zeitgeber
n.— «Light and temperature are the only periodic or quasi-periodic environmental variables to which endogenous oscillation can be coupled: in nature they entrain the endogenous oscillation, thereby controlling period and establishing appropriate phase. They are, to use Aschoff’s phrase, the principal Zeitgeber.» —“On the Significance of Transients in Daily Rhythms” by Colin Pittendrigh, Victor Bruce, Peter Kaus Proceedings of the Natl. Acad. of Sciences (US) Sept. 15, 1958. (source: Double-Tongued Dictionary)
Further reading
Advice about college essays from the winner of a top prize for children’s literature: Kelly Barnhill encourages teens to write about experiences that are uniquely their own, from a point of view that is theirs and no one else’s. Plus, why do we say...
Susan from Virginia Beach, Virginia, shares the phrase her mother used when the kids refused to eat: It’ll grow hair on your back teeth. This supposed motivator likely blends two older traditions: a German idiom, Haare auf den Zähnen haben...