That is a completely infeasible suggestion for most people.
More robots are needed.
> In my view, everyone should always free run his or her sleep unless it makes it impossible to function in society along one's chosen profession, specialization, education, etc., or where it makes it impossible to take care of the young ones.
Is that not almost everyone? I often don't get tired till or 4 am and have to get up not long after that for work.
I think the author is arguing that by using alarm clocks and artificial light and otherwise caving to the expectations of society, we are wrecking our internal sleep clocks and they cannot be trusted for measurements until you have actually removed yourself from all that for a while. That includes your 4 am is sleepytime measurement.