Forum: Author Hangout

It looks like you are using the correct term, but I had to look it up. Why not just have him ask if there is a regular day-night cycle?

Because it's an AI asking the question.

Because it's an AI asking the question.

Sorry, I must have misunderstood the original post:

In a story I'm working on at the moment, the protagonist asks his AI whether the spaceship he's just captured is operating a diurnal cycle.

That looked like he asked the AI, not the other way around.

OTOH an AI should have been programmed to use the simplest language available and relevant so it should not use "diurnal" because some/many/most users wouldn't understand.

The problem with that approach, is that either the AI comes across as relatively primitive rather than advanced which could make it out of place in a far future science fiction story or it comes across as too "human".

The problem with that approach, is that either the AI comes across as relatively primitive rather than advanced which could make it out of place in a far future science fiction story...

If it is the AI asking, the most likely response will be 'Huh? What does that mean?' at which point the AI would have to explain that it means a day/night cycle.

... it comes across as too "human".

I see nothing wrong with an AI being 'too human' when interacting with humans unless it is trying to demonstrate its superiority.

I see nothing wrong with an AI being 'too human' when interacting with humans unless it is trying to demonstrate its superiority.

Or the AI is still learning about the crew and their level of knowledge/education, or just humans in general.

OTOH an AI should have been programmed to use the simplest language available and relevant so it should not use "diurnal" because some/many/most users wouldn't understand.

A sufficiently advanced AI should be able to gauge the lingual capabilities of the person it is speaking to and tailor its speech accordingly. So it'll use "5 dollar words" for one person, and simpler phrasing for another depending on a number of factors(potentially including expressed preferences. IE if we used StarGate SG1 as an example, Colonel O'neill would likely get the lay-person version, while Major Carter would be getting techno-babble).

Sometimes the "5 dollar word" is the best option, particularly if you know the person being spoken to can understand it. (Obviously, this is a problem in fiction when it is the READER you're concerned about being able to comprehend what is being said)

The rationale is simple: The 5 dollar word conveys a load of information in a handful of words rather than dedicating a a paragraph or more to talking your way around just using the word. Not quite as pronounced in the case of using "diurnal cycle" instead of "day/night cycle" or alternative phrasing, although "diurnal cycle" still remains the most efficient option, even if it isn't the most effective(as many readers may have never encountered it before).

I was aware of the term previously, but I was expecting Urinal jokes in this thread all the same, not disappointed.

but I was expecting Urinal jokes in this thread all the same

If you insist.

Diurnal: Where male zombies go to pee.

I was expecting Urinal jokes in this thread all the same, not disappointed.

I made the first urinal joke, but it was not gratuitous. I literally did see 'urinal' the first time I read the word.

Zooplix

Be careful not to mis-spell that "Lixpooz".

What! There are people who don't know AI = Animated Imagery.

Luddite!

What! There are people who don't know AI = Animated Imagery.

And here I spent all this time thinking it meant Anal Intrusion.... :)

Crumbly Writer: You could use "circadian cycle", but not only might readers not understand it, I doubt an alien AI would either.

I don't think so. Firstly a circadian cycle is roughly 24 hours whilst such a ship would run on perfect timing. Secondly it seems to exist based on the average 12 hours of daylight and 12 hours of darkness (and we feel differently with15 hours of sunlight). Another planet / universe or whathaveyou may have say a 72 hour rotation and therefore its inhabitants and other life forms would be based on such periodicity. Therefore the use of the word circadian is likely to be misleading to the aliens

Still, I'd guess the aliens would have mastered the mathematics needed to calculate relative day night cycles for circling planets in a stable system.

For which part of the planet? At which point in the year(orbital cycle)?

Crumbly Writer
Still, I'd guess the aliens would have mastered the mathematics needed to calculate relative day night cycles for circling planets in a stable system.

For which part of the planet? At which point in the year(orbital cycle)?

Not only aliens but transplanted earth people sent to Mars and called Greenies (Al Steiner) created their own calendar, day/night etc.

Crumbly Writer seemed to concentrate on passengers in spacecraft where a circadian rhythm for earth dwellers would be appropriate but are we not hoping that they will safely disembark on another world?

Crumbly Writer seemed to concentrate on passengers in spacecraft where a circadian rhythm for earth dwellers would be appropriate but are we not hoping that they will safely disembark on another world?

