Elizabeth and Teddy Dean are learning about the Italian scientist Galileo, so they troop into the kitchen, where their mother Lisa starts by reviewing some facts about the Renaissance. Elizabeth, 11, and Teddy, 8, have never gone to school. Their teachers are primarily their parents, which puts them into what is believed to be the fastest-growing sector of the U.S. education system -- the homeschool movement. For their science lesson, Teddy and Elizabeth are joined by three other homeschooled children and their mother, who live down the street in their suburb midway between Baltimore and Washington, D.C. Before the lesson...