How scientists through the ages have conducted thought experiments using imaginary entities-demons-to test the laws of nature and push the frontiers of what is possible Science may be known for banishing the demons of superstition from the modern world. Yet just as the demon-haunted world was being exorcized by the enlightening power of reason, a new kind of demon mischievously materialized in the scientific imagination itself. Scientists began to employ hypothetical beings to perform certain roles in thought experiments-experiments that can only be done in the imagination-and these impish assistants helped scientists achieve major breakthroughs that pushed forward the frontiers of science and technology. Spanning four centuries of discovery-from Rene Descartes, whose demon could hijack sensorial reality, to James Clerk Maxwell, whose molecular-sized demon deftly broke the second law of thermodynamics, to Darwin, Einstein, Feynman, and beyond-Jimena Canales tells a shadow history of science and the demons that bedevil it. She reveals how the greatest scientific thinkers used demons to explore problems, test the limits of what is possible, and better understand nature. Their imaginary familiars helped unlock the secrets of entropy, heredity, relativity, quantum mechanics, and other scientific wonders-and continue to inspire breakthroughs in the realms of computer science, artificial intelligence, and economics today. The world may no longer be haunted as it once was, but the demons of the scientific imagination are alive and well, continuing to play a vital role in scientists' efforts to explore the unknown and make the impossible real.

On April 6, 1922, in Paris, Albert Einstein and Henri Bergson publicly debated the nature of time. Einstein considered Bergson's theory of time to be a soft, psychological notion, irreconcilable with the quantitative realities of physics. Bergson, who gained fame as a philosopher by arguing that time should not be understood exclusively through the lens of science, criticized Einstein's theory of time for being a metaphysics grafted on to science, one that ignored the intuitive aspects of time. The Physicist and the Philosopher tells the remarkable story of how this explosive debate transformed our understanding of time and drove a rift between science and the humanities that persists today. Jimena Canales introduces readers to the revolutionary ideas of Einstein and Bergson, describes how they dramatically collided in Paris, and traces how this clash of worldviews reverberated across the twentieth century. She shows how it provoked responses from figures such as Bertrand Russell and Martin Heidegger, and carried repercussions for American pragmatism, logical positivism, phenomenology, and quantum mechanics. Canales explains how the new technologies of the period--such as wristwatches, radio, and film--helped to shape people's conceptions of time and further polarized the public debate. She also discusses how Bergson and Einstein, toward the end of their lives, each reflected on his rival's legacy--Bergson during the Nazi occupation of Paris and Einstein in the context of the first hydrogen bomb explosion. The Physicist and the Philosopher is a magisterial and revealing account that shows how scientific truth was placed on trial in a divided century marked by a new sense of time.

In the late fifteenth century, clocks acquired minute hands. A century later, second hands appeared. But it wasn't until the 1850s that instruments could recognize a tenth of a second, and, once they did, the impact on modern science and society was profound. Revealing the history behind this infinitesimal interval, "A Tenth of a Second" sheds new light on modernity and illuminates the work of important thinkers of the last two centuries.

Tracing debates about the nature of time, causality, and free will, as well as the introduction of modern technologies--telegraphy, photography, cinematography--Jimena Canales locates the reverberations of this "perceptual moment" throughout culture. Once scientists associated the tenth of a second with the speed of thought, they developed reaction time experiments with lasting implications for experimental psychology, physiology, and optics. Astronomers and physicists struggled to control the profound consequences of results that were a tenth of a second off. And references to the interval were part of a general inquiry into time, consciousness, and sensory experience that involved rethinking the contributions of Descartes and Kant.

Considering its impact on much longer time periods and featuring appearances by Henri Bergson, Walter Benjamin, and Albert Einstein, among others, "A Tenth of a Second" is ultimately an important contribution to history and a novel perspective on modernity.

How scientists through the ages have conducted thought experiments using imaginary entities-demons-to test the laws of nature and push the frontiers of what is possible Science may be known for banishing the demons of superstition from the modern world. Yet just as the demon-haunted world was being exorcized by the enlightening power of reason, a new kind of demon mischievously materialized in the scientific imagination itself. Scientists began to employ hypothetical beings to perform certain roles in thought experiments-experiments that can only be done in the imagination-and these impish assistants helped scientists achieve major breakthroughs that pushed forward the frontiers of science and technology. Spanning four centuries of discovery-from Rene Descartes, whose demon could hijack sensorial reality, to James Clerk Maxwell, whose molecular-sized demon deftly broke the second law of thermodynamics, to Darwin, Einstein, Feynman, and beyond-Jimena Canales tells a shadow history of science and the demons that bedevil it. She reveals how the greatest scientific thinkers used demons to explore problems, test the limits of what is possible, and better understand nature. Their imaginary familiars helped unlock the secrets of entropy, heredity, relativity, quantum mechanics, and other scientific wonders-and continue to inspire breakthroughs in the realms of computer science, artificial intelligence, and economics today. The world may no longer be haunted as it once was, but the demons of the scientific imagination are alive and well, continuing to play a vital role in scientists' efforts to explore the unknown and make the impossible real.

In the late fifteenth century, clocks acquired minute hands. A century later, second hands appeared. But it wasn't until the 1850s that instruments could recognize a tenth of a second, and, once they did, the impact on modern science and society was profound. Revealing the history behind this infinitesimal interval, "A Tenth of a Second" sheds new light on modernity and illuminates the work of important thinkers of the last two centuries.

Tracing debates about the nature of time, causality, and free will, as well as the introduction of modern technologies--telegraphy, photography, cinematography--Jimena Canales locates the reverberations of this "perceptual moment" throughout culture. Once scientists associated the tenth of a second with the speed of thought, they developed reaction time experiments with lasting implications for experimental psychology, physiology, and optics. Astronomers and physicists struggled to control the profound consequences of results that were a tenth of a second off. And references to the interval were part of a general inquiry into time, consciousness, and sensory experience that involved rethinking the contributions of Descartes and Kant.

Considering its impact on much longer time periods and featuring appearances by Henri Bergson, Walter Benjamin, and Albert Einstein, among others, "A Tenth of a Second" is ultimately an important contribution to history and a novel perspective on modernity.

The founding of the university in 1867 created a unique community in what had been a prairie. Within a few years, this creative mix of teachers and scholars produced innovations in agriculture, engineering and the arts that challenged old ideas and stimulated dynamic new industries. Projects ranging from the Mosaic web browser to the discovery of Archaea and pioneering triumphs in women's education and wheelchair accessibility have helped shape the university's mission into a double helix of innovation and real-world change. These essays explore the university's celebrated accomplishments and historic legacy, candidly assessing both its successes and its setbacks. Experts and students tell the eye-opening stories of campus legends and overlooked game-changers, of astonishing technical and social invention, of incubators of progress as diverse as the Beckman Institute and Ebertfest. Contributors: James R. Barrett, George O. Batzli, Claire Benjamin, Jeffrey D. Brawn, Jimena Canales, Stephanie A. Dick, Poshek Fu, Marcelo H. Garcia, Lillian Hoddeson, Harry Liebersohn, Claudia Lutz, Kathleen Mapes, Vicki McKinney, Elisa Miller, Robert Michael Morrissey, Bryan E. Norwood, Elizabeth H. Pleck, Leslie J. Reagan, Susan M. Rigdon, David Rosenboom, Katherine Skwarczek, Winton U. Solberg, Carol Spindel, William F. Tracy, and Joy Ann Williamson-Lott.