On the nature of time: Cycles

Well, so far I haven't been doing a very good job of making regular posts in this blog (or in my other blog on LiveJournal, for that matter). I intend to get back to writing regularly on the topic soon.

As part of that resolution ;-), I offer the following observations.

My wife, Shadowfoot, was reading a post to me yesterday about a circular calendar that someone was using to help in planning. Rather than using the block calendar so typical in Western cultures currently, with one row for each week and one page for each month, the poster was thinking of using a circular calendar, so that all of the dates were clearly visible, and he could get a better idea of how long it was going to take for something to be completed (such as planting to harvest) by seeing how much of an arc the event would take; for example, you could quickly see that 90 days would take approximately a quarter of a year, or that 120 days would take approximately one third of a year.

The examples above may seem fairly obvious, but you could also see quickly if your planting schedule would cause your harvest time to be staggered or all fall on about the same date.

You can do this with the block calendar, of course, but it may involve some complicated arithmetic, depending on the nature of the planning, but the visualization of thinking of a circle for the year can help you get a grasp on what that arithmetic means.

It occurred to me that I often visualize a year that way, like a giant clock with the Winter Solstice or New Year at the 12:00 position (depending on context). Further reflection revealed to me that I do not think of calendar months that way, although I do think of the phases of the moon that way.

Our Grove gathered for a little holiday socializing yesterday, and since we are a "teaching grove", we typically get into some interesting subjects of discussion even when we aren't having an "official" meeting. One of the topics that came up (I may have been the person who brought it up) was the Mayan calendar.

Anyone who has seen the Mayan calendar knows that it is a circular calendar.

Since I've been doing research on calendars used by various cultures, both past and present (and some speculative calendars for the future), I was past time for looking at this calendar. Without going into the significance of the Mayan calendar's end of the Long Count (Winter Solstice 2012), there were two particular points in the calendar that I was not expecting.

First of all, the Mayan calendar is not a lunar calendar. It does not follow the cycles of the lunar phases, although it might mark those phases.

Second, the Mayan calendar is not a true solar calendar, either, although one (!) of the definitions of "year" that is used is 365 days long (the other is 260 days long). There is no adjustment of that year over time, so the equivalent "new year" under that system falls behind the actual astronomical event by about a day every four years.

I was not expecting either of those points.

The Mayans were accomplished astronomers. They knew quite well that the fixed, 365 day year wasn't exact, that particular solar events would fall on different dates over the years. However, rather than make periodic adjustments to the length of the year (e.g. using leap days as in the Gregorian calendar), they accounted for it by knowing how many iterations of the calendar it would take before a particular solar event (such as the Winter Solstice) occurred on the same date in that calendar.

Timekeeping in general has to keep in mind two major components: cycles and forward progression. The cycles help us to know when something is likely to repeat, and the progression helps us know when discrete events have happened or when they will happen.

The hours of the day are cyclic in nature: there's a beginning, middle, and end, and then it starts over again for the next day. Daylight follows night time, and night time follows daylight, over and over. We record the progression of days by counting how many times this cycle occurs, usually picking some point as the beginning/ending of the day (typically midnight in modern Western cultures, sundown in several historical Western cultures as well as several Middle Eastern cultures).

The same can be said for lunations: new moon, first quarter, full moon, last quarter, and new moon again, to use the way that the phases of the moon are recorded on modern Western calendars. Again, we count the progression of lunations to record their progression, picking some point in the cycle (typically new moon or first quarter) as the zero point.

The solar year also follows that pattern: Vernal Equinox, Summer Solstice, Autumnal Equinox, Winter Solstice, and then back to Vernal Equinox again. We pick a [somewhat arbitrary] point in the cycle of the year as "New Year", and count how many times that event has passed (we also use our own birth date for marking the repeats of the solar year, or a date of marriage).

We use these cycles and their progressions, numbering or naming them, to record when things happened or predict/schedule when they will happen. We can predict when a crop is likely to be ready to be harvested by the date that we plant, and we can schedule that planting according to when they will likely need to be harvested.

We know when we need to get certain farm equipment out of storage and checked over, because we have an idea of when we are going to need it to be ready to work.

We know how old the chickens need to be before they will start producing eggs that we can use or sell, and how old they will be when they are likely to stop producing, so we can schedule when we need to get replacement chickens.

We know when we're supposed to be at work, so we have a decent idea of when we should get up in the morning in order to be able to get ready and travel to the work site (if you're a farmer, the farm is the general work site, but you may need to travel to different parts of the farm -- I need to go up onto one of the hillsides today or tomorrow to clear some fallen tree branches before the next snows). We also have a good idea of what time we should be getting to sleep the previous evening, so that we can be sufficiently rested when we wake in the morning.

And the next day, we get up and do it all over again.

Each day is unique for what happens during that day, but the cyclic nature of the day gives us an idea of what to expect for certain things.

Happy New Year! May the progressive nature of the year cycles make it better for you than last year.