Black holes are like the dangerous kids drinking in the corner at a party: everyone’s heard of them, no one goes near them, and nobody can pin down exactly what’s going on inside them.
First posited in 1783, and predicted in the theory of general relativity, black holes were thought for years to be too bizarre to be anything but a mathematical curiosity. What Marcia Bartusiak calls the “stark and alien weirdness” of the idea of matter squeezed to the point where it sucks in everything in the vicinity seemed anathema to the theoretical physics world. It took until the 1960s for black holes to “go mainstream”; astrophysical measurements made since then have provided evidence that they are not just mainstream, but real. Black holes are the poster children for all that is non-intuitive about physics, and this book gives the history of how we have grown to accept and understand them.
Einstein’s theory of general relativity was published 100 years ago, and given the popularity of black holes in cutting-edge science, fiction and imagination, it is surprising that popular histories of the development of black hole theory are relatively rare. Black Hole couldn’t be more timely, and has the benefit – or frustration, depending on your point of view – of keeping the science simple. Bartusiak’s field of scholarship is science writing, and her text is lively and dramatic, sometimes relentlessly so. There are some fascinating stories that show just how awkward the history of black holes really is. We learn that science fiction embraced the term “black hole” at least a year before science officially did. And in a twist worthy of fiction, we hear of the Gravity Research Foundation, founded by businessman Roger Babson in 1948 to find antigravity, but which would inadvertently help to revive interest in general relativity and reward the work of future Nobel prizewinners.
If you are a fast reader, you may find Bartusiak’s descriptions piling up in your head faster than your brain can process them. Analogies and pictures are sprinkled liberally throughout the text: cosmic jets “like the fierce stream of a fire hose”; supermassive black holes sucking in surrounding matter “like a chowhound at an all-you-can-eat buffet”; rotating objects dragging space-time “like the cake batter that circulates in a bowl around a whirling beater”. There’s no danger of being bored, only of sensory overload. If you haven’t come across these ideas yet, you may just find your head going into overdrive. If you have, you’ll still be entertained.
The trouble with black holes is that even today no one really understands them. Nevertheless, Bartusiak does a good job at tracing the twisted route that our understanding has followed, from Newton to Einstein and to today as we try to extend gravity to quantum scales, too. The book’s final chapter brings us bang up to date, mentioning efforts to join gravity and quantum mechanics together to obtain a theory of everything. Progress in this area is so fast that experiments must scramble to catch up; we still seek evidence for the quantisation of gravity. Unintentionally, the strange ideas contained in the last few pages provide a neat illustration that black hole science is hard science, logical and obvious only in retrospect, and still a work in progress.
Tara Shears is professor of physics, University of Liverpool.
Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled on by Hawking Became Loved
By Marcia Bartusiak
Yale University Press, 256pp, £14.99
Published 4 June 2015