Science Content Section 1

Light as a Cue for Living Things

Light is life. When you think of life on this planet- plants, animals, humans- they are all impacted by light and the cycle of the sun. Light is the oldest input, and a significant nutrient for biological functions throughout the web of life.

Light is the most powerful time cue for our 24-hour circadian clock. It tells us when to wake up, when to get sleepy, when to produce certain hormones and when to lower or raise our temperatures. It regulates our sleep, which is imperative for health and cognitive function, as sleep aids in healing, restoring and rejuvenating the physical body and our mental capacity.

The most impactful wavelength to humans’ biology in the visible spectrum is blue. Within the visible spectrum, 480 nanometers (visibly blue) is most impactful to humans and circadian rhythm regulation, and its presence or absence triggers a multitude of biological responses.