Is there an explanation somewhere about the different time zones for worlds of different sizes? Does an hour still equal an hour, and if so does a much smaller or larger world throw off the length of a day and inhabitant's circadian rhythms? Or am I more confused than normal?
World time zone?
- Thread starter Leitz
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GypsyComet
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That's certainly possible.
The need for time zones and their characteristics will depend on a number of factors, including population, tech level, whether there is surface habitation (and thus a need to pay attention to the local star), whether the body is a world or a moon (in some cases) and whether it is tidally locked.
A local sentient race might want a diurnal-slaved set of time zones, while Imperials who don't care about local days probably won't since they are more concerned with the Imperial calendar.
A backwater with only 20,000 people in two communities only 200km apart on the whole world might not need timezones since there is no one on the far side of the world to care.
A mid-tech world with lots of people and a tradition of paying attention to day vs night might implement timezones, while a world that lives entirely underground probably doesn't need them since everyone can be on the same clock.
BlackBat242
SOC-14 1K
An hour is an arbitrary period of time which, on Terra, was determined by dividing the rotational period of the planet (day) into 24, for various mathematical and cultural reasons, by one particular civilization (Greeks).
There is absolutely nothing magic about either that period of time nor of the division of the rotational period into 24 parts (just as dividing a circle into 360 parts [degrees] instead of another number was a choice, not a cosmic certainty).
If the planet has no indigenous sentient life, then the number of divisions of the rotational period will be decided by the culture/species that colonizes it - and they can decide to either:
1. keep the same number of "hours" per day they had on their home-world - likely resulting in an "hour" of different length than "back home"
2. keep the same length of "hour", and thus likely have a different number of hours in a day
3. or develop a new system of measuring time within a day (with a different number of hours of different length than "back home" (possibly with a completely different name) - just to make clear the "new start" of their colony.
If the planet does have indigenous sentient life, then the number of divisions of the rotational period will be decided by the culture/species that already inhabits the planet*, and colonists will then face the same 3 choices as above, with the addition of:
4. adopt the natives' system
* As determined by their own mathematical/religious systems - they could have 10 "hours" per day, or 10 hours for the light period and 10 per dark period - or perhaps they use an octal numbering system, and have 16 hours per day.
Or perhaps they determine time by some other standard - starting with a short period (the time it takes to walk/fly/swim a certain distance, for example [maybe the The Holy Furlong**]) and all other time measures are derived from that.
** The distance a great spiritual leader of the past walked to perform a certain miracle.
There is absolutely nothing magic about either that period of time nor of the division of the rotational period into 24 parts (just as dividing a circle into 360 parts [degrees] instead of another number was a choice, not a cosmic certainty).
If the planet has no indigenous sentient life, then the number of divisions of the rotational period will be decided by the culture/species that colonizes it - and they can decide to either:
1. keep the same number of "hours" per day they had on their home-world - likely resulting in an "hour" of different length than "back home"
2. keep the same length of "hour", and thus likely have a different number of hours in a day
3. or develop a new system of measuring time within a day (with a different number of hours of different length than "back home" (possibly with a completely different name) - just to make clear the "new start" of their colony.
If the planet does have indigenous sentient life, then the number of divisions of the rotational period will be decided by the culture/species that already inhabits the planet*, and colonists will then face the same 3 choices as above, with the addition of:
4. adopt the natives' system
* As determined by their own mathematical/religious systems - they could have 10 "hours" per day, or 10 hours for the light period and 10 per dark period - or perhaps they use an octal numbering system, and have 16 hours per day.
Or perhaps they determine time by some other standard - starting with a short period (the time it takes to walk/fly/swim a certain distance, for example [maybe the The Holy Furlong**]) and all other time measures are derived from that.
** The distance a great spiritual leader of the past walked to perform a certain miracle.
12 is a likely division for time and circles- prime factorization is 1*2*2*3 - which gives whole number ÷2, ÷3 & ÷4.
