the illustrations were published in his Sidereus Nuncius in 1610 and in the Letters of Sunspots of 1613. Previously the moon was considered to be smooth, but Galileo through these images demonstrated the irregularity of the moon surface. He also discovered satellites around Jupiter and sunspots, and he recognized that the Milky Way consisted of thousands of stars.
Probably, Galileo's images were the first ones used by astronomers. Before 1608, when telescope was discovered, astronomy was not a visual discipline at all; there were just astronomical tables and diagrams. It was the telescope what turned astronomy into a physical discipline that studies the way astronomical bodies look like.
Mario Biagioli also found interesting the fact that astronomy has to do with images of things that are not quite stable objects yet. At the moment of their observation, it is often not clear what these things are, but at least in these cases the act of representation of a phenomenon is part of what turns it into an object. Such images do not illustrate the object but construe it. In the case of early telescopic discoveries, the images produced by Galileo look like still images but in fact they try to simulate the movement of these newly discovered things. They do so in combination with the book's text, which narrates what the reader is supposed to imagine by looking at the images. Surprisingly, these still images function as a sort of "movie".
Fixed Stars vs Satellites
In January 1610, Galileo observed some bright dots near the planet Jupiter. At first, Galileo thought he was observing three fixed stars, but in a few days he was surprised to see only two stars which also seemed to have changed position in relation to Jupiter. Galileo couldn't believe that Jupiter had moved so quickly, and realized that it was the stars that had moved instead. The were not fixed stars but satellites of Jupiter. He later presented these observations and those he made in the following weeks, in the Sidereus nuncius, showing how the stars moved continuously, day after day. These diagrams ended up occupying about 20 pages of the book, making it the longest section and showing how important it was to Galileo to show that, if you understand how an object move, you will understand what it is.
Is the Moon Smooth?
Galileo's drawings of the Moon were few compared to the number of the diagrams he had dedicated to the satellites of Jupiter, but they too tried to convince the reader of the irregular surface of the lunar surface by showing how its look changed as it went through its various phases. The text instructed the reader on how to imagine that change, that movement, by describing how these images were part of a sequence, with many other intermediate stages. Also, the accuracy of the images was contextual; to make his point Galileo did not need to provide a photograph-like image of the Moon but just to show that there were irregularities and that it was not smooth as everyone, following Aristotle, believed it was. He did not need to provide an accurate representation of the Moon, but just to show that Aristotle was wrong, and that the moon had imperfect mountainous surface and craters.
What Are Sunspots? Galileo vs Scheiner
"Epistemologically speaking, sunspots are nightmare," this way Mario Biagioli began the last part of his speech. The argument was that they are fuzzy, dark, and always changing. As sunspots move, they grow, break up,, disappear, and drift apart. These were the strange phenomena that Galileo tried to explain as he engaged in an increasingly bitter argument with the German astronomer Christoph Scheiner, who claimed to have been the first to discover them.
Both Galileo and Scheiner believed that the spots were real, but Scheiner, who was a Jesuit, tried to interpret them in a way that would not upset the church. He preserved the Aristotelian idea about the perfection of the sun by arguing that the sunspots were not on the surface of the sun, but rather that they were solar satellites that, because of the sun's luminosity, they appeared like dark spots. On the other hand, Galileo was not that sure about what he discovered, he just knew that the spots were on the surface of the sun, and that they changed in very complex ways. Both scientists relied on the images to make their points.
Scheiner observed the sun only early in the morning or during sunsets with a telescope through colored glasses. He did it not do it day by day. Scheiner strived to make the illustrations clear for the people to support his ideas, which means that he drew small, schematic illustrations that made it possible for him that they were satellites.
Galileo instead created large, detailed images, one every day over 44 days, with only three gaps. The animation based on Galileo's images of the sunspots shows that there are patterns in their apparently chaotic change. In order not to damage his eyes, Galileo did not look through the telescope, but exposed a flat white sheet of paper, upon which the telescope projected a circular image of the sun's disk. He described a circle on the paper and drew the sunspots. These images were much more detailed than those of Scheiner, and remained so after they were turned into engravings and printed in Galileo's book. More importantly, if you flipped through the pages quickly, you could almost see the sunspots "move". Galileo won.
Mario Biagioli finished his lecture commenting more generally on how some scientific images like those used by Galileo look like still images but function as sequences simulating patterns of change.
Anna Fateeva