Review of Knocking on Heaven's Door: How Physics and Scientific Thinking Illuminate the Universe and the Modern World by Lisa Randall

I love physics. I love that we know so much about physics, and that we still have so much left to learn! I love reading about how far we have come from Ptolemaic ideas of geocentricity to mapping the cosmic microwave background radiation itself. And don’t get me started about the Large Hadron Collider: 7 TeV? Really? Up to 14 TeV in the next few years? Various atrocious self-help books claim they’ll help you unlock “the secrets of the universe”. The scientists and engineers at CERN are quite literally doing that as we speak. Science is awesome.

Lisa Randall is a good companion to have along for a ride on the “science-is-awesome” rollercoaster. Her enthusiasm is inescapable as she explains everything from effective theories to the mystery of missing antimatter—it’s clear that Randall is more than a science writer, that she not only studies these topics for a living but loves them too. This makes the book so much more enjoyable, which is a must for something so steeped in particle physics.

Knocking on Heaven’s Door has something of a chimeric feel to it. At first it seems like a standard popular science book. Randall begins with an exploration of scale from the subatomic end: “The universe is big! Atoms are small! Protons are smaller! Quarks are smaller still!” It’s fascinating and, for the neophyte, probably enlightening, but it was nothing I hadn’t seen before. When she does branch out, she branches out into tangents … she spends an entire chapter talking about the 2008 economic crisis, risk management and analysis, etc., and comparing it to how scientists do their research. If I want to read a book about why short-sighted and greedy bankers caused the economic crisis, I’d do that. I came here for particle physics, Randall! And call me an expert snob, but I prefer to read about economics from economists and physics from physicists—Randall’s attempts at some kind of comparison or syncretism leave much to be desired and feel like a stretch.

The rest of the philosophy part of this book varies greatly, from somewhat flat to outright inspirational. While I agree with a lot of what Randall says about the science versus religion quagmire, she’s not really saying anything new. On the other hand, I loved her discussion of Galileo’s contributions to science and her explanation for why scientific thinking and inquiry is valuable. In particular, her explanation of effective theories and domains of validity remind me a lot of Hawking and Mlodinow’s discussions of model-dependent reality in The Grand Design.

Randall clears up some of the confusion that seems to accumulate as a result of the annual tradition known as “everything you learned in last year’s science class is wrong … here’s how it actually works”. She mentions this phenomenon herself, and I hated it when I was in school. Obviously I don’t expect us to try using the same kind of language to describe the universe to small children as we do to adults, but that’s no reason we need to perpetuate things like the solar-system model of the atom without even mentioning that it’s rather inaccurate. I’m a fairly enthusiastic and literate person when it comes to science, and if I’m working very hard in my spare time to undo the misunderstandings I’ve inherited from formal education, I can only imagine the harm done to my peers who aren’t on a similar quest. Hence, I once again wish philosophy were a more explicit part of the curriculum, for learning about science requires the ability to think like a scientist (and maybe a little bit like a philosopher).

The bulk of Knocking on Heaven’s Door is an explanation of the workings and goals of the Large Hadron Collider. The former will make even the most devoted engineer’s eyes glaze over—nonetheless, Randall succeeds in conveying the impressive sense of scale and achievement that the LHC represents. It’s the largest machine we’ve built, and it’s designed to look at the smallest things we can imagine! So the technical details can be a bit much at times, but Randall certainly clarifies each detector’s role in the experiments, as well as how particle accelerators in general worked. I liked hearing her explanations of when one would want to collide a particle and its antiparticle versus a particle and itself. However, I would have liked to learn more about how the LHC might provide insight into the matter/antimatter asymmetry.

I was quite pleased by the opening of this book in terms of its accessibility to various audiences. Now I’m not so sure to whom I would recommend it. Parts of it are too simple for most science geeks, while others are too complicated unless one pretty much has a degree in the subject. This unevenness of difficulty level means that Knocking on Heaven’s Door, while comprehensive, is not likely to be uniformly enjoyable by anyone. It’s one of the most detailed physics books I’ve encountered, and when I did understand them, Randall’s explanations were enlightening. Plus, it provides very cogent explanations of how particle accelerators operate. If this sounds like your cup of tea, check it out. Otherwise, I suspect there are plenty of other popular physics texts that replicate much of these explanations and ideas.