The Measurement of Time

Time, Frequency and the Atomic Clock

Author: Claude Audoin,Bernard Guinot

Publisher: Cambridge University Press

ISBN: 9780521003971

Category: Reference

Page: 335

View: 7242

A unique insight into the measurement of time and its applications, at an introductory level.
Posted in Reference

The Quantum Beat

The Physical Principles of Atomic Clocks

Author: F. G. Major

Publisher: Springer Science & Business Media

ISBN: 1475729235

Category: Science

Page: 475

View: 9725

This work reviews the principles underlying quantum-based atomic clocks, with introductory chapters placing them in context with the development of mechanical clocks and electronic quartz-controlled clocks. The book details design principles of the rubidium, cesium, hydrogen maser, and mercury ion standards; changes enabled by the advent of the laser; and the time-based global navigation systems, Loran-C and the Global Positioning System. The new edition includes such recent developments as clocks based on quantum resonance at optical frequency in individual ions confined in miniature electromagnetic traps. The Quantum Beat explores the subject with a minimum of mathematical formalism.
Posted in Science

Frequency Standards

Basics and Applications

Author: Fritz Riehle

Publisher: John Wiley & Sons

ISBN: 3527605959

Category: Science

Page: 540

View: 2632

Of all measurement units, frequency is the one that may be determined with the highest degree of accuracy. It equally allows precise measurements of other physical and technical quantities, whenever they can be measured in terms of frequency. This volume covers the central methods and techniques relevant for frequency standards developed in physics, electronics, quantum electronics, and statistics. After a review of the basic principles, the book looks at the realisation of commonly used components. It then continues with the description and characterisation of important frequency standards from atomic clocks, to frequency stabilised lasers. The whole is rounded of with a discussion of topical applications in engineering, telecommunications, and metrology.
Posted in Science

About Time

Author: Adam Frank

Publisher: Oneworld Publications

ISBN: 1780740603

Category: Science

Page: 432

View: 1708

From Stonehenge to beyond the Big Bang, an exhilarating scientific exploration of how we make time Time is the grandest conception of the universe that we humans have been able to imagine – and its most intimate, the very frame of human life. In About Time, astrophysicist and award-winning writer Adam Frank tells the scientific story of this wonderful and tyrannical invention. A Palaeolithic farmer moved through the sun-fuelled day and star-steered night in a radically different way than the Elizabethan merchants who set their pace to the clocks newly installed in their town squares. Since then, science has swept time into increasingly minute and standardized units – the industrial efficiency of ironworks’ punch clocks; the space-age precision of atomic fountains and GPS satellites; the fifteen-minute increments of Outlook’s digital revolution. And in the past decade, string-theory branes, multiverses, and “clockless” physics have begun to overturn our ideas about how the universe began – the Big Bang – in ways that will completely rewrite time and our experience of it. Weaving cosmology with day-to-day chronicles and a down-to-earth style, About Time is both dazzling and riveting as it confronts what comes next.
Posted in Science

The Measure of Manhattan: The Tumultuous Career and Surprising Legacy of John Randel, Jr., Cartographer, Surveyor, Inventor

Author: Marguerite Holloway

Publisher: W. W. Norton & Company

ISBN: 0393089800

Category: Biography & Autobiography

Page: 336

View: 1323

“Randel is endlessly fascinating, and Holloway’s biography tells his life with great skill.”—Steve Weinberg, USA Today John Randel Jr. (1787–1865) was an eccentric and flamboyant surveyor. Renowned for his inventiveness as well as for his bombast and irascibility, Randel was central to Manhattan’s development but died in financial ruin. Telling Randel’s engrossing and dramatic life story for the first time, this eye-opening biography introduces an unheralded pioneer of American engineering and mapmaking. Charged with “gridding” what was then an undeveloped, hilly island, Randel recorded the contours of Manhattan down to the rocks on its shores. He was obsessed with accuracy and steeped in the values of the Enlightenment, in which math and science promised dominion over nature. The result was a series of maps, astonishing in their detail and precision, which undergird our knowledge about the island today. During his varied career Randel created surveying devices, designed an early elevated subway, and proposed a controversial alternative route for the Erie Canal—winning him admirers and enemies. The Measure of Manhattan is more than just the life of an unrecognized engineer. It is about the ways in which surveying and cartography changed the ground beneath our feet. Bringing Randel’s story into the present, Holloway travels with contemporary surveyors and scientists trying to envision Manhattan as a wild island once again. Illustrated with dozens of historical images and antique maps, The Measure of Manhattan is an absorbing story of a fascinating man that captures the era when Manhattan—indeed, the entire country—still seemed new, the moment before canals and railroads helped draw a grid across the American landscape.
Posted in Biography & Autobiography

From Sundials to Atomic Clocks

Understanding Time and Frequency

Author: James Jespersen,Jane Fitz-Randolph

Publisher: Courier Corporation

ISBN: 0486409139

Category: Science

Page: 345

View: 8261

Clear and accessible introduction to the concept of time examines measurement, historic timekeeping methods, uses of time information, role of time in science and technology, and much more. Over 300 illustrations.
Posted in Science

