The story of one of the greatest unsolved problems in mathematics What is the shortest possible route for a traveling salesman seeking to visit each city on a list exactly once and return to his city of origin? It sounds simple enough, yet the traveling salesman problem is one of the most intensely studied puzzles in applied mathematics—and it has defied solution to this day. In this book, William Cook takes readers on a mathematical excursion, picking up the salesman's trail in the 1800s when Irish mathematician W. R. Hamilton first defined the problem, and venturing to the furthest limits of today’s state-of-the-art attempts to solve it. He also explores its many important applications, from genome sequencing and designing computer processors to arranging music and hunting for planets. In Pursuit of the Traveling Salesman travels to the very threshold of our understanding about the nature of complexity, and challenges you yourself to discover the solution to this captivating mathematical problem.
The computer science problem whose solution could transform life as we know it The P-NP problem is the most important open problem in computer science, if not all of mathematics. Simply stated, it asks whether every problem whose solution can be quickly checked by computer can also be quickly solved by computer. The Golden Ticket provides a nontechnical introduction to P-NP, its rich history, and its algorithmic implications for everything we do with computers and beyond. Lance Fortnow traces the history and development of P-NP, giving examples from a variety of disciplines, including economics, physics, and biology. He explores problems that capture the full difficulty of the P-NP dilemma, from discovering the shortest route through all the rides at Disney World to finding large groups of friends on Facebook. The Golden Ticket explores what we truly can and cannot achieve computationally, describing the benefits and unexpected challenges of this compelling problem.
This book presents the latest findings on one of the most intensely investigated subjects in computational mathematics--the traveling salesman problem. It sounds simple enough: given a set of cities and the cost of travel between each pair of them, the problem challenges you to find the cheapest route by which to visit all the cities and return home to where you began. Though seemingly modest, this exercise has inspired studies by mathematicians, chemists, and physicists. Teachers use it in the classroom. It has practical applications in genetics, telecommunications, and neuroscience. The authors of this book are the same pioneers who for nearly two decades have led the investigation into the traveling salesman problem. They have derived solutions to almost eighty-six thousand cities, yet a general solution to the problem has yet to be discovered. Here they describe the method and computer code they used to solve a broad range of large-scale problems, and along the way they demonstrate the interplay of applied mathematics with increasingly powerful computing platforms. They also give the fascinating history of the problem--how it developed, and why it continues to intrigue us.
In her newest well-tuned, witty, and altogether wonderful novel, bestselling author Elinor Lipman dares to ask: Can an upper-middle-class doctor find love with a shady, fast-talking salesman? Meet Alice Thrift, surgical intern in a Boston hospital, high of I.Q. but low in social graces. She doesn’t mean to be acerbic, clinical, or blunt, but where was she the day they taught Bedside Manner 101? Into Alice’s workaholic and wallflower life comes Ray Russo, a slick traveling fudge salesman in search of a nose job and well-heeled companionship, but not necessarily in that order. Is he a conman or a sincere suitor? Good guy or bad? Alice’s parents, roommate, and best friend Sylvie are appalled at her choice of mate. Despite her doubts, Alice finds herself walking down the aisle, not so much won over as worn down. Will their marriage last the honeymoon? Only if Alice’s best instincts can triumph over Ray’s unsavory ways.
A Publishers Weekly best book of 1995! Dr. Michael Guillen, known to millions as the science editor of ABC's Good Morning America, tells the fascinating stories behind five mathematical equations. As a regular contributor to daytime's most popular morning news show and an instructor at Harvard University, Dr. Michael Guillen has earned the respect of millions as a clear and entertaining guide to the exhilarating world of science and mathematics. Now Dr. Guillen unravels the equations that have led to the inventions and events that characterize the modern world, one of which -- Albert Einstein's famous energy equation, E=mc2 -- enabled the creation of the nuclear bomb. Also revealed are the mathematical foundations for the moon landing, airplane travel, the electric generator -- and even life itself. Praised by Publishers Weekly as "a wholly accessible, beautifully written exploration of the potent mathematical imagination," and named a Best Nonfiction Book of 1995, the stories behind The Five Equations That Changed the World, as told by Dr. Guillen, are not only chronicles of science, but also gripping dramas of jealousy, fame, war, and discovery.
