Chronon energy or chronon radiation (also known as time energy) was a form of radiation that was linked to temporal anomalies. TARDISes released chronon energy (WC: Attack of the Snowmen) and Magnus Greel's arrival in the time cabinet in the 1800s via a zygma beam caused massive discharges of chronon radiation which flowed along the Earth's telluric currents, forming the Dragon Paths. The segments of the Key to Time were traced by the chronon radiation they gave off. (PROSE: The Shadow of Weng-Chiang) The Vist were capable of "smelling" time energy. (AUDIO: The Forbidden Time)