John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
A full moon can cause nights of shorter, worse sleep, according to European researchers.
While there might not be any factual basis behind "moon madness" – attacks of the bonkers triggered by a brilliantly beaming moon – that's not to say our craggy space-buddy has no effect on our minds. New research from Switzerland indicates that the lunar cycle does indeed influence our brain patterns, with full moons prompting nights of shorter, more restless sleep.
With streetlights and illuminated buildings turning the skies into a phosphorescent, cottony wash, it sometimes might be hard to spot the moon from the city. But it's up there, and it's in control of our "endogenous rhythms of circalunar periodicity," to use the words of scientists at the University of Basel and elsewhere. They arrived at this conclusion while monitoring 33 volunteer somnia-nauts in a lab setting that eliminated the bias of moonshine affecting sleep behavior, according to a study in Current Biology. Neither the volunteers nor the people monitoring them at the time were aware of what truly was being measured.
When nights with full moons rolled around, the researchers noticed startling changes in the volunteers: They took about 5 minutes longer to fall asleep, and when they did roll into dreamland the parts of their brains linked with deep sleep experienced 30 percent drops in activity. A hormone that regulates sleeping rhythms, melatonin, also dropped to lower concentrations in their bodies. On average, the volunteers lost 20 minutes of good sleep on nights with a full moon, and when they awoke in the morning they reported they felt like crud.
This experiment provides the world's first "reliable evidence" that lunar phases influence sleep in the lab setting, claim the researchers. So what's behind this moony bond to our brains? One possible explanation is offered in Medical XPress:
According to the researchers, this circalunar rhythm might be a relic from past times, when the moon was responsible for synchronizing human behavior. This is well known for other animals, especially marine animals, where moon light coordinates reproduction behavior. Today, other influences of modern life, such as electric light, masked the moon's influence on us. However, the study shows that in the controlled environment of the laboratory with a strict study protocol, the moon's hold over us can be made visible and measurable again.
If you read that part about "marine animals" and rejoiced that we're behavioral cousins to majestic whales and playful dolphins, you're in for a rude awakening. The animals that use moonlight to time their spawning, notes Uncharted Atolls, include corals, reef fish, mollusks, sea cucumbers and Phormosoma placenta, a tubercle-covered lurker of the deep that looks like this: