Preface

When I was asked by Bentham Science Publishers to propose an idea for an e-book on current issues in physics I thought it was a no-brainer. For several decades the ambition of unifying all of physics under one fundamental set of rules that “fit on one side of a T-shirt” (as some physicists are fond of saying) has been an increasingly nagging objective of basic research. Many ideas were proposed, and this book explores some of the most recent of them, but there has never been a more exciting time in the history of this search: Our most complex experimental tool yet; the $10 billion “Large Hadron Collider”, in Geneva Switzerland, has been turned on and has already had some results published. Who knows what wonderful things it will produce over the next few years and in what directions of research will it guide us. It is then the perfect time to slow down, take a deep breath, and ask ourselves “Are we there yet?” This is what this book is about.

The book is (roughly) structured following the theme:

History ⇨ Articles on String Theory ⇨ Articles on other theories (Loop Quantum Gravity etc.) ⇨ New ideas and speculations ⇨ General discussions

The articles, however, are self-contained, hence the readers may choose to read them in any order they feel comfortable with. Inevitably, there is some overlap in the material as different authors briefly review the same concepts. This is done, however, using different styles and approaches and is not repetitious. In most of these articles, the authors present their own views on what the future will be like and what possible new tools physicists may need. The following are brief biographical notes about the contributors, in order of appearance:

• The Foreword was written by John Donoghue; professor of theoretical physics at the University of Massachusetts at Amherst. His expertise ranges over several branches of physics at once, having published papers in six research fields: theoretical high energy physics, phenomenology of high energy physics, general relativity, quantum gravity, astrophysics and nuclear physics. He is currently developing ideas in the field of emergent physics. Professor Donoghue is co-author to a classic textbook on quantum field theory “Dynamics of the Standard Model”, published by Cambridge Monographs on Particle Physics, Nuclear Physics and Cosmology” (1992) and editor of “CP Violation and the Limits of the Standard Model (TASI 1994)” published by “World Scientific” (1995). (http://blogs.umass.edu/donoghue/).
• “The Fire in the Equations”. Tasneem Zehra Husain is a string theorist; currently assistant professor at the LUMS School of Science & Engineering, Sector U, D.H.A, Lahore, Pakistan. She received her PhD from Stockholm University, followed by a postdoctoral research position for two years at Harvard University. Prior to that she had acquired a scholarship at the International Center for Theoretical Physics (ICTP) in Trieste, Italy. Her research interests have so far focused on eleven dimensional supergravity theory. Dr. Husain is the first Pakistani woman to ever achieve such high accomplishments in science.
• “String Theory and the Failure of Unification”. Peter Woit is a mathematical physicist, currently Senior Lecturer in the mathematics department at Columbia University. After a doctoral degree in particle theory from Princeton, he was a postdoctoral researcher at the YITP in Stony Brook and MSRI in Berkeley before arriving at Columbia. His book “Not Even Wrong” was published in 2006, and he has been maintaining a blog by the same name since 2004 at (http://www.math.columbia.edu/~woit/blog).
• “Can String Theory Survive Complete Falsification?” Moataz H. Emam is assistant professor of physics at the State University of New York College at Cortland, where he focuses his research on particular aspects of symmetries that arise in certain string-theoretic models as well as developing various teaching curricula with particular focus on involving undergraduate students in theoretical physics research. His future writing plans involve a technical text on certain aspects of the string theory landscape as well as an undergraduate textbook on spacetime physics in both special and general relativity.
• “String Theory in the Classroom. A Case Study”. D. Cho is currently assistant professor of physics at Kenyon College. His area of specialty is gravitational physics. He has worked on a range of problems from gravitational radiation reaction to quantum gravity in higher dimensions. His recent research is focused on gravitational radiation reaction problems associated with rapidly rotating neutron stars, and quantum field theory in the early universe.
• “Science Fiction of Everything”. Florian Conrady is currently a postdoctoral researcher at the Perimeter Institute for Theoretical Physics in Waterloo, Canada. He previously held a postdoctoral position at Penn State University and he received his doctorate from Humboldt University in Berlin. The main topics of his research are quantum theories of gravity and topology; in particular loop quantum gravity and spin foam models.
• “A Vision of Quantum Gravity”. Tim Koslowski is currently a postdoctoral researcher with the quantum gravity group at the Perimeter Institute. He is working on various approaches to quantum gravity, in particular loop quantum gravity and the asymptotic safety scenario. He studied physics at The University of Texas at Austin and the University of Würzburg.
• “Does History Repeat Itself in a Non-Cyclic Universe?” Sundance Bilson-Thompson obtained his PhD in lattice quantum chromodynamics (QCD) from the University of Adelaide, followed by a year of postdoctoral work in Seoul, South Korea. Dr. Bilson-Thompson proposed a model of the substructure of quarks and leptons which turned out to have possible relevance to quantum gravity. This earned him a three year postdoctoral research position at the Perimeter Institute. In late 2009 he was awarded a postdoctoral research position at the University of Adelaide.
• “Shooting in the Dark”. Sabine Hossenfelder is assistant professor of physics at the Nordic Institute for Theoretical Physics (NORDITA) in Stockholm, Sweden. She focuses on research in physics beyond the standard model and the phenomenology of quantum gravity. Together with her husband, Dr. Hossenfelder maintains a physics blog called “Backreaction” at (http://backreaction.blogspot.com/).
• “Deciphering Quantum Theory”. P. Goyal is a theoretical physicist specializing in information physics and the foundations of quantum theory. His recent research focus has been on creating an information-theoretic underpinning for quantum theory. Currently a postdoctoral fellow at the Perimeter Institute, he was previously at the Cavendish Laboratory at the University of Cambridge, where he did his doctoral research and was subsequently a departmental research fellow. In September 2010, he will start a new position as assistant professor in information physics at the State University of New York at Albany.

I would like to thank all of the authors for pouring their minds and souls into these articles; sharing with the reader their views on this most exciting of times. Particular thanks and gratitude are due to Professor John Donoghue for writing the foreword. Such a contribution from a scientist of his caliber is an honor and a privilege. Many thanks are due to Dr. Tasneem Husain for agreeing to act as editor to my own contribution and providing valuable feedback. I am also very indebted to my friend Dr. Mohamed Anber for going through the manuscript in detail and proposing essential corrections. Last, but by no means least, I would like to take the liberty in representing all authors in deep thanks to all of our unsung heroes, those who are always the backbone of any effort: family members, spouses, children, mentors, friends and all significant others.

Manal and the rest of the M5: this is for you …