This is a nicely written book aimed at anyone who has had at least one semester of calculus.  The range of topics addressed is quite impressive.  We see an introduction to mathematical modeling (including a nice differential equation describing the melting of a snowball), Fermi problems, the experimental value of dimensional analysis and the Buckingham $\\pi$ Theorem, phyllotaxis and the Fibonacci sequence, waves, optics, Lyapunov stability, Bessel functions, random walks, and diffusion—all given through applications appearing in nature!

Every mathematics major should be required to read this book.

The author is Professor of Mathematics at Old Dominion University in Virginia.