Photography and the Invisible

For many years, an oft-repeated theme in relation to science photographs has been the revelatory concept of making invisible things visible. Reiterated in exhibition and book titles, the concept has become commonplace without ever submitting to significant scrutiny. It needs scrutiny, however, since scholarship by Edwards, Tucker, Kelsey, Daston, Galison and others have made it very clear that there is much more to photography’'s role in science than as a simple, passive conduit, translating the invisible ‘out there’ to the visible ‘here and now’. The entire concept is too large to address entirely in a short blog, as it would have to question the notion of what is ‘visible’ and go back through the philosophy of science and perception from Hacking to Berkeley. But there is one part that we could usefully address here, and that is the making of objects by photography.

This is best discussed with an example in mind. Take a particular image from Henri Becquerel'’s 1903 publication Recherches sur une propriété nouvelle de la matiére. In this photolithograph, Becquerel has ‘documented’ what are now known as the alpha, beta and gamma rays emitted from a radioactive source. There are two reasons why we should be interested in the photograph: first, that these photographs at one time helped scientists form an idea of the research object that was radioactivity, and secondly, because the photos were quickly superseded by other research methods.

When we say that photography ‘makes the invisible visible’, we generally refer to much more stable visual objects - electric sparks as used by Sugimoto or Trouvelot perhaps, or microscopical images of the eye of a fly. Electric sparks of course can be measured in any number of ways, but the images of ‘electricity’ hold a certain fascination. –They make the concept of electricity visually concrete in a way that numbers do not. To think of these photographed objects as things that are transient, like Becquerel’'s radioactivity photographs, allows us to conceive of how far photography influences our notion of the idea of an object.

One way of looking at the problem would make it easier. In an article published in May 2000, André Gunthert discusses photography as a particular sort of human knowledge; – he bases his description of scientific photography not on some inherent technical quality in photography, but on the reception of the photographs. (A. Gunthert, “"La rétine du savant: La fonction heuristique de la photographie”", Études Photographiques 7, May 2000). Like Appadurai’'s commodities, bodies of knowledge appear and disappear. They are constituted by the society of scientists that agree that the object is indeed an object in the way photography represents it. When research or concepts move on, as they soon did in the first decade of the twentieth century, the photograph might no longer represent the object, and it becomes obsolete. Photography then, could be said to generate objects. Not objects in the conventional sense that they exist in the real world, but ‘objects’ that normally have no corporeal presence. These might be physical phenomena, or, taking the example of Becquerel, however, they might also be scientific concepts.

What then, does photography ‘reveal’ when it ‘makes invisible things visible’? I would argue that it doesn'’t ‘reveal’ anything; it is not a passive conductor of invisible reality to the eyes of scientists. Instead, scientific photographs construct objects in complicated ways that reflect the nature of the questions asked by the scientist/photographer, the technology of the time, and the particulars of the experiment.