> was a similar reduction in sleep on those nights in many of the undergraduates in Seattle, a large city where artificial light drowns out moonlight and students often have no idea when the full moon even is.

Can someone who actually lives in Seattle weigh in on whether the article was right to so quickly dismiss moonlight as the explanation?

I live in a suburban neighborhood near a sports stadium where the lights are on either all night or at least as late as I ever stay up. Between street lights, the stadium, and bright LEDs from my neighbors, light pollution is high enough that I can't see most constellations, just a scattering of a few dozen stars at most on a good night.

And yet I can always tell when the full moon is out because it shines like a beacon around the edges of my blackout curtains in a way that none of the artificial light in the neighborhood does.

I've never lived in downtown Seattle (or any large downtown), but I'm having a hard time imagining light pollution so bad that a full moon would be completely imperceptible at even an unconscious level. It seems to me that even subtle changes in light levels are a much more likely explanation than humans having gravitational senses.