Time (the measure of)

[rhoenix]

Though this post has selfish roots, in that it would help me with my current writing project, this concept has also occupied my mind philosophically, as well.

Time, as we currently measure it here and now on Earth, is on a 24 hour rotating clock divided into 60 minute intervals comprised of 60 seconds each, operating at 365.25 cycles per year, to account for the odd day of Leap year.

The villain, as Asimov put it from The Tragedy of the Moon, is not the year or the day, but the month. We use a loose twelve month counting for our months, but it's certainly not even.

He also proposed as a solution a four-period split to a year, with 91 days per quarter. This would leave Year Day and Leap Day as not counted on purpose calendar-wise, which emotionally sounds just fine to me, and logically seems workable.

This is all well and good, until we come to the point of one governing body and multiple planets.

If one has just a few worlds to account for, one could conceive of a beaurocracy willing to account for the different times of worlds, but that would very quickly grow messy with each additional world's time and calendar.

One solution to the obvious problem would be to use the galaxy's rotation as a time scale and translate to "X's local planetary time," though this would concievably be also short-sighted.

What would you propose as a solution?

[Hawkwings]

Well, the way it's done in some sci-fi universes is that the interplanetary government works off one system of time, usually the capital planet, and the local government works off the local time. For planetary business, planetary time is fine, but for travelers, you'd want to use the official time system.

[darthbob88]

Well, the way it's done in some sci-fi universes is that the interplanetary government works off one system of time, usually the capital planet, and the local government works off the local time. For planetary business, planetary time is fine, but for travelers, you'd want to use the official time system.

You mean like, "Train from Tycho City to Hong Kong Luna will be leaving at 0400 and arriving at 0630", as compared to "All applications for employment in the Imperial Civil Service must be in by 2400 Coruscant time"?

[Spoonist]

several scifi authors just use seconds, so that you measure time in
s
ks
Ms
Gs
Ts

if all your planets had the same 'start' point in time you could then refer to it was the era of the 2nd Terra
however its better at relative time than it is in giving fixed date

[Ariphaos]

I actually dipped into this a bit (and Kuroneko fixed some of my math) in this thread.

In a sense, for my own setting, I have a set of calendars that eventually get subsumed into the 'Helios calendar'. Basically it defines the second, calculates the amount of dilation a person experiences, and calculates accordingly, with cultural additions to define hours (3600 seconds), days (25 hours), months (40 days), and cycles (1000 months).

A calendar needs to serve several purposes. The key ones that come to mind are social, economic, and chronological. In my opinion, given sufficient computing power, this suits well.

The converter proper is here. Along with an Arean calendar that I designed because... I do things like that (it's based loosely on the Darian one). Don't take it's accuracy -too- far, though, especially with the whacked DeltaV equation I have in there.

It really is a sort of glorified Julian Day, but, when using an aplanetary (is that a word?) calendar, that's best IMO.

[petesampras]

Well, the way it's done in some sci-fi universes is that the interplanetary government works off one system of time, usually the capital planet, and the local government works off the local time. For planetary business, planetary time is fine, but for travelers, you'd want to use the official time system.

Wouldn't relativistic effects come in to play and make a universal time impossible? I guess it depends on the velocities of the star systems.

[Patrick Degan]

Since all time is subjective, it is a certainty that any space civilisation would require at least two calendars as well as entirely subjective shipboard calendars/chronometres and a mathematical standard to compute the differences between them for records keeping purposes. Which is how several SF authors have handled the concept.

In reference to the measure of the year on Earth, some people advocate using a lunar calendar based on 13 months of 28 days each and a Year Day.

[Teleros]

"All applications for employment in the Imperial Civil Service must be in by 2400 Coruscant time"?

Wonder if they could use Centrepoint Station to alter orbits...

[TheLemur]

In reference to the measure of the year on Earth, some people advocate using a lunar calendar based on 13 months of 28 days each and a Year Day.

How is that a lunar calendar? It would very quickly get out-of-sync with the phases of the Moon. And the Muslims would start protesting, since the Koran explicitly states:

The number of months with Allah has been twelve months by Allah's ordinance since the day He created the heavens and the earth.

[Patrick Degan]

In reference to the measure of the year on Earth, some people advocate using a lunar calendar based on 13 months of 28 days each and a Year Day.

How is that a lunar calendar? It would very quickly get out-of-sync with the phases of the Moon.

There are 13 distinct lunar phases of one type or another through the year. Which ones they are vary: some years it will be 13 full moons, other years it will be 13 half-moons, or quarter-moons, or new moons.

And the Muslims would start protesting, since the Koran explicitly states:

The number of months with Allah has been twelve months by Allah's ordinance since the day He created the heavens and the earth.

Who cares?

More seriously, yours is not a wholly unreasonable objection. However, an alternative method of basing a calendar on 13 months of 28 days plus an annual transition day from the one year to the next works out about as well as the current system does albeit a bit more neatly in terms of simple arithemetic. You still have the extra day every four years, but it can be tacked on at the end of the year for two transition days. Makes things just a bit tidier, perhaps. That it would be impractical to expect such a change as long as the present culture remains dominant goes without saying, naturally.

[Teleros]

And the Muslims would start protesting

Don't worry, we're talking about the future here ...

[kheegster]

Well, the way it's done in some sci-fi universes is that the interplanetary government works off one system of time, usually the capital planet, and the local government works off the local time. For planetary business, planetary time is fine, but for travelers, you'd want to use the official time system.

Wouldn't relativistic effects come in to play and make a universal time impossible? I guess it depends on the velocities of the star systems.

Even galaxies are moving at speeds of the order ~500 km/s relative to each other, which is only very mildly relativistic, although it would certainly affect long-term timekeeping.

However, even though in relativity it's not possible to define a universal frame of reference in principle, in practice it IS possible: at least within the visible universe, the cosmic microwave background provides a means through which it is possible to define a universally-agreed frame of reference.

[Sriad]

Well, the way it's done in some sci-fi universes is that the interplanetary government works off one system of time, usually the capital planet, and the local government works off the local time. For planetary business, planetary time is fine, but for travelers, you'd want to use the official time system.

Wouldn't relativistic effects come in to play and make a universal time impossible? I guess it depends on the velocities of the star systems.

Even galaxies are moving at speeds of the order ~500 km/s relative to each other, which is only very mildly relativistic, although it would certainly affect long-term timekeeping.

However, even though in relativity it's not possible to define a universal frame of reference in principle, in practice it IS possible: at least within the visible universe, the cosmic microwave background provides a means through which it is possible to define a universally-agreed frame of reference.

Pete might have meant that without FTL travel using Earth time in another star system would be pointless, because at best Earth Standard Time would be Six Years Ago.