Joseph M. Kats got his Ph.D. in Math and Physics from Soviet Academy of Sciences in 1976. He immigrated to United States in 1980 and since then worked as a computer programmer, a physicist, and a math teacher. He retired in 2006 and began to write this book, which was finished in 2010. Dr. Kats likes classical music, he is an amateur composer. When he is not busy with math and music, he likes cooking. He lives in the village of Mount Kisco in Westchester County, NY with his wife.