The Circadian Room
Here’s a nice detail in the Amex Lounge in LAX: They have rooms for managing jet-lag.
Everything suffers jet-lag. Not just people, but plants and animals, too. In a classic study, crabs kept their same daily rhythms running up-shore to dodge high-tide, and running down shore to chase low tide, after they’d been flown to a different time zone where the tides weren’t at those old times any more. Plants opened their leaves and flowers when the sun rose and set in their home time zone, after having been flown to a new time zone. All multicellular life on our planet has an internal clock that remembers when it’s time to do everything that needs doing, and when we fly to a new time zone, it takes about a day for each time zone we moved for that clock to adjust to the change. Fly 8 time zones away, and your body will take more than a week to shift to the new sunrise/sunset times.
So the Amex lounge at LAX has rooms to help you start moving your circadian clock while you’re waiting for your next flight: A room with bright “daylight” light 24/7, and a room with dim “sunset” light 24/7.
Light is the main cue your body uses to figure out when sunrise and sunset is, and shift your internal clock to match. Strangely, the signals from your eye to your brain get crossed over en route: The nerves that come from your right eye go to the left side of your brain, and the nerves from you left eye go to the right side of your brain. And where they cross, there’s a little brain region that just tracks how much blue light you’re seeing. Sunrise and sunset are mostly reds, and oranges, and pinks, so blue light is a signal for the main part of the day. And that’s what your body uses to signal when it should be waking up and sleeping.
Naturally, days get a little longer as we approach the peak of summer, and shorter as we approach the depths of winter. So our bodies needed to shift our sleep/wake rhythms before there were airplanes, and even for rooted plants that couldn’t walk to a new time zone. But those shifts are only minutes a day. Shifting your sleep/wake rhythms maxes out at about an hour per day; that’s already faster than anything your body evolved to experience before the modern era.
So: The Day room and the Twilight room are cool tools.