Skip to main content

Gravitational Waves - Brian Clegg ****

The message of this book is summed up in its subtitle: 'How Einstein’s spacetime ripples reveal the secrets of the universe.' Gravitational waves really do reveal secrets – astronomical phenomena that can’t be observed any other way. The Einstein connection comes via general relativity – his alternative to Newton’s theory of gravity which is, notoriously, almost indistinguishable from it for most practical purposes. There are a few situations where the two theories make slightly different predictions, and in these cases general relativity comes out on top. When the Laser Interferometer Gravitational Wave Observatory (LIGO) reported the detection of gravitational waves in February 2016, most journalists treated it as just another of these academic “ticks in the box” for Einstein.

That’s underselling one of the most exciting breakthroughs in modern science – and this book aims to put the record straight. According to Brian Clegg, the LIGO announcement 'signalled the beginning of the biggest change to astronomy since the introduction of telescopes.' I’m not sure I’d go quite that far – the radio astronomy revolution of the 20th century was probably bigger – but gravitational waves may end up a close second. In principle they offer a means of directly observing hitherto purely theoretical concepts – from black holes and dark matter to the Big Bang itself.

When that first LIGO detection occurred, it wasn’t just a sharp spike above the noise background that people assumed had to be a gravitational wave (which is how I’d pictured it, based on media reports, before I read this book). It was a structured signal that, brief though it was, contained a huge amount of meaningful information. When properly interpreted, it told researchers not just  that the signal came from the merger of two black holes, but that they were located about 1.4 billion light years away, and had masses approximately 36 and 29 times that of the Sun. That’s not just 'confirming a theory' – it’s doing proper observational astronomy.

This is relatively short book, but it covers most of what an interested, non-specialist reader is going to want to know. It succinctly explains what gravitational waves are, how their existence was predicted, and methods by which they might be detected. It describes the design and construction of LIGO, the detections that have been made with it, and their physical interpretation. And there’s a substantial concluding chapter on what the future holds for gravitational wave astronomy.

With such a tightly packed book, it’s inevitable that some topics get covered in depth at the expense of others. For my taste, there was rather too much about the statistical analysis of the data to remove false alarms, and not enough about actually interpreting the data in terms of the astrophysical processes that produced it. But issues like that aren’t really a problem now that we have the internet. If you finish a book and your head is buzzing with unanswered questions, at least you know what to type into a Google search.


Paperback:  

Kindle:  


Review by Andrew May
Please note, this title is written by the editor of the Popular Science website. Our review is still an honest opinion – and we could hardly omit the book – but do want to make the connection clear.

Comments

Popular posts from this blog

Rockets and Rayguns - Andrew May ****

The Cold War period saw dramatic developments in science and technology, coinciding with the flourishing of the science fiction genre. In Rockets and Rayguns, Andrew May draws on the parallels between reality and fiction, each influencing the other.

Inevitably a major Cold War theme was the threat of nuclear war, and May opens with the bomb. It's fascinating that fiction got there first - nuclear weapons were featured in science fiction when many physicists were still doubting the practicality of using nuclear energy. Of course, it's a lot easier to simply take a concept and dream up a weapon than it is to make it for real - for example, H. G. Wells' prophetic nuclear bombs from his 1914 The World Set Free were nothing like the real thing. And some science fiction devices concepts - notably ray guns and force fields - came to very little in reality. However this doesn't prevent the parallels being of interest.

May gives us a mix of the science - describing how nuclear we…

Galileo Galilei, the Tuscan Artist – Pietro Greco ****

Near the beginning of John Milton’s epic poem Paradise Lost, he refers to a ‘Tuscan artist’ viewing the Moon through an optic glass. He’s talking about Galileo – one of history’s greatest scientists, but not the most obvious person to slap an ‘artist’ label on. Yet Galileo lived at a time – the Renaissance – when it was fashionable to dabble impartially in both the arts and sciences. Look up ‘Renaissance man’ on Wikipedia and you’ll see Galileo’s picture right there underneath Leonardo da Vinci’s. It’s a less well-known side to his life, but it crops up again and again – interspersed among his many scientific achievements – in this excellent new biography by Pietro Greco.

If you’re looking for interesting trivia, you’ll find plenty in this book. Galileo’s father was a musician with scientific leanings, who carried out some of the first experiments on musical acoustics – which Galileo may have assisted with. As a young professor of mathematics, Galileo delivered a couple of lectures on …

The Ultimate Interplanetary Travel Guide - Jim Bell **

Not too long ago, NASA brought out a series of spoof ‘space tourism’ posters for various destinations in the Solar System. For people like me, who have watched NASA depressingly fail to send humans to the other planets for decade after decade, it was just another painful twist of the knife. On the other hand, the posters probably have more appeal for younger and less cynical minds, by presenting familiar astronomical objects in a new and engaging way. There may even be scope for a whole book along these lines – and that’s what Jim Bell has attempted here.

The main thing I learned from it is that my brain is programmed to read either fiction or non-fiction, and can’t handle a 50:50 mix of the two – which is what this book is. It drove me mad –  not least because I could see that the same material, presented as straight non-fiction, could have made a really excellent book. Using the NASA posters as a starting point, he could have enumerated the potential ‘tourist sights’ at each location…