Tuesday, October 11, 2011

Marking time

Calculating when Jewish holidays occur is now pretty easy, but it didn't used to be that way.  Since the months started on the new moon, and the holidays started at sunset in Jerusalem, messengers were dispatched to let other communities know when the festivals should be celebrated.  When the second temple was destroyed by the Romans, there were no more messengers, so many communities (the diaspora) started celebrating festivals over two days, just to be sure.  (Even today, they celebrate on two days out of tradition.)

And although a day seems like a simple thing to keep track of, it isn't.  That's because the time it takes for the earth to rotate (one day) has nothing to do with the time it takes for the moon to revolve around the earth (one month) which has nothing to do with the time it takes for the earth to revolve around the sun (one year).  So a lunar month lasts 27 days and 8 hours; a lunar year is 354 days 9 hours; a solar year is either 365.24219 days (tropical) or 365.2564 days (sidereal). Not to mention the moon is moving away at 4 inches per year, slowing its rotation, and the length of days may be affected by global warming as higher seas create a greater drag on the earth's rotation!

More trivia: The moon revolves at the same rate it rotates around Earth (that is, every 27 days and 8 hours) which is why the same face is always pointing towards Earth, and we didn't see the far side until 1959!

The ancient Sumerians had a pretty sophisticated "lunisolar" calendar -- 12 months, each starting with the sighting of a new moon, and an extra month was added periodically to keep the months in the same seasons.  (The Sumerians also gave us 60 minutes -- they liked 60 because it can be easily factored by 2, 3, 4, 5, 6, and 10.) The Jews used the Sumer  calendar (with some variations) while Europe adopted the Roman "Julian" calendar, which made the months slightly longer but got rid of the "leap month."  The Muslims, by contrast, adopted a strict lunar calendar, so a Muslim year is 354 days, and the months change seasons, because they lose abut 12 days every year -- so in 10 years a holiday that was in December will now be in October! (According to the European calendar, anyway).

Incidentally, it was the Egyptians who subdivided daytime and nighttime into twelve hours each, but the length of the hour depended on the season.  The Greeks--who also liked the number 60 but wanted a stable measurement of time--defined the hour as 1/24th of a day, a "minute" (as in "diminutive") as 1/60th of an hour, a "second" as 1/60 of a minute, a "third" as 1/60 of a second, a "fourth" as 1/60 of a third, and so on.  Of course, we no longer use "thirds" and "fourths" but "seconds" stuck.

More trivia: "Idus" is latin for "half division" and referred to the half moon (what we would call the full moon).  Since months started on the new moon, the "idus" was generally on the 13th of the month; however, when Julius Ceasar changed the months so they no longer followed the lunar cycle, "ides" was no longer relevant.  However, the term was still in use when Julius was assassinated on the 15th of March -- now known as the "Ides of March."

Of course, the Julian system wasn't perfect -- the years were fixed at 365.25 days, but the solar year is about 11 minutes shorter.  That means it gained one day every 131 years -- not bad, but the calendar was in use for over 2000 years!  In addition, early timekeepers got confused and started adding leap days every 3 years -- as a result, when Augustus took over in 4CE, he had to drop 3 days from the calendar to fix it.  In addition, there was no fixed point for starting the calendar, and so it was generally based on the rule of the regnant (i.e. 1 Julius, or 1 August).

More trivia: It is an urban myth that February used to have 29 days, and Augustus decided to move one day to August so it had the same number of days as Julius (July).  You probably didn't even know that rumor, but now you know it isn't true.

The idea of Anno Domini was set out in the 6th century and adopted sporadically, but it wasn't until the 16th century that the Gregorian calendar replaced the Julian calendar, and even that wasn't adopted universally until the 1920s. (Seriously!)  Of course, since Anno Domini translates as "The Year of our Lord" and refers to Jesus Christ, the Jews adapted it politically but not religiously.  (And even politically, the term "common era" is used.)  As countries adopted the Gregorian calendar, they had to skip ten days to move the spring equinox back to March 21.

