String Theory For Dummies

387 Pages·2009·6.1 MB·English

by  Andrew Zimmerman Jones

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Science
Making Everything Easier!™
Your plain-English guide to this
complex scientific theory
Open the book and find: S h e o r y
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String theory is one of the most complicated sciences (cid:127) T he questions string theory t S t r i
attempts to answer
being explored today. Not to worry though! This
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informative guide clearly explains the basics of this hot (cid:127) Easy-to-follow examples
i
topic, discusses the theory’s hypotheses and predictions, n
(cid:127) Explanations of Einstein’s theory
and explores its curious implications. It also presents the of relativity, quantum theory, and
particle physics g
critical viewpoints in opposition to string theory so you can
draw your own conclusions. (cid:127) T he successes and failures of string

theory
T
(cid:127) Understand the “theory of everything” — grasp the key concepts
(cid:127) Fascinating bits of string theory
and importance of the theory, and learn why scientists are so h
including strings and branes
excited about finding a theory of quantum gravity
(cid:127) W ays that string theory can be e
(cid:127) It all comes down to physics — discover how string theory is built tested
upon the major scientific developments of the early 20th century
o
(cid:127) Discussions of loop quantum
(cid:127) Building the theory — trace the creation and development of gravity and other possible
string theory, discover its predictions, and see whether accurate alternative theories of gravity r
conclusions can be made y
(cid:127) How the theory may relate to
cosmic mysteries, from the origin
(cid:127) Take string theory for a spin — explore the core issue of extra
of matter to black holes
dimensions, the implications for cosmology, and how string
theory could explain certain properties of our universe
(cid:127) Boldly go where no one has gone — see what string theory has to Learn:
say about possible parallel universes, the origin and fate of our
universe, and the potential for time travel Go to Dummies.com® (cid:127) T he basic concepts of this controversial
for videos, step-by-step examples, theory
(cid:127) Hear from the critics — listen in on the heated debates about
how-to articles, or to shop!
string theory and weigh the alternatives being offered
(cid:127) How string theory builds on physics
concepts
(cid:127) The different viewpoints in the field
(cid:127) S tring theory’s physical implications
$19.99 US / $23.99 CN / £15.99 UK
Andrew Zimmerman Jones received his physics degree and graduated ISBN 978-0-470-46724-4
with honors from Wabash College, where he earned the Harold Q. Fuller
Prize in Physics. He is the Physics Guide for the New York Times’ About.com
Andrew Zimmerman Jones
Web site. Daniel Robbins received his PhD in physics from the University
Physics Guide, About.com
of Chicago and currently studies string theory and its implications at Texas Jones
A&M University. Robbins with Daniel Robbins, PhD in Physics
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String Theory
FOR
DUMmIES‰
by Andrew Zimmerman Jones
with Daniel Robbins, PhD in Physics
String Theory For Dummies®
Published by
Wiley Publishing, Inc.
111 River St.
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www.wiley.com
Copyright © 2010 by Wiley Publishing, Inc., Indianapolis, Indiana
Published by Wiley Publishing, Inc., Indianapolis, Indiana
Published simultaneously in Canada
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Library of Congress Control Number: 2009937832
ISBN: 978-0-470-46724-4
Manufactured in the United States of America
10 9 8 7 6 5 4 3 2 1
About the Author
Andrew Zimmerman Jones is the Physics Guide at About.com,
a New York Times Company, where he writes and edits news
and articles on all areas of physics. He spends his days working
as an editor for an educational assessment company. He holds a
bachelor’s degree in physics from Wabash College, where he also
studied mathematics and philosophy, and a master’s degree in
mathematical education from Purdue University.
In addition to work for About.com, Andrew has written a number
of nonfiction essays and reviews, which have appeared in The
Internet Review of Science Fiction, EpicSFF.com, Pink Floyd and
Philosophy, Black Gate, and Heroes and Philosophy. His fiction
credits include short stories in Abyss and Apex, KidVisions, The
Four Bubbas of the Apocalypse, and International House of Bubbas.
He has been a member of Mensa since the eighth grade and has
been intensely interested in both science and science fiction since
even earlier. Along the way, he’s also become an Eagle Scout, a
Master Mason in the Freemasons, and won the Harold Q. Fuller
Prize in Physics at Wabash College. His plan for world domination
nears completion with the publication of this book.
Andrew lives in central Indiana with his beautiful wife, Amber,
and son, Elijah. When he’s not writing or editing, he is most often
found reading, playing games, watching television, investigating
bizarre scientific phenomena, or updating his personal Web page,
which can be found at www.azjones.info. Andrew also regularly
reports on any new string theory implications on his Web site at
physics.about.com.

