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."

This popular book on special relativity was first published in Moscow back in 1961 under the Russian title ' ? , ', which can be roughly translated as 'Is it evident? No, it's unexplored yet!'This clear exposition of the history of the development of physical ideas which eventually led to the discovery of special relativity is a narration of how physicists, from Galileo, Newton to Lorentz, Poincare and Einstein were distracted in their reflections by numerous fallacies (like aether, dragged or not). Then by experiment, it was finally understood that the laws of cinematics and dynamics of the objects moving at high speed can only be formulated with physical definions for what is distance, time or force. After that and from the two basic Einstein postulates - the principle of relativity and the constancy of the speed of light - everything else followed.As the emphasis is on being exact from the scientific viewpoint, it is also accessible to any person with a high school background. The last chapter 'Photon dreams' is addressed to science fiction fans. However, the author proves to the disappointed reader that the laws of physics that we know do not allow the construction of spaceships that could reach even the nearest stars during the life span of the team.

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.

Unlike many textbooks or popular science books, A Simple Guide to Popular Physics has truly been crafted for the uninitiated or those spooked by the subject's complexity. Harris's inviting guide promises to give "absolute beginners" from "teens to centenarians" a basic grounding in particle physics, quantum physics, and cosmology-all without making readers do math. With the goal of introducing the basics and encouraging readers to explore more deeply afterwards, Harris notes "Like the fish we have no notion of what is beyond the boundaries of our knowledge, but unlike the fish, we know there is something." He starts by presenting those boundaries, the fundamentals of classic physics (Newton's law, states of matter, types of energy), with crisp clarity before laying out an accessible explanation of Einstein's theory of relativity, the structure of the atom, the mysteries of quantum mechanics and cosmology. Readers will not need to search online for key terms or explanations of concepts that have been glossed over. Instead, one by one, with patience and good humor, Harris introduces each of these building blocks of our universe, taking a little time to invite readers to contemplate the momentousness of the information, as in the chapter titled nothing less than "What Is Reality?" The watchword, here, is clarity, which Harris offers throughout, with professional illustrations and illuminating accounts of experiments and breakthroughs, offering a solid foundation for understanding and future reading.

This book tells the human story of one of man's greatest intellectual adventures - how it came to be understood that light travels at a finite speed, so that when we look up at the stars, we are looking back in time. And how the search for a God-given absolute frame of reference in the universe led most improbably to Einstein's most famous equation E=mc2, which represents the energy that powers the stars and nuclear weapons. From the ancient Greeks measuring the solar system, to the theory of relativity and satellite navigation, the book takes the reader on a gripping historical journey. We learn how Galileo discovered the moons of Jupiter and used their eclipses as a global clock, allowing travellers to find their Longitude. And how Ole Roemer, noticing that the eclipses were a little late, used this to obtain the first measurement of the speed of light, which takes eight minutes to get to us from the sun. We move from the international collaborations to observe the Transits of Venus, including Cook's voyage to Australia, to the achievements of Young and Fresnel, whose discoveries eventually taught us that light travels as a wave but arrives as a particle, and all the quantum weirdness which follows. In the nineteenth century, we find Faraday and Maxwell, struggling to understand how light can propagate through the vacuum of space unless it is filled with a ghostly vortex Aether foam. We follow the brilliantly gifted experimentalists Hertz, discoverer of radio, Michelson with his search for the Aether wind, and Foucault and Fizeau with their spinning mirrors and lightbeams across the rooftops of Paris. Messaging faster than light using quantum entanglement, and the reality of the quantum world, conclude this saga.