Monday, September 27, 2010

Seasonal Essay for October

In the clear skies of October we are encouraged to look upward and marvel at the vastness of the universe. The book, "October Skies", and its derivative movie tell of a teenager with a driving fascination with rocket propulsion. It is by such means that in the far distant future, humankind may break free from a decaying solar system and seek another home. Even now, with robotic travel to Mars and other planets, we are taking the first tentative steps toward that ultimate necessity.

It was in the 1950's that I heard the astronomer Harlow Shapley tell of Edwin Hubble's finding in 1924 that many of those stars we see in such profusion are not suns like ours, but great numbers of clustered suns like our Milky Way galaxy, though far distant from it. Many astronomers think it reasonable to suppose, there being such an enormous number of galaxies, each containing within it such an enormous number of suns, that among these suns must be some with planets which are similar enough to ours to support life as we know it. Already astronomers have detected 490 such extrasolar planets within our own galaxy. It comforts me to think, as George Wald the Harvard physiologist expressed it, that it is possible if not probable that, if our life on earth should somehow destroy itself or not escape our planet home before it self-destructs, there will be life forming somewhere else in some far distant star or galaxy and we wish it well.

Friday, September 3, 2010

Seasonal Essay for September

In September tufts of white fly across fields and roads, liberated from the swollen pods where they developed. Milkweed seeds, like the clouds of aspen seeds we see in June, are being carried to new fields in the eternal struggle for survival and expansion of range. The milkweed flower which forms the seeds is a complex structure, so formed that insects seeking food there find their legs trapped in crevices. In extricating them, they tear free small packets of pollen which they then carry to other milkweed plants where fertilization occurs. Occasionally one sees a dead insect hanging in the flower, trapped too tightly to escape.

Also in September, Monarch butterflies begin their long flight southward. Their lives and that of milkweed plants are closely intertwined. As is true of many plants, milkweeeds contain a substance which is poisonous to some kinds of insects, but Monarch caterpillars are able to detoxify it and to feed on milkweed leaves. And it is within a silvery case attached to these milkweed plants that the caterpillar transforms into the adult we know so well. One fall, finding one of these cases, I picked the leaf it was fastened to and took it on a visit to a grandson, telling him to watch carefully for the emergence. Sure enough, a day or so later he called out, "Come quickly, it's happening!" And there it was, the slow emergence, the expansion of wings and their drying out. Then we bid it goodbye as it left to begin its long journey.