Sunday Times, 06 March 2016
Black Holes Blues
And Other Songs from Outer Space
by Janna Levin
At the moment when the gravitational wave that made the headlines a few week ago was passing through Alpha Centauri — a group of three stars located a mere 4.37 light years away — Janna Levin, evidently deeply embedded with the team of wave-hunters, started working on this book. Publication now marks two cosmically incredible events. First, the detection of the wave vindicates Albert Einstein’s General Theory of Relativity and, secondly, this is a popular science book that is very, very well written.
Popular science is usually where the English language goes to die. Of course there are exceptions — Richard Dawkins, Edward O Wilson, James Lovelock — but, to a rough approximation, all of the worst writing I have ever been forced to read has been popsci. You may now understand why I reached the beautiful ending of this book with a little sob of gratitude.
Levin has inverted the usual formula. Your average popsci hack plods breathlessly through the technicalities, inserting little fragments of reportage for drama and to make the story more “human”. This is a terrible idea. Levin starts from the humans and the story, and lets the science emerge organically until, finally, the science and the human become one.
The detection of the wave happened in September (the announcement was delayed to check this was a genuine signal) almost exactly 100 years after the publication of Einstein’s theory that predicted the existence of such waves. The wave was detected within one hour of the $300m detection machines becoming fully operational. Furthermore, if the machines hadn’t been turned on at exactly that moment — and they nearly weren’t — they would have missed the faint sounds of the merging of two black holes 1.4 billion light years away, a distant gasp from one of the most explosive — and rare — events in the history of the universe. Plainly there is a benign power watching over this project.
The story begins in November 1915 when Einstein announced his general theory of relativity, the blockbuster sequel to the special theory published 10 years earlier. He had turned the universe into a four-dimensional fabric of space and time; gravity, we now knew, was a distortion of this fabric. So, in theory, there should be waves of gravity, a ripple zone in the fabric, spreading outwards from every event. Gravity being the weakest fundamental force, only very large events would produce detectable waves.
With that final statement physics becomes politics. In recent years, physicists’ theories have become so complex and ambitious that the process of experimental verification has become hard — or sometimes impossible — to fund. Government queasiness in America about cost and result, for instance, prevented them from building a supercollider, handing the triumph of the discovery of the Higgs boson to the better-funded Europeans at Cern.
By this logic, gravity wave detectors would be a) expensive, b) not guaranteed to work, because a powerful detectable event may not have happened at the right moment, and c) what was the point anyway? Neither the Higgs boson nor gravitational waves are going to help anybody get through Thursday. So Levin’s story is a tale of political, philosophical and financial finagling over decades, with many casualties along the way.
The casualties are crucial to the book and heartbreaking for Levin and her readers. The first and strangest is Joe Weber. For 30 years he worked and fought for his case that, in 1969, he had detected the waves in the vibrations of a suspended 3,000lb aluminium cylinder. Steadily it became clear to everybody but Joe that he had not, and he became an outcast and an embarrassment. He died in 2000.
Then there was the Scot Ron Drever, a “scientific Mozart” who never fitted in, perhaps because, as Levin comments, “everyone around him was forced to play Salieri”. Back in Scotland, now suffering from dementia, he could only watch news of the discovery from a care home.
Such people — and many others — devoted their lives to the waves. Somehow they convinced others to fund the building of Ligo, the Laser Interferometer Gravitational-Wave Observatory, or, rather, to be sure of any detection, two Ligos, almost 2,000 miles apart in Louisiana and Washington state. The locations give Levin some light relief. One overheard conversation suggests some Louisiana locals thought it was a government time-travel machine. Over in herbivore Washington they just worried about the effects on the ecosystem.
The Ligos are L-shaped structures, each arm being 2½ miles long. One will stretch when a wave passes, the other will contract, but the muscular verbs are misleading. The changes are insanely tiny — less than the width of an atomic nucleus. To measure this, lasers fire down the lengths of the arms and are reflected back by mirrors. This, you can imagine, raises one or two engineering issues. Levin is brilliant on this, and I’m not going to do a spoiler and give away all her best lines here.
As the waves whispered in from Alpha Centauri, Levin lived the Ligo life right up to that fine, fine day last September when the arms stretched and squashed and great Albert was vindicated. New dreamers of new machines must now come along; gravity waves are a whole new form of astronomy.
The waves whisper on regardless, six light months beyond the earth as I type this. But now we know they are everywhere all the time; I am making them with these keystrokes. Detecting them was like suddenly noticing the air we breathe. We also noticed something that lies far beyond us: “Black holes. That’s what the old-timers were after,” says Rainer Weiss, one of the scientists who stayed the Ligo course, “pure geometry. Pure spacetime coalescence.” Or to put it another way — and this is the gist of Levin’s ending — we had detected the silent end of the cosmos into which all our knowledge and vanities are heading.