I have read that the sleep cycle is driven by melatonin, and that there is a natural 24h "sine-wave" of melatonin, where during the day, melatonin is at low levels, while during the night, it is at high levels.
However, I'm wondering, if one adopts a biphasic sleep cycle, where one e.g. sleeps 4 hours during the night and 4 hours during the afternoon, or 6 hours during the night and 2 hours during the afternoon, will that turn the circadian rythm/melatonin-sine-wave into a "double-frequency sine wave"? i.e. will there be a bumb in melatonin during your afternoon nap?