Walking through Ginkgo Allée on the eastern side of Olin Library after the leaves have fallen is an experience in itself. The leaves form a yellow-green carpet, turned golden in the sunlight, and crinkle gently with every step. On both flanks, the almost-centenarian ginkgo trees have lost their leaves, but not their majesty, and they stand tall, bare and proud. The scene is both serene and beautiful, but, even though the leaves fell just last Thursday night, Nov. 7, they’ll be gone before the month is out.