60 is even more likely, as it adds ÷5 (Prime Factor 1*2*2*3*5)
360 prime factorization (1*2*2*2*3*3*5), for easy divisions ÷2, ÷3, ÷4, ÷5, ÷6, ÷8, ÷10, ÷12, ÷15, ÷20, ÷25, ÷30, ÷36, ÷40, ÷45, ÷60, ÷72, ÷90.
2520 is better still - (1*2*2*2*3*3*5*7) but too large for most people...
3*4*5*7 gives a base of 420, prime factorization of 2*2*3*5*7, ÷2, ÷3 ÷4, ÷5, ÷6, ÷7, ÷10, ÷12, ÷14, ÷15.
Most human calendars have stuck close to the natural phenomena - 28-32 day months, 360-366 day years, with several using an inter-calendary period of 5 or 6 days to actually have a "360 day year"...
Almost all have divided the day into either 12 or 24 chunks of a day, nominally translating as "hours"... (The Japanese 12 hour day was linked to their 12 month astrological calendar - the same order as the months, and the years also in same order.)
24 is the product of 1*2*3*4.
120 is the product of 1*2*3*4*5 - and so should not be uncommon... but it is.
Mathematical bases in use have been an interesting mix, too.
Preindustrial societies have used Base 5, base 12, base 20, base 60, and base 10, with 10 being dominant. Note that both 20 and 60 generally have used compounded symbols (5's and 1's).
A world's hour-equivalent should be one of:
- expressed in 10 or 100 in whatever base they use (which is likely 3, 4, 5, 10, 12, or 16, with an outside chance of 20 or 60)
- an even multiple of the product of the first several primes (6=1*2*3, 30=1*2*3*5, 210=1*2*3*5*7)
- an even multiple of the product of the first X integers (6=1*2*3, 24=1*2*3*4, 120=1*2*3*4*5, 720=1*2*3*4*5*6)
Subunits are likely to be similarly configured, but not of any need the same configuration... but 360's pretty likely, as is 3600 and or 60, for simple divisibility.
Nice summary Aramis, nailed it. I'd just like to throw in a few points.
As Aramis pointed out, 360 is a very convenient number to work with and is also very close to the number of days in a year to almost 1% accuracy. This is important because when making astronomical observations, the heavens is offset by roughly 1/360 of a circle each day. So when calculating the motion or position of a star in the sky, you can offset based on the day of the year to get a reasonably accurate value using relatively simple calculations.
The number 12 is also very convenient to work with when counting. If you look at the four fingers of your hand, each finger has three bones or segments separated by the joints, making a total of 12. This makes it very easy to count up to twelve by pointing to these finger segments with your thumb, and you can quickly do base 12 arithmetic using both hands using your thumb as a pointer. Using number systems based on multiples of 12 goes way back to the Babylonians at least, but there are big gaps in our knowledge of their mathematical and astronomical lore.
It could be a fun exercise to come up with calendrical and counting systems for different worlds and alien races.
Simon Hibbs
As Aramis pointed out, 360 is a very convenient number to work with and is also very close to the number of days in a year to almost 1% accuracy. This is important because when making astronomical observations, the heavens is offset by roughly 1/360 of a circle each day. So when calculating the motion or position of a star in the sky, you can offset based on the day of the year to get a reasonably accurate value using relatively simple calculations.
The number 12 is also very convenient to work with when counting. If you look at the four fingers of your hand, each finger has three bones or segments separated by the joints, making a total of 12. This makes it very easy to count up to twelve by pointing to these finger segments with your thumb, and you can quickly do base 12 arithmetic using both hands using your thumb as a pointer. Using number systems based on multiples of 12 goes way back to the Babylonians at least, but there are big gaps in our knowledge of their mathematical and astronomical lore.
It could be a fun exercise to come up with calendrical and counting systems for different worlds and alien races.
Simon Hibbs
Brillant stuff, but it gave me a headache reading it.
Interesting. So, in an ATU that's 300 years port-Imperium, would the colonized planets use the holdover from Imperial time? Did Imperial time stay on 24 hour days of 60 minute hours?
