Representing difference: Ernst Mach and Peter Salcher's ballistic-photographic experiments

Photographs of the processes taking place in the air around a flying bullet, which the Austrian physicists Ernst Mach and Peter Salcher published in 1887, very soon became emblematic for the power of scientific photography over the human eye. But the main advantage was merely that photography allowed the phenomena in question to be recorded. This permitted a new experimental approach. The scientists were therefore not visualising phenomena by studying a single photograph but by comparing the differences between several.