Are We “Timed” For a 24-Hour Day Or a 25-Hour Day?
Many chronobiologists contend our “natural” circadian cycle is a 25-hour cycle, not a 24-hour one. People living in caves for extended periods of time tend to follow a 25-hour circadian cycle. But human beings don’t live in caves (unless you’re a Morlock). Exposed to continuous darkness or reduced lighting conditions, we frequently switch over to…