Probably most of us know the title phrase from The Byrds’ cover of the Pete Seeger song usually referred to as “Turn, Turn, Turn.”
Well at least the older of us know it thus; older still, know this from Ecclesiastes. Those who are Bible literate of any age will recognize the phrase. “…A time to kill, and a time to heal…”
The whole passage from Ecclesiastes is remarkable. My purpose here is to remark on that detail of …a time to heal.
As those of you who have read many of my posts know, I urge attention to rhythms, cycles: biology, human biology, cannot be understood without attention to rhythms, cycles…without paying attention to seasons. From the temperate climates north, the seasons are sensed by the change in the length of the daylight and of the temperature. What you may not have noticed is the change in the color of the light. It too has a seasonal cycle. Winter light is a colder blue, a thinner blue. Even when it is brightest it is a thin blue. There are technical ways to describe this change in the color temperature but for now I only want to refresh your memory of winter skies and their color.
Whatever the geological history of continental shift and genetic drift over the thousands of years of human history, and whether we have the pigment of a tropical ancestry or the absence of pigment of men from the North, our biology is deeply driven by light, its color and temperature and how we adapt to it.
Environmental temperature is the easiest to talk about so I will give that brief attention before I turn to the role of light in our biology and health.
Remember that as our mitochondria generate energy there are many intersecting and interacting metabolic variables, including genetic predisposition, that determine the allocation of that energy to thermoregulation, for example keeping us warm, and to other muscular and metabolic needs like running or hunting or sleeping. The body allocates, directs, energy to these two functions, to others as well, but for now to these two roles. How well it accomplishes this allocation varies: women are always cold and men are always hot. At least something nearing this is true if I am to believe what dozens of couples, and my wife, tell me. If the thyroid hormone levels are low we feel cold; another element in thermoregulation and energy allocation. I don’t want to spend too much time on this but keep in mind that there are deep biological systems at work, and evolved or derived to do the amazing thing of making our entire body adaptable to varying temperatures. Pointing out that Polar Bears have fur and that many equatorial peoples are tall and thin as a way to shed heat doesn’t change my point. Deep biological systems are available and serve deep needs of health and healing in all of us.
As I mentioned what I really want to talk about is light.
There is fascinating chemistry associated with the human body’s ability to detect color, too much of a diversion for me just now, but be clear that the body has developed very sophisticated systems, and not merely the eye, to detect chromophores, the parts of molecules that make them emit visible colored light energy, and that those detection systems are not there just to enhance our appreciation of sunsets, though they do that very nicely.
If I were a better poet or perhaps novelist, I could paint a verbal picture, blurred as the picture, the story is told of movement over thousands of years of mankind through the mountains, valleys, the long treks near starvation, the wonderful summer evenings when well fed in good company, smiling without guile, fear or plans; only happy to be alive because that is not often assured and so loved for the moment when it just is. That picture, even for those blind who were not born so, is sketched in colors, in outlines of contrast and blending colors.
As we have been hewn out of the possible by time, and remain one with the earth rather than cast off as the chips of that time-driven hewing and thus lost as a species to the evolutionary past; as that has happened nothing was lost, there was no excess of the possible that did not contribute to our survival. The night when we slept was when we were healed and prepared for the next day’s life and death struggle or another day of rest. The change in the light, the herald of fall coming, was our signal to seek out those biologically necessary foods, rich in chromophores, colorful foods, that would help us survive the winter. The historically original blueberries were hardy fruits of fall, of cold places. They are brightly colored, rich in chromophores, and very nutritious. Our deep biology knew that; we used to seek out the raucous palette of colored foods. We eat white food now and become sick.
Well even this diversion is not what I wanted to talk about, though it illustrates my main point about the importance of light and of the color of light. Food and our need for colorful foods and the amazing meshing of evolutionary and biological necessity is part of my point; but only part.
What I am trying to make clear, to emphasize, is the role of sleep and its need to correspond to the light and day of sun and moon, of short summer nights and longer winter ones. What I am trying to make clear is that we live out of season with the lights of Spring and Autumn at our peril, we are tempting the terrible evolutionary fate of extinction, when we ignore the deep biological rhythms driven by change in the color of the sky.
The nearly funny, no hilarious, truth is we are like a foraging, raging bear preparing to hibernate. But we don’t know when to start or where to begin or what to eat or when to fast, when to run and when to walk, and being so tempts that fate not only for our species but for each of us in this mortal life.
For those of you looking for a simple list of do’s and don’ts this will have been one of my more frustrating blogs. For those of you who are trying to discover how to live in this world, to be healthy in this world and to be happy in this world this blog alludes to the deeply technical and points to where to find practical direction. Pay attention. The color of the light matters.
Smile, Have Fun, God Speed,
P.S. Are you sure you need those sunglasses?