On Tue, 10 Oct 2017 07:57:35 -0700 (PDT), Quadibloc
wrote:

Viewing the dynamics of the Earth as a rotating body in the simplest fashion -
factoring out the complexities of the Earth's orbit around the Sun from that
rotation - does not in any way interfere with accepting the primacy of the
day/night cycle when studying biological cycles.

It seems obvious that circadian rhythms are regulated by light/dark
cycles. It's not like we have some sort of Focault pendulum organ in
our heads to detect the actual rotation period of the Earth.

In any case, it is known that when humans are isolated from the
day/night cycle, their internal clocks float somewhat off a 24-hour
cycle. It's a different amount for different people, and there's at
least ten minutes of uncertainty in any identified mean values- a
value larger than the mere four minutes that separate a solar and
sidereal day.