Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How would you organize arbitrary day cycle on an exoplanet?

  1. Oct 30, 2014 #1
    -there is no serious astronomical phenomena determining that - either the planet is tidally locked, has too long day cycle, or is too far away from its star and inside bases anyway humans rely on artificial light;
    -there is a colony of a size of at least medium city;
    -post scarcity economy is still far away.

    Sure, no one would mind artificial day-night cycle. However, wouldn't it be wasteful? I mean office / shop /classrooms tend to be closed for night. Using 3 (or at least 2) shifts would at least seem a more effective alternative.

    The first impression was that no one would be unhappy about it, after all I would mind being sent nowadays for night shift. However, I would not care if the "night" was 100% arbitrary. Nevertheless I started to wonder how would in such case family life look like. If each part of the family was permanently on a different shift?

    How would you think that organizing life would be the most effective? Arbitrary day and night? Citizen divided in to 3 shifts? (2?) Or maybe 6 shifts to avoid existence of rush hours?

    Suffering jet lag each time after changing school / job does not seem excessive. However, suffering jet lag to be able to attend an event (let's say - a staff meeting) - starts being inconvenient.

  2. jcsd
  3. Nov 2, 2014 #2
    I would go with an artificial day-night cycle. If for some reason industry et cetera must run at 100% capacity 24/7, then a three-shift system would probably be the best choice. A colony on another world would probably be designed from bottom up to have a working mass transit system, so rush hour wouldn't be much of a problem. It of course depends on the configuration of the colony in question, is it a compact colony or is it "spread out" like cities on Earth? I'm thinking the friendlier the climate, the more spread out the buildings, factories et cetera will tend to be.

    EDIT: Come to think through it, a more than three shift system would be a good idea, if person A needs to meet person B, overlap is needed, though there will always be people who are "inaccessible" from each other. Some kind of long-term rotation would be needed...
  4. Nov 2, 2014 #3
    Personally i vote to the Earth like cycle, for a long time, most people will be coming from Earth.
    If they are coming from Mars, sol is similar to a day on Earth.
    I'm not entirely sure, but i think plants also need day and night cycle, so it can be good to switch off the lights inside an O'Neill cylinder also.
  5. Nov 2, 2014 #4


    User Avatar
    2017 Award

    Staff: Mentor

    24-hour cycles as humans are adapted to them, sure, but sleeping and working hours do not have to be the same for everyone.

    Some different system would certainly help as it makes all the infrastructure much more efficient - you could use roads, shops, factories and other things evenly the whole day. Assuming 1/3 "day" work and 1/3 sleep, every possible combination of two working times allows to arrange sleeping times to have 1/3 of a "day" in common.
    Larger groups would need some more coordination.

    The problem is not new - many meetings in science and business are international and you have to find a convenient time for those meetings. Some examples:
    Europe and US: evening in Europe, morning in the US
    China/Japan and Europe: evening in China/Japan, morning in Europe
    US and China/Japan: evening in the US, morning in China
    All three combined: You have a problem.
  6. Nov 5, 2014 #5
    how far away is the colony from the solar system? if the colonists spent years getting to the location then the time cycles would reflect the ship time cycles which would not be earth cycles. any corporation would insist the workers do at least 12 hrs work/day to recoup the vast cost of space flight chances are they would tip the 16hr/days which after a few years would become the normal way of life for most colonists. the most likely factor for determining the day length would be either shipping rotations based on planetary cycles (how many times a planetary year can transports be sent on their way to reduce the costs) a 24/7 industry would simply be divided into work shifts and not all that dependent on day length nor would the workers.
    if half the planetary year cycle is no good for shipping you would now have two seasons A) production season B) transport season not that production would stop but more effort is spent on sending off the products/resources when the window is open.

    how a corporation decides to treat its employees to make profit would be the determining factor in how the day/week/month cycles come to be.
    if they have a 5 shifts on 2 shifts off week similar to our week or any combination that amounts to 7 the week would become the norm again but its also possible shifts could be split into pay cycles so the week may disappear and become 10 shifts on 5 off or whatever combo before a pay cycle happens and people would then plan their lives accordingly.

    as was pointed out previously overlap has to occur so different shifts can communicate if the standard work day was 16 hrs a 3 hr overlap on each end so each shift can always meet any other shift you'd have a 30 hr day. 16 work 8 sleep 6 living. its likely to reduce costs they would reduce the work day to 14 hrs knocking 2 hrs from the overlap so 14 work 8 sleep 8 living with the same 30 hr day and at least 10 on shift days 3-4 off.
  7. Nov 6, 2014 #6


    User Avatar
    2017 Award

    Staff: Mentor

    Humans are adapted to a 24-hour cycle (with a few exceptions). Deviating from this cycle length for a longer time has bad effects on health.
    Also, if working hours are too long the quality of work goes down.
  8. Nov 6, 2014 #7
    People in an artificial environment can easily adapt to a changed day length. especially if the change is adapted for at least 2 generations like in an extended space flight to a new planet 50-100 years away.

