Book review: ‘Quantum Legacies, Dispatches from an Uncertain World’

For more than a century, scientists have been pitting their wits against the conceptual uncertainties of quantum theory, trying to make sense of a messy world in which cats can be famously alive and dead at the same time (providing they’re in a box) and some particles tunnel through walls while others share entangled fates.

While for the lay reader the science can be hard enough to come to grips with, the scientists who enter into the fray of the nebulous and bizarre have had to deal with the wider uncertainties of a tumultuous 20th century in which world wars and the emergence of the nuclear age have cast political bias over their activities. ‘Quantum Legacies: Dispatches from an Uncertain World’ (University of Chicago Press, £21, ISBN 9780226698052) is American physicist and science historian David Kaiser’s valiant attempt to bring it all together, placing the intellectual and scientific conundrums in a wider context of global events.

As with so many statements about 20th-century science, ‘Quantum Legacies’ starts with Einstein or, to be more precise, the author’s first encounter with Einstein’s papers at the Princeton University Library in the 1990s, ever since which Kaiser has been “riveted by a kind of doubleness of scientific research”. You could call this doubleness ‘pure’ and ‘applied’, where the former is simply what the scientists did in their laboratories, while the latter is what the author elegantly describes as “the surrounding particulars of the world”.

It is these particularities of time and place that can shape scientific approach, the shifting ground of the “rise of Nazism and cataclysmic world war… the relentless calculation of nuclear brinkmanship during the Cold War” and the whiplash suddenness with which the Cold War came to an end. These turning points, says Kaiser, propel scientific discovery in certain directions as much as they can limit an individual’s horizons.

With this duality in mind, Kaiser sets out to introduce to the more general reader the most important episodes in the 20th-century scientific quest to understand space, time and matter, and the famous names behind it. From Einstein to Heisenberg, Schrödinger to Hawking, Kaiser humanises the people and by extension their ideas, all the while making connections between the inner world of the academic quantum theory community and the outer world of global events. This sociopolitical standpoint is a key factor in making the technical science relevant to the non-expert reader.

It’s easy to get swamped in the abstract: theoretical physicist Paul Ehrenfest is quoted here as feeling incompetent to “have even the most modest grasp about what makes sense in the flood of articles and books.” Kaiser knows this well and in this collection of highly entertaining essays he finds the perfect line between scientific scholarship and telling a good story. In fact, the sort of thing we’ve come to expect from a man whose previous books include ‘Groovy Science’.