Thomas Arny - Explorations: Introduction to Astronomy

Explorations

An Introduction to Astronomy

Ninth Edition

Thomas T. Arny & Stephen E. Schneider

Explorations

An Introduction to Astronomy

Ninth Edition

Thomas T. Arny

Professor Emeritus

Department of Astronomy

University of Massachusetts, Amherst

Stephen E. Schneider

Professor of Astronomy

University of Massachusetts, Amherst

EXPLORATIONS: AN INTRODUCTION TO ASTRONOMY, NINTH EDITION

Published by McGraw-Hill Education, 2 Penn Plaza, New York, NY 10121. Copyright 2020 by McGraw-Hill Education. All rights reserved. Printed in the United States of America. Previous editions 2017, 2014, and 2010. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of McGraw-Hill Education, including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning.

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ISBN 978-1-260-15051-3 (bound edition)

MHID 1-260-15051-8 (bound edition)

ISBN 978-1-260-43214-5 (loose-leaf edition)

MHID 1-260-43214-9 (loose-leaf edition)

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Library of Congress Cataloging-in-Publication Data

Arny, Thomas, author. | Schneider, Stephen E. (Stephen Ewing), 1957-author.

Explorations : an introduction to astronomy / Thomas T. Arny

(professor emeritus, Department of Astronomy, University of Massachusetts,

Amherst), Stephen E. Schneider (professor of astronomy, University of Massachusetts, Amherst).

Ninth edition. | New York, NY : McGraw-Hill Education, 2019. | Includes index.

LCCN 2018013865 | ISBN 9781260150513 (alk. paper)

LCSH: AstronomyTextbooks.

LCC QB45.2 .A76 2019 | DDC 520dc23

LC record available at https://lccn.loc.gov/2018013865

The Internet addresses listed in the text were accurate at the time of publication. The inclusion of a website does not indicate an endorsement by the authors or McGraw-Hill Education, and McGraw-Hill Education does not guarantee the accuracy of the information presented at these sites.

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Brief Contents

Contents

Preface

Our motivations for writing Explorations: An Introduction to Astronomy are many, both personal and pedagogic. Perhaps foremost among these is a desire to share with students our own sense of wonder about the Universe.

That sense of wonder grows deeper when we begin to understand why things happen. Many astronomy books today seem to simply say, This is how it is. We want instead to offer explanations that draw as much as possible on simple, everyday experiences. For example, why do some stars pulsate? A simple analogy of steam building up pressure under the lid of a pan offers a model of this phenomenon that is easy to understand and reasonably accurate. You can even learn how planets get their internal structure by examining a previously-melted box of chocolate chip ice cream. When we can thus link physical principles to everyday observations, many of the more abstract and remote ideas become more familiar. Throughout the book we have made heavy use of analogies, along with carefully designed illustrations to make those analogies more concrete.

Knowing the facts about astronomical objects is important, but it is equally important to understand how astronomers deduce those facts. Thus, an additional aim throughout this text is to explain how astronomers have come to their understanding of our Universe. New observations can force astronomers to revise their ideas of how a given process occurs. As part of showing how scientists arrive at their ideas, we have set many of the modern discoveries in their historical context to illustrate that science is a dynamic process and subject to controversymany ideas are not immediately accepted, even if they ultimately prove to be correct. We hope that by seeing the arguments for and against various ideas, you will gain a better understanding of how science works.

Seeing a clear night sky spangled with stars is a wondrous experience. And yet the beauty and sense of wonder can be enriched even more by an appreciation of the complex processes that make the Universe work. We hope this book will similarly increase your appreciation of our Universes wonders.

A READERS GUIDE TO EXPLORATIONS

Explorations has been designed with a number of special features to help you better comprehend the many wide-ranging aspects of astronomy. Familiarize yourself with these features, and take advantage of them to deepen your understanding as you read.