Dedication
This book is dedicated to my loving and lovely wife,
Amber Eckert-Jones. While physicists still search for a law to
unify all of the forces in the physical universe, I don’t need to,
because all the forces in my universe come together in you.
Author’s Acknowledgments
I must first profoundly thank my agent, Barb Doyen, for approaching
me with this project. My deepest thanks and appreciations go out
to the wonderful editorial staff at Wiley: Alissa Schwipps for her
valuable input at every step in the process, Vicki Adang for her
ability to turn my scientific babble into coherent explanations, and
Stacy Kennedy for gathering together such a great team in the first
place. I also very much appreciated the constructive and at times
critical input of Dr. Rolf Schimmrigk of Indiana University, South
Bend, who provided initial technical editing on the book. In
addition, I’m profoundly thankful for the extremely detailed
technical expertise, review, and frequent discussions offered by
Dr. Daniel Robbins of the Weinberg Theory Group at the University
of Texas at Austin.
Without the wonderful staff at About.com, notably the Education
Channel editor Madeleine Burry, I would never have had the
opportunity to grow as a writer in this field. Also to author Robert
J. Sawyer, for his mentorship and friendship over the years.
Thanks to you all!
Many thanks to physicists Lee Smolin and John W. Moffat of the
Perimeter Institute for Theoretical Physics, Leonard Susskind of
Stanford University, and Sylvester James Gates, director of the
University of Maryland’s Center for String and Particle Theory,
for e-mail exchanges that have helped to clarify various points
throughout the writing of this book.
Finally, my thanks go out to my wife, Amber, and son, Elijah, for
putting up with me, even when I was driven frantic by deadlines.
Thanks also to my mother, Nancy Zimmerman, and mother-in-law,
Tina Lewis, for their help in keeping the family entertained while I
worked feverishly in the basement.
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Contents at a Glance
Introduction ................................................................ 1
Part I: Introducing String Theory .................................. 7
Chapter 1: So What Is String Theory Anyway? ..............................................................9
Chapter 2: The Physics Road Dead Ends at Quantum Gravity ..................................25
Chapter 3: Accomplishments and Failures of String Theory .....................................39
Part II: The Physics Upon Which
String Theory Is Built ................................................. 49
Chapter 4: Putting String Theory in Context: Understanding
the Method of Science ..................................................................................................51
Chapter 5: What You Must Know about Classical Physics .........................................63
Chapter 6: Revolutionizing Space and Time: Einstein’s Relativity ............................81
Chapter 7: Brushing Up on Quantum Theory Basics ..................................................99
Chapter 8: The Standard Model of Particle Physics ..................................................119
Chapter 9: Physics in Space: Considering Cosmology and Astrophysics ..............137
Part III: Building String Theory:
A Theory of Everything ............................................. 159
Chapter 10: Early Strings and Superstrings:
Unearthing the Theory’s Beginnings ........................................................................161
Chapter 11: M-Theory and Beyond: Bringing String Theory Together ...................183
Chapter 12: Putting String Theory to the Test ...........................................................209
Part IV: The Unseen Cosmos: String Theory On the
Boundaries of Knowledge ......................................... 227
Chapter 13: Making Space for Extra Dimensions .......................................................229
Chapter 14: Our Universe — String Theory, Cosmology, and Astrophysics .........245
Chapter 15: Parallel Universes: Maybe You Can Be Two Places at Once ...............261
Chapter 16: Have Time, Will Travel .............................................................................275
Part V: What the Other Guys Say:
Criticisms and Alternatives ....................................... 295
Chapter 17: Taking a Closer Look at the String Theory Controversy .....................297
Chapter 18: Loop Quantum Gravity: String Theory’s Biggest Competitor .............313
Chapter 19: Considering Other Ways to
Explain the Universe ...................................................................................................323
Part VI: The Part of Tens .......................................... 337
Chapter 20: Ten Questions a Theory of Everything Should (Ideally) Answer .......339
Chapter 21: Ten Notable String Theorists ..................................................................345
Index ...................................................................... 351