Astronomers’ Universe For further volumes: http://www.springer.com/series/6960 Richard N. Boyd Stardust, Supernovae and the Molecules of Life Might We All Be Aliens? Richard N. Boyd Ohio State University (Emeritus) 5846 Leona Court Windsor, CA 95492, USA [email protected] ISSN 1614-659X ISBN 978-1-4614-1331-8 e-ISBN 978-1-4614-1332-5 DOI 10.1007/978-1-4614-1332-5 Springer New York Dordrecht Heidelberg London Library of Congress Control Number: 2011942323 © Springer Science+Business Media, LLC 2012 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not i dentified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Cover illustration: Earth picture from http://earthobservatory.nasa.gov Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) Preface In writing this book I gradually realized that I was addressing two very disparate scientific communities: biochemists and astrophys- icists, and that these communities are rarely in scientific commu- nication. Furthermore, the astrophysicists were further divided into two additional not-very-interactive communities, nuclear astrophysicists and neutrino astrophysicists. What this forced me to do is try to present what I regard as at least a minimal level of information from each of those communities in the context of the primary subject of this book, the chirality of the amino acids. The biochemists will quickly realize that my allegiances are with the astrophysicists; I hope I have done a reasonably credible job of rep- resenting the chemists. Trying to gain a reasonable level of personal credibility in biochemistry has certainly represented a major com- ponent of the time I spent in writing this book. In recognition of the wide diversity of topics, and the inevitable nomenclature that goes with each, I’ve tried to include a pretty complete glossary. Since this book is about origins, I felt it appropriate to pres- ent several types of origins, notably, the Big Bang, the origin of the elements, and finally the origin of the molecules of life in the cosmos and on planet Earth (and quite possibly on other planets). I have tried to present all of these subjects at a level that someone with a minimal background in science, but a strong interest in learning new things, can digest. This might also make the book appropriate for a course for undergraduates who are not science majors: “amino acid chirality for poets” (but with significant addi- tional input from the teacher, probably with the help of the many references to supplement the areas of professorial non-expertise). For those readers who have more of a science background, I hope I’ve not insulted your intelligence too much; the subjects in this book are sufficiently varied that I can almost guarantee that you will eventually find something discussed in which you’re not an expert. In any event, I have tried to describe the subjects of the v vvii Preface book in such a way that a class of undergraduates could use the book to truly get a grounding in astrobiology. Although I have certainly emphasized the model that I, together with my colleagues Toshitaka Kajino and Takashi Onaka, have built, I have also tried to present enough generality in the subjects relevant to the origin of life that students can gain an overall impression of the basic features of the subject. And, of course, I’ve included some physics background subjects that are favorites of mine, which are relevant to origins, and which can serve as general knowledge for students and other readers who are generally curious about science. In writing this book I’ve violated one of the basic tenets asso- ciated with attempts to popularize science: don’t include equa- tions. I’ve included lots of equations. In one instance the equation was unavoidable: that was the discussion of the Drake equation, which is pretty basic to discussions of detecting extraterrestrial life. However, my other equations are not the sort of thing you find in algebra books, rather they are more shorthand ways of stat- ing processes or reactions. These are not equations that could be solved for one of the variables; they don’t contain variables! I hope the readers will find them useful. I am deeply indebted to many people for contributing to my knowledge of this subject, and therefore to the content of this book. First and foremost in this regard are my collaborators on the development of the Supernova Neutrino Amino Acid Process- ing model, Toshitaka Kajino and Takashi Onaka, for their many contributions to our efforts. This book could not have been writ- ten without their inputs to our two papers. I must include in my acknowledgements two other people who gave a boost to the early efforts: Isao Tanihata and Reiko Kuroda. And, finally, I gratefully acknowledge my wife, Sidnee, who although she is a nonscientist, read through the manuscript, and in many instances pointed out the places where the physicist in me had gotten carried away with physics-speak. The places where the physics-speak still lurks are my fault, but the readers can be sure that there are many less such places than there would have been without Sidnee’s efforts. Windsor, CA, USA Richard N. Boyd About the Author Dr. Richard N. Boyd was the Science Director of the National Igni- tion Facility, Lawrence Livermore National Lab from 2007 to 2010 and now serves as a staff physicist at LLNL. He earned his Ph.D. in physics from the University of Minnesota in 1967, and has been a physics professor at the University of Rochester from 1972 to 1978 and a professor of physics and astronomy at Ohio State University from 1984 to 2002. Dr. Boyd also served as a program officer at the National Science Foundation from 2002 to 2006, managing the NSF portfolios in nuclear and particle astrophysics as well as nuclear physics. Following that, he was a visiting professor at the National Astronomical Observatory in Japan. Dr. Boyd has enjoyed a research career that resulted in more than 200 publications, both experimental and theoretical, and one graduate-level textbook on nuclear astrophysics. He received an Outstanding Scholar award from Ohio State University in 1982, and was named a Fellow of the American Physical Society and of the American Association for the Advancement of Science. He was named an honorary Native American of the Santa Clara Pueblo in 1997, and an Eminent Scientist of the Institute for Physical and Chemical Research in Japan in 1998–1999. vii Contents Preface ........................................................................................ v About the Author ...................................................................... vii 1. Introduction ........................................................................ 1 1.1 In the Beginning ......................................................... 1 1.2 What Is “Life?” ........................................................... 6 1.3 The Miller Urey Experiment ..................................... 10 1.4 General Background and Definitions ........................ 13 References ........................................................................... 17 2. What is the Origin of the Lightest Elements? ................... 21 2.1 The Big Bang ............................................................... 21 2.2 The Supernova Cosmology Project ........................... 25 2.3 The Wilkinson Microwave Anisotropy Probe .......... 27 2.4 Olber’s Paradox .......................................................... 30 2.5 Big Bang Nucleosynthesis (BBN) ............................... 31 References ........................................................................... 38 3. What is the Origin of the Rest of the Elements? .............. 41 3.1 Introduction to Stellar Nucleosynthesis .................. 41 3.1.1 Hydrogen Burning .......................................... 43 3.1.2 Helium Burning .............................................. 49 3.1.3 Subsequent Burning Stages ............................ 50 3.2 After Stellar Burning .................................................. 53 3.2.1 Creating a Core-Collapse Supernova Explosion ...................................... 54 3.2.2 Synthesizing the Heavy Elements ................. 56 3.2.3 White Dwarfs .................................................. 61 3.2.4 Type Ia Supernovae ......................................... 62 References ........................................................................... 63 ix