Physical Experiment and its Leading Features

Abstract

Experiment can be described as the autonomous search for new reactions or their interconnections. Physical experiment was earlier mentioned as the natural sequel to thought experiment, and it occurs wherever the latter cannot readily decide the issue, or not completely, or not at all. Even accidental observation of something striking can instinctively provoke a special mode of motor reaction, that yields us knowledge about new reactions or the links between them. Such cases can be observed in animals, or even in ourselves, if we are sufficiently attentive: this we might call instinctive experimenting. However, if a casual observation reminds us in some unusual way of some connection already known, above all if the observation is in obvious contrast with what is known or familiar, the result is to suggest thoughts that may be regarded as the specific motive power behind the physical experiments that now follow. Amongst many cases of this kind we recall Galileo’s swinging lamp, Grimaldi’s coloured strips on the edge of shadows, Boyle’s and Hooke’s colours in soap bubbles, and in fine cracks in glass, Galvani’s frog, Arago’s damping of magnet needles by a copper disc and his discovery of chromatic polarisation, Faraday’s discovery of induction, and so on.