See the world in a completely new way as an esteemed mathematician shows how math powers the world—from technology to health care and beyond.
Almost all of us have sat in a math class, wondering when we'd ever need to know how to find the roots of a polynomial or graph imaginary numbers. And in one sense, we were right: if we needed to, we'd use a computer. But as Ian Stewart argues in What's the Use?, math isn't just about boring computations. Rather, it offers us new and profound insights into our world, allowing us to accomplish feats as significant as space exploration and organ donation. From the trigonometry that keeps a satellite in orbit to the prime numbers used by the world's most advanced security systems to the imaginary numbers that enable augmented reality, math isn't just relevant to our lives. It is the very fabric of our existence.
"It would be easy to conclude that mathematics has become outdated," but modern life would "fall apart" without it, argues mathematician Stewart (Does God Play Dice) in this straightforward survey. With 13 examples that cover movie animation, internet traffic, medicine, photography, and navigation apps, Stewart explains the ways math makes modern life possible. He ties the math of airline routing to the classic "traveling salesman problem" (a way to make a route the most efficient), and explains that GPS users employ Einstein's theory of relativity each time they plan a trip. Graph theory, meanwhile, is used to match organ donors with recipients, and computer-generated imagery is built on 175-year-old math. He also describes how various mathematical concepts were developed, which, taken together, provide a thumbnail history of mathematics. Stewart goes incredibly deep into the difficult math that informs his examples, a choice that will undoubtedly stretch even the most mathematically inclined readers (pseudorandom number generators, he writes, are "generally based on abstract algebra, such as polynomials over finite fields, or number theory, such as integers to some modulus"). But those who stay the course will find that Stewart succeeds in conveying his wonder at the power math has to shape the world.