I know of several people who seem to be more at ease at night. They seem to enjoy themselves more, seem to feel saver, less pressured. I’m actually one of them.
I always thought that’s because most people around me are off from work at night. The pressure from the collective mind, the human morphogenetic field, is missing. Permission to enjoy the free time. And all that.
But there might be something else at work, or better, off work: solar pressure. Light from the sun is not merely radiation, but exerts pressure on matter.
„For example had the effects of the sun’s radiation pressure on the spacecraft of the Viking program been ignored, the spacecraft would have missed Mars’ orbit by about 15,000 km (9,300 mi)”, to quote Wikipedia.
Maybe down here on our planet’s surface we can feel that solar radiation pressure too. And when it’s absent, we feel more at ease. But then, after a while, we need it again. In fact, maybe we might only feel at ease at night if we had enough pressure from our sun that day. Or at any some days before.