Light and The Circadian Rhythm


The very thing that allows us to stay up as long as we want, may be reprogramming our bodies. You'll learn about the effect of light and darkness on the human circadian rhythm, and we'll explore how sleep has changed since the advent of stable artificial lighting.


Podcast Lecture: The Somniloquy, Episodes 5 & 6



Lavie, The Enchanted World of Sleep: Ch. 6

Ekirch, At Day's Close: Ch. 12



1. What is the circadian rhythm?

2. What does Lavie mean by the "25-hour Day?"

3. How do light and darkness our bodies chemically?

4. According to Ekirch, how did pre-industrial people sleep differently from modern day people? What is "first sleep?"



Sleep with the Sun: Find out what time the sun rises and sets in your local area and for one day, follow the sun's schedule. Get up at dawn and go to bed at sunset. Keep a log of your sleep times. What is the quality of your sleep and what is the quality of your wakefulness? Is the sun's schedule radically different from your normal rhythm?