Pendulum: Leon Foucault and the Triumph of Science

In 1853, before the upper crust of French society — including the emperor Napoleon III — a little known physicist named Leon Foucault staged a dramatic demonstration inside the Pantheon in Paris. He set in motion a seventy meter long pendulum that swung slowly across the interior of the large ceremonial hall, hanging from its high ceiling. Foucault's famous experiment revolutionized the entire world of science, and of society itself: He had proven, beyond a doubt, that the earth does indeed rotate on its axis. In Pendulum, renowned scientist and author Amir Aczel brings readers the first detailed nonfiction account of how this struggling physicist came to his remarkable breakthrough, as well as the opposition he faced — both before and after his demonstration — at the hands of the scientific community in France. Drawing a wonderfully vivid portrait of Napoleon III and Paris during the Second Empire, Aczel chronicles France's scientific glory during the 1850s, and evaluates how Foucault's theories and achievements are viewed in the current perspective of modern science. Both factual and fascinating, Pendulum is a spellbinding account hailed as long-overdue by science and history lovers alike.

He was neither a mathematician nor a trained physicist and yet Léon Foucault always knew that a mysterious force of nature was among us. Like Newton, Galileo, Copernicus, and others before him, Foucault sensed a dramatic relationship between the rotating skies above and the seemingly motionless ground beneath our feet. But it wasn't until 1851 — in Paris, inside the Panthéon, and in the company of fellow amateur scientist Napoleon III — that Foucault swung a pendulum and demonstrated an extraordinary truth about the world: that it turns on its axis.

Pendulum is a fascinating journey through the mind and findings of one of the most important and lesser-known characters in the history of science. Through careful research and lively anecdotes, world-renowned author Amir D. Aczel reveals the astonishing range and breadth of Foucault's discoveries. For, in addition to offering the first unequivocal proof of Earth's rotation, Foucault gave us the modern electric compass and microscope, was a pioneer in photographic technology, and made remarkable deductions about color theory, heat waves, and the speed of light.

At its heart, Pendulum is a story about the illustrious period in France during the Second Empire; the crucial triumph of science over religion; and, most compelling, the life of a struggling, self-made man whose pursuit of knowledge continues to inform our notions about the universe today.

Amir D. Aczel is the bestselling author of ten books, including Entanglement, The Riddle of the Compass, The Mystery of the Aleph, and Fermat's Last Theorem. He lives in Brookline, Massachusetts.

Contents Preface

A Stunning Discovery in the Cellar

Ancient Logic: Bible and Inquisition

Failed Experiments with Falling Bodies

A Science "Irregular" in the Age of the Engineer

The Meridian of Paris

"Come See the Earth Turn"

Mathematical Bedlam

A New Bonaparte

The Force of Coriolis

The Panthéon

The Gyroscope

The Coup d'État and the Second Empire

An Unemployed Genius

The Observatory Physicist

Final Glory

A Premature End

The Defeat at Sedan

Aftermath

Appendix: Proofs of Foucault's Sine Law

Acknowledgments

Notes

Bibliography

Index