The true story of how a scientist saved the planet from environmental disaster. Mexican American Mario Molina is a modern-day hero who helped solve the ozone cr

America is the greatest democracy in the world . . . isn't it? Author Elizabeth Rusch examines some of the more problematic aspects of our government but, more

Water, air, sunlight, plants . . . we need these elements to live in this world. But does the world need us? And what would happen to the world if humans were g

A boy rides a bicycle down a dusty road. But in his mind, he envisions himself traveling at a speed beyond imagining, on a beam of light. This brilliant mind wi

Water is all around us. It moves through the water cycle. It brings water to all parts of the planet. Every living thing needs water to survive. Introduce stude