The Unnatural Time Interval

[chanbengchin]

A day is a natural time interval, namely that between the rising and setting of the sun.

The month is a natural time interval, namely that from new moon to new moon.

The year is a natural time interval, namely that from harvest to harvest, or spring to spring, summer to summer.

The second is also a natural time interval, namely that it takes for a certain atom to vibrate a certain number of time.

But what of the week?

[Guest]

Coul be biblically basec

[chanbengchin]

But in all cultures? with or without the knowledge of the bible?

[X_post_mortem_X]

But in all cultures? with or without the knowledge of the bible?

All cultures don't have a week...

~After Death~

[Matt]

Well, the 28 days of a lunar month divides by 7, which fits with the 4 significant phases of the moon too, that's probably where it all stemmed from originally. Then it entered religious legend in the form of genesis and probably plenty of other religions before it. I suppose if you're looking to make people do things with a certainregularity 14 days is too long, but 7 days is about right.

The real odd one is the month as it's not from new moon to new moon.

[X_post_mortem_X]

Millenium- One thousand years; no real importance.
Century- One hundred years; no real importance.
Decade- Ten years; no real importance.
Earth Year- 365.25 days; time for the Earth to revolve around the sun.
Month- Approximate time for moon to go from new moon to new moon.
True Month- 28.5 days; time from new moon to new moon.
Week- ~.25 of a month.
True Week- 7.125 days; New; Waxing; Half; Full.
Day- Time for the Earth to rotate once.
Hour- 1/24 of a day; no real importance.
Minute- 1/60 of an hour; no real importance.
Second- 1/60 of a minute; no importance.

~After Death~

[DarkMagus]

anyone else think that's a silly question?

[kyry]

A day is the time it takes for the earth to revolve once, not the time for the moon to revolve around the earth, which is a month.

[DarkMagus]

there is no natural or unnatural time interval. any interval of time is arbitrarily determined. when you compare the ten minutes i spent (i experienced) on earth with the ten minutes i spent (experienced) in a spaceship orbiting a neutron star (really dense star with seriously unimaginable gravity)... you find that these two intervals of what i experience as "TEN MINUTES" are NOT THE SAME. they cannot be compared to some external, objective viewpoint. this question is silly because:

time has no absolute, primary reference point... at least according to einstein:

"The law of the constant velocity of light in empty space, which has been confirmed by the development of electro-dynamics and optics, and the equal legitimacy of all inertial systems (special principle of relativity), which was proved in a particularly incisive manner by Michelson's famous experiment, between them made it necessary, to begin with, that the concept of time should be made relative, each inertial system being given its own special time. ...According to the special theory of relativity, spatial co-ordinates and time still have an absolute character in so far as they are directly measurable by stationary clocks and bodies. But they are relative in so far as they depend on the state of motion of the selected inertial system." (Einstein, 1934)

read up on it.

[chanbengchin]

there is no natural or unnatural time interval. any interval of time is arbitrarily determined ...

You are right in the strictest notion of time. But I am talking about our real human earthly experience of time. Yes you can define the "year" arbritarily, but why have peoples in all the world, apparently ever since there were people, and without global agreement, authorities and coordination, all arrived at a common notion of a year, which is based on the earth's revolution round the sun?

Yes the common experience of the natural seasons can be one explanation. Another could be it is just useful coordination to synchronise argricultural and economic activities within local communities, and again as it is "natural" and common experience, the year, as a notion of time becomes a common concept on all the world.

Similar explanations can be made for the month and day.

But of the week?

[DarkMagus]

this is more of a historical or sociological question, it has nothing to do with philosophy. no serious person on this board reads this and says "WHOAAAA THAT REALLY BLOWS MY MIND." its not philosophically interesting at all. where are you getting these ideas?

[chanbengchin]

I dont think you can speak for every "serious person" on this board ... they can speak for themselves, and silence does not mean anything ...

[Sheâ„¢]

week: menstrual cycle? (average 'period' lasts a week, once a month)

Cycles involving agriculture, astronomy, and reproduction very important in all sort of religions, ancient and otherwise...

[Sheâ„¢]

this question is silly because:

time has no absolute, primary reference point

...

According to the special theory of relativity, spatial co-ordinates and time still have an absolute character in so far as they are directly measurable by stationary clocks and bodies. But they are relative in so far as they depend on the state of motion of the selected inertial system."

-- DarkMagnus, contradicting him/herself

For the purpose of this thread, the 'system' seems to be the moon's orbit of the earth, relative to their rotation around the sun. Although the system is in a state of motion, and nothing is in reality stationary, it can still be measured, or we would not have a useful calendar w/ a year's worth of months, weeks, and days...

[DarkMagus]

this question is silly because:

time has no absolute, primary reference point

...

According to the special theory of relativity, spatial co-ordinates and time still have an absolute character in so far as they are directly measurable by stationary clocks and bodies. But they are relative in so far as they depend on the state of motion of the selected inertial system."

-- DarkMagnus, contradicting him/herself

For the purpose of this thread, the 'system' seems to be the moon's orbit of the earth, relative to their rotation around the sun. Although the system is in a state of motion, and nothing is in reality stationary, it can still be measured, or we would not have a useful calendar w/ a year's worth of months, weeks, and days...

well, i dont think so. besides, the first statement is mine, the second statement is einstein's. even still, the contradiction doesn't jump out at me or anything... hmm i think you're getting caught up on the line spatial co-ordinates and time still have an absolute character in so far as they are directly measurable by stationary clocks and bodies. its true that there is no absolute frame of reference by which to judge all things having to do with time. but when masses and speeds increase significantly, things change.

so if you consider the earth and the moon together to be one "inertial frame of reference" then you can make accurate, "universal" measurements of time and space/distance/whatever. but as soon as you consider the two part system "1)earth & moon (together) revolving around the 2)sun", things get tricky. time (among other things) would be measured differently for both frames of reference on account of their different relative speeds (and masses i guess you could say).

for all practical purposes, time can be measured or broken up in one way or another. whichever way you choose, actually. so i think the week is an arbitrary measurement. (that's why i said its more of a historical/cultural kind of question) but strictly speaking in terms of science, its certainly not exact when you're dealing with faraway places/things and the (sometimes) extremely disparate relative velocities between these places/things.

[X_post_mortem_X]

week: menstrual cycle? (average 'period' lasts a week, once a month)

Cycles involving agriculture, astronomy, and reproduction very important in all sort of religions, ancient and otherwise...

The average menstrual cycle is three days...:-X

~After Death~

[Sheâ„¢]

This is the first link that comes up when you type in "menstrual cycle" into Google:

http://www.fwhc.org/health/moon.htm Scroll down to "Moon Time" and "Native American (Lakota)" and "Calendars"

Yes, Dark Magus, the moon and earth are one system, the sun and earth are one system. But I said, the moon's orbit of the earth, relative to their (together) rotation of the sun. I said this, because, we say the moon takes 28.5 days to orbit the earth -- but how do we define the length of a day? The time it takes for the earth to rotate once (not around the sun, duh, just to clarify), using the sun and horizon as a marker (sunrise to sunset, granted the sun does not rise or set).

[DarkMagus]

we're not talking about the same thing. its cool though.

[Sheâ„¢]

okay