 Most of the book uses geometrized units, meaning the fundamental natural constants formula_3 (Newton's gravitational constant) and formula_4 (the speed of light in vacuum) are set equal to one, except when predictions that can be tested are made.According to Daniel Finley, a professor at the University of New Mexico, this textbook offers good physics intuition.However, the author did not use the most modern mathematical methods available, and his treatment of cosmology is now outdated.