People on earth adapt to long days or long nights. However, I'm not sure how they would adapt to short days or nights. How short is "short"?If a smaller or larger planet has an earth like spin speed, the day would be shorter for smaller planets or longer for bigger ones. Something to ponder.
People on earth adapt to long days or long nights. However, I'm not sure how they would adapt to short days or nights. How short is "short"?If a smaller or larger planet has an earth like spin speed, the day would be shorter for smaller planets or longer for bigger ones. Something to ponder.
Human beings are probably going to need SOMETHING close to a 24 hour unit to allow for natural human biology and the need for sleep cycles. From submarines, I believe that people can adapt to a 'day' of three six hour shifts ... so there is probably some wiggle room, but I doubt an entire human population could adjust to a 6 hour day of awake 4 hours and a 2 hour sleep cycle.
I could imagine a world with a 7 earth-hour rotation period having a name for a unit of three days where people are awake for 2 local days and sleep one local day.
I briefly thought about doing something about hours and days on Biter for the PbP game, but quickly decided that the reward in 'color' would not be worth the extra bookkeeping and confusion ... so the PbP has 24 earth hour days to keep MY life easier.
I could imagine a world with a 7 earth-hour rotation period having a name for a unit of three days where people are awake for 2 local days and sleep one local day.
I briefly thought about doing something about hours and days on Biter for the PbP game, but quickly decided that the reward in 'color' would not be worth the extra bookkeeping and confusion ... so the PbP has 24 earth hour days to keep MY life easier.
Each world will have its own solution, which will most likely be one of two kinds: a) The full day is divided into as many standard hours as will fit, with the final hour of the day being a suitable odd number of minutes; or b) the day is divided in nonstandard hours and minutes that make the number of hours come out neatly.
Examples:
Hans
Examples:
"Regina’s day is 25 hours, 31 minutes, and 37 seconds long. Making the players aware of that is one simple way of reminding them that “they’re not on Earth anymore, Toto”. However, some players (and some GMs) feel that it is pointless, tedious, and irritating to keep track of a day that differs from the familiar 24 hour day. In such a case it is better to ignore the whole thing.
Regina’s day is divided into 24 standard hours and one extra long hour of 91 minutes and 36 seconds called Contemplate (The original pilgrims set aside this period for spiritual contemplation, hence the name. Traditionally many worlds handle day lengths that don’t fit with standard hours by having a special hour called Compensate. Historians disagree on whether it was a deliberate or an accidental joke). In any case, clocks go from 24:91:36 to 0:00:00 at 45 minutes and 48 seconds past midnight; Contemplate straddles midnight so as to make makes noon fall at 12:00:00 precisely. The one-second discrepancy is adjusted once a local year.
Since Regina’s day is roughly an hour and a half longer than the Imperium’s standard 24 hour day, Regina’s local calendar skips a weekday every 16th day. I.e. the 101st day of Regina’s Local Year 586 (RY 101-586 – ‘RY’ stands for Reginan Year) corresponds to the first day of the Imperium’s Year 1120 (001-1120). RY 102-586 corresponds to 002-1120 and is thus a Wonday and RY 103-586 corresponds to 003-1120 and is thus a Tuday. But RY 104-585 corresponds to 005-1120 and is thus a Forday. This doesn’t make much practical difference to Reginans, except the every second or third week is six days long instead of seven. Note that when a Senday is skipped, the result is not a 13 day work week; people just take Sixday off instead." [Regina Startown]
By happenstance Forboldn's day is almost exactly 10% longer than 24 standard hours (1,584 minutes). The day is divided into 24 hours of 66 minutes each.
EDIT: This is my opinions, not canon.Regina’s day is divided into 24 standard hours and one extra long hour of 91 minutes and 36 seconds called Contemplate (The original pilgrims set aside this period for spiritual contemplation, hence the name. Traditionally many worlds handle day lengths that don’t fit with standard hours by having a special hour called Compensate. Historians disagree on whether it was a deliberate or an accidental joke). In any case, clocks go from 24:91:36 to 0:00:00 at 45 minutes and 48 seconds past midnight; Contemplate straddles midnight so as to make makes noon fall at 12:00:00 precisely. The one-second discrepancy is adjusted once a local year.
