Here a physicist and a professor of literature guide general readers through the ideas that revolutionized our conception of the physical universe.

Die vorliegende Schrift behandelt die Kalenderlehre unter bewuBter Ausscheidung aller historischen Betrachtungen. Liegt darin einerseits e: ne Beschrankung, so glaubt der Ver fasser andererseits durch die Loslosung von der vielverschlungenen und daher mit mancherlei Ballast behafteten Entwickelungs geschichte des Kalenderwesens dessen mathematischen Kern sozusagen reinlicher herausschalen zu konnen, als es bei einer historischen Darstellung moglich ware. Die Schrift wendet sich an einen sehr allgemeinen Leser kreis. Sie mochte jedem Gebildeten zuganglich sein, der mathe matischen Oberlegungen einfachster Art Interesse entgegen bringt. Da und dort mag vieHeicht der Historiker bei chrono logischen Untersuchungen aus ihr Nutzen ziehen konnen. Eine besondere Freude ware es dem V erfasser, wenn zuweilen ein Feldgrauer nach dem Schriftchen griffe; weiB er doch aus eigener Erfahrung, wie es Zeiten gibt, in denen der Soldat nach irgendwelcher geistigen Anregung hungert - ganz ab gesehen davon, daB es im Felde von praktischem Interesse sein kann, nach kurzer Dberlegung zu wissen, welche Mondphase einem gegebenen Datum zukommt. Aber dariiber hinaus mochte das Biichlein auch dem an gehenden Mathematiker etwas zu sagen haben, und vor aHem dem Unterricht an hoheren Schulen dienen. Sollte die Schrift einem so verschiedenartigen Leserkreise gerecht werden, so war dies nur moglich durch eine besondere Behandlungsweise des Stoffes: die Darstellung zerfallt gewisser maBen in mehrere "Kreise," deren jeder in sich geschlossen und verstandlich ist. Der engste erfordert kaum mehr, als die Kennt nis der vier Grundrechnungsarten. Der nachste setzt schon Vorwort."

Gravity is one of the four fundamental interactions that exist in nature. It also has the distinction of being the oldest, weakest, and most difficult force to quantize. Understanding gravity is not only essential for understanding the motion of objects on Earth, but also the motion of all celestial objects, and even the expansion of the Universe itself. It was the study of gravity that led Einstein to his profound realisations about the nature of space and time. Gravity is not only universal, it is also essential for understanding the behaviour of the Universe, and all astrophysical bodies within it. In this Very Short Introduction Timothy Clifton looks at the development of our understanding of gravity since the early observations of Kepler and Newtonian theory. He discusses Einstein's theory of gravity, which now supplants Newton's, showing how it allows us to understand why the frequency of light changes as it passes through a gravitational field, why GPS satellites need their clocks corrected as they orbit the Earth, and why the orbits of distant neutron stars speed up. Today, almost 100 years after Einstein published his theory of gravity, we have even detected the waves of gravitational radiation that he predicted. Clifton concludes by considering the testing and application of general relativity in astrophysics and cosmology, and looks at dark energy and efforts such as string theory to combine gravity with quantum mechanics. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable.

Dawkin's militant atheism is well known; his profound faith less well known In this book, atheist philosopher Eric Steinhart explores the spiritual dimensions of Richard Dawkins' books, which are shown to encompass: * the meaning and purpose of life * an appreciation of Platonic beauty and truth * a deep belief in the rationality of the universe * an aversion to both scientism and nihilism As an atheist, Dawkins strives to develop a scientific alternative to theism, and while he declares that science is not a religion, he also proclaims it to be a spiritual enterprise. His books are filled with fragmentary sketches of this 'spiritual atheism', resembling a great unfinished cathedral. This book systematises and completes Dawkins' arguments and reveals their deep roots in Stoicism and Platonism. Expanding on Dawkins' ideas, Steinhart shows how atheists can develop powerful ethical principles, compelling systems of symbols and images, and meaningful personal and social practices. Believing in Dawkins is a rigorous and potent entreaty for the use of science and reason to support spiritually rich and optimistic ways of thinking and living.