Philosophical Problems of Space and Time

Second, enlarged edition

Author: Adolf Grünbaum

Publisher: Springer Science & Business Media

ISBN: 940102622X

Category: Science

Page: 884

View: 2155

It is ten years since Adolf Griinbaum published the first edition of this book. It was promptly recognized to be one of the few major works in the philosophy of the natural sciences of this generation. In part, this is so because Griinbaum has chosen a problem basic both to philosophy and to the natural sciences - the nature of space and time; and in part, this is so because he so admirably exemplifies that Aristotelian devotion to the intimate and mutual dependence of actual science and philosophical understanding. More than this, however, the quality of his work derives from his achievement in combining detail with scope. The problems of space and time have been among the most difficult in contemporary and classical thought, and Griinbaum has been responsible to the full depth and complexity of these difficulties. This revised and enlarged second edition is a work in progress, in the tradition of reflective analysis of modern science of such figures as Ehrenfest and Reichenbach. In publishing this work among the Boston Studies in the Philosophy of Science, we hope to contribute to and encourage that broad tradition of natural philosophy which is marked by the close collaboration of philoso phers and scientists. To this end, we have published the proceedings of our Colloquia, of meetings and conferences here and abroad, as well as the works of single authors.
Posted in Science

Lasers, Clocks and Drag-Free Control

Exploration of Relativistic Gravity in Space

Author: Hansjörg Dittus,Claus Lämmerzahl,Slava G. Turyshev

Publisher: Springer Science & Business Media

ISBN: 9783540343776

Category: Science

Page: 642

View: 4938

Written by international experts, this book explores the possibilities for the next 20 years in conducting gravitational experiments in space that would make the most of the new and much-improved existing capabilities. They start from the premise that over the next decade the gravitational physics community will benefit from dramatic improvements in many technologies critical to the tests of gravity. This volume contains a comprehensive presentation of the theory, technology, missions and projects on relativistic gravity in space.
Posted in Science

China Satellite Navigation Conference (CSNC) 2013 Proceedings

Precise Orbit Determination & Positioning • Atomic Clock Technique & Time–Frequency System • Integrated Navigation & New Methods

Author: Jiadong Sun,Wenhai Jiao,Haitao Wu,Chuang Shi

Publisher: Springer Science & Business Media

ISBN: 3642374077

Category: Technology & Engineering

Page: 749

View: 759

China Satellite Navigation Conference (CSNC) 2013 Proceedings presents selected research papers from CSNC2013, held on 15-17 May in Wuhan, China. The theme of CSNC2013 is: BeiDou Application: Opportunities and Challenges. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou system especially. They are divided into 9 topics to match the corresponding sessions in CSNC2013, which broadly covered key topics in GNSS. Readers can learn about the BeiDou system and keep abreast of the latest advances in GNSS techniques and applications. SUN Jiadong is the Chief Designer of the Compass/BeiDou system, and the Academician of Chinese Academy of Sciences (CAS); JIAO Wenhai is a researcher at China Satellite Navigation Office; WU Haitao is a professor at Navigation Headquarters, CAS; SHI Chuang is a professor at Wuhan University.
Posted in Technology & Engineering

Electromagnetic Radiation: Atomic, Molecular, and Optical Physics

Atomic, Molecular, And Optical Physics: Electromagnetic Radiation

Author: N.A

Publisher: Academic Press

ISBN: 9780080860190

Category: Science

Page: 406

View: 2174

Combined with Volumes 29A and 29B, this volume is a comprehensive treatment of the key experimental methods of atomic, molecular, and optical physics, as well as an excellent experimental handbook for the field. Thewide availability of tunable lasers in the past several years has revolutionized the field and lead to the introduction of many new experimental methods that are covered in these volumes. Traditional methods are also included to ensure that the volumes will be a complete reference source for the field.
Posted in Science

The Mechatronics Handbook, Second Edition - 2 Volume Set

Author: Robert H. Bishop

Publisher: CRC Press

ISBN: 1420042459

Category: Technology & Engineering

Page: 1272

View: 9301

Mechatronics has evolved into a way of life in engineering practice, and indeed pervades virtually every aspect of the modern world. As the synergistic integration of mechanical, electrical, and computer systems, the successful implementation of mechatronic systems requires the integrated expertise of specialists from each of these areas. Destined to become a standard reference for engineering professionals around the world, The Mechatronics Handbook provides a unique, detailed overview of this vibrant, dynamic field and sets forth its state of the art. More than 60 articles authored by a stellar panel of academics and practitioners explore every facet of the field, from an overview of its history, through the underlying theories, systems, processes, and practice to perspectives on the field's current and future trends. The world of mechatronics is wide open, full of potential and bright possibilities. The Mechatronics Handbook is a landmark work that is both your portal to that world and your roadmap through its intricacies.
Posted in Technology & Engineering

