Time asymmetry, time reversal and irreversibility.
D049668:History, 15th Century; D049669:History, 16th Century; D049670:History, 17th Century; D049690:History, Ancient; D049691:History, Medieval; D049711:History, Modern 1601-; D008433:Mathematics / Q000266:history; D013995:Time; D013998:Time Perception