The best known example of "numerology" in science involves the coincidental resemblance of certain large numbers that intrigued such eminent men as mathematical physicist Paul Dirac, mathematician Hermann Weyl and astronomer Arthur Stanley Eddington. These numerical coincidences refer to such quantities as the ratio of the age of the universe to the atomic unit of time, the number of electrons in the universe, and the difference in strengths between gravity and the electric force for the electron and proton. ("Is the Universe Fine Tuned for Us?", Stenger, V.J., page 3).