Scientific tests conducted in public are paradoxical in that lay persons are expected to draw firm conclusions from experiments that normally require expert interpretation, and in that these firm conclusions may be matters of dispute among the experts themselves. To resolve these paradoxes, a distinction is drawn between experiments and other forms of scientific display. These differences are illustrated by reference to the `experimental' televised collision between a train and a `nuclear flask', organized by the (British) Central Electricity Generating Board (CEGB), and by an airplane crash intended to test the effectiveness of `Anti-Misting Kerosene', organized by the (American) Federal Aviation Authority (FAA). It is concluded that some `public experiments' are a form of `pathological science'.