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Date: 23 Aug 2006 15:50:42
From:
Subject: One quick question
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I was speculating on how the year, month, and day were all determined
by celestial movements. My teacher at school says that weeks are the
odd ones out but...
Is it possible that weeks were formed to end/start at every quarter of
the moon seeing how it takes ~28 days for the moon to rotate and 28/7=4
evenly. I would appreciate if anyone answered this one.
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Date: 23 Aug 2006 16:05:49
From: Brian Tung
Subject: Re: One quick question
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> I was speculating on how the year, month, and day were all determined
> by celestial movements. My teacher at school says that weeks are the
> odd ones out but...
> Is it possible that weeks were formed to end/start at every quarter of
> the moon seeing how it takes ~28 days for the moon to rotate and 28/7=4
> evenly. I would appreciate if anyone answered this one.
It's possible, but it's hard to say for sure. One problem is that the
(synodic) month isn't exactly 28 days, but more like 29.5. Errors build
up, so that after only a short time, the notion of the weeks wouldn't
keep in sync, unless they were made irregular (much as months are).
The fact that there were seven planets (Sun, Moon, Mercury, Venus, Mars,
Jupiter, and Saturn) seems to have been significant in Western history,
since most names for the days of the week are based on planet names.
It's that way in some Asian languages, too, but this may simply be a
later borrowing.
There have been weeks of other lengths--I seem to recall 10 and 4
floating around, although 10 might have come from the French proposal
for a decimal year. So 7 wasn't cast in stone originally, although it
might as well be now; with just about all of the world using such a
week, it will be very difficult to dislodge.
At any rate, the origins of the week are likely lost in the mists of
time.
--
Brian Tung <brian@isi.edu >
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.html
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Date: 24 Aug 2006 03:09:07
From: oriel36
Subject: Re: One quick question
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wiiwiillwiin@gmail.com wrote:
> I was speculating on how the year, month, and day were all determined
> by celestial movements. My teacher at school says that weeks are the
> odd ones out but...
> Is it possible that weeks were formed to end/start at every quarter of
> the moon seeing how it takes ~28 days for the moon to rotate and 28/7=4
> evenly. I would appreciate if anyone answered this one.
The most basic unit of human timekeeping is the 24 hour day,you can
expand it to determine weeks or the annual orbit of the Earth or divide
it into smaller divisions of hours,minutes, seconds or smaller
proportions but again,the 24 hour day governs everything.
The creation of the 24 hour day is one of the greatest achievements of
humanity,iwhat makes it work is knowing that our own existence is tied
to the daily cycle to which it refers,you wake,create you existence and
go to sleep by this cycle.
At the bottom of the human devised system is a standard pace by which
all other motions are measured and although it is refered to as
'Time',the specifics of clocks and the hand sweeping across its face
refer only to a standard pace,go ahead and look at that pace on a
watch or a clock and you will begin to see how that pace is comforting.
The creation of that standard pace emerges from keen observations of
how one cycle compares to the next cycle by means of a shadow on a
dial.The system is so old that nobody can say who created the system of
the equable 24 hour day,what you can say is that it is impossible to
create the calendar system with a leap day correction without the
equable 24 hour day therefore its creation must come first.
Do you clearly understand this basic principle that the 24 hour day is
the most basic timekeeping unit ?,if so we can move on to how the
equable 24 hour day was created from the natural unequal; length of the
day.This is the tricky part and few emerge with the correct idea of
what the total length of the day represents.
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