    changing from 24 to 30 hour days would have very little physical impact as long as its consistent. as for work day length and efficiency in production jobs 12 hr shifts of work time plus 2 hrs of breaks and swing time has proven to be sustainable over a long period with very little loss in efficiency as long as the shifts have a balanced on and off shift period 5-2, 10-5, 21-12 have all been used in both local and isolation work areas and proven to have the least problems among the employees working the shifts. longer shifts like 16hr days are common on oil rigs but the on off ratio is higher 4 weeks on 3 weeks off.

    its the light at he end of the tunnel method. as long as we can see it we can keep motoring on with little loss in efficiency
  9. Nov 6, 2014 #8


    User Avatar
    2017 Award

    Staff: Mentor

    Source? This study, for example, reports several issues with a modified cycle. And jet lag is a common effect when crossing multiple timezones in a day.
    Source? ;)
  10. Nov 6, 2014 #9
    biggest problem with that study is its done on earth with a non artificial environment (the earths rotation will still be a factor) same is true of jet lag. hard to switch out a system when the very essence which created the system is present (the sun cycle). as I read it. it seems even on earth with the constant influence of the planets rotation they did manage to create 28hr days for extended periods [30+ days] in the tests.where the subjects became accustomed to the new length of day.

    also jet lag is a short term effect or people would be miserable for the entire trip abroad instead of the first day or two depending on how sensitive the individual is.

    the theory of evolution shows just how adaptable organisms are given a stable/consistent change to an environment the longer the change is (just like moving to another country) the better adapted to the change we become (move from NA to Europe and next year{i don't imply it'll take a whole year} you will be in sync with the local time)
    Last edited: Nov 6, 2014
  11. Nov 6, 2014 #10
    I actually toyed with idea of changing length of days. (more often sleep, people more regenerated) However, I saw how such (16 hour days) idea in US submarine navy is expected to be scrapped because it was generally disliked, people tried to follow default 24 h days and the whole scientific background for this idea was weak.
    So I am even less optimistic about 30 hours days.
  12. Nov 6, 2014 #11
    problem is anything done on planet earth will naturally be affected by the planetary cycle. the spin affects us subconsciously. the space station is also within the influence. on another planet the planet in question would create its own influence but on say an asteroid or simply a deep space ship it would be much easier to alter the length of days.

    getting 8 hrs sleep for every 30 hrs would be well within our abilities to adapt to the change.

    the 16 hr day on subs was a way to mitigate lack of bunk space 3 sleep shifts for the same bunk making two shifts have to be out for 16 hrs each. the work period is closer to 12 hrs with breaks amounting to the other 4 hrs.

    I mentioned oil rigs as another 16 hr work shift and they have shorter break time but travel from camp to the rig is included and after work besides eating there's very little to do at the remote camps.
    Last edited: Nov 6, 2014
  13. Nov 7, 2014 #12
    Spin affect us subconsciously?? The body and mind needs rest, that is it. Maybe one wake up easier if it isnt dark outside, but one still need rest.
  14. Nov 7, 2014 #13


    User Avatar
    2017 Award

    Staff: Mentor

    Please give a source for claims like this. Note that wild speculation is not allowed here, and presenting it as fact makes it worse.
    Note that the ISS is not spinning at all. But it makes one revolution every 90 minutes.

    The experiments I mentioned all used no daily light cycle or an artificial light cycle with a different length, so sunlight did not influence the experiments.

    You can have a 28h-cycle, but as far as I see in the studies it was not as good as the 24h-cycle.

    It is a short-term effect because you have the shift just once, not every day.

    Evolution has a negligible effect over two generations, especially for things that have been nearly constant for billions of years where no flexibility was needed.
    Moving from one continent to another does not change the length of a day.
  15. Nov 7, 2014 #14
    Any ideas that do not involve karoshi? ;)

    I mean I think from claim "it's feasible" (where you are possibly right) you move to a position "it's a good idea".

    Anyway, I have one more thought: What's the limiting factor - capital or labour force?

    For example:
    - high specialist, inexpensive office building - care about workers being happy and having good chance to coordinate their work, no one cares whether chair is being utilised over 90% of time ;)
    - expensive equipment, unqualified people doing McJobs - put them in to shifts.

    Damn, in such space exploration stuff both humans and equipment are going to be expensive.

    From simple - math 40 hours work week and 168 hours week, it seems that under perfect conditions there is place for something like 4 shifts utilising all equipment almost fully and having all people with plenty of free time. (free may actually mean being sent to some trainings, whatever). Yes, I know each day 6 h of work/day, but presumably some free weekend would be advisable. Any ideas how to coordinate that?

