Sunday, March 20, 2011

LET THERE BE LIGHT

            I’m a light person. The more light, the better, as far as I’m concerned. Tim’s and my little house is painted oyster white throughout, with bright white woodwork. Makes it airy and spacious-feeling. My mom liked to paint her walls different colors, changing one room or another every other year or so. As adults, most of my sisters followed suit, doing their parts to keep Sherwin-Williams and Benjamin Moore in business. I took the road less traveled. I like white. I like light.

            Much good news for light-lovers this weekend. The moon went full on Saturday at 2:10 p.m. and the vernal equinox occurred at 7:18 p.m. this evening.

Every month’s full moon carries a descriptive name derived from various folklores. March’s is known as the Worm, Sap or Crow Moon. (I understand “Sap,” but Sky-Guy didn’t explain where “Worm” and “Crow” come from.) The March moon traditionally decides the date of the primo Christian holiday, Easter, based on a third-century formula called the Computus. Like many carved-in-stone rules, it has been modified over the years. Most recently—in 1583—Pope Gregory XIII decreed that henceforth Easter would fall on the first Sunday after the first full moon after the vernal equinox. That’s not at all arbitrary, is it? Unlike Christmas, whose date was fixed to coincide with pagan solstice celebrations even though biblical scholars have long held that Jesus was most likely born in early spring.

            Be all that as it may, this year the March moon falls the day before the equinox, moving the so-called Pascal Moon forward 28 days. Accordingly, Easter occurs about as late in the year as possible, on April 24.

The weekend’s full moon also coincided with a perigee of the lunar cycle, which means the full moon rose within an hour of it being the closest to Earth it’s going to get this year, or a mere 356,577 kilometers. (The most distant apogee happens only 16 days later, on April 2, when the moon will recede to 406,655 klicks away from Earth. That’s a difference of 50,078 kilometers, or about 31,048 miles. Isn’t this astronomy stuff fascinating?) Apparently, the full-moon-at-perigee phenomenon isn’t all that common: the last time it happened was March 8, 1993. Sky-Guy says the perceived diameter of the moon varies by 15% or so, smaller at apogee, larger at perigee. Tim and I decided to check it out.


Saturday night's
"Super" moon

After dinner, we drove to a local beach for the show. Although the thermometer hit 80° during the afternoon, by 7 p.m. the northeasterly breeze freshened: down on the strand, it was cold. (In retrospect, I probably should have worn shoes. Or at least socks.) Nonetheless, we stuck it out. A small crowd congregated on the highest point of the boardwalk to the beach, cameras at the ready to capture what Sky-Guy calls “Moon illusion.” At 7:45, a red disc edged over the roofs of the houses.

Well, she was pretty, all right, but I wouldn’t call her a “super” moon. As she cleared the last roof-ridge, T and I opted to go home and make a pot of coffee. I planned to pour mine on my feet.


Here is a diagram of the
celestial coordinate system.
Note the ecliptic circle,
which is at a 23-&-a-half-degree
angle to the galactic equator.
Or something like that.

The astronomical beginning of spring, the vernal equinox, means more to me. Equinox occurs at the moment the sun reaches an ecliptic longitude of zero degrees, which has more to do with the celestial sphere than that old saw about the sun crossing the geographical equator so everywhere on the planet experiences 12 hours of daylight. That’s piffle, of course. Oak Island’s 12-hour day occurred on March 17th. Today we enjoyed 12 hours and eight minutes between sun rise and set. I don’t really understand the concept of the ecliptic and other celestial coordinates, so I snipped a diagram of the system. You can puzzle it out for yourselves.

I’m just glad it’s officially spring.

*****
Light affects all life on earth in various ways. We’re all subject to circadian rhythms, for instance. Webster defines circadian—from the Latin “circa” (around) and “diem” (day)—as “designating or of behavioral or physiological rhythms associated with the 24-hour cycles of the earth’s rotation, as, in man, the regular metabolic, glandular and sleep rhythms which may persist through dislocations of day and night…” I understand the concept viscerally, as I have just acclimated to the advent of Daylight Savings Time. Every year, I experience springing forward and falling back as jet-lag.

 But there are other light effects, most clearly demonstrated by plants.

First there is phototropism, or the hormone-induced bending of plant structures toward a source of light, either natural or artificial. Sunflowers are the best-known example of flowers that orient themselves in relation to the sun, a related phenomenon called heliotropism.


