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.

Dieser Buchtitel ist Teil des Digitalisierungsprojekts Springer Book Archives mit Publikationen, die seit den Anfangen des Verlags von 1842 erschienen sind. Der Verlag stellt mit diesem Archiv Quellen fur die historische wie auch die disziplingeschichtliche Forschung zur Verfugung, die jeweils im historischen Kontext betrachtet werden mussen. Dieser Titel erschien in der Zeit vor 1945 und wird daher in seiner zeittypischen politisch-ideologischen Ausrichtung vom Verlag nicht beworben.

Motion is always relative to some thing. Is this thing a concrete body like the earth, is it an abstract space, or is it an imagined frame? Do the laws of physics depend on the choice of reference? It there a choice for which the laws are simplest? Is this choice unique? Is there a physical cause for the choice made? These questions traverse the history of modern physics from Galileo to Einstein. The answers involved Galilean relativity, Newton's absolute space, the purely relational concepts of Descartes, Leibniz, and Mach, and many forgotten uses of relativity principles in mechanics, optics, and electrodynamics - until the relativity theories of Poincare, Einstein, Minkowksi, and Laue radically redefined space and time to satisfy universal kinds of relativity. Accordingly, this book retraces the emergence of relativity principles in early modern mechanics, documents their constructive use in eighteenth- and nineteenth-century mechanics, optics, and electrodynamics, and gives a well-rooted account of the genesis of special and general relativity in the early twentieth century. As an exercise in long-term history, it demonstrates the connectivity of issues and approaches across several centuries, despite enormous changes in context and culture. As an account of the genesis of relativity theories, it brings unprecedented clarity and fullness by broadening the spectrum of resources on which the principal actors drew.

The book aims to give a mathematical presentation of the theory of general relativity (that is, spacetime-geometry-based gravitation theory) to advanced undergraduate mathematics students. Mathematicians will find spacetime physics presented in the definition-theorem-proof format familiar to them. The given precise mathematical definitions of physical notions help avoiding pitfalls, especially in the context of spacetime physics describing phenomena that are counter-intuitive to everyday experiences.In the first part, the differential geometry of smooth manifolds, which is needed to present the spacetime-based gravitation theory, is developed from scratch. Here, many of the illustrating examples are the Lorentzian manifolds which later serve as spacetime models. This has the twofold purpose of making the physics forthcoming in the second part relatable, and the mathematics learnt in the first part less dry. The book uses the modern coordinate-free language of semi-Riemannian geometry. Nevertheless, to familiarise the reader with the useful tool of coordinates for computations, and to bridge the gap with the physics literature, the link to coordinates is made through exercises, and via frequent remarks on how the two languages are related.In the second part, the focus is on physics, covering essential material of the 20th century spacetime-based view of gravity: energy-momentum tensor field of matter, field equation, spacetime examples, Newtonian approximation, geodesics, tests of the theory, black holes, and cosmological models of the universe.Prior knowledge of differential geometry or physics is not assumed. The book is intended for self-study, and the solutions to the (over 200) exercises are included.

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."

Somewhere near the heart of existence, shimmers the ethereal beauty of the mystery of Time. Though seemingly familiar to us all, time harbours secrets that penetrate the very deepest levels of reality, and though we feel certain in our conviction that we're swept forth upon the crest of its never-ending flow, with Einstein's discovery of relativity came what is perhaps the most stunning realisation in the entire history of scientific thought - the wondrously breathtaking revelation that in reality, there's actually no such thing as the passage of time... How can this extraordinary truth be reconciled with the reality we so surely suppose to experience? What does it mean for the very human concerns of life and death, free will, identity, and self? What should it mean for our philosophy? And how should it inform our world view? The search for answers leads through the fantastical realm of quantum physics, and the strange parallel worlds it describes, as we discover that the answers which such questions provoke, are perhaps even more profound than the questions themselves. Buried deep within the riddle of time, lies the staggering beauty of the world. As we peel back the layers to try and sneak a glimpse into eternity, we find a light shining not only upon the nature of reality, but on the nature of ourselves...