Red marked places are the mistakes I made when recording.
Anthropology
Listen to part of a lecture
in an anthropology class.
Okay, I want to
start today by talking about calendars. I know, some of you are thinking it’s not all that fascinating, right?
But listen; the next
time you look at a calendar, I want you to keep something in mind. There are at
least tree natural ways to measure the… the passage of time- by day, by month and by year. And these are all pretty easy to see, right? I mean, a day is based
on one rotation of earth. A month is how long
the moon takes to move around the earth. And a year is the time it takes for Earth to move around the Sun, right? So they are all
based on natural events, but the natural clocks of Earth, the Sun, the Moon run on different times, and
you can’t divide any one
of these time periods by another one without having
some messy fraction left over. I mean, one lunar month- that’s the
time it takes for Moon to move around the Earth- one month is
about 29.5 twenty-nine and a half days, not really a nice round number. And one
year is little more than 365 days. So these are obviously
numbers don’t divide into
each other quite neatly. And this makes it pretty difficult to create some sort
of tidy calendar that really
works.
Not those different cultures haven’t
tried. Have any of you ever been to Stonehenge. No… you know that amazing circle of giant stones in England? Well, if you ever go, and
find yourself wondering why this culture way back in prehistory England would go to so much
work to construct this monumental ring of enormous stones,
…well, keep in mind that a lot of us think it was
designed, at least partially as calendar- to mark when the seasons of the year
begin, according to the exact day when the sun comes up
from a particular direction. I have colleagues who insist it’s a temper, maybe, a tome … but they can’t deny it was also used as a calendar… probably to help figure out, for
example, when farmers should begin their planting each year.
The Mayans, in Central America, also invented a calendar, but for a different purpose. The
Mayans, especially the royalty and priests, wanted to look at
long cycles of history -
so the calendar the used had to be able
to count far into the future as well as far into the past. And not only were
the Mayans keeping track of the natural timekeepers we mentioned before
- earth, the sun, and the moon - but another natural
timekeeper: the planet Venus.
Venus rises in the
sky as the morning star every 584 days, and the Venus cycle was incorporated in the Mayan calendar. So the Mayan kept track of
long periods of time, and
they did it accurately, in fact, that their calendar is considered about as complicated and sophisticated
as any in the world.
Now, the ancient
Chinese believed very strongly in astrology- the
idea that you can predict the future events
based on the positions of the stars and the planets
like, say Jupiter. Incidentally,
the whole Chinese system of astrology was based on the fact that the planet Jupiter goes around the Sun once every twelve years, so one orbit of Jupiter lasts
for 12 of our earth years. Apparently that’s why the Chinese
calendar has a cycle of 12 years, you know, like
“the year of dragon”, “the year of tiger” and so on… all
parts of the twelve year astrological cycle that
we get from the orbit of Jupiter.
Calendars based on
the orbits of other planets, though, are a lot less common than those based
on the cycle of the Moon, the lunar month. I could mention any number of important cultures around the
world that have depended on lunar calendars, but there really isn’t time. So, let’s go
right to the calendar that’s now used throughout most of the world- a solar calendar- based on
the number of days in a year.
This calendar is mainly derived from the one of the ancient
Romans derived a couple thousand years ago. I mean, the Romans- with more than a little help from the Greeks - realized that a year
actually lasts about 365 and a quarter days. And so
they decide to round off most years to 365 days
but make every fourth year into a leap year. I mean,
somehow, you have to account for that extra one fourth of a
day each year, so every four years, they made
the calendar one day longer. By adding the leap year, the Romans were able to make
a calendar that worked
so well – that, with a
few minor adjustments, this calendar is still widely used today.
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