How do technicians repair broken communications cables at the bottom of the ocean without actually seeing them? What's the likelihood of plucking a needle out of a haystack the size of the Earth? And is it possible to use computers to create a universal library of everything ever written or every photo ever taken? These are just some of the intriguing questions that best-selling popular math writer Paul Nahin tackles in Number-Crunching. Through brilliant math ideas and entertaining stories, Nahin demonstrates how odd and unusual math problems can be solved by bringing together...

From H.G. Wells to Isaac Asimov to Ursula K. Le Guin, time travel has long been a favorite topic and plot device in tales of science fiction and fantasy. But as any true SF fan knows, astounding stories about traversing alternate universes and swimming the tides of time demand plausible science. That's just what Paul J. Nahin's guide provides.

An engineer, physicist, and published science fiction writer, Nahin is uniquely qualified to explain the ins and outs of how to spin such complex theories as worm holes, singularity, and relativity into scientifically sound fiction. First...