Emily and Charlotte Brontë, insomniacs both, would walk together in circles around the dining room table until they were tired enough to sleep. When Emily died and Charlotte suffered alone, her insomnia worsened; she added to her route, often wandering down neighborhood streets and into the cemetery until daybreak.

Annoyed by a prohibition against nocturnal work in late medieval France—enacted because candles provided insufficient light for quality performance—employers complained to Louis XI that workers occupied themselves from “four or five o’clock until the next day with various games and dissipations, and hardly want to apply themselves to do well.” In the winter of 1467, they received permission to extend working hours to ten pm.

Asked whether it was night or day that first emerged when the universe came into existence, sixth-century-bc Greek philosopher Thales of Miletus replied, “Night, earlier by a day.”

In September 1776, fearing illness from night air, John Adams asked Benjamin Franklin to close the window of their room in a New Jersey inn. “I believe you are not acquainted with my Theory of Colds,” Franklin responded, launching into “a harangue upon air and cold and respiration and perspiration” in favor of leaving windows open. “I was so much amused,” Adams wrote in his journal, “that I soon fell asleep and left him and his philosophy together.”

“Darkness has come upon me,” a hymn in the Rig Veda laments. “O Dawn, banish it like a debt.” The morning light is here asked, suggested translator Wendy Doniger, to act as a collection agency—to “make good what darkness had incurred or ‘exact’ the darkness from night as one would exact money.”

“When the white man landed on the moon, my father cried,” a young Oklahoma Indian told psychologist Robert Coles in the 1970s. “He was sure Indians were crying up there, and trying to hide, and hoping that soon they’d go back to their earth, the white men.” The boy also spoke to his aunt. “The moon is yours to look at and talk to,” she told him, “so don’t worry.”

In 2005 the British Cheese Board attempted to dispel the idea that eating cheese before bed causes nightmares. No evidence of this “evil myth” was reported among two hundred volunteers, though eating Stilton was found to lead to “crazy” dreams, while eating cheddar often led to dreams of celebrities. “We hope that people will think positively about eating cheese before bed,” said the board secretary.

“The difference between us is very marked,” wrote Frederick Douglass to Harriet Tubman in 1868. “Most that I have done and suffered in the service of our cause has been in public, and I have received much encouragement at every step of the way. You, on the other hand, have labored in a private way. I have wrought in the day—you in the night.”

Psychologists at the University of California recognized a lack of sleep “as a social repellent” and its effect contagious: “People who come in contact with a sleep-deprived individual, even through a brief one-minute interaction, feel lonelier themselves as a result.”