OUR PLACE IN THE uNIVERSE Norman k. Glendenning Lawrence Berkeley National Laboratiry World scientific Imperial College Press Published by Imperial College Press 57 Shelton Street Covent Garden London WC2H 9HE and World Scientific Publishing Co. Pte. Ltd. 5 Toh Tuck Link, Singapore 596224 USA office: 27 Warren Street, Suite 401-402, Hackensack, NJ 07601 UK office: 57 Shelton Street, Covent Garden, London WC2H 9HE Library of Congress Cataloging-in-Publication Data Glendenning, Norman K. Our place in the universe / Norman K. Glendenning. p. cm. Includes bibliographical references and index. ISBN-13 978-981-270-068-1 -- ISBN-10 981-270-068-4 ISBN-13 978-981-270-069-8 (pbk) -- ISBN-10 981-270-069-2 (pbk) 1. Cosmology. 2. Galaxies--Formation. 3. Galaxies--Evolution. 4. Astrophysics. 5. Solar system--Origin. I. Title. QB981 .G585 2007 523.1--dc22 British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. Cover picture: The Horsehead is a reflection nebula; it is located in the much larger Orion Nebula, an immense molecular cloud of primordial hydrogen and helium, together dust cast off by the surfaces of stars. The clouds that form the Horsehead are illuminated from behind by a stellar nursery of young bright stars. Credit: Photo taken at Mauna Kea, Hawaii with the Canada-France-Hawaii Telescope. Copyright © 2007 by Imperial College Press and World Scientific Publishing Co. Pte. Ltd. All rights reserved. This book, or parts thereof, may not be reproduced in any form or by any means, electronic or mechanical, including photocopying, recording or any information storage and retrieval system now known or to be invented, without written permission from the Publisher. For photocopying of material in this volume, please pay a copying fee through the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA. In this case permission to photocopy is not required from the publisher. Printed in Singapore. Kim - Our Place in the Universe.pmd 1 2/23/2007, 4:00 PM March 8, 2007 10:24 Our Place in the Universe | Trim Size: 10in x 7in book The author, Marin County, California. Photo taken by Elke May Glendenning. Norman K. Glendenning took his bachelor and masters degrees at McMaster University in Canada, and PhD in theoretical physics at Indiana University in 1959. Glenn T. Seaborg invited him to continue his research at the Lawrence Berkeley Laboratory in 1958. There he has spent his entire professional career aside from frequent short-term visits of a month to a year as visiting professor in Paris and Frankfurt. He won the Alexander von Humboldt prize in 1994. He has published 273 scientific research papers in scholarly journals and in the proceedings of international conferences as invited lecturer | in North and South America, Europe, Asia, and India. As well, he has published a technical book in each of the two major fields in which he has done research over the years, Direct Nuclear Reactions (Academic Press, 1983), and Compact Stars (Springer-Verlag, 1st ed., 1997, 2nd ed., 2000). A technical book on General Relativity is being published by Springer, New York. More recently, he studies | as a student | the work of others, and writes what he has learned for lay readers, students, and scientists in other fields | After the Beginning: A Cosmic Journey through Space and Time. This book was selected by Scientific American Book Club as an alternate selection in July 2005. The present book, Our Place in the Universe is his fifth book | also for the lay reader and for use in a general college course on the solar system. March 8, 2007 10:24 Our Place in the Universe | Trim Size: 10in x 7in book I dedicate this book with love to my family: my son Nathan his mother Laura and Elke and Alan. Greek Creation Myth: In the beginning there was an empty darkness. The only thing in this void was Nyx, a bird with black wings. With the wind, she laid a golden egg, and for ages she sat upon this egg. Finally, life began to stir in the egg and out of it arose, Eros, the god of love. One half of the shell rose into the air and became the sky and the other became the earth. Eros named the sky Uranus and the Earth he named Gaia. Then Eros made them fall in love. Credit: Lindsey Murtagh (her website was completed for a high school Latin course). v March 8, 2007 10:24 Our Place in the Universe | Trim Size: 10in x 7in book Preface Our small place in space | this planet Earth | together with Sun and other planets of our solar system and their