[HN Gopher] OpenBSD Adds Support for Coordinated Mars Time (MTC)
___________________________________________________________________
OpenBSD Adds Support for Coordinated Mars Time (MTC)
Author : dbolgheroni
Score : 132 points
Date : 2021-04-01 18:36 UTC (4 hours ago)
(HTM) web link (marc.info)
(TXT) w3m dump (marc.info)
| gerdesj wrote:
| We already had GMT which ended up being called UTC - "Universal".
| If we'd stuck with GMT or defined E(arth)TC or similar, then MTC
| would make sense.
|
| I do like it though, good to see some innovation in the AFD jokes
| department.
| HugoDaniel wrote:
| Alien technology
| cproctor wrote:
| This could really bite you:
|
| > It is currently not possible to use ssh to login between
| systems on MCT and any earth time zone
| cphajduk wrote:
| need to set the SSH timeout to 44 minutes.
| koolba wrote:
| Also make sure you're not behind a NAT that drops what it
| thinks are idle connections.
|
| Full handshake requires a few hours of round trips.
| zeristor wrote:
| What about leap seconds for Mars?
| kevwil wrote:
| Honestly, no idea if this is an April Fool's Day prank or not.
| Seems reasonable, but inconsistent naming makes me suspicious.
| wongarsu wrote:
| Coordinated Mars Time (MTC) is an actual thing [1]. The
| abbreviation follows from UTC, which is abbreviated that way
| because English speakers wanted CUT (coordinated universal
| time) and French speakers wanted TUC (temps universel
| coordonne), so we compromised on an abbreviation that works in
| neither language (I wish I was joking).
|
| The commit going on to call the config TZ=MCT could totally be
| a typo that will persist for eternity, just like the "referer"
| header.
|
| 1:
| https://en.wikipedia.org/wiki/Timekeeping_on_Mars#Coordinate...
| jamesfmilne wrote:
| I bet the MCRN Rocinante's computers are running OpenBSD.
| lsllc wrote:
| So, what you're saying is that 2307 is going to be the year of
| the OpenBSD Desktop? (on Mars at least, the Earthers probably
| use NetBSD and the Belters FreeBSD).
| bpodgursky wrote:
| To be pedantic, it was only the MCRN Tachi. "Now" it's just the
| Rocinante.
| HeckFeck wrote:
| It's the only OS the protomolecule couldn't breach.
| gbrown_ wrote:
| Doors and corners...
| lsllc wrote:
| Please, let's _not_ have SST on Mars! (Sol-light Savings Time)
| haddr wrote:
| What about Belters?
| gbrown_ wrote:
| For Beltalowda!
| 082349872349872 wrote:
| Judging from the extant _lang belta_ vocabulary, Belters are
| likely on an ISO week date calendar. They have 7 weekday names
| but don 't seem to bother with our months, and they celebrate
| (a presumably earth calendar based) New Year. (calculating new
| years day relative to week 1 is probably for them the
| introductory CS equivalent of calculating easter for us.
| _Seritenyidiye_ , "a 30-day", exists as a word for month, but
| probably refers to the earth concept, among those unlucky
| enough to have to interface with earth calendars.)
|
| Beltalowda showxa ere tim wit:
| https://en.wikipedia.org/wiki/ISO_week_date keya? Beltalowda
| tili du pati (wit walowda walowda dansa unte walowda walowda
| rowm unte da adewu "Piyat Minut"?) fo Yitim unte showxa ere
| Mundiye, Tusidiye, unte kopeng. Amash beltalowda na tenye wowt
| fo "months" tumang. Imalowda tu inya, tu "legacy", sasa ke?
| imwm wrote:
| "mars can't wait" lol
| anthk wrote:
| Well...
|
| https://astro-gr.org/openbsd/
| znpy wrote:
| I wonder if SpaceX has anything to do with this.
| znpy wrote:
| I'm getting downvoted... Of course I forgot today is April 1st.
| yellowapple wrote:
| I know this is probably an April Fool's joke, but I'd be thrilled
| if this was real.
| BuildTheRobots wrote:
| I'm almost certain it's a joke, the question is for how much
| longer? The crypto interoperability issues are amusing, thiugh
| I do seriously wonder how you deal with anything from a 10 to
| 40 minute round trip time.
| ronsor wrote:
| You have caching servers and set really, really long
| timeouts.