Had any of these civilizations been particularly clever, they would have jettisoned the entire lunar calendar, because the moon isn't relevant to the seasons, it's just a pretty bauble in the night.  Then they could have come up with a meaningful division of years that didn't involve the pattern "31,28,31,30,31,30,31,31,30,31,30,31".  The Vikings actually tried this, but they may have oversimplified it a bit: They divided the year into two seasons, summer and winter, from April to October and October to April.  They then divided each season into weeks, and got rid of the months.  Apparently this worked quite well for them, as they didn't adopt the Gregorian calendar until the 1800s, some 200 years after it had been introduced.

More trivia: In the Sumerian calendar, there were no weeks; just days. The Jews defined the seven day week based on Genesis (God created the world in 6 days and rested on the 7th).  Why seven days?  Who knows. Maybe it was because of the four phases of the moon (28 day lunar cycle / 4 phases = 7 days.)  Maybe it just seemed like a good idea to rest every seven days. The Romans started with an 8-day week but later adopted the Jewish 7-day week.  The Chinese and Egyptians had a 10-day week, and the Celts (in Britain) had an 8-day/9-night week, which was closer to the 27.3 day lunar cycle, but must have been very confusing.

And last bit of trivia--actually, it's more of a rant: As the moon rotates every 27.9 days, and revolves around the sun every 365 days (same as earth), there are actually only 13 days a year on the moon!  If an earth sunset lasts 2-3 minutes (depending on season and latitude), then the equivalent lunar sunset would last 84 minutes! In fact, you'd only have to travel 10 mph to stay ahead of the terminator line!  So why is it that every science fiction film shows the lunar sunset overtaking the hapless astronauts in a matter of minutes?

Saturday, October 8, 2011

What Jews believe

Jews believe that God created the world on Rosh Hashana (literally 'head of the year') 5,772 years ago, and that on Rosh Hashana God reviews your life for the past year and pencils you in the book of life, giving you ten days to repent, give to charity, and otherwise convince God that you are worthy before he seals the book on Yom Kippur (literally, 'day of atonement').  On Yom Kippur, Jews fast for 25 hours, from sunset to sunset (plus a little extra just in case), and spend most of that time in church, praying.  Jews are not allowed to eat, drink, work, wash, have sex, smoke, or wear leather shoes.

The Bible said: "On the first day of the seventh month you are to have a day of sabbath rest, a sacred assembly commemorated with trumpet blasts. Do no regular work, but present a food offering to the LORD.... The tenth day of this seventh month is the Day of Atonement. Hold a sacred assembly and deny yourselves, and present a food offering to the LORD." (Leviticus 23)

So, how did we get from two days of rest to 10 days of atonement?  That's the beauty of religion.

First, how did the "first day of the seventh month" get to be the "head of the year"?  Well, in Judaism, there are four new years -- one for kings, one for animals, one for vegetables, and one for trees.  Not suprisingingly, the new year for animals is in the spring, vegetables in the summer, and trees in the autumn.  The one for kings is actually the first day of the first month of the Jewish calendar, but somehow the vegetable new year became the day they changed the year.  It would be like us celebrating New Year's day on April 1 -- how crazy would that be? 

Oh wait, that's exactly what we did until 1582, when the calendar was changed and the new year was moved to January 1.  Never mind.

Second, how was it decided that world was created on Rosh Hashanah?  Well, if you actually believe our planet is less than 6,000 years old, you have other issues, so I'm going to skip this one.

Third, when did Rosh Hashanah and Yom Kippur become linked?  Leviticus didn't say anything about "high holydays" or "days of awe." It didn't say anything about a book of life, or about giving to charity, or apologising to people you've wronged -- it just said on Rosh Hashana you should blow a horn, and on Yom Kippur you should deny yourself and atone.  Leviticus doesn't link these two holidays; in fact, they are part of a list of six holidays, one of which comes five days after Yom Kippur, but it's not linked at all!  Somehow, these ten days not only became linked, but somehow became the most important in the Jewish calendar.  There's no rhyme or reason.