    Or maybe 2 shifts of 8 hours would be actually the best compromise? I mean there is place to use most institutions both during the "day" and "night", but in the same time there is no problem to have a while to clean the up the stuff in the mean time and there would be no gigantic rush hours.
  16. Nov 7, 2014 #15
    what percent of automation is expected from a far colony? if most of the work force consists of controllers for mass automation facilities you'd probably see 24/7 work. splitting it up into whatever kinds of shifts the amount of employees could easily sustain. one shift (day shift) would see the executive branch, the management branch, specialists branch and Maintenance branch do their thing with any meetings between them held then.

    my emphasis on the corporate dollar dictating things is looking at how space exploration has proceeded till now. we expect astronauts who would travel to mars to get used to the idea of drinking recovered urine because shipping a few years of water is simply not cost efficient compared to recovering a much smaller amount. its not like we can't send that much water but the cost of getting it into space is too great to justify it. the expectation that 6 people do 10 peoples worth of work because the cost of sending ten exceeds a budget for a mission means they will make six people work like they were 10 people.
    Last edited: Nov 7, 2014
  17. Nov 7, 2014 #16


    User Avatar

    Staff: Mentor

    Please note the rules for posting in this section.


    Any further posts that break these rules will be deleted and proper action taken.
  18. Jun 21, 2015 #17
    I thought about a colony, only one underground city, very high level of automation, good mass transportation. I wondered, maybe it could be good to have a five hour shift for a common machine overseer/maintenance worker, some hours of siesta (I can hardly work after lunch) then an other five hour shift? (But maintain 24/7 working time with different shifts.)
    Maybe the quiet hours could be ones between shifts.
    Well i find it hard to break entirely from having 8 hours of day (bright lighted streets) and 8 hours of night (barely lighted streets) time.
  19. Jun 21, 2015 #18
    You may support that with studies showing that siesta is a good idea for brain. The problem starts with leaving all equipment unsupervised during those siestas... you know, no next shift comes...

    For arguments sake, one may drop 24 hours or 7 days week if it made a better schedule... (just right now I don't see it)

    So far my best ("best" - the one which sounded for me the most reasonable) was 3 shifts, 8 hours each. The good thing was then when you end your shift, everything (retail, services, whatever) is open because the next shift started their job. Also the good thing was no overhours, as the next shift occupies your place. Plus a free weekend or in jobs requiring work on weekend different free 2 days.

    Idea 2: 6 working days per week, in each 6 h 40 min of work and 1 h 20 min siesta. But would one sacrifice a weekend for siesta?

    In those ideas there is no universal day / night cycle.

    "But maintain 24/7 working time with different shifts."
    Sounds good... have you tried to work out such schedule with siestas? ;)
  20. Jun 21, 2015 #19


    User Avatar
    Staff Emeritus
    Science Advisor

    The issue I see with this is coordination between the shifts. Having multiple workers on one project that don't work together at the same time can be a nightmare. Time would have to be set aside for writing summaries for the next shift, reading summaries of the last shift and dealing with anything that wasn't put back or written down (e.g. "where the hell did he leave the spanner?!"). For some jobs this would be a negligible loss of productivity (e.g. shelf stackers) for others potentially disastrous (e.g. nurses).
  21. Jun 21, 2015 #20
  22. Jun 21, 2015 #21
  23. Jun 21, 2015 #22


    User Avatar
    2017 Award

    Staff: Mentor

    That works fine with 8-hour shifts (+ a bit more for overlap).

    For projects you can change shifts so the whole group has the same shift (or not, if the project requires to operate machinery for more than 8 hours per day). Changing shifts is frequently done on Earth as well.
  24. Jun 21, 2015 #23
    I wrote the following timetable:

    Start Siesta End
    8 12 16.30
    12 16 20.30
    16 20 24.30
    20 24 4.30
    24 4 8.30
    4 8 12.30

    Two shifts at anytime.
    Well i wonder, whether the whole colony should have this kind on lifecycle, or only factories and life-support?
    People who care about the needs of workers also have to be prepared for every shift.
    Maybe executives, and the ones with creative jobs could have a rather Earth like cycle, and they decide about street lights.
  25. Jun 21, 2015 #24
    Gottcha, thanks.

    People who care for people who care for needs of workers would also work in shifts... I thought in line of "all shifts are equal, but some of them are more equal than other". ;)

    What about making 3 shifts, just divide each shift in to 2 groups that have a nap at a bit different hours?

    Not so simple with those creative ones. Do you want to use labs / university lecture halls / offices for 8 hours with some overhours? Wouldn't that be a bit wasteful?

    I thought about opening market exchange only for one shift (and in case of my setting just once a week). That would a bit enforce which is the business shift. Also parliament would have to have its shift, but I'd expect the rest of gov to be open for serf... I mean citizen at any moment. (any idea for which kind of activity it would be really much more convenient to have one shift?)

    Second, more serious problem that I see is family life. With 3 shifts one still have chances to coordinate that. With more - even more challenging.
  26. Jun 22, 2015 #25
    Good points, but why more shifts make family life so difficult? They can arrange to work in the same shifts (maybe half shift for one parent, most times, for the mother), maybe most people in a living hive (city block) can have the same shifts.
    Hmm, for the tycoons and the leader, it is convenient if they all awake at once, and can negotiate business. Maybe the main AI also have cycles of peak and low activity (sort, filter, sweep enermous amounts of data, instead of dreaming) Well, if there is a preferred day time, people's timetable has to rotate so they dont miss all celebrations kept in day time.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook