Many of us in the Northern Hemisphere, Earth are enjoying autumn. For me, every year at this time the weather is comfortable, waves are up for surfing, beaches are empty, and for those of us more northern, the leaves of deciduous plants are changing colors, providing us vibrant purple, red, orange, yellow, and green nature scenes. I enjoy observing the natural world and learning from the individuals who have studied it for millennia. Do you know why leaves change colors? The Earth, it seems, has been revolving for more than 4 billion years around the Sun, as the Sun itself travels through...