The relation of a walker to its history is different. The system remains the same but
its sensitivity to its own history is mediated by the existence of a recorded memory.
This situation is met in biology or anthropology more often than in physics. In
general terms, a memory requires the encoding of information, its storage and the
possibility of a later access to this information. Here, each bounce of the droplet, by
disturbing the interface, records information about the spatio-temporal localization
Information stored in Faraday waves: the origin of a path memory 29
of the collision.