Which isn't getting into the weirdness that is circadian rhythms in the first place. IIRC, it's highly variable from person to person should you ever get them in an environment where they can figure that out. (Such as a space ship) But it has been a long time since I looked into any of the associated research.

As memory serves many of the people who have been party to such research usually settled into a "day" that was longer than 24 hours, with 30+ hour "days" not being unusual for participants. So for a space faring society where a substantial portion of the population lives/works in artificial environments, things can get interesting. The people in space may shift to a different time keeping methodology entirely, among other things.

Although even that may not be standardized. Agricultural oriented efforts would likely be more focused on tricking their crops into maximum production, rather than the humans.

A mining colony may tie the length of its day to some blend of "optimum production" from the worker, leisure, and actual rest periods. With leisure being minimized obviously. ;)

While a more generic spaceport with a more manufacturing/commercial/administrative purpose may go for a 30+ hour day just because they can.

Ironically, that may be a beneficial thing for say, a SpacePort in Earth orbit if it is not servicing a specific nation/continent/time zone as that means their "day" would span the workday on much of Earth as well, and ensures they're not particularly bound to any one time zone.

Which isn't getting into the weirdness that is circadian rhythms in the first place. IIRC, it's highly variable from person to person should you ever get them in an environment where they can figure that out. (Such as a space ship) But it has been a long time since I looked into any of the associated research.

As memory serves many of the people who have been party to such research usually settled into a "day" that was longer than 24 hours, with 30+ hour "days" not being unusual for participants.

I was aware that it varies (I thought it was more like 22 or 23 hours but so what). What concerns me more is the idea of officially having longer days - 30 or 36 earth hours for example. The average human cannot even concentrate for 60 minutes in a row and is likely to get exhausted after about 8 hours even with a 60 minute meal break. They would need the current 16 hours to recover for the next day's labours.
I used to do very detailed work for a 14 hour day, four/five days a week, 9 hours on alternate Saturdays and 9 hours a day three Sundays out of four. However, alternate Fridays I had to work 33 hours straight through to Saturday evenings. Every day there was two hours travel to add. I survived but we had a high mental collapse rate - that is what work in the City of London can be like.

30 hour days are just not "on" for earth humans.

I was aware that it varies (I thought it was more like 22 or 23 hours but so what). What concerns me more is the idea of officially having longer days - 30 or 36 earth hours for example. The average human cannot even concentrate for 60 minutes in a row and is likely to get exhausted after about 8 hours even with a 60 minute meal break. They would need the current 16 hours to recover for the next day's labours.

Probably more on the order of working "4 tens"(already becoming fairly common with some employers) where you go with a 30-hour day so three 10 hour shifts would cover the full day/night cycle. Then after 4 "days" they've hit their 40 hours and get a day off(not two or three as happens currently, as one of those "days" was lost to the longer days to begin with), before going back again.

Obviously, jobs where human psychology works against such a long shift would call for alternative arrangements to be made. Depending on a few factors(proximity to work place) that may translate into going to work twice in a day instead of once. Maybe it's 5 on 5 off 5 on 15 off for example? 5on-10off would also work well on a 30 hour cycle if we're talking a spaceship or spaceport where the worker is literally 5 minutes or less away from their workplace.

I was in the Navy, spent 4 years at sea, I've seen all kinds of shift/duty rotations get put into play. By my own division, and by others on board as well. (That and the non-smokers in particular for some specialties were able to sometimes go days/weeks and occasionally months without seeing daylight...)

6on-6off seemed to be positively brutal, it didn't matter if you spent your time freezing in CIC or in the depths of "the pit" where it could be 110 degrees at the Air Conditioner vent...

Thankfully my division/workcenter never tried that.

(That and the non-smokers in particular for some specialties were able to sometimes go days/weeks and occasionally months without seeing daylight...)

Don't forget, when the ships are back in their home ports, the sailors get MONTHS to recover, even though still technically on duty.

Ah, but do they fully recover. A friend from Bodo (north of the Arctic Circle) in Norway tells me that they have a worse suicide problem than in the south due to the regular annual periods of darkness. I have heard that Finland has the same.
I wonder if the lack of Vitamin D and its source, sunlight makes the situation worse.
It would thus seem unwise to have long periods of wakefulness away from sunlight or its equivalent. As to the question of adaptation, yes, humans could adapt over generations but I wonder if an earthborn person could fully adapt to a say 24+24 hour "day"

Crumbly Writer seemed to concentrate on passengers in spacecraft where a circadian rhythm for earth dwellers would be appropriate but are we not hoping that they will safely disembark on another world?