This book offers a collection of 256 guidelines on the art of coding to help you write better Perl code--in fact, the best Perl code you possibly can. The guidelines cover code layout, naming conventions, choice of data and control structures, program decomposition, interface design and implementation, modularity, object orientation, error handling, testing, and debugging. - Publisher
What mathematical modeling uncovers about life in the city X and the City, a book of diverse and accessible math-based topics, uses basic modeling to explore a wide range of entertaining questions about urban life. How do you estimate the number of dental or doctor's offices, gas stations, restaurants, or movie theaters in a city of a given size? How can mathematics be used to maximize traffic flow through tunnels? Can you predict whether a traffic light will stay green long enough for you to cross the intersection? And what is the likelihood that your city will be hit by an asteroid? Every math problem and equation in this book tells a story and examples are explained throughout in an informal and witty style. The level of mathematics ranges from precalculus through calculus to some differential equations, and any reader with knowledge of elementary calculus will be able to follow the materials with ease. There are also some more challenging problems sprinkled in for the more advanced reader. Filled with interesting and unusual observations about how cities work, X and the City shows how mathematics undergirds and plays an important part in the metropolitan landscape.
The books that we read, whether travel-focused or not, may influence the way in which we understand the process or experience of travel. This multidisciplinary work provides a critical analysis of the inspirational and transformational role that books play in travel imaginings. Does reading a book encourage us to think of travel as exotic, adventurous, transformative, dangerous or educative? Do different genres of books influence a reader's view of travel in multifarious ways? These questions are explored through a literary analysis of an eclectic selection of books spanning the period from the eighteenth century to the present day. Genres covered include historical fiction, children's books, westerns, science-fiction and crime fiction.
A remarkable guide to the quests that give our lives meaning—and how to find your own—from the New York Times bestselling author of The $100 Startup and 100 Side Hustles “If you like complacency and mediocrity, do not read this book. It’s dangerously inspiring.”—A. J. Jacobs, author of The Know-It-All When he set out to visit all of the planet’s countries by age thirty-five, compulsive goal-seeker Chris Guillebeau never imagined that his journey’s biggest revelation would be how many people like himself exist—each pursuing a challenging quest. These quests are as diverse as humanity itself, involving exploration, the pursuit of athletic or artistic excellence, or battling against injustice and poverty. Everywhere that Chris visited he found ordinary people working toward extraordinary goals, making daily down payments on their dreams. These “questers” included a suburban mom pursuing a wildly ambitious culinary project, a DJ producing the world’s largest symphony, a young widower completing the tasks his wife would never accomplish—and scores of others writing themselves into the record books. The more Chris spoke with these strivers, the more he began to appreciate the direct link between questing and long-term happiness, and he was compelled to complete a comprehensive study of the phenomenon. In The Happiness of Pursuit, he draws on interviews with hundreds of questers, revealing their secret motivations, their selection criteria, the role played by friends and family, their tricks for solving logistics, and the importance of documentation. Equally fascinating is Chris’s examination of questing’s other side. What happens after the summit is climbed, the painting hung, the endurance record broken, the at-risk community saved? A book that challenges each of us to take control—to make our lives be about something while at the same time remaining clear-eyed about the commitment—The Happiness of Pursuit will inspire readers of every age and aspiration. It’s a playbook for making your life count. “The Happiness of Pursuit is smart, honest, and dangerous. Why dangerous? Because it is as practical as it is inspiring. You won’t just be daydreaming about your quest—you’ll be packing for it!”—Brené Brown, Ph.D., LMSW, author of Daring Greatly