| wongarsu wrote:
| The same way we deal with speed-of-light delay on earth:
| CDNs, asynchronous protocols like email, or just ignoring it
| when we can get away with it (e.g. "instant" messaging). SSH
| might be a bit tricky, but just pretend your system on mars
| is a production server and send it a tested bash file (using
| any of your favorite automation tools).
| Fern_Blossom wrote:
| Same here, this is so far the best one yet. Far better than
| VW's shitty attempt.
|
| Though, it dawned on me, Mars could have _real_ time zones. Not
| the stupid political mess we have today. Perfect, logical
| longitudinal time zones from the get go. That right there is
| more than enough reason for me to leave this planet.
|
| But let's be honest, Mars will be colonized, politics will
| arise and the same fuckery will happen eventually.
| monocasa wrote:
| Better yet, no time zones. Just one clock for the planet.
| jakear wrote:
| Obligatory https://qntm.org/abolish
| monocasa wrote:
| When you're already destroying enough of the legacy
| timekeeping systems by switching to a planet without a 24
| hour day, most of those arguments lack muster.
|
| Also, don't call people out of the blue and expect them
| to pick up anyway. Maybe your uncle had to work late and
| is sleeping even though the sun is technically out.
| elygre wrote:
| If they are zones, how can they be perfect? The middle might
| be, but anywhere else will be imperfect.
| yellowapple wrote:
| You're right. We need to constantly adjust our clocks
| depending on exact longitude.
| midasuni wrote:
| And velocity. And altitude.
| nwallin wrote:
| A time system useful on Mars needs additional consideration;
| considerations we haven't given it yet. It requires more
| thinking than just time zones. The various things we've sent to
| Mars haven't had any need for a colloquially time; they're
| computers, they just know that 21,872 seconds or whatever into
| the day is that far into an 87,755 second day and that's good
| enough to calculate shadow angles and expected solar panel
| efficiency from.
|
| If we were to build a colony on Mars with normal people doing
| normal everyday things, we need something more than that. The
| first question we want to ask ourselves is, do we want to keep
| the SI defined second? If we don't care, then we have free
| reign to do whatever we want. We can define a Mars second to be
| 1/86,400th of a Mars day, and keep the 24 hour, 60 minute, 60
| second time system we use on Earth. Or we switch to a metric
| time system, with a 10 hour day, 100 minute hours, 100 second
| minutes. Or a 1 day long day, and deci, ceni, milli, micro
| days. Or whatever.
|
| If we want to keep SI compatibility, we need to keep the
| second. The Martian solar day is 87,755.224 seconds long.
| 87,755 factors into 5^2 * 53 * 67. So we can do 25 hours per
| day, 53 minutes per hour, 67 seconds per minute to give an
| 87,755 second day. Unfortunately there would need to be a leap
| second once every 4-5 days.
|
| Then there's the question of the calendar. Perhaps fortunately,
| this gives us the opportunity to restart from scratch, because
| the calendar we use is such a goddamned clusterfuck, even worse
| than our time system. Unfortunately, the number of days in a
| Martian year (668 and change) does not lend itself to a clean
| division into tidy periods. You could have 23 months of 29 days
| each, with each month having 4 7 day weeks plus one holiday.
| This will give you a 667 day year. Add another annual holiday
| at the beginning of the year, plus an optional leap-holiday in
| the middle of the year.
|
| Or you could split it up into 37 months of 3 weeks, each with 6
| days. This gives you a 666 day year, so sprinkle in 2-3 bonus
| holidays per year.
|
| There are a lot of considerations. It needs to be given more
| thought. Hopefully more thought than we've given to Earth's
| timekeeping systems.
| skissane wrote:
| > The first question we want to ask ourselves is, do we want
| to keep the SI defined second?
|
| I think absolutely yes. Any Mars colony is going to import a
| lot of equipment and technology from Earth. All of that is
| going to assume the SI second. Not just for measuring time,
| but also as part of the definition of derived units such as
| Newtons. Martian colonists will have no practical choice but
| to use the SI second since all their Earth-manufactured
| equipment is going to assume it.
|
| Plus, if they tried to introduce a distinct Martian second,
| soon they'd have a mix of SI units (based on the SI second)
| and slightly different Martian units (based on the Martian
| second), and that would produce Mars Climate Orbiter style
| disasters.
