Stump a physicist

Think back to the last time you took a physics exam. Was your heart racing? Did you gulp when you realized that you had no idea – really no idea at all – how to solve the first problem? And then, just as the fear threatened to engulf you, did you hear a tiny, confident voice in the back of your head saying, “Hold on a minute, what if I do this…”? If any of these experiences sound familiar to you – and if they inspire a certain wry fondness rather than a panic attack – then you need to add Physics on Your Feet to your library. Subtitled “Ninety Minutes of Shame but a PhD for the Rest of Your Life,” the book is a collection of the best questions posed to physics students at the University of California, Berkeley, during the oral exams that were, until 2010, part of the standard postgraduate training programme. The curators of this collection, Dmitry Budker and Alexander Sushkov, have been on both sides of the examiner/examinee divide (both of them earned their PhDs at Berkeley, and Budker is now a physics professor there), and the questions that appear in their book are both fiendish and fascinating. A few can be solved using only high-school-level physics, carefully applied. But be warned: some problems that seem simple actually contain hidden depths, and a few of them might even lead to heated debates in departmental tea rooms and company cafes as senior physicists argue over the answers. (Try the one about tides during a solar eclipse on an unsuspecting friend.) Budker and Sushkov have supplied their own solutions to each of the problems, but they do not claim that these are the only answers; some of the questions are, in any case, open-ended enough to permit several possible approaches. Readers who work their way through all of these questions won’t get a PhD for doing so, but they will get a much better appreciation for the richness of physics as a discipline.

• 2015 Oxford University Press £19.99pb 224pp

Going deep underground

The inside of the Earth is intimately connected to the universe outside it. Many of the treasures hidden there originated in distant stars and galaxies, and theories of our solar system’s very early years, when the Earth and its neighbours coalesced, can also tell us much about our planet’s present composition. This deep connection helps explain why an astronomer, David Whitehouse, has chosen to base his latest book on the Earth’s interior. Journey to the Centre of the Earth takes its title from Jules Verne’s novel, which celebrates its 150th anniversary this year, and, like Verne, Whitehouse has a magpie’s eye for interesting facts and stories. Perhaps the oddest of these little nuggets is the revelation that the brand name Bovril comes from Vril, an early science-fiction novel about a subterranean race of super-humans. None of these tales of the deep Earth is told in very much detail, though, which is sometimes a pity. Humankind’s various attempts to drill through the Earth’s crust and into the mantle, for example, occupy a mere eight pages in Journey, yet it is clear from Whitehouse’s description that an entire book could be written about the Kola Superdeep project alone. This effort lasted for 25 years and produced a 12 km-deep borehole before technical and monetary difficulties ended operations, and Whitehouse calls it “one of the great scientific projects of the 20th century”. Perhaps someone will write a book about it one day, but in the meantime, there is plenty to enjoy in this one. As Whitehouse puts it, “if you want strangeness and surprises, look below”.

• 2015 Weidenfeld & Nicholson £20.00hb 288pp