Since Regina’s day is roughly an hour and a half longer than the Imperium’s standard 24 hour day, Regina’s local calendar skips a weekday every 16th day. I.e. the 101st day of Regina’s Local Year 586 (RY 101-586 – ‘RY’ stands for Reginan Year) corresponds to the first day of the Imperium’s Year 1120 (001-1120). RY 102-586 corresponds to 002-1120 and is thus a Wonday and RY 103-586 corresponds to 003-1120 and is thus a Tuday. But RY 104-585 corresponds to 005-1120 and is thus a Forday. This doesn’t make much practical difference to Reginans, except the every second or third week is six days long instead of seven. Note that when a Senday is skipped, the result is not a 13 day work week; people just take Sixday off instead." [Regina Startown]
By happenstance Forboldn's day is almost exactly 10% longer than 24 standard hours (1,584 minutes). The day is divided into 24 hours of 66 minutes each.
Hans
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For Regina, my JTAS article about Regina Startown. For Forboldn the rotation period is mentioned in my writeup on PYRAMID (reposted on JTAS Online). I think the clock is mentioned in one of my adventures set on Forboldn (with an illustration of a clock face), but I'm not quite sure it was brought, and as I don't have a subscription to JTAS Online any more, I can't go check.
Hans
BlackBat242
SOC-14 1K
All that is dependent on decimal math (base 10), and invalid for other base systems.
Only on Terra - 99.999999999% of other planets will NOT have a 360(roughly) day year, thus invalidating the "360 = one circle" concept for those worlds.
Yes - 12 is good for beings with 12 countable body parts. I can't see a 3-fingered/toed 6-limbed being with 3 segments per finger/toe finding 12 a logical number to use.
Drakon
SOC-14 1K
I can. The math works out regardless of how many "countable body parts" there may be. 12 is an even multiple of 1, 2, 3, and 4.
Or perhaps the 12 works so well for other reasons is the reason we find only so many body parts.
Wrong...
integers are fundamental concepts - the most basic concept of numeracy knows NOTHING but integers.
Primes are a later concept, but still, for mathematics, very early in the development.
the multiples of primes and integers are fundamental elements of basic functional mathematics. They would have to have no conceptual mathematics to not have a fundamental division into fractions of 1/2, 1/3, 1/4, and 1/12.
Only the reference for "decimalization" (one of the three considerations) is base dependent. And then, "rational unitization" will be "10" or "100" in whatever base... if they use octal 108=810 will be their day, with "shifts" or "hours" of 1/8 that - for a roughly 20-30 hour day, it's most likely 208. If the use hexidecimal, their day, will either be 16 or 32 "hours" ... either 1016 or
again, wrong. Any world in the habitable zone of a G_v star is going to be close to 360 days. Or an R_iii... because that's where the hab zone will be. For a type F, it will be longer. The worlds most likely to be habitable are those around F, G and K sizes V and VI ...
12 is good because, whether you have 3, 4, or 5, countable body parts, it divides evenly into 3, 4, and 6 subunits, no matter what integer base your math system uses.
In octal: 14/3 = 4, 14/2=6, 14/6=2 74/5=14
In hexidecimal: C/3=4 C/2=6 C/6=2 3C/5=C
In base 20 (0123456789ABCDEFGHJK): C/3=4, C/6=2, 30/5=C
Has NOTHING AT ALL to do with countable body parts - tho' the base chosen likely will. (but doesn't always- see also Babylonian and assyrian base 60, and south american base 5 and base 20 systems, or african and australian base 2 systems)...
You're making a grandly fallacious assumption that base matters for utilitarian measures and numeracy. Smaller bases do mean less rote memorization... but that has nothing to do with the utility of the product of primes.
In the broadly habitable zones of stars that realistically have planets with earthlike life, most will be close to some convenient multiple of 12 or 60, simply because it's mathematically useful for subdivisions, no matter which base you're working in.
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