Steve Coman of RES Pyro on how fireworks work. Stephen Burg of New America explains the need for more scholarships for poor students. Lisa Cook, Michigan State Univ, on how black people have been denied patents. Sam Payne of the Apple Seed shares a story. William Luther, Florida Atlantic Univ, explains the coin shortage. Phillip Goodrich, author of "Somersett," on what sparked the American Revolution.