If the day/night cycle for the new world is known, couldn't the AI slowly adjust the on-board cycle during the journey to match that of the destination? That would help the passengers bodies adjust to the new cycle. Of course, that is a moot point if the passengers are in stasis or some form of extended hibernation.

(braincell explodes)

Hopefully it wasn't the last one. :)

It's not just Vitamin D (they have pills for that) but getting adaquate light. Nowadays, most people with problems get medical facial lights. 20 min to an hour a day helps reset the normal clock and offsets the incurring depression. Not so much 50 years ago. (Also not good if they're not religious in it's application.)

Which isn't getting into the "daylight" lights and other such artificial lighting options. In that respect just run "Daylight" lighting in designated work spaces, and use more "spectrum efficient"(lower power use) lighting in the rest of the ship or station. Then you suddenly have people's internal clock naturally trying to "sync" to their workspaces.

The only challenge there is the "customer service" jobs that may be dealing primarily with off-duty personnel. But hey, we have automation options for many of those. The only real challenge would be medical services, and even then....

Technically, it's believed that actual light is what allows the body to produce and process Vitamin D (i.e. without the sunlight on the face, the pills will be worthless).

SAD (Seasonal Affective Disorder) is thought to be part chemical based, but they also suspect some of it is neurological in nature, ie something to do with the brain and the human eye and its response to what it identifies as "sunlight."

http://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/basics/causes/con-20021047

Mayo Clinic doesn't mention Vitamin D at all on their list of potential causes. But on that topic, it should be noted that is possible for people to overdose on Vitamin D supplements without much trouble. While going for the "natural method" (sun bathing) will result in your body naturally dropping off Vitamin D production once the "proper levels" are reached. Which isn't to mention a whole slew of other chemicals the body produces in response to sunlight that they're only recently starting to learn about.

Some of which they suspect to have cancer fighting/preventing properties, ironically enough.

Other fun things are conditions like psoriasis where the medical profession can get to be rather schizophrenic about what their patients are supposed to do. As they've found that UV light exposure (to the impacted areas) can help treat many/most patients. But because of various factors, many doctors like to push for them to get their UV exposure "in a clinically controlled environment" rather than just go outside and sunbathe periodically for gradually increasing periods of time. They can't bill you for that. ;)

The argument is, you get a full day's exposure in only an hour or so of exposure to the medical device. Whether that's true or not, it might be in the far northern (and southern) climes.

But not so much in most of Western Europe and the lower 48 States here in America.

But not so much in most of Western Europe and the lower 48 States here in America.

Well, in certain cities in Western Europe and the lower 48 states (Seattle, London) that one hour on the medical device could be a whole week's exposure to natural sunlight. :)

In what case are Seattle and London anywhere near the bottom of the country.

Who said either was near the bottom of the country.

Seattle is in the lower 48, which is all of the states except Alaska and Hawaii.

London is in England.

How far north or south they are or aren't is besides the point.

Both cities are somewhat famous for dreary weather (rain/fog) Arguably Nome Alaska gets more sun than either Seattle or London.

@Dominion's Son

Both cities are somewhat famous for dreary weather (rain/fog) Arguably Nome Alaska gets more sun than either Seattle or London.

@CrumblyWriter

That's cause both cities are: on nearly the same latitude, near the coast, subject to coastal moisture and cold fronts. Since the Pacific Stream brings cold water south

There is a vast difference in weather between London and Seattle - primarily due to the ocean currents that affect them.

Despite being at a significantly higher latitude, average temperatures are about 6 degrees higher in London than Seattle during the mid-winter months, and about the same during mid-summer months.

Seattle is affected by a current that has come a long way across the Pacific at the same (high) latitude. That current splits when it hits North America, with almost half going back via the Alaskan coast, and just over half taking cold water down to California.

London is affected by the same current that warms Florida. It travels a shorter distance before reaching Europe, and is heading North as it crosses the Atlantic.

That current is still warm when it reaches Europe!

If not for that warm current, most of Europe would be a similar sort of "frozen wasteland" as across much of Russia and Canada, and the Northern Mediterranean would have similar weather the the Great Lakes.

BTW, London's reputation for fogs is no longer valid. They have virtually because of laws controlling industrial pollution.

London is affected by the same current that warms Florida. It travels a shorter distance before reaching Europe, and is heading North as it crosses the Atlantic.

