Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Europe pushing for lunar time zone

apnews.com

Post reply on HN
Print view View original

351–360 of 406 posts

Re: Europe pushing for lunar time zone

#351

Post by jjkeddo199 »

I am just a fool who doesn't know anything, so take my thoughts with a grain of salt, but I think all the ideas shared here are too complicated and have too many breaking changes. I think a lunar timezone or martian timezone is a horrible idea. We need instead to have planetary offsets. How many insidious and horrible date/time bugs would we signing 22nd century programmers up for by trying to mishmash different planetary timezones together?

Keep it simple! If we added a celestial offset, it would work for the moon, mars, and any other planet we wanted to visit! Time could be stored as follows:

``` 1) Time of day 2) Timezone 3) Celestial Offset (PlanetX:Earth seconds per day ratio) 4) Calendar (Gregorian, Japanese, Islamic, Lunar, Martian) 5) Solar System ```

Boom! Problem solved.

Re: Europe pushing for lunar time zone

#352

Post by adastra22 »

yencabulator wrote: post #318
nixpulvis wrote: post #311

Earlier quoted context omitted.

True, but UTC drift calculations on earth are different from on the moon. Fundamentally there is another time standard on the moon. How we account for that is up to us, but it makes sense to formalize this IMO. You could perhaps try to first derive a galactic or stelar time standard, then make both the moon's and earth's a derivative, but that seems even more complex in a way, though perhaps the most elegant in anoth…

> True, but UTC drift calculations on earth are different from on the moon. Hey reference clock, what time do you see? Oh, it's X? And I'm at Y? Okay, I'll adjust my drift correction factor to Z. They might drift more than good modern-day clocks, and the latency to the reference clock might be higher, but the basic mechanism of correcting for the drift shouldn't be any different. What's the difference between taking…

It's not drift. Time passes more quickly on the moon, to such an extent that there are 56 microseconds more each day on the lunar surface than on Earth. This is a an effect of general relativity.

For everyday human-scale stuff, sure this doesn't matter. For precise scientific and industrial use cases, it does.

Re: Europe pushing for lunar time zone

#353

Post by adastra22 »

fluoridation wrote: post #338
makeitdouble wrote: post #329

Earlier quoted context omitted.

I read it as computers being the primary target for any clock system

Computers don't really care about the current wall time. They just care about measuring time between events. If a piece of software about the current day of the week it's only because a person cares about it and wants to do something special on certain days of the week. So, yes, time systems should be designed around the needs of people.

The time between events is different as measured on the Moon than on Earth. That's what is being talked about here.

Re: Europe pushing for lunar time zone

#354

Post by adastra22 »

r2_pilot wrote: post #292
dylan604 wrote: post #289

Earlier quoted context omitted.

"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.

So I'm not an expert, but this behavior actually would behave differently in different gravity wells. Due to relativity, while you would observe a cesium clock working normally on the moon, your Earth buddy would disagree with your clock because the buddy would be down in a larger gravity well.

Sortof. It would behave the same to the observer sitting next to the atomic clock no matter their local frame of reference. The point though is that we have atomic clocks on both Earth and (soon) the Moon, so we need some sort of standard for coordinating between them.

Re: Europe pushing for lunar time zone

#355

Post by tdba »

dsfyu404ed wrote: post #345
kelseyfrog wrote: post #319

Earlier quoted context omitted.

Despite this, I'm an advocate for martian self-determination when it comes to deciding their timekeeping system. Earthlings, despite their good intentions, should stay out of the matter categorically.

Everyone says this but reality never seems to work out that way when push comes to shove. Will you be singing that tune when a religious minority you hate moves there, establishes a theocratic government, starts teaching women to read, hanging undesirables and troublemakers and regressing on pretty much every human right your ancestors died for, bonus points for starting a war with the locals. That said, in the histo…

You are of course talking about the Ottoman conquest of Constantinople.

Re: Europe pushing for lunar time zone

#356

Post by jjkeddo199 »

cornholio wrote: post #125

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…

Planetary body should be a new offset category/type that defaults to Earth. Instead of tracking time as time:offset:date:calendar, we should do time:offset:date:calendar:planetTimeOffsetRatio. If calendarplanetTimeOffsetRatio is 1.02777778 (Mars:Earth days), number of seconds available in the day is increased by 2.777778%

Re: Europe pushing for lunar time zone

#357

Post by hn8305823 »

cornholio wrote: post #125

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…

Nobody is going to be having real-time Zoom calls between Earth and Mars so I'm not sure how in sync it needs to be.

It does make sense to at least keep the second the same since that is a critical base SI unit that affects lots of other things.

One interesting problem will be that high precision atomic clocks will run at a slightly different rate on the surface of Mars due to the lower gravitational potential, but this is easily solvable as it is on GPS satellites.

Re: Europe pushing for lunar time zone

#358

Post by kelseyfrog »

dsfyu404ed wrote: post #345
kelseyfrog wrote: post #319

Earlier quoted context omitted.

Despite this, I'm an advocate for martian self-determination when it comes to deciding their timekeeping system. Earthlings, despite their good intentions, should stay out of the matter categorically.

Everyone says this but reality never seems to work out that way when push comes to shove. Will you be singing that tune when a religious minority you hate moves there, establishes a theocratic government, starts teaching women to read, hanging undesirables and troublemakers and regressing on pretty much every human right your ancestors died for, bonus points for starting a war with the locals. That said, in the histo…

I refuse to get involved in Martian politics. You can CIA them however you want though. I'm sure you can find just as many instances where foreign meddling and infantilization of people had disastrous consequences.

You'll be happy to know that you can appreciate their input on Earth matters as much as they'll appreciate yours on martian matters.

Re: Europe pushing for lunar time zone

#359

Post by throw0101a »

kelseyfrog wrote: post #319
cornholio wrote: post #125

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…

Despite this, I'm an advocate for martian self-determination when it comes to deciding their timekeeping system. Earthlings, despite their good intentions, should stay out of the matter categorically.

What about Belters?

* https://en.wikipedia.org/wiki/The_Expanse_(novel_series)

Re: Europe pushing for lunar time zone

#360

Post by throw0101a »

hn8305823 wrote: post #357
cornholio wrote: post #125

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…

Nobody is going to be having real-time Zoom calls between Earth and Mars so I'm not sure how in sync it needs to be. It does make sense to at least keep the second the same since that is a critical base SI unit that affects lots of other things. One interesting problem will be that high precision atomic clocks will run at a slightly different rate on the surface of Mars due to the lower gravitational potential, but t…

> Nobody is going to be having real-time Zoom calls between Earth and Mars so I'm not sure how in sync it needs to be.

If a contract say "the payment must be received before March 1, 2123", then you have to worry about time syncing between the planets. How fast are fund transfers between planets?

Post reply on HN