It’s autumn. That means it’s time for you to once again reflect upon the many valuable things you learned during high school science class, in that smelly room with the stone-stopped tables and the Bunsen burner devices and the sinks with the odd curved faucets. In addition to dissecting frogs and enduring that first whiff of formaldehyde, a smell that you will dread for the rest of your life, you learned about photosynthesis, and why leaves change color during the autumn.
Photosynthesis is the process by which our arboreal friends take water and carbon dioxide and convert them into oxygen and glucose. The leaves have chlorophyll, a substance that is the crucial agent in the photosynthesis process and uses the power of sunshine to complete the chemical change that is essential to life on our planet. You learned that chlorophyll is a deep, rich green, and during the height of spring and summer, when the chlorophyll is hard at work, its presence masks the other colors found in the leaves.
But when autumn comes, and winter approaches, and the supply of water and sunshine will decline, the chlorophyll decides that it’s time to take a vacation. It leaves the leaves, and when it does the other hidden colors emerge — like the bright reds that you see in sugar maple leaves. And sometimes you can see this process in action. It’s the sort of thing your high school science teacher would enjoy.