THIS FALL I have been struck more than usual by autumn light. In spring the light is green and fresh and naively optimistic, like the first leaves. In summer it can shimmer with heat, scent, swarms of insects. Winter has a cold light, pure but short on substance, pale as the December sun. But fall light has the burnish of turning leaves and the melancholy of shortening days (or finite lives). The air smells like apples; the sky squanders all its resources of blue on a string of perfect, cloudless days. The end is near, but not yet. This year, that gorgeous flare as we sink into winter has lasted longer than usual. This year, as I chopped up the nut browns, the cranberry reds and sage or celery greens for Thanksgiving, I was grateful for the weather.