|
| > Perhaps fortunately, this gives us the opportunity to
| restart from scratch
|
| People won't. People will want to use the Earth calendar
| because they are keeping in sync with Earth news and Earth
| culture. Maybe after a few centuries, Mars will feel
| sufficiently independent from Earth, that it might want to
| introduce a new calendar. However, by then Martians will be
| thoroughly used to the Earth calendar, it will be a
| centuries-old part of their Martian culture heritage, and
| they probably won't want to change it.
| kryptiskt wrote:
| It's not a future problem, JPL personnel already work after
| Mars time: https://www.businessinsider.com/nasa-perseverance-
| team-mars-...
| kibwen wrote:
| Days, months, and years based on the cycles of the planet
| make sense on Earth, but not as much on Mars.
|
| Almost all Martian settlers will be living underground, and
| even aboveground the light at mid-day is extremely dim. You
| can set the day to whatever length you want, regardless of
| the Martian sol, and nobody will notice.
|
| Likewise, months and years on Earth are for tracking
| agricultural seasons, but nobody will be growing crops on the
| Martian surface. Set the year to whatever you want, with or
| without months, and no civilians will notice.
| PeterisP wrote:
| For a person living on Mars it makes sense to align the time
| to Martian solar day iff their daily life is linked to
| outdoors activities in sun. However, if they are expected to
| stay indoors or even underground facilities (which IMHO is
| very, very likely at least for the first decades for various
| reasons) then the outdoors day is simply irrelevant, and it
| makes all sense to coordinate with Earth time for all your
| activities and just look up local solar time only when you
| need to schedule activity outside the base in the
| "wilderness" - where you're anyway going to spend just some
| hours, not a whle day/night cycle.
| zokier wrote:
| If we are to send people to Mars then presumably we want
| some interaction with the surface. Otherwise we might as
| well send those people to underground bunkers on Earth.
| Zenst wrote:
| It certainly does raise a forward thinking issue and that is
| networking across planets and TZ handling. TZ's are already a
| PITA what with leap seconds.
|
| Then there is defining standards on Mars, 24hour days kinda not
| going to translate, so again, more forward thinking needed. As
| for Mars GPS, bit of a way off, but I'm sure the good old
| atomic clocks will work.
|
| I guess the job title of "Systems Engineer of Time" may become
| a reality one day after all.
| skissane wrote:
| > 24hour days kinda not going to translate
|
| The Martian day, called a "sol", is about 24 hours 39 minutes
| 35 seconds. So it is just a bit longer than an Earth day. Of
| course, that extra 39 minutes and 35 seconds adds up - after
| a bit over a month, it adds up to a whole Earth day, and a
| count of sols would be one behind a count of Earth days.
|
| Idle speculation: I reckon people on Mars may initially use a
| hybrid calendar of Mars days (sols) but Earth years. They'd
| want to use the sol because they'd want to keep in sync with
| Mars day-night cycle, especially since that would be
| important for when they go outside and do stuff (in their
| spacesuits). On the other hand, they'd still be in heavy
| communication with Earth and absorbing a lot of Earth news
| and Earth culture, so they'd likely want to keep the Earth
| year. The Martian year is longer (about 22.5 months long),
| and it would likely have less significance to them - Mars has
| seasons, but seasons only have limited relevance when you
| have to spend all your time indoors.
| seiferteric wrote:
| Kind of makes me wonder about local time on a space ship
| going some significant % of the speed of light. Time itself
| would be at a different rate than back home. Perhaps we need
| to introduce the concept of a space-time zone.
| zokier wrote:
| We have few time standards that already take relativity
| into account:
|
| https://en.wikipedia.org/wiki/Barycentric_Dynamical_Time
|
| https://en.wikipedia.org/wiki/Barycentric_Coordinate_Time
|
| https://en.wikipedia.org/wiki/Geocentric_Coordinate_Time
| wongarsu wrote:
| The most practical solution is probably to introduce a
| global time beacon, like a satellite broadcasting it's own
| time, or everyone counting the flashes of some known
| pulsar. Then you have one time reference everyone agrees
| on, it just ticks at different speeds depending on how fast
| you are moving.
|
| Luckily so far the practical propulsion concepts we have
| max out around 10% the speed of light for reasonable
| amounts of propellant, so we have a couple decades left to
| figure this out.
| vsareto wrote:
| Writing some test software based on Martian time might be a
| good way to prevent some DateTime issues when we do start
| living there.
| korethr wrote:
| The best April Fools jokes are the ones with enough
| plausibility that they _could_ be real.
