Friday, April 22, 2011

Earth Day Rumination

Holidays fascinate me, particularly in the context of cultural cycles. To be sure, the existence of cultural cycles is debatable. Some who study history perceive them, others do not. Both those who do and those who don’t must ignore important regions of fact in order to become didactic in their assertions. Still, poetically speaking, I see real cultural cycles, and in that sense holidays fascinate me. The seasons have their celebrations. In religious, inward-looking cultural periods, these have a transcendental focus; in secular times a material.

This year Earth Day occurs two days before Easter Sunday and coincides with the darkest day of the Christian cycle, Good Friday. Some believers who haven’t had time to think about this might rashly conclude that Earth Day is a kind of modernist affront. Yes, each culture has its holidays, but as best as I can determine, and I have the time for such things now, no offence was intended when Senator Gaylord Nelson launched Earth Day at a teach-in on April 22, 1970.

The two dates, as it happens, rarely coincide. In 1970 Easter Sunday came on March 29, hence a conscious alignment of the two isn’t credible. These days we observe the Gregorian Easter, based on a calculation. It bounds the dates of that holiday between March 22 and April 25. In the period 1875 through 2124, Easter falls most frequently (11 times) on April 10 and April 17. In this entire period, Easter on April 24 will take place this year and again in 2095, one of the least frequent dates. This link provides all the years.

The date of Easter is, roughly, based on a lunar calendar and falls on the first Sunday after the first full moon that appears after the vernal equinox. The differences, which give rise to complex calculations, are that the full moon is not what you actually see but the 14th day of lunar month. The other is that, in this dating system, the vernal equinox is assumed to fall on March 21. In nature it might occur on March 19 or 20 as well. True to form, our age has produced a wondrous mathematical computation for this date. Here are the equations for the month and the day:

month = floor (h + L − 7m + 114) / 31
day = ((h + L − 7m + 114) mod 31) + 1

How the variables h and L and m are calculated—and more, much more—is shown here for those who are likely to enjoy the indescribable delights of mathematical juggling.

The odd thing is that the event actually celebrated at Easter, Christ’s crucifixion and resurrection, took place at the time of mass celebrations of the Passover—and were part of the social dynamics of that celebration. That celebration, it so happens, has no seasonal meaning. It marks the beginning of the Jews’ successful escape from Egypt which, based on the date of Passover, took place on the fifteenth day of Nisan, a month that falls into the March-April period.

“Deep, one might say infinitely deep, is the well of the past.” Thomas Mann in Joseph and His Brothers.

No comments:

Post a Comment