Did you know? The term "circadian" comes from the Latin phrase “circa diem”, meaning “around a day.” 🌎 Earth takes a full spin on its axis every 24 hours. Over time, all life on the planet has adapted itself to this daily cycle through the circadian rhythm: the invisible internal body clock. The human body's circadian rhythm works in sync with the planet's 24-hour day, optimizing functions including the sleep-wake cycle. It's why we feel tired when darkness appears, stimulating melatonin production, and why we feel more awake during daylight hours, when melatonin secretion stops. This is just one of the ways our bodies have adapted to Earth's natural hours of light and dark. #FunFact: An aptly named protein known as "CLOCK" is an essential component in directing circadian rhythms in the body, regulating the internal oscillations to ensure everything stays in sync.