Periodic environments and biological oscillations
- Day/night
- Tides
- Moon phases
- Cells anticipate periodic environments
- Circadian clocks run without cues (free run).
- Clocks are entrainable
Nobelprize 2017: Elucidation of the Molecular Mechanisms of Circadian Clocks
Jeffrey Hall
Michael Rosbach
Michael Young
Images by Nobel media, Nobelprize.org
Physical and biochemical oscillators
- Pendulum
$$\frac{d^2\theta(t)}{dt^2} = \frac{g}{L}\sin \theta(t) \approx \frac{g}{L}\theta^2$$
- period $$T = 2\pi \sqrt{\frac{g}{L}}$$
- Oscillation driven by back and forth between kinetic and potential energy.
- No equivalent of kinetic energy
- Multi-component systems with interdependent regulation