I am going overseas for the summer, I need a book or two so I can learn about mathematics (overviews, engineering applications, history, connection with other branches of science) without actually working on much of the problem during when I am transiting between cities via air or waiting for my next train or killing time in a hotel room.
In the past this has worked out pretty well for me. I read about Riemann Zeta Function with a book by John Derbyshire, I read about knot theory using Farmer and Stanford, I read about connection between mathematics and physics with Roger Penrose's Road to Reality not to mention a dozen of books on interesting historical and contemporary characters such as Ramanujan, Perelman, and John Nash which gave me motivation to study nested series, differential geometry and game theory respectively.
Since I am an engineer, I am particularly interested on gaining a subjective understanding of concepts in pure math. I wonder if there are some books out there that provides an overview to advanced concept in pure math and their potential applications without having to dig too much into the notation and underlying mechanic, just so I know that it exists and will look back more deeply when I am interested later on. But for now I am open to suggestions!