From the book reviews: "Most of the book requires no more than standard mathematical education and thus this book should be a must-read (opinion of reviewer) for any well-educated person, but can be also of much help for mathematicians working in education or popularization for finding new ideas or even themselves learning some not so well-known recent developments, and also it should be interesting for anybody curious what mathematics is about." (Franka Miriam Brueckler, zbMATH, Vol. 1300, 2015) "Krantz (Washington Univ. in St.Louis) and Parks (Oregon State Univ.) have an admirable goal: to demonstrate to uninitiated readers that mathematics is exciting and ongoing. ... Complemented by an extensive index and references, the book clearly tries to make the mathematics accessible to readers willing to make the effort. ... Summing Up: Recommended. Lower-division undergraduates through researchers/faculty." (J. Johnson, Choice, Vol. 52 (4), December, 2014) "It is clearly and invitingly written, and addresses not only some of the current issues in mathematics but also some history and some indication of the human side of the subject...it is clear to me that this book belongs in any good university library. It is also a book that should be at least looked at by any faculty member who teaches upper-level courses and has frequent contact with math majors...I certainly intend to recommend it to some of my students in the near future." -Mark Hunacek, MAA Reviews