Re: [LEAPSECS] building consensus

From: John Cowan <>
Date: Wed, 7 Jun 2006 23:58:13 -0400

Rob Seaman scripsit:

> References for this? Your explanation makes a lot of sense and I'm
> prepared to be convinced, but have been skeptical of experimental
> design as applied to questions of human behavior since participating
> in studies as a requirement of undergraduate psychology coursework.
> And if this cycle is inferred from the behavior of undergraduates,
> I'm even more skeptical :-)

I think there's some confusion here between the 24.7h period of the
diurnal mammal free-running clock and the 28h artificial cycles that
Nathaniel Kleitman and his student B.H. Richardson tried to put themselves
on over a 33-day period in Mammoth Cave back in 1938. Richardson was
able to adapt to a 19h awake / 9h asleep cycle, but the much older
Kleitman was not.

The 24.7h result is quite consistent across diurnal mammals kept in
continuous darkness, including humans. Google for "circadian rhythms"
for lots more detail.

John Cowan
No man is an island, entire of itself; every man is a piece of the
continent, a part of the main.  If a clod be washed away by the sea,
Europe is the less, as well as if a promontory were, as well as if a
manor of thy friends or of thine own were: any man's death diminishes me,
because I am involved in mankind, and therefore never send to know for
whom the bell tolls; it tolls for thee.  --John Donne
Received on Wed Jun 07 2006 - 20:58:50 PDT

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