5 ms·

A zone of what though? Time zones, are zones of our planet where we observe time in some coordinated fashion. If we're adding the moon, what part of our globe

A zone of what though? Time zones, are zones of our planet where we observe time in some coordinated fashion. If we're adding the moon, what part of our globe should it be considered a part of? This all seems pretty silly.

deleted 4y ago
[deleted]
doctor_eval 4y ago
It’s not about creating an earth based zone for the moon. It’s about creating a system of recording time that works on the moon. Time doesn’t work the same on the moon as on earth, so why should they be linked? Earth clocks are basically about the position of a point on earth, relative to the sun. The moon’s relationship with the sun is quite entirely different. So where is the equivalent of Greenwich on the moon? Does that even make sense? What is the equivalent of a day? Will there be weeks? Earth clocks and moon clocks don’t run at the same time, due to relativity. And I guess the relationship between earth and moon time is far from linear depending on their relative positions and the sun’s. So there is lots of interesting stuff to be worked out, and I don’t think it’s silly at all.
- Daz1 4y ago
  Why needlessly complicate things? Use GMT + 0, earth days, and earth weeks. Why introduce all this unnecessary confusion? There is no practical need to measure local time on the moon. >Earth clocks and moon clocks don’t run at the same time, due to relativity. I'm sure the 1/3000th of a millisecond per year won't be a problem
  - wyldfire 4y ago
    > There is no practical need to measure local time on the moon Could it be useful to know when the sun would rise and set, or when Earth rises and sets, for the sake of having routines related to solar power or LOS communications? Having a Luna-native time-of-day might be handy for some things. I think it makes some sense to come to an agreement, even if that agreement was to use UTC (TFA does mention that it's used for ISS).
    - thaumasiotes 4y ago
      > Could it be useful to know when the sun would rise and set, or when Earth rises and sets, for the sake of having routines related to solar power or LOS communications? The sun rises and sets over exactly one (Earth) lunar month, 29.5 days. That's what the phases of the moon are, the progression of sunlight over the face of the moon. Earth never rises or sets; the near side of the moon always faces toward Earth, and the far side of the moon never faces toward Earth. (This is known as "tidelocking".) So no, neither of those could be useful.
  - doctor_eval 4y ago
    > I'm sure the 1/3000th of a millisecond per year won't be a problem But that’s several orders of magnitude incorrect. FTA: > Clocks run faster on the moon than on Earth, gaining about 56 microseconds each day Unless my maths is wrong isn’t it actually 200 milliseconds per year? It’s not a lot of time, sure. But it seems important to people like scientists. Which, not coincidentally, is probably the most ”practical” thing people will be doing while spending time on the moon.
    - thaumasiotes 4y ago
      > Unless my maths is wrong isn’t it actually 200 milliseconds per year? 20, not 200.
      - doctor_eval 4y ago
        Yes, you are right. 0.02 seconds; I made a conversion error to ms.
- brigandish 4y ago
  > why should they be linked? Two reasons. Firstly, human biology, it'll be better for the people living/working there to experience via things like lighting and having visual clues from things like clocks to regulate their life. Secondly, for communication with those on Earth in a way that makes sense to both parties. We only use our system of time because it is useful (daylight saving might be an exception to that;) so why bother with a more "correct" version of that on the Moon? It's not like you'll be using the days there if it's light for one Earth month and dark for another.
  - doctor_eval 4y ago
    I would have thought that a local moon time would primarily be for the benefit of people on the moon. Obviously, if you’re calling people on earth then you need to do a conversion anyway, just like we have to do when making international calls. But if you’re on the moon, perhaps there is a better way of keeping time that will benefit others also on the moon.

deleted 4y ago

[deleted]

doctor_eval 4y ago

It’s not about creating an earth based zone for the moon. It’s about creating a system of recording time that works on the moon. Time doesn’t work the same on the moon as on earth, so why should they be linked? Earth clocks are basically about the position of a point on earth, relative to the sun. The moon’s relationship with the sun is quite entirely different. So where is the equivalent of Greenwich on the moon? Does that even make sense? What is the equivalent of a day? Will there be weeks? Earth clocks and moon clocks don’t run at the same time, due to relativity. And I guess the relationship between earth and moon time is far from linear depending on their relative positions and the sun’s. So there is lots of interesting stuff to be worked out, and I don’t think it’s silly at all.

Daz1 4y ago
Why needlessly complicate things? Use GMT + 0, earth days, and earth weeks. Why introduce all this unnecessary confusion? There is no practical need to measure local time on the moon. >Earth clocks and moon clocks don’t run at the same time, due to relativity. I'm sure the 1/3000th of a millisecond per year won't be a problem
- wyldfire 4y ago
  > There is no practical need to measure local time on the moon Could it be useful to know when the sun would rise and set, or when Earth rises and sets, for the sake of having routines related to solar power or LOS communications? Having a Luna-native time-of-day might be handy for some things. I think it makes some sense to come to an agreement, even if that agreement was to use UTC (TFA does mention that it's used for ISS).
  - thaumasiotes 4y ago
    > Could it be useful to know when the sun would rise and set, or when Earth rises and sets, for the sake of having routines related to solar power or LOS communications? The sun rises and sets over exactly one (Earth) lunar month, 29.5 days. That's what the phases of the moon are, the progression of sunlight over the face of the moon. Earth never rises or sets; the near side of the moon always faces toward Earth, and the far side of the moon never faces toward Earth. (This is known as "tidelocking".) So no, neither of those could be useful.
- doctor_eval 4y ago
  > I'm sure the 1/3000th of a millisecond per year won't be a problem But that’s several orders of magnitude incorrect. FTA: > Clocks run faster on the moon than on Earth, gaining about 56 microseconds each day Unless my maths is wrong isn’t it actually 200 milliseconds per year? It’s not a lot of time, sure. But it seems important to people like scientists. Which, not coincidentally, is probably the most ”practical” thing people will be doing while spending time on the moon.
  - thaumasiotes 4y ago
    > Unless my maths is wrong isn’t it actually 200 milliseconds per year? 20, not 200.
    - doctor_eval 4y ago
      Yes, you are right. 0.02 seconds; I made a conversion error to ms.
brigandish 4y ago
> why should they be linked? Two reasons. Firstly, human biology, it'll be better for the people living/working there to experience via things like lighting and having visual clues from things like clocks to regulate their life. Secondly, for communication with those on Earth in a way that makes sense to both parties. We only use our system of time because it is useful (daylight saving might be an exception to that;) so why bother with a more "correct" version of that on the Moon? It's not like you'll be using the days there if it's light for one Earth month and dark for another.
- doctor_eval 4y ago
  I would have thought that a local moon time would primarily be for the benefit of people on the moon. Obviously, if you’re calling people on earth then you need to do a conversion anyway, just like we have to do when making international calls. But if you’re on the moon, perhaps there is a better way of keeping time that will benefit others also on the moon.