Warped Passages - Lisa Randall [3]
Greg Elliott and Jonathan Flynn executed the beautiful pictures contained in this book, and I’m extraordinarily grateful for their important contribution. I thank Rob Meyer and Laura Van Wyk for helping me obtain permissions for the many quotes throughout the book. I have made every effort to properly credit sources. If you think you have not been credited properly, please let me know.
I also want to thank my collaborators on my research that I describe in this book, particularly Raman Sundrum and Andreas Karch, who were both great to work with. And I’d like to acknowledge the contributions of the many physicists who have thought about these and related ideas, including those that I didn’t have room to discuss.
I’d also like to express my appreciation to my Ecco Press editor, Dan Halpern, my Penguin editors, Stefan McGrath and Will Goodlad, and my copy editors in the U.S. and England, Lyman Lyons and John Woodruff, for their many helpful suggestions and for their support for this book. And I wish to thank my literary agent, John Brockman, as well as Katinka Matson, for their important commentary and advice, and for their invaluable help in getting this book launched. I’m also grateful to Harvard University and to the Radcliffe Institute for Advanced Study for providing some time to focus on this book, and to MIT, Princeton, Harvard, the National Science Foundation, the Department of Energy, and the Alfred P. Sloan Foundation for supporting my research.
Finally, I wish to thank my family: my parents, Richard Randall and Gladys Randall, and my sisters, Barbara Randall and Dana Randall, for backing my scientific career and for sharing their humor, thoughts, and encouragement over the years. Lynn Festa, Beth Lyman, Gene Lyman, and Jen Sacks were extremely supportive and I thank them all for their wonderful advice and suggestions along the way. And lastly, I’m so grateful to Stuart Hall for his insightful perspective, helpful comments, and unselfish support.
I thank you all and hope you find your contributions are repaid.
Lisa Randall
Cambridge, MA
April 2005
Introduction
Got to be good looking
’Cause he’s so hard to see.
The Beatles
The universe has its secrets. Extra dimensions of space might be one of them. If so, the universe has been hiding those dimensions, protecting them, keeping them coyly under wraps. From a casual glance, you would never suspect a thing.
The disinformation campaign began back in the crib, which first introduced you to three spatial dimensions. Those were the two dimensions in which you crawled, plus the remaining one by which you climbed out. Since that time, physical laws—not to mention common sense—have bolstered the belief in three dimensions, quelling any suspicion that there might be more.
Figure 1. A baby’s three-dimensional world.
But spacetime could be dramatically different from anything you’ve ever imagined. No physical theory we know of dictates that there should be only three dimensions of space. Dismissing the possibility of extra dimensions before even considering their existence might be very premature. Just as “up-down” is a different direction from “left-right” or “forward-backward,” other completely new dimensions could exist in our cosmos. Although we can’t see them with our eyes or feel them with our fingertips, additional dimensions of space are a logical possibility.
Such hypothetical unseen dimensions don’t yet have a name. But should they exist, they would be new directions along which something might travel. So when I need a name for an extra dimension, I’ll sometimes call it a passage. (And when I explicitly discuss