But wait! What's that? That burst of emerald green. Le rayon vert! Not altogether unexpected, but rare enough to make one gasp.
Someone said to me once that the greatest prayer is "Wow!" The sky a symphony of color suddenly punctuated by a trumpet blast of green. More beauty than would seem to be necessary for the mere business of turning night into day.
But, of course, nothing in nature is "mere."
Which raises the very "un-mere" question: Why is the green flash beautiful? Or alternately, why do we think the green flash is beautiful?
The 19th-century naturalist Alfred Russel Wallace, co-originator with Darwin of the theory of evolution by natural selection, encountered a birdwing butterfly on an island in the Malay archipelago. His description is worth quoting at length:
The beauty and brilliancy of the insect are indescribable, and none but a naturalist can understand the intense excitement I experienced when I at length captured it. On taking it out of my net and opening the glorious wings, my heart began to beat violently, the blood rushed to my head, and I felt much more like fainting than I have done when in appreciation of immediate death. I had a headache the rest of the day, so great was the excitement produced by what will appear to most people a very inadequate cause.I suspect that most people encountering a birdwing butterfly in the forest for the first time would have a similar response. There is something universal about our perception of beauty, something that seems to be a part of human nature.
"Beauty is Truth, Truth Beauty," says Keats (or more accurately, says his Grecian urn). The poet W. H. Auden disagrees: Truth and beauty are not identical, he says. Beauty is that "which gives us delight precisely because of its contrast to our historical existence with all its insoluble problems and inescapable suffering." In other words, beauty is that which distracts us from truth.
The critic John Ruskin, in "Modern Painters," describes a time when he gazed in wonder upon a storm in the Alps -- thunder and lightning crashing among towering spires of rock, valley, river, forest. He writes: "And then I learned -- what till then I had not known -- the real meaning of the word Beautiful." Beauty, he tells us, is that which turns the human soul from gazing upon itself.
All of which sounds terribly profound, but none of which tells us much about the source of "Wow!"
Oh, I can explain the optics of the green flash. But whence the "Wow!" Our ability to recognize and respond to beauty almost certainly has an evolutionary origin. Our brains were shaped by interaction with a world that contains a neatly balanced mix of order and chaos. Negotiating our way successfully through such a world undoubtedly placed selective value on certain kinds of perceptual responses. Our aesthetic sense may be subtly adaptive, or perhaps a byproduct of some useful adaptation.
Beauty may be in the eye of the beholder, but only because our brains are adapted to a beautiful world. "Beauty is nature's fact," wrote Emily Dickinson, and there might not be much more to say than that.