Mechatronics

An Introduction

Author: Robert H. Bishop

Publisher: CRC Press

ISBN: 9781420037241

Category: Technology & Engineering

Page: 312

View: 671

Mechatronics has evolved into a way of life in engineering practice, and it pervades virtually every aspect of the modern world. In chapters drawn from the bestselling and now standard engineering reference, The Mechatronics Handbook, this book introduces the vibrant field of mechatronics and its key elements: physical system modeling; sensors and actuators; signals and systems; computers and logic systems; and software and data acquisition. These chapters, written by leading academics and practitioners, were carefully selected and organized to provide an accessible, general outline of the subject ideal for non-specialists. Mechatronics: An Introduction first defines and organizes the key elements of mechatronics, exploring design approach, system interfacing, instrumentation, control systems, and microprocessor-based controllers and microelectronics. It then surveys physical system modeling, introducing MEMS along with modeling and simulation. Coverage then moves to essential elements of sensors and actuators, including characteristics and fundamentals of time and frequency, followed by control systems and subsystems, computer hardware, logic, system interfaces, communication and computer networking, data acquisition, and computer-based instrumentation systems. Clear explanations and nearly 200 illustrations help bring the subject to life. Providing a broad overview of the fundamental aspects of the field, Mechatronics: An Introduction is an ideal primer for those new to the field, a handy review for those already familiar with the technology, and a friendly introduction for anyone who is curious about mechatronics.
Posted in Technology & Engineering

Frequency Measurement and Control

Advanced Techniques and Future Trends

Author: Andre N. Luiten

Publisher: Springer Science & Business Media

ISBN: 9783540676942

Category: Science

Page: 394

View: 1841

With contributions by numerous experts
Posted in Science

Laser Spectroscopy

Proceedings of the XV International Conference

Author: Steven Chu,Vladan Vuleti,Andrew J. Kerman,Cheng Chin

Publisher: World Scientific

ISBN: 9789810247812

Category: Science

Page: 380

View: 9731

The XV International Conference on Laser Spectroscopy brought together spectroscopists from all over the world working in the very diverse and still growing field of laser spectroscopy. It addressed a large number of modern scientific issues at the highest level.
Posted in Science

GOES Satellite Time Code Dissemination

Description and Operation

Author: Roger E. Beehler,Dick Davis

Publisher: N.A

ISBN: N.A

Category: Geostationary satellites

Page: N.A

View: 9065

Posted in Geostationary satellites

Metrology at the Frontiers of Physics and Technology

Author: L. Crovini,T.J. Quinn

Publisher: Elsevier

ISBN: 0444597832

Category: Science

Page: 673

View: 6436

The spectroscopy of trapped ions or laser-cooled atoms offers the prospect of visible frequency standards to match or even exceed the accuracy of the caesium standard. The development of satellite methods for time comparisons has improved by more than an order of magnitude the accuracy with which national laboratories can routinely compare their clocks. Mechanical metrology has not been left behind. Driven by the need to improve manufacturing technology, major advances have taken place in computer control machining and mechanical measuring systems. These, and many other fascinating developments in the field of metrology are presented in this book.
Posted in Science

An Assessment of Precision Time and Time Interval Science and Technology

Author: National Research Council,Division on Engineering and Physical Sciences,Naval Studies Board,Committee for an Assessment of Precision Time and Time Interval Science and Technology

Publisher: National Academies Press

ISBN: 0309168856

Category: Science

Page: 88

View: 4280

Knowledge of time is essential to precise knowledge of location, and for this reason the Navy, with its need to navigate on the high seas, has historically played an important role in the development and application of advanced time realization and dissemination technologies. Discoveries coming from basic research funded by the Office of Naval Research (ONR) lie at the heart of today's highest performance atomic clocks, Naval Research Laboratory (NRL) expertise played a role in developing the space-qualified atomic clocks that enable the Global Positioning System (GPS), and the U.S. Naval Observatory (USNO) maintains and disseminates the standard of time for all of the Department of Defense (DOD). The Navy has made major investments in most aspects of precision time and time interval (PTTI) science and technology, although specific PTTI-related research has also been funded by the Defense Advanced Research Projects Agency (DARPA) and non-DOD agencies such as the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the Department of Commerce. Navy funding, largely through ONR, has a history of being an early enabler of key new developments. Judicious funding decisions by the Navy-particularly by ONR program officers-have underpinned most of the major advances in PTTI science and technology (S&T) in the last 50 years. PTTI is important to modern naval needs, and indeed to all the armed Services, for use in both navigation and communications. Precise time synchronization is needed to efficiently determine the start of a code sequence in secure communications, to perform navigation, and to locate the position of signal emitters. Precise frequency control is required in communications for spectrum utilization and frequency-hopped spread-spectrum techniques. There are many examples of essential military operations that depend on PTTI and could benefit from improvements in PTTI technology. These include: -GPS clocks and autonomous operations, -Weapon system four-dimensional coordination, -GPS antijamming, -Network-centric warfare, and -Secure military communications. This report summarizes that reductions in the size, weight, and power requirements and increases in the ruggedness of PTTI devices without sacrificing performance would put more accurate and precise timekeeping in the hands of the warrior, improving capabilities in all of the above operations.
Posted in Science