Like most people trying out digital photography for the first time, when I got my first digital SLR (a Canon 20D), I was intoxicated with the ability to take thousands of pictures without worrying about film or processing costs. This feature alone makes digital photography a medium truly distinct from film photography, one with its own rules and limitations (one such limitation is that one typically has to wade through those thousands of images).
Another limitation or feature of the medium is sensor noise, which is absent in film (the closest equivalent is film grain). As one learns in experimental physics, noise is a characteristic of all electrical sensors. I began to think of the camera simply as a detector of radiation (which, in fact, it is) and even tried to record cosmic rays passing nearby or through the camera, without success.
In addition to physics, I’m also obsessed with painting, and the painterly quality of night-time images taken while in motion, where light is painted sloppily across the photo sensor, appealed to me.
Thinking along these lines, I began taking pictures at night in Wisconsin and Illinois, with long shutter speeds, often taken from moving cars. Each resulting image represents a sort of physics event, lasting from milliseconds to seconds, involving radiation both generated and received by electrical devices (and most likely transmitted to your eyes electrically as well). They are evidence of my camera’s trajectory through a field of photons and other particles, each with its own trajectory — motes of energy, interacting in darkness.