Etymology: Zeitgeber literally translates from German as “time giver.” The term was coined in the late 1950s by physician Jürgen Aschoff, a pioneer in the study of biological rhythms, or chronobiology. Aschoff established that humans and animals synchronize their circadian rhythms, meaning the cycles that command the body’s internal clock, to the Earth’s rotation. According to his research, our notion of time and the way our bodies adapt to it respond to zeitgebers—environmental time cues—such as sunlight or feeding cycles. In This story is from Kinfolk Issue Forty-Nine Buy Now Related Stories Arts & Culture Issue 48 Word: Kaloprosopia A word that celebrates the masks we wear. Arts & Culture Issue 47 Word: Döstädning A Swedish solution to the mess of death. Arts & Culture Issue 46 Word: Wintering When to withdraw from the world. Arts & Culture Issue 45 Word: Explication An explanation to end all explanations. Arts & Culture Issue 44 Word: Anecdata Fact, meet fiction. Arts & Culture Issue 43 Word: Knolling The fascinating history of the flat lay.