Today, you may have heard that the Chilean miners trapped inside a mine for 70 days were finally rescued. Despite the satirical Onion post proclaiming their rescue–“Shit, How Funny Would It Be if We Died As They Finished the Tunnel’–this incident may have had long-term consequences on these miners’ “circadian” health aside from the pervasive pulmonary side effects associated with underground mining.

Why? Well, when you are sitting in constant darkness for a few weeks much like my little furballs do at the end of an experiment, your internal clock overrides cues from the environment, such as your alarm clock, traffic, sunset and sunrise, that tell you when to wake up and when to sleep. And because our internal clock has a rhythm period longer than 24 hrs, these miners were probably waking up later and later each day. But then there’s also an issue of stress-related sleep deprivation here….so all we can really hypothesize is that the miners sleep and wake rhythms were pretty fracked up.

The earliest human circadian experiments were actually conducted in a cave–Mammoth Cave–by Nathaniel Kleitman, or the “grandfather of sleep medicine.” Kleitman sought to determine the length of the endogenous rhythm period, and what affect the removal of environmental cues had on sleep.

Unlike these miners, his subjects didn’t have to constantly worry about the risks of dehydration, starvation, and imminent death. Circadian misalignment associated with these type of adverse environmental conditions has been shown to increase risks of psychiatric disorders (depression, bipolar), substance abuse, and cancer. Let alone that this incident may also induce PTSD.