Darkness and the night sky

Mark DiVecchio

Special to the Village News

Chapter 2 – Why darkness is important (and not just to astronomers)

Circadian rhythm and melatonin

Like most life on Earth, humans adhere to a circadian rhythm – our biological clock. It's a sleep-wake pattern governed by the day-night cycle. Our biological clocks are important. They interact with our body systems, changing our hormone levels and even modifying our genetic code.

Natural light helps set our clocks to Earth's 24-hour day-night cycle. Exposure to artificial light at night disrupts this process, increasing our risks for cancers and other...