That current is still warm when it reaches Europe!

If not for that warm current, most of Europe would be a similar sort of "frozen wasteland" as across much of Russia and Canada, and the Northern Mediterranean would have similar weather the the Great Lakes.

That simplifies it. The Gulf Stream hits Ireland and Cornwall and turns north; the southern French coast is little affected. In summer the sea in Devon ( SW England) seems warmer for swimming than Les Landes (SW France) and Gibraltar west side was about the same as Devon.

Also, because of the melting of the Greenland icecap the Gulf Stream is weakening and will eventually disappear which will make the UK cooler under present conditions (global warming could counteract that cooling)
The Gulf Stream is not the only factor - the 1600s were a time of change from fairs on the iced over Thames to great heat. The 1910 to 1940s were a cold period (I remember 1948/9 winter too well!) and we are now coming through a warm spell - all due to periodic hot and cold.

That simplifies it.

I was going for the simplified version, noting the Gulf Stream has a significant impact on temperatures across the whole of Europe. ;)

the 1600s were a time of change from fairs on the iced over Thames to great heat.

Are you sure that wasn't the 1700s?

There have been extended periods of extreme global-wide cold, roughly corresponding to minimums in sunspot activity.

Sunspot activity virtually disappeared during the Maunder Minimum, which lasted right through the second half of the 1600s. The Dalton Minimum lasted for about the first third of the 1800s, but sunspot activity was merely very much lower then.

To my knowledge, those periods corresponded to things like "The Year with No Summer" - when the Rhine River was iced over the entire year. There's evidence to support the hypothesis that similar minimums caused famines which resulted in the demise of the Inca and Khmer civilisations, and were the economic trigger for the Napoleonic Wars.

I recall looking closely as historical data for sunspots about seven years ago. The end of cycle #24 seemed so familiar to the one ending about the year 1800, I was sure the coming cycle would be very low. I hoped it would be almost non-existent, but it has been merely very much reduced. There is still a chance the following ones could get further down.

I had hoped another sunspot "Minimum" would bring on another lengthy period of extreme (comparative) cold. I had hoped an extreme minimum would at least mitigate the effects of man-made global warning over the next 50+ years. It currently appears more likely this minimum will not be extreme enough for that.

BUT, at best it would only have reduced the damage caused, AND if the politicians would still have to get their act together soon enough to avoid wholesale disasters. That is not happening, so our descendants will surely fry from the double-whammy of increasing temperatures from man-made causes, plus a return to more normal temperatures when sunspot activity returns to its more typical levels.

The good news for most contributors to this forum is we'll all be dead before that happens. ;)

Before that, they were known for shit dumped in the streets, filthy rivers, rampant plagues and pour hygene.

But that describes every major city in Europe prior to the 1800s.

Huh? All they did in London was turn the tributaries to the Thames into sewers, which they later enclosed in many places. They went back later and subsequently diverted those same Tributaries/Sewers away from the Thames until well away from London. Where they have since added sewage treatment plants before returning said water to the Thames.

Huh? All they did in London was turn the tributaries to the Thames into sewers, which they later enclosed in many places. They went back later and subsequently diverted those same Tributaries/Sewers away from the Thames until well away from London. Where they have since added sewage treatment plants before returning said water to the Thames.

They did somewhat more than that.

Six main interceptor sewers, totaling almost 160 km (100 miles) in length, were constructed, some incorporating stretches of London's "lost" rivers.

The intercepting sewers, constructed between 1859 and 1865, were fed by 450 miles (720 km) of main sewers that, in turn, conveyed the contents of some 13,000 miles (21,000 km) of smaller local sewers. Construction of the interceptor system required 318 million bricks, 2.7 million cubic metres of excavated earth and 670,000 cubic metres of concrete.
All the open sewers were enclosed & the outflow was diverted from the Thames proper to the Thames Estuary, well away from the main centre of population.

But that describes every major city in Europe prior to the 1800s.

Perhaps we should exclude Rome of the Caesars from the shit on the streets category. Certainly that Rome was prior to the 1800s and noted for sewers and aqueducts.

In that case, it ain't fog, but smog. Then again, I'm not sure the situation cleared because of global warning (back before anyone was monitoring it) than just industrial cleanup, still, England's 'Industrial Era' spans from the early 1800s to later 1900s, which is when their reputation for fog was established.

