The Earth is an energy conversion and recycling machine. Plants rearrange soil, water, and sunlight into leaves, fruit, and wood. Animals tear each other apart to rearrange flesh into new flesh. The planet constantly transforms matter from one form to another, molecule by molecule, and converts energy from one state to the next. What it cannot rearrange by itself, it accomplishes through living creatures: bees make honey, silkworms spin silk, oysters form pearls, and humans produce plastic.