‘Detectors: cameras and time machines’ explores methods of investigating particles. Early methods for detecting particles used scintillating material which flashed on contact with particles. Detectors were then developed which sensed the trail of ionization left by particles. Cloud chambers were effective but very slow, photographic emulsions proved to be much quicker. Newer chambers were developed, which operated faster — bubble chambers were superseded by computerised wire spark chambers, multiwire proportional chambers, and drift chambers. Silicon strip detectors can detect extremely short lived particles, and neutrinos can be detected by making them move faster than light. In colliders, huge detectors at collision sites can measure billions of collisions per second.