Science News - February 12, 2011

North Pole, South Pole: The Epic The first known compasses were used
Quest to Solve the Great Mystery in China by practitioners of feng shui
of Earth’s Magnetism to auspiciously orient homes, villages,
Gillian Turner fields and tombs, Turner notes. Only
Many creatures — birds, bees and but- much later were the instruments used
terflies, for example — use the planet’s by European explorers to help them
magnetic field to navigate, but humans conquer the seas and expand empires.
are the only ones to do so with instru- As early as the 14th century, Euro-
ments rather than an innate sense. In pean navigators noticed that at many
her first book, Turner, a geophysicist, locations the compass didn’t point
looks at how people due north. Three centuries later oth-

The Great White Bear Kieran Mulvaney Starting with the fact that polar bears have black skin, this book offers surprises and up-to-date information

about the Arctic’s iconic top predator.

Houghton Mifflin Harcourt, 2011, 251 p., $26.

came to invent the ers detected signs that the direction
compass and what of Earth’s magnetic field had changed.
has been learned Then in the 20th century, researchers
since about the came to realize that the field had actu-
magnetic field that ally reversed itself many times over the
drives it. course of Earth’s history — which, in
Chapter by chap- turn, led to discoveries that bolstered
ter, the author walks then-controversial theories of seafloor

Geographies of Mars K. Maria D. Lane Explore Mars as scientists and the public saw it around the beginning of the 20th century, when canals

readers through the history of study- spreading and continental drift. ing Earth’s magnetic field, from the By deftly combining threads from ancient Greeks’ fascination with natural science and history, Turner weaves a magnets called lodestones to today’s fascinating geophysical tale that spans supercomputer simulations of field- several millennia. — Sid Perkins generating processes in the planet’s core. The Experiment, 2011, 272 p., $15.95.