Every cell in your body keeps time. A molecular negative-feedback loop — CLOCK, BMAL1, PER — ticks with a 24-hour period set before multicellular life existed.
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Circadian clocks, biological rhythms, and oscillating gene networks
Chronobiology simulations model the molecular and physiological oscillators that govern the daily timing of life. Circadian clock models simulate the transcription-translation feedback loop of clock genes (CLOCK, BMAL1, PER, CRY) as a system of coupled ordinary differential equations, reproducing the ~24 h period and how it entrains to light-dark cycles. Ultradian rhythm simulations model ultradian pulse generators for hormone secretion and sleep-stage cycling.
Phase-resetting curve simulations compute how light pulses of different timing shift the circadian phase — the mathematical basis of jet-lag recovery and shift-work scheduling strategies. Population models show the Kuramoto synchronisation of coupled cellular oscillators, explaining how a molecular clock in each cell drives organ-level rhythms. These models connect biochemistry to physiology and are used in chronopharmacology and sleep-medicine research.
Each simulation in this category is built with accuracy and interactivity in mind. The underlying mathematical models are the same ones used in academic research and professional engineering — just made accessible through a web browser. Changing parameters in real time and observing the results is one of the most effective ways to build intuition for complex scientific and engineering concepts.
Topics and algorithms you'll explore in this category
Common questions about this simulation category
Every Chronobiology simulation here runs free in your browser, letting you experiment with each interactive Chronobiology model — circadian oscillator dynamics, light-pulse phase resetting, sleep-wake cycle modelling, jet-lag recovery timelines and seasonal photoperiod response — without installing anything. Adjust light exposure timing, oscillator coupling strengths and free-running period lengths, then observe real-time results and learn Chronobiology online at your own pace, whether you are a neuroscience student, a sleep researcher or a curious reader. The same mathematical framework used in these simulations informs clinical chronotherapy — scheduling chemotherapy, blood-pressure medication and shift-work interventions to align with a patient's internal clock and maximise effectiveness while minimising side effects. Understanding how biological rhythms entrain to environmental cues is increasingly recognised as fundamental to public health, from managing adolescent sleep deprivation to optimising athletic performance.