# Math & Physics

My second book, Linearity, Symmetry, and Prediction in the Hydrogen Atom, is a textbook for an undergraduate course for math, physics and physical chemistry majors, explaining how the mathematical study of representation theory (known to physicists and chemists as group theory) can be used to predict some of the structure of the hydrogen atom without using the Schroedinger equation. For more information and reviews, please click on the yellow book image on the left. If you find errors, please let me know so I can add them to the errata.

My first book, Symmetry in Mechanics: A Gentle, Modern Introduction" was published in March 2001 by Birkhauser Boston. The book received some enthusiastic reviews! One is in the January 2002 issue of Physics Today, on page 57. One is in the May 2002 issue of Current Science (Vol. 82, No. 9, p. 1170. ) Yet another is in the April, 2003 issue of the American Mathematical Monthly. Still another is at Amazon.com. For more information, or to purchase the book, please click on the cover image on the left. If you find errors, please let me know so I can add them to the errata.

George Mackey, representation theorist and father of one of my best friends, passed away in 2006. When I was a sophomore in college, wavering between mathematics and physics, he was kind enough to write me two long letters (one and two). He also sent me the text of a speech he had given, entitled *What Do Mathematicians Do?*.