Probably had a lot to do with steam powered everything resulting in a high ambient humidity in significant portions of the city. Electrification probably played a significant role in the reduction in both fog and smog alike as it moved those sources further away from London.

Had something not exactly like that happen in my hometown, where we had very frequent occurrences of winter fog, as well as smog problems when we had not one, but two large phosphate plants running outside of town(and they both pumped out a lot of steam). Most of the fog problem existed within a couple miles of those two plants. They did eventually clean up the smog problem for the most part by the late 1990's, but the fog was another matter.

But by 2000 the company operating one of the two plants decided to shut down operations, pack up the entire plant, and ship it overseas. Fog problem has been nearly non-existent since.

Which isn't to mention a whole slew of other chemicals the body produces in response to sunlight that they're only recently starting to learn about.

Some of which they suspect to have cancer fighting/preventing properties, ironically enough.

Almost exactly what I was going to write.

However, looking at a later posting I read the suggestion that in the lower 48 USA States you could get enough natural exposure (there is an argument about Washington state/Seattle) but surely in the mid west you have winters so severe that body exposure would be suicide and in the summer body exposure would result in a dehydrated crisp
Here in the UK facial exposure year round is possible but in France for example I had winter daytime temperatures of minus 17°C and summer at over 50°C - both unsuitable for skin exposure and made work difficult.

I should add that I was one of a multitude to get skin cancer (mine was mild and easily treated but most were not - two friends must avoid sunlight for the rest of their lives!)

However, looking at a later posting I read the suggestion that in the lower 48 USA States you could get enough natural exposure (there is an argument about Washington state/Seattle) but surely in the mid west you have winters so severe that body exposure would be suicide and in the summer body exposure would result in a dehydrated crisp

People can, and do, get sun burns while skiing. As to winter sunlight exposure in general, I wasn't really commenting on it one way or another, although "Sun rooms" are a thing as well. They're basically "glassed in" rooms not much unlike a greenhouse, where thanks to being enclosed, the temperature can be controlled. From there an occupant can sun bathe, or not, at their leisure.

My main focus was on the more temperate months and summer, where it then just becomes a matter of limiting your exposure and being properly prepared. Typically speaking, in the summer months in particular, 15 minutes outside sun bathing per day is likely to be more than enough. And a lot cheaper than visiting the doctor multiple times a week for "clinical services."

That and 50°C(122 degrees for us Yanks) isn't that difficult to survive, particularly if you're next to naked and keep yourself well hydrated(sunscreened up if not deeply tanned already, etc). Now if you're dressed like it's 12.7°C(55) and it's that hot outside, yeah, you're going to suffer. Of course you could go the Arab route and put on a couple layers of light, flowing clothes that do little to restrict air flow, but a lot to screen sunlight...

I should add that I was one of a multitude to get skin cancer (mine was mild and easily treated but most were not - two friends must avoid sunlight for the rest of their lives!)

From what I'm hearing, the universal correlation for skin cancer seems to be Sun Burns, not so much sun tans. Particularly when you look to the two major types of skin cancer. Which is where they're starting to correlate information in some other ways.

The most easily treated form of skin cancer typically happens on parts of the body that have seen a lot of sun exposure(which I imagine was the case for you).

While the more difficult to treat cases tend to happen in places that can get burned during sun bathing for example, but doesn't generally see much sunlight otherwise due to shirts/pants/etc.

Also keep in mind that with skin cancer and Sun Burns: up until the 19th Century(and the 20th in many places) the most extreme case most people would encounter is maybe 1 sun burn per year. Because after that, they developed a tan which protected them from thereon which they maintained for the rest of the season because they mostly worked outdoors.

Now move to the present day, where some people can experience(/self-inflict) a sun burn multiple times in a month, because of all the time they spend indoors. And now wonder at the rates of skin cancer being witnessed.

From what I'm hearing, the universal correlation for skin cancer seems to be Sun Burns, not so much sun tans. Particularly when you look to the two major types of skin cancer. Which is where they're starting to correlate information in some other ways.

The most easily treated form of skin cancer typically happens on parts of the body that have seen a lot of sun exposure(which I imagine was the case for you).

Your second quoted paragraph is right; basal cell carcinoma on the forehead. I was spending a lot of time either building / roofing or on a tractor in sunlight

The other type I referred to is Melanoma - one friend had six places where they had operated. None of them (with one exception)was that active and one was around only for short periods on holiday.

