In this lesson, students consider the various ways we illuminate our world. They conduct a scientific experiment to determine how much thermal energy various types of lightbulbs emit and consider the pros and cons of each light source. When they see that some types of bulbs are far more energy efficient than others, they consider the environmental implications of those more efficient options—hazardous waste. As students review the cost, energy use, lifespan, and disposal requirements of different kinds of bulbs, they learn that making thoughtful, considered choices about the products we use is an important aspect of sustainable intelligence.