CHRISTOPHER P. JARGODZKI, Ph.D., is Associate Professor of Physics at Central Missouri State University and the author of two previous books of science braintwisters. He was born in Warsaw, Poland, and received his B.S. and Ph.D. degrees in theoretical physics from the University of California. FRANKLIN POTTER, Ph.D., is an Associate Professor of Physics at the University of California at Irvine and conducts research in elementary particle physics and cosmology. He received his B.S. degree from Cal Tech and Ph.D. in physics from Texas Tech University.