Fourth, how does "deny yourself" become translated as "don't eat, drink, work, wash, have sex, smoke, or wear leather shoes"?  Not eating or drinking are self-evident.  Not having sex makes sense, but the real reason is that elsewhere in the Bible it says coming in contact with semen makes you ritually unclean.  (In fact, I was told that before the destruction of the Temple, the High Priest was kept awake the night before Yom Kippur lest he have a wet dream, and thus be unable to perform his duties the next day.)

But really, wear leather shoes?  The best explanation I've heard is that back then the only types of shoes were leather, and so going without them (i.e. barefoot) was a hardship.  However, to get around this proscription today, people wear trainers, which are even more comfortable!  Go figure.

And smoking wasn't prohibited because it was a pleasure you should deny yourself, but because the cigarette butt has to pass your lips, so it's almost like eating.  You know I'm not making this stuff up.

And finally, the rules around working are absolutely hilarious.  Keep in mind, we're talking 2,500+ years ago in an agrarian society; there were no weekends or holidays for the workers. The Jewish calendar was a revelation!  And you'd think common sense would dictate that "do no regular work" would mean just that -- no work in your regular occupation.  However, the Rabbis couldn't content themselves with something so simple, so they defined 39 prohibited activities:

Ploughing earth, sowing, reaping, binding sheaves, threshing, winnowing (separating chaff from grain), selecting (separating debris from grain), grinding, sifting, kneading, baking, shearing wool, washing wool, beating wool, dyeing wool, spinning, weaving, making two loops, weaving two threads, separating two threads, tying, untying, sewing stitches, tearing, trapping, slaughtering, flaying, tanning, scraping hide, marking hides, cutting hide to shape, writing two or more letters, erasing two or more letters, building, demolishing, extinguishing a fire, kindling a fire, putting the finishing touch on an object and transporting an object between the private domain and the public domain, or for a distance of 4 cubits (about 6 feet) within the public domain.

Today, observant Jews won't drive on Saturday (or any holiday) because the petrol engine is "kindling a fire."  (And they won't drive an electric vehicle because creating a spark is also considered kinding a fire.)  They also won't flip a switch for the same reason -- so if a light is on, it stays on the entire time.

Finally, what happened to the food offerings to the LORD?  Well, the LORD only presided in the Temple, which the Romans destroyed in 70 CE.  No Temple, no LORD, no food offerings.  More for us.

OK, so that's what the Jews believe.  What *I* believe is that the link between fasting and spirituality (or maybe just hallucinating) is well established, and denying yourself one day of the year -- to really make you appreciate your place in the world -- is a wonderful tradition.  I believe that coming to synagogue to pray for forgiveness *as a community* (not an individual) also reinforces your place in that community, and reminds you that you are your brother's keeper.  I believe that giving you ten days to "make good" really forces you to consider the past year; it's not going to church on Easter and getting it over with.  I believe that breaking the fast with friends and family, all of whom have been denying themselves as well, is what really makes it holy.

So tomorrow I will be hungry, tired, and sitting in a gym all day.  (Most Jews only attend synagogue on these two days of the year, so they have to be moved to a larger venue.  Last year it was under a tent; this year it is in a gym.)  I will be practicing my Hebrew and haltingly singing the few songs I know. I will be alone amongst about 500 people, with no friends or family, but I will feel a certain kinship with every one of them, because they are there for the same reasons I am.  Not because they believe God commanded them to, or because they are worried about being written in the book of life, and certainly not because they enjoy being hungry and hanging out with people who haven't bathed, but because they instinctively feel the need to come together, to reflect and consider, to deny themselves for one day, and to do so as a community.

My community.