How Far Beyond Einstein We Are Now

Warped Passages
Lisa Randall
Ecco. 512 pp. $27.95.
 
Einstein was legendarily larger-than-life. He revolutionized modern physics while employed as a clerk in a patent office in Switzerland. He was photogenic in a silly sort of way, setting the prototype for the twentieth century’s depiction of mad science. He was quotable: “only two things are infinite, the universe and human stupidity, and I’m not sure about the former.” His name, to this day, is synonymous with genius. However, popular culture seems to think modern physics ended shortly after Einstein, with quantum mechanics. It very much didn’t.
That’s why Warped Passages: Unraveling the Mysteries of the Universe’s Hidden Dimensions is a valuable book. Lisa Randall, a Harvard professor of theoretical physics, guides a reader through the many significant discoveries in particle physics that have taken place over the past hundred years, which are generally united in a theory called the Standard Model. Basic physics, as you may have learned it in high school or in entry-level college courses, leaves many questions about the nature of the universe unanswered. Those questions are not remote from everyday life, either, but concern such fundamental questions as why anything has mass.
Randall starts her survey with a review of relativity and quantum mechanics in one short chapter each. Those chapters explain their concepts incredibly well given the space they take to do it, but they could easily leave a reader, particularly one who was seeing those concepts for the first time, reeling a little. That is a pattern that will continue through the rest of the book. Randall then dives into the search for ever-more elementary particles that has occupied physics for years. The Large Hadron Collider (LHC) in Switzerland, the one which you’ve probably seen on the news, was built to try to find two types of Higgs particles, a type of sub-nuclear particle. She explains why they would matter: the two types should, theoretically, have very similar masses. However, preliminary experimental results suggest that one’s mass is ten trillion times that of the other. Once physicists can create a theory that cleanly accounts for both, we will be much closer to understanding both mass and gravity.
Finally, Randall reaches the heart of her book, the theoretical possibilities of the warped dimensions of the title. It’s heady stuff, but slightly easier, and more fun, than the background it took to get to it. It’s still theoretical, but holds the promise of explaining some of the mysteries of physics. The particular one that these dimensions hope to explain is one of gravity’s properties.
There are four fundamental forces in the universe: gravity, the electromagnetic force, the strong force, and the weak force. The weak force’s name is misleading, because gravity is the weakest of the forces in our universe by many, many orders of magnitude. The weak force was so named because gravity is so weak that it can be almost entirely ignored on a sub-atomic scale, and the weak force is the weakest of the remaining three. Randall, in collaboration with Raman Sundrum, proposed a theory in 1999 that could help explain why gravity is so much weaker than the other three. That theory, which she explains, posits that gravity is so much weaker because it works on a more complicated set of dimensions than those of which we are usually aware, which offset its force. The background took the reader up to the present. Randall’s work explains where physics might go in the future.
As I said earlier, this book can leave a reader’s head spinning. However, Randall does a good job with an extraordinarily difficult subject. She does a near-perfect job of walking the middle road between the two cardinal sins of science writing: on the one hand, using equations instead of words, and on the other, making the science stupid. There is not one solitary equation in the text of the book, although there is a short set of endnotes with more math. Randall might have gone too far when she did so, as there were a few places where bringing the endnotes into the text, or just stating an idea in both an equation and the text, would have clarified. Nevertheless, writing this 450-page tome on high-level physics is a monumental feat, even if I quibble with it on the margins. Even without equations, however, Warped Passages is extremely informative. It cannot be accused of being overly dumbed-down. Instead, the book is a warp tour through the past hundred years of big ideas in modern physics, and even into the future. As for the symptom of head-spinning when the number of big ideas gets to be too much, take it slowly. This book isn’t too difficult. As long as a reader consumes it in small portions, it’s all eminently digestible, and worth the time it takes to think about it.
I think that the best illustration I have for why one should read this book is in the changed reaction I had to news stories about the LHC. Before I read this book, my thoughts tended to run along the lines of “Ah, the scientists! In Switzerland! Where they do sub-atomic things. Explosions, maybe?” Having read Warped Passages, I now understand, as much as somebody who doesn’t even know much calculus can, what the scientists there are trying to do. I understand the problems that they’re trying to solve, and the ways in which they expect that those problems might be solved, and the areas where they don’t know what to expect. I also understand the theoretical models to which physics might turn if and when the Standard Model fails.