The tomato seedlings on my piano
lean toward the light source.
This is called phototropism.

The biological mechanisms behind photo- and heliotropism are amazing. Motion is accomplished by specialized potassium-pumping cells in a flexible segment, called the pulvinus, just below a flowerhead or in a plant’s stem. In the presence of blue light rays, potassium ions change the turgor pressure in nearby tissues. On the shady side of the stem or flower, increased rigidity causes elongation of the pulvinus cells, causing the plant to “follow” the light.  

Little miracles happen around us all the time, don’t they?

*****
One can have too much of a good thing, however.

I belong to the generation of sun worshippers who saw nothing odd in slathering ourselves with iodine mixed in baby oil before taking off as much clothing as our mothers would allow and settling ourselves in the backyard or on the beach to broil. Why I don’t resemble a raisin today, 40 years on, is another of those quotidian miracles.

Tim’s dermatologist, a transplant from Rochester, New York, once remarked that he saw more cases of skin cancer in his first two years working in Brunswick County, North Carolina, than in the 25-plus years he practiced up north. This is an important observation, and one worth giving some thought to. “Full sun” on the southeastern coast is an entirely different animal from “full sun” in Connecticut or Ohio, and the difference affects both plants and people. Pot geraniums (Pelargonium spp. cvv.), for instance, welcome summertime southern and western exposures up north; but down here, don’t even think about it past, say, mid-June. Your skin has a lot in common with geraniums that way, so take proper precautions when you go out at all times of the year, even if you’ve got “good” skin.

Sunflowers provide the best-known
example of heliotropism
            Interestingly enough, Tim and I represent opposite ends of the skin continuum. He characterizes himself as “Irish iridescent blue.” He’s had several skin cancers removed—basal cell, squamous cell and one very scary pre-Stage I melanoma—since we moved to North Carolina in 1997. He now anoints all exposed skin daily with sunscreen containing titanium dioxide to thwart both UVA and UVB rays, never ventures out shirtless or barefoot, rarely wears shorts, and always keeps his head covered.

            I, on the other hand, have marvelous skin. Naturally a kind of honey color, I tan readily and hardly ever burn. (I’m not bragging. The Good-Skin Fairy smiled upon me at birth, so it’s not a circumstance I had any control over. And, because there is balance in the cosmos, the Good-Fingernail Fairy loathed me at first sight.) Nonetheless, my Southern-Belle upbringing—most of which didn't take—makes me sensitive to the responsibility of maintaining my good fortune. My face has not left the house without sunscreen (or mascara) since the 1970s, not counting the two ill-thought-out two-a.m. trips to the hospital forced on me by childbirth. Since the ’90s, I’ve extended coverage to all exposed skin. Here are links to the skin-saving products depicted nearby: Rocky Mountain Sunscreen; Oil of Olay Complete Facial Moisturizer and Lubriderm Daily Moisture Lotion (both SPF 15); and Burt’s Bee’s Lip Protection. I also rarely wear shorts when we’re working, but that’s mostly because I like to give the deer ticks and chiggers as small a target as possible.


Protect your skin, every day

            I also wear a hat, at my doctor’s behest and not because I look good in one. He advises me that everyone, particularly light-eyed folks, need to protect their eyes from glare. He also recommends sunglasses to go with the hat, but I don’t do sunglasses. It’s up to the visor of my Fitzgeralds Gardening ball-cap to defend my baby-blues against incipient retinal harm. If you are not sunglasses-phobic like me (I have my reasons), so much the better.

            One other quick note on sun protection—and I’m deadly serious about this topic despite my jocular tone: Rit, the washing-machine fabric-dye people, makes a laundry additive called Sun Guard that increases the SPF of most of your clothing from about 6, in the case of cotton, to 30. (It won’t work on polyester, but no one wears polyester anymore. Do they?) I treat all Tim’s work shirts with it. It allegedly holds up to 20 washings, and Tim has enough shirts so, if kept in proper rotation, once in late March and once in July helps shield his back and stomach through high spring and summer. Did you know you can burn through your clothes?

*****
It’s spring now, the days are getting longer. We spend more time outside, the sun’s rays are stronger. It’s okay to love the light, but don’t be stupid about it, please.

Thanks for dropping by. See you next time.

                                                                     Kathy