The last one (who also worked outdoors) also contracted some blood disorder which sounds like a form of leukemia - my European Portuguese** wasn't good enough for medical detail. He also will never work outdoors again

(**European and Brazilian Portuguese are very different - I imagine like European French and Canadian French)

That and 50°C(122 degrees for us Yanks) isn't that difficult to survive, particularly if you're next to naked and keep yourself well hydrated(sunscreened up if not deeply tanned already, etc).

Whilst I would normally agree but it wasn't a question of survival but doing a job. Being near naked is not quite safe when handling heavy machinery or sometimes a chainsaw etc in uncleared undergrowth where there are snakes. You need heavy gloves, heavy boots and strong clothing covering all skin.

I am also all too well aware that you can get a serious tan at down to minus 25°C when you are out all day, every day for three months - in those days SPF hadn't been invented.

Now move to the present day, where some people can experience(/self-inflict) a sun burn multiple times in a month, because of all the time they spend indoors. And now wonder at the rates of skin cancer being witnessed

.

Although more people have more time to sunbathe would you not accept that a thinning of the ozone layer also is a contributory factor, especially as many of the humans are now using suitable protective lotions?

Although more people have more time to sunbathe would you not accept that a thinning of the ozone layer also is a contributory factor, especially as many of the humans are now using suitable protective lotions?

Won't dispute that. UV light causes sun tans, and sun burns, and as I said there is a strong link to sun burns, it would follow that increased exposure to UV light(due to less ozone) would mean more sun burns, meaning more risk of skin cancer.

You're also correct in regards to "more time to sunbathe" (and [almost] burn) in the quest for "the perfect golden tan" which should also result in more risk for skin cancer, particularly if exposed to increased amounts of UV light.

However, that doesn't mean that going out to sun bathe for 15 minutes at a time, every other day on average is going to significantly increase your odds of skin cancer(in most parts of the world, during most parts of the day; I imagine that there are some places that could almost bake you in that time frame after repeated exposure). For many people, that probably would be barely enough to maintain a slight tan, particularly the further north(or south in relation to the equator) you go.

It's working out where those magic lines are, and sometimes a question of being able to do the (medical) testing to find out. Such as the blood testing to determine when you hit your "optimum level of Vitamin D in your blood stream, after which more sunlight exposure is largely superfluous and not needed/warranted/advised.

It's working out where those magic lines are, and sometimes a question of being able to do the (medical) testing to find out. Such as the blood testing to determine when you hit your "optimum level of Vitamin D in your blood stream, after which more sunlight exposure is largely superfluous and not needed/warranted/advised.

Yes; those magic lines are the problem and one which is constantly changing.

I haven't bothered about sun tanning since the early sixties when the only thing we could get was a mix of olive oil and vinegar!!!!!!!

Brought up by the seaside and in boats since I was ten I have got semi- immune to tanning. Working on the farm (and it took us three weeks to re-roof it in the hottest summer on recent record) I hardly got any tan - but just a slight touch of skin complaint.

As for sunlight and the body, including but not limited to vitamin D, I have no idea how much and with what frequency exposure is required. Can a summer's daily exposure cover a body for an 7 month winter lack? I simply don't know. As for artificial means I simply hope it is not like the specialist red/blue lights I use for my plants.

As for artificial means I simply hope it is not like the specialist red/blue lights I use for my plants.

They're White/Blue lights actually, IIRC.

The red/blue lights for plants are because photosynthesis doesn't really make much use of the rest of the spectrum so it is wasted on them.

Making a guess but the Navy probably does that for ships and different ports which would be in different time zones. The ship would have to operate on a regular schedule of crew shifts(term is probably wrong). So ship clocks could be widely different from local clocks.

Navy typically uses whatever time zone they happen to be in for the most part. With a little bit of give or take in the event that they're just cruising through a given time zone, in which case they may delay or accelerate a time shift so it happens overnight rather than when they actually enter it.

There aren't many ocean going ships that could routinely cross more than one time zone in a day unless they're cruising through an area where local government have moved the time zone boundaries around.

What if the space ship were to be from a planet that has multiple suns that produce a more complex cycle than our simple day-night cycle?

Or no day-night cycle at all, there is always at least one sun in the sky. An AI designed by a race from such a planet might not even understand the concept of "night".

The terms Diurnal and Circadian both refer to a 24 hour cycle which is what we experience here on Earth.

Not Diurnal.
Diurnal refers to being active during the day. Nocturnal refers to being active during the night. Nothing to do with the period of light or darkness or how long it takes for 1 cycle.

