"The scientist is not much given to talking of the riddle of the universe. "Riddle" is not a scientific term. The conception of a riddle is "something which can he solved." And hence the scientist does not use that popular phrase. We don't know the why of anything. On that matter we are no further advanced than was the cavedweller. The scientist is contented if he can contribute something toward the knowledge of what is and how it is."