“Tides: The Science and Spirit of the Ocean” offers a grand mix of science history, ocean lore and literary travel writing. Author Jonathan White will make an appearance at the University Lutheran Church on Sept. 12.

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“Tides: The Science and Spirit of the Ocean”

by Jonathan White

Trinity University Press, 335 pp., $28

At Shark Reef Sanctuary in Washington state’s San Juan Islands, you can hear the rapids before you see them. But it’s not a river that’s singing out. It’s the turning tide between Lopez and San Juan Island.

Writer and marine conservationist Jonathan White lives in the San Juans and for years has sailed the Inside Passage between Puget Sound and Southeast Alaska. He has navigated whitewater extremes of tidal activity, but it was only after being stranded by a 14-foot tide on a mud flat near Sitka that he was spurred to investigate the forces behind tidal activity more closely.

“I thought I’d find my answer in a book or two,” he writes, “but the more I read, the more complex and mysterious and poetic the subject became.”

Author appearance

Jonathan White

The author will appear at 7:30 p.m. Tuesday, Sept. 12, University Lutheran Church, 1604 N.E. 50th St., Seattle; $5 (206-652-4255 or townhallseattle.org).

The results of his research are marvelous.

“Tides: The Science and Spirit of the Ocean” offers a grand mix of science history, ocean lore and literary travel writing. It transports you to Venice, Mont St. Michel and the Bay of Fundy with their unusual tidal situations. It also ventures to less obvious locales, including Ungava Bay in the Arctic where, at low tide in winter, you can poke around the ice shelf to gather mussels.

Along the way, White fills you in on various cultures’ ancient myths about the tides and the gradual discovery by scientists of what triggers tides’ rise and fall. He makes gnarly subtleties lucid, and his writing can be gorgeous as he takes us from the long-held belief in tides as evidence of a living, breathing Earth (as Plato and Leonardo da Vinci thought) to the realization that they had something to do with the monthly phases of the moon.

The shift from a geocentric to a heliocentric vision of the solar system in the 16th century cast an increasingly complicated light on the workings of the tides. Sir Isaac Newton’s groundbreaking “idealized tide model” stemmed from his equilibrium theory, which envisaged a universe following tidy astronomical laws. Where he fell short was on the fluid dynamics that shaped the turbulent activity below the ocean’s surface.

Newton’s findings were succeeded by 19th-century concepts of tidal “resonance,” in which seas and oceans, triggered by the pull of the moon and sun, oscillated “back and forth at a characteristic frequency, like a wave in a bathtub.” Hundreds of tidal “harmonic constituents,” including weather, underwater topography and the wobble of the Earth’s axis, were found to be part of the picture, too.

More surprising: Over millions of years the tides themselves, as they drag against the ocean floor, have triggered tiny changes in Earth’s rotation-speed and the distance between our planet and the moon. White cites evidence that the moon was once much closer to Earth, resulting in 100-foot tides and intertidal zones hundreds of miles wide. He also reveals how, thanks to a reflector left on the lunar surface in 1969, we know that the moon drifts an inch and a half farther from us every year.

He touches on rising sea-levels triggered by climate change, the latest efforts to tap tidal energy for our electrical power needs, and much more — all in a prose that’s as beguiling as it is informative.