So the question about "operating a diurnal cycle." doesn't really make any sense.
Asking about "operating on a nocturnal cycle" would be the same.

However it appears the word is often used in relation to a daily cycle in general usage.

Diurnal refers to being active during the day. Nocturnal refers to being active during the night.
... However it appears the word is often used in relation to a daily cycle in general usage.

The Oxford Dictionary lists two meanings:
1. (animals) active during the day (i.e. the opposite of nocturnal)
2. (astronomy) taking one day (e.g. the diurnal rotation of the earth)

The Oxford Dictionary lists two meanings:
1. (animals) active during the day (i.e. the opposite of nocturnal)
2. (astronomy) taking one day (e.g. the diurnal rotation of the earth)

No 1 is the original meaning of the word.
No 2 is what has developed over the years. The misuse has become accepted over time, and the example given would make more sense if it were "a single rotation of the Earth" and not "the diurnal rotation of the Earth" or even just say "24 hours".

The misuse has become accepted over time

I think the process is more one of metaphorical usage becoming accepted over time as another meaning.

example given would make more sense

The example (which BTW was not mine, but a direct quote from the Oxford Dictionary) makes perfect sense. It shows 'diurnal' being used as an adjective to describe something in the field of astronomy (the period of one rotation of the earth). 'Diurnal' means exactly the same as 'taking one day' (or if you prefer, twenty-four hours).

'Diurnal' means exactly the same as 'taking one day' (or if you prefer, twenty-four hours).

That is the way it has been misused over the years, and how it has developed that second meaning, very different from it's original meaning.
It's gone from just meaning "mostly active during the day" to also meaning "daily".
So I guess that means nocturnal also now means "nightly".

Legitimising incorrect usage of a word really doesn't help things.

Diurnal refers to being active during the day. Nocturnal refers to being active during the night

Sounds good except that it can only refer to those parts of the world between the Arctic and Antarctic circles. Elsewhere you can get 24 hours of day and elsewhere 24 hours of night and anything in between.
I do hate these not properly thought out quasi scientific terms.

So the question about "operating a diurnal cycle." doesn't really make any sense.

Diurnal means happening or active during the daytime .

Diurnal cycles refer to patterns within about a 24-hour period that typically reoccur each day.

Diurnal means happening or active during the daytime.

Yep. Agreed.

Diurnal cycles refer to patterns within about a 24-hour period that typically reoccur each day.

Yet there is no such usage using nocturnal cycle for things that occur every 24 hour period that typically reoccur each night.
It would just be something that happens daily, and occurs mostly at night.

The comment becomes confusing for saying the nocturnal cycle for things that occur every 24 hour period is the same thing as saying the things that occur at night.

Juts like the use of Diurnal to mean two different things.
Just because something has morphed over the years to what it is now, and has been accepted as such, doesn't mean it's a good thing.

For storytellers/writers I would only suggest that whatever the clock/time is based on. Keep it consistent and relatively simple to understand. How many readers will want to constantly have to calculate how much or how little time has passed between scenes or events.

That's typically where some other kind of "constant variable" typically gets thrown in, even in the professional stuff. Going back to the Naval Example, ships may run on local time, but the deck log records will reference "Zulu Time"(GMT) all the same.

So if it's hit that point where timing is that critical, then inserting a "twinned" time reference isn't unusual. One reference to the "standard" being applied, and another reference to the "local time" in either order, just so long as it's standardized across the work.

ships may run on local time, but the deck log records will reference "Zulu Time"(GMT) all the same.

Based on a quick look at South African Time Zone (I almost wrote zones, but it turns out there is only one) it seems that South African Standard time is Greenwich Mean Time plus two hours. That means that Zulu time (the Zulus live in South Africa) is GMT plus 2. The right way, the wrong way and the Navy way.

That means that Zulu time (the Zulus live in South Africa) is GMT plus 2. The right way, the wrong way and the Navy way.

The Phonetic Alphabet isn't too concerned about such matters.

So if it's hit that point where timing is that critical, then inserting a "twinned" time reference isn't unusual. One reference to the "standard" being applied, and another reference to the "local time" in either order, just so long as it's standardized across the work.

Don Lockwood came up with an interesting application. Heroine has just arrived in Switzerland and gets "morning sickness" during a press conference. Questioned by a reporter that it can't be "morning sickness" in the afternoon she points out that she is on Wisconsin time.