many moons is located about two-thirds from the center of the disk-shaped galaxy that we know as the Milky Way. When we look toward its center on a clear night what we see is the faint luminosity of billions of stars that make up this galaxy. There are other galaxies too, far away, that look to our naked eyes just like any other star. But they too contain billions of stars. From our vantage point on Earth, orbiting a rather insignificant star that we call Sun, located in the Milky Way Galaxy in one of its many solar systems | we gaze in wonder. At last, I have come to that stage in life and career that I can put aside the urge to understand some little details, however fundamental they may be in the edifice of a particular science | in my case nuclear and astrophysics | and look to the grander scale of our place in the universe with its Sun and planets and their many moons stretching far away. I tell, too, the story of life, its needs, and vicissitudes on Earth and in its seas, as well as other possible habitable zones on other planets and on the larger moons of some of them. It is a story that often as children we yearn to comprehend, and concerning which, as adults, we may achieve a degree of understanding. I write with the urge of writing, because it makes me happy. I step eagerly to my desk in the morning to research what the experts in many special fields of science have learned. I try to understand what they so painstakingly have researched over the decades, making sense of the pieces and then synthesizing what I have learned with some poesy I hope, to please myself and the reader like me | not an expert. In other words I write for the general lay reader, college students taking a general science course, as well as scientists in other fields. And in the evening, tired, I leave, only to take up where I left off the next day. Some days though, when the Sun shines warmly I leave early; we vii March 8, 2007 10:24 Our Place in the Universe | Trim Size: 10in x 7in book Our Place in the Universe were made to love the Sun and its life-giving rays of energy. Sunday is my day of rest from study and writing. Norman K. Glendenning Lawrence Berkeley National Laboratory April 9, 2004 A faint nebula in the northern hemisphere is associated with the bright star Rigel in the constella- tion of Orion. The Witch Head Nebula glows primarily by reflected light. Credit and permission: John C. Mirtle. viii March 8, 2007 10:24 Our Place in the Universe | Trim Size: 10in x 7in book Acknowledgments I am deeply indebted to my dear friend, Joerg Huefner, Professor Emeritus at the University of Heidelberg. He has read most of the chapters throughout their writing and many rewritings. I have greatly enjoyed the many emails we have exchanged, both of a technical and a personal nature. To the extent that the book is coherent and self-contained now, I owe him great thanks, which I record here. I am grateful to Dr. Viola Ruck, Professor at North Lake College, Irving, Texas, my one-time valued research associate here in Berkeley, for her encouraging words for my previous book, After the Beginning, and her generosity in reading the present one. She has proofread the manuscript with great care and called my attention to innumerable details which needed attention. I owe her special thanks for this careful work: it was a great favor and the book owes much to her. To Laura Louis for her never-ending generosity, support and encourage- ment, I say thank you from the bottom of my heart. And to our dear and fine son Nathan I dedicate this book with love. Any acknowledgment would be incomplete if it did not pay tribute to the National Aeronautics and Space Administration (NASA), its personnel, and the many successful missions that have so enriched our knowledge of the universe at both the scientific and cultural levels. ix This page intentionally left blank March 8, 2007 10:24 Our Place in the Universe | Trim Size: 10in x 7in book Contents Preface vii Acknowledgments ix List of Figures xv Chapter 1. A Day without Yesterday 1 1.1 Instant of Creation . 1 1.2 Size and Age of Earth, Sun and Milky Way . 8 1.3 Einstein's Static Universe . 11 1.4 Expanding Universe . 12 1.5 Universe without Center . 16 1.6 Karl Schwarzschild and Black Holes . 18 1.7 Questions . 19 1.8 Boxes 1 9 . 30 Chapter 2. Formation of Galaxies 37 2.1 Fragmentation of Giant Clouds into Galaxies and Galaxy Clusters . 37 2.1.1 Galaxies and Stars . 39 2.2 Types of Galaxies .