Hakan wrote
> I read an essay by an author who says that the ancient Egyptians
had a
> 365-day calendar which caused them some trouble. Since one year is
in fact
> slightly longer than 365 days, their calendar started to "wander",
according to him,
> so that holidays which belonged in the winter occured in the
summer. This
> caused a lot of "anger and confusion", he writes. Is this true?
All ancient peoples had trouble with calendars, which is what made
astronomy such a basic science for them. The Egyptians originally
had a 360 day calendar, but from Dynasty 1 had interpolated 5
intercalary days of celebration. They also dated their calendar from
the rising of the Nile in flood - which varied a little from year to
year - it is why the Nilometer kept at Aswan was so famous - records
extend back even to the Thinite Age before the Old Kingdom.
Averaging out the periods between floods they came to a 365.25 day
year fairly early. This was equated with the rising of Sothis
(Sirius) which is one reason why the Great Pyramid has a channel from
the kings chamber pointed at this star.
> As far as I know, all ancient civilisations who had calendars, from
South America to
> Asia, were aware of this problem and had more or less accurate
systems of
> leap years, extra months etc. to compensate for this. They didn't
know that
> the Earth was orbiting the Sun, but they knew when the winter
solstice was,
> and were able to measure the length of one year accurately enough.
All ancient
> civilisations were pretty good astronomers and it seems
> hard to believe that they were "forced to celebrate Christmas in
the summer"
> (as this guy writes).
>
> But wait... what about the Islamic calendar? If I remember
correctly (I once
> worked with some people from Turkey), islamic holidays, like
Ramadan,
> are moving around the year like this, because
> of the Islamic calendar. Perhaps someone on this list could
> straighten this out? I'd be grateful for any information about how
Egypt and
> other ancient civilisations handled this problem.
The Islamic calendar is a lunar calendar, based on 12 lunar months,
not the luni-solar calendar which bears only a limited relationship
with the solar year. Hence Ramadan does move and the muslim years
since the hegira (Mohammed's flight to Medina in 632 CE) is not
exactly equal to 2000-632 (1368 years).
The Zodiac is a very ancient construction, and was common to most
cultures as it roughly corresponds to the number of clear
constellations covered by the sun in one of the moon's cycle phases
to the next. It is built into the structure of the stars itself
which is why the zodiac (albeit with different constellation names)
is found so widely.
The greatest astronomers of the ancient world (prior to the Hellenics
like Eratosthenes who fairly accurately measured the curvature and
diameter of the Earth), were the Babylonians. Their Zodiac travelled
very early on to Egypt, where it is found as the basis even of the
pyramid texts of 4th Dynasty Pharaoh Unis.
There is some evidence that there was originally a 13 month year
(13*28 days=364 days). A full solar year was thus 1 year plus 1 day,
which explains why so many European folk contracts were made for a
year and a day (for example if a feudal serf managed to "escape" for
a year and a day he henceforth was a "free" man). The "day" in
concern was 1st May, which was they day of "misrule", in which
someone could be appointed "king for the day" in order to attract all
the bad luck acrued by the real king. In Assyrian times, the pseudo
king was later executed. Tanist systems of this sort are suspected
in PIE, (the divine twins, one immortal the other mortal etc). The
thirteenth month (with the sign of the zodiac of the serpent) was
later suppressed, which attached a lot of superstititon to the number
13. Thus Friday (the only day of the week named after a woman!) 13
was considered especially inauspicious. It is interesting that
Friday was considered especially bad luck for sailors. At one period
the British navy decided to scotch the supersition for all times.
They laid a ships keel on a Friday, launched it on a Friday, called
it the HMS Friday, and set sail on its maiden voyage on a Friday.
Trouble was, it was never seen again!
Interesting point
Regards
John Croft