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Europe pushing for lunar time zone

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Re: Europe pushing for lunar time zone

#282

Earlier quoted context omitted.

They really should have been on TAI. I guess it doesn't matter now if we won't get any more leap seconds.

It's worth noting that even atomic clocks run on Mars faster than on Earth, due to the different gravity. So you might expect say half of the 50 microsecond daily gain quoted in this article for the Moon, 10 miliseconds per year or a full second per century, more than enough to make you your spaceship completely miss its intended orbit. And martians will definitely want to run their own atomic clocks, making sync ver…

Not sure whether sync will be 'very problematic'.

We already have that sort of sync happening today: when your computer is off, it runs a quartz watch. When you turn it on, it syncs via ntp.

Some special boffins on Mars would run atomic clocks, and worry about synchronisation with earth.

For the rest of the people running quartz clocks, they wouldn't even notice.

Re: Europe pushing for lunar time zone

#283

I am a proponent of a Martian timekeeping system where each day has 24 hours 39 minutes and 35.244 seconds and all the rest of time units have standard lengths. For example, at midnight your martian clock would show the time as 24:39:35 for a fraction of a second, then wound back to 00:00:00. The calendar then would track the Earth calendar as close as possible, with shortened months to accommodate for the longer day…

> each day has 24 hours 39 minutes and 35.244 seconds > at midnight your martian clock would show the time as 24:39:35 for a fraction of a second A similar idea could be to have exactly 24h 39min 35s each day (i.e. the last second before midnight is 24:39:34), then add a leap second every 4 days to compensate for the missing 0.244s, then skip it when the 0.006s errors cumulate up to 1s. This just because in my opinio…

> This just because in my opinion it is easier to live with leap seconds than with non-integer seconds.

That is not the opinion of a bunch of folks who want to get rid of the leap second on Earth:

* https://www.nature.com/articles/d41586-022-03783-5

* https://news.ycombinator.com/item?id=33658541

Re: Europe pushing for lunar time zone

#284

> There are also technical issues to consider. Clocks run faster on the moon than on Earth, gaining about 56 microseconds each day, the space agency said. Further complicating matters, ticking occurs differently on the lunar surface than in lunar orbit. At first this sounded like they were describing a mechanical issue with analog clocks, but they're not: time on the moon actually moves this much faster relative to E…

This is interesting… and I wonder how this plays out across different planetary bodies. It effectively means how we define a second will be different across the board.

Can anyone weigh in on whether the MKS standard of a second is based on something in free space, or here on earth?

If universal (based on free space) Would this mean we should all convert to/from this second, and treat our own second as relative?

Re: Europe pushing for lunar time zone

#286
Do they work with two time zones or time systems when you have a team on Earth and another Team on The Moon coordinating tasks? So the team on the Moon follows a Moon time zone and the team remaining on Earth follow a chosen Earth time zone and then they sync things up?

What is the use case for teams using two time zones/systems or does the earthbound team use the Moon time zone and is that better than the team on the Moon following an Earth time zone?

Re: Europe pushing for lunar time zone

#287

Earlier quoted context omitted.

Do you honestly consider modifying the core idea of the 24 hour day to be a "slight tweak"? I can't even imagine how many different things rely on that assumption. (and I'm sorry, but what does "naming months and seasons in Mars" have to do with this?)

For software that runs on Mars, I think "Mars date/time" has to be a brand new set of APIs and data types. The existing date/time APIs/types are for Earth times only. The "local time zone" on Mars would just be UTC. That way there wouldn't be much possibility of bugs based on confusing Earth and Mars time scales – all pre-existing software would still work with Earth date/times, and anything that needed to deal with…

No, Mars has less mass than Earth, so if you use Earth UTC, Mars seconds will be longer than SI seconds, which does not seem like a good idea.

Re: Europe pushing for lunar time zone

#288

I truly do not see the point. Use UTC in space. Time is made up. No need to adapt it to whatever rock you happen to be standing on.

Did you read the article? The mass of the rock you happen to be standing on determines how fast time passes, so "UTC everywhere" would result in longer or shorter seconds depending on location.

Re: Europe pushing for lunar time zone

#289

> There are also technical issues to consider. Clocks run faster on the moon than on Earth, gaining about 56 microseconds each day, the space agency said. Further complicating matters, ticking occurs differently on the lunar surface than in lunar orbit. At first this sounded like they were describing a mechanical issue with analog clocks, but they're not: time on the moon actually moves this much faster relative to E…

This is interesting… and I wonder how this plays out across different planetary bodies. It effectively means how we define a second will be different across the board. Can anyone weigh in on whether the MKS standard of a second is based on something in free space, or here on earth? If universal (based on free space) Would this mean we should all convert to/from this second, and treat our own second as relative?

"The second [...] is defined by taking the fixed numerical value of the caesium frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9192631770 when expressed in the unit Hz, which is equal to s−1.[1]"

https://en.wikipedia.org/wiki/Second

so unless caesium behaves differently at different locations in the universe, this definition should be pretty uniform.

Re: Europe pushing for lunar time zone

#290
post #275
post #145

Earlier quoted context omitted.

Wouldn't that get incredibly confusing with the calendar always being slightly off, despite using the same names? At that point why not just stick to a integer day count for the date. Having a non-integer number of hours in a day might also get confusing. It would be near-impossible to make an analog clock, for example, and stuff like dividing up a day into three shifts would be really cumbersome. For day-to-day life…

> It would be near-impossible to make an analog clock, for example, Why would that be an issue? You still have the hours hand make a full rotation in one period, and you make markings at each hour. You just have separate markings at 24 o'clock and 0 o'clock.

and the minute hand?
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