circadian rhythm サーカディアン・リズム

The natural internal clock all organisms possess. The daily biological rhythm this clock produces is called a circadian rhythm, while monthly and seasonal rhythms can be classified as biorhythms. If a person's circadian rhythm becomes disrupted, this can have various negative effects on the body. All space colonies and bases establish a daily rhythm of day and night to help their inhabitants maintain their circadian rhythm. On Beyond Coast, this even includes creating the illusions of dawn and dusk, to which organisms are known to be sensitive.