Look Up Every Unfamiliar Word You See
An article by Mark Sisson called Circadian Rhythms: Zeitgebers, Entrainment, and Non-Photic Stimuli used the word “zeitgeber”:
Both photic information (like blue light) and non-photic information (like temperature, social cues, food availability, to name a few) act as zeitgebers with the ability to entrain (circadian synchronization in accordance with an outside cue is called entrainment) internal clocks.
From Wiktionary—zeitgeber:
Noun
- A rhythmically occurring cue given by the environment, such as a change in light or temperature, to reset the internal body clock.
Wikipedia on zeitgeber:
A zeitgeber is any external or environmental cue that entrains or synchronizes an organism's biological rhythms to the Earth’s 24-hour light/dark cycle and 12-month cycle.
The term “zeitgeber”...was first used by Jürgen Aschoff, one of the founders of the field of chronobiology. His work demonstrated the existence of endogenous (internal) biological clocks, which synchronize biological rhythms. In addition, he found that certain exogenous (external) cues, which he called zeitgeber, influence the timing of these internal clocks.