Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!vsi1!apple!ems From: ems@Apple.COM (Mike Smith) Newsgroups: sci.space Subject: Re: `Days' in space Summary: It's been done in the USA already... Message-ID: <550@internal.Apple.COM> Date: 7 Feb 89 00:39:25 GMT References: Organization: Circle C Shellfish Ranch, Shores-of-the-Pacific Ca Lines: 63 In article GILL@QUCDNAST.BITNET writes > > A few weeks ago, there was a report on the boob-tube about a lady >in France who had spent about 60 days inside a cave (mineshaft?), >completely isolated with no timepieces. She was startled when they >brought her out and said her time was up, as it seemed that she had >often spent 40 - 60 hours awake at a stretch without noticing. > This is likely to be due to her own quirky construction. I find this claim (40-60 hour days) a bit hard to swallow. Are you sure it is correctly quoted? > The question then becomes, how ingrained are our sleep patterns to >our environment? How does this effect manifest itself in long-term >orbits (like in Mir)? Does the proximity of timepieces and the day-cycle >of the earthbound communications force the astronauts to keep the >`normal' day cycle? What is the effect of having two or more people >setting up their own `day' cycles? Our sleep patterns are pretty strongly engrained. There have been several other studies that have resulted in the conclusion that most folks have a 'natural day' of about 22-27 hours. More people tend to be a bit on the long side than on the short, but some are in each camp. Changes of a few hours are OK, but much beyond that is chaotic. I would surmise that since most folks will be close to a 24 hour day anyway, it would be simplest to just keep them in sync at 24. When 2 or more folks are allowed to 'free run' and set up their own days, one of them becomes the biological leader and the others drift into sync with them. This person may not be the social leader. [Mars speculation deleted ...] > If nothing else, more experiments could be done on isolation >experiments similar to the French one (i.e. no contact, no *clocks*), >especially the effect of having two people involved (against setting up >your own rhythms). Just a thought - go to it, thought-busters! It has already been done. I know from first hand experience. I was one of the subjects in a study of social isolation and circadian rythyms done at UCDavis in about 1972. When SkyLab was going for 85 days in space, we were going for 105 days on the ground. They played all kinds of games with our timing (including several weeks at a time of 'free running') and switching 'noon' to happen at our biological 'midnight'; talk about jet lag! We had no idea what day, date, or time is was. Several interesting conclusions were derived. (I'll be brief and only list a couple...). One was that the social leader did not corelate with the biological leader (positive or negative corelation). Another was that the scale of 'augementer/reducer' did corelate. (This means, to grossely simplify, that night people like to be left alone in the dark while morning people like stimulation and crowds and bright lights...) One guy in our group had a natural day of about 23 hours. Mine was about 25.5 hours. We 'settled' on 25 hours (i.e. I was the biologic leader and moved his pattern more than he moved mine.) The third guy was a 24is hour type and didn't have much influence on the drift rate. No group had anyone much beyond a 26 hour day during 'free run' intervals. My experience would lead me to suspect anyone who claimed that a 40-60 hour day was not noticed by the participant(s). I would look closely at the issue of 'naps', also. If anyone wants me to add more on this, let me know; otherwise I'll assume that this posting was already too long!