| jamal-kumar wrote:
| Imagine reading:
|
| "DANGER: ABI incompatibility. Updating to this kernel requires
| extra work or you won't be able to login: install a snapshot
| instead"
|
| and raging
| sfblah wrote:
| It mentions the days being longer, but what about the years? What
| even constitutes a year on Mars? Seems like more thought needs to
| go into how this would work if/when we become interplanetary.
| Assuming knowing where you are in the year has any value on Mars,
| we'd want some way to track that. I wonder also how this would
| work on the moon.
| 4147eded-4d4f wrote:
| My background is physics and during an extended beer session my
| group talked extensively about what properties an
| interplanetary time keeping system would need to have.
|
| The answer we came up with was: thank god we'd be retired or
| dead by the time it became a problem that we had to deal with
| day to day.
|
| You would need something like international atomic time to be
| the basis for it, but unlike TAI which is the weighted average
| of some 400 atomic clocks on the surface of the planet, you
| would need to define it with respect to free space (which we
| can't access) and with respect to a single event that's
| accessible to everyone yet human scaled enough that it happened
| in written history (the best we came up with was the first
| nuclear blast).
|
| Then you would need to have a calculation that turned it into
| local time which would be completely decoupled from any actual
| time keeping. Think printing the result of a square root in
| Roman numerals vs trying to do the calculation in Roman
| numerals.
|
| Unix epoch is laughably inadequate for anything like that.
| Basically we have nothing today and you'd need an international
| agreement to have a sane time keeping system going forwards.
| swiley wrote:
| Judging by DST and the gregorian calander I'm sure we'll end
| up with a system that doesn't even approach the utility of
| what you're thinking.
|
| Everyone will probably just use Eastern Time on mars complete
| with Daylight saving, _maybe_ TAI if we 're lucky.
| smitty1e wrote:
| One anticipates a network that operates with a faster-than-
| light "because" pipe, or you just have a planetary local NTP
| server and let something upstream do the Einsteinian
| gymnastics with the timestamps.
| wahern wrote:
| What's wrong w/ TCB
| (https://en.wikipedia.org/wiki/Barycentric_Coordinate_Time)
| and TDB
| (https://en.wikipedia.org/wiki/Barycentric_Dynamical_Time)?
| yellowapple wrote:
| Probably best to just drop the notion of "days", "years", etc.
| entirely, and instead just track the number of kiloseconds,
| megaseconds, etc. since the Unix Epoch.
| jhgorrell wrote:
| In the novel "A Deepness in the Sky" by Vernor Vinge, the
| characters tell time this way. I had to do some math early in
| the book to get a feel for what 1Msec & 1Gsec was.
|
| In addition, they also keep track of their cold sleep time,
| because if you want to meet your spouse 50 years from now,
| you want to try and keep the same relative age.
| zrm wrote:
| Since the Unix Epoch where? Isn't being on another planet
| going to have to deal with the relativistic passage of time?
| bonzarm wrote:
| France used the decimal time for a few years beginning in
| 1792 during the French Revolution. It didn't go well.
| yjftsjthsd-h wrote:
| I was under the impression that the OS _did_ only track time
| in seconds since the epoch, and whenever you see something
| else it 's just the software translating for human
| convenience. If that's the case, then it this doesn't really
| make sense; humans will want something friendlier than epoch
| time on Mars, too.
| bonzini wrote:
| Sort of. Unix time does not count leap seconds, all days
| are 86400 seconds long in Unix time. So the actual number
| of seconds since the epoch is a bit larger than what time()
| returns.
|
| I don't know how Windows deals with leap seconds (its epoch
| is in 1601 or something like that). Edit: it doesn't, the
| clock goes 1 second ahead of UTC and it's then fixed by
| NTP.
| pedrocr wrote:
| So time() is actually days since epoch with 1/86400
| precision. That makes the Google solution to smear leap
| seconds with NTP instead of making them explicit make
| even more sense.
| rzimmerman wrote:
| It's technically even more complicated than just scaling the
| day/seconds by to match a Martian sol. There are relativistic
| corrections that add up over time (Earth clocks would observe
| Mars clocks ticking at a different and non-constant rate). Good
| thing this is real :)
| fsh wrote:
| This is already the case on earth. UTC is defined at sea level
| and clocks run faster at higher elevations due to the lower
| gravitational redshift. This effect is easily observable with
| atomic clocks and has to be taken into account in any accurate
| clock comparison.
___________________________________________________________________
(page generated 2021-04-01 23:00 UTC)