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:  
Using these links earns us commission at no cost to you

 
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.
Labels:

Comments

Post a Comment

Popular posts from this blog

The Meteorite Hunters - Joshua Howgego *****

This is an extremely engaging read on a subject that everyone is aware of, but few of us know much detail about. Usually, if I'm honest, geology tends to be one of the least entertaining scientific subjects but here (I suppose, given that geo- refers to the Earth it ought to be astrology... but that might be a touch misleading). Here, though, there is plenty of opportunity to capture our interest. The first part of the book takes us both to see meteorites and to hear stories of meteorite hunters, whose exploits vary from erudite science trips to something more like an Indiana Jones outing. Joshua Howgego takes us back to the earliest observations and discoveries of meteorites and the initial doubt that they could have extraterrestrial sources, through to explorations of deserts and the Antarctic - both locations where it tends to be easier to find them. I, certainly, had no idea about the use of camera networks to track incoming meteors, which not only try to estimate where they wi...
Post a Comment
Read more

Phenomena - Camille Juzeau and the Shelf Studio ****

I am always a bit suspicious of books that are highly illustrated or claim to cover 'almost everything' - and in one sense this is clearly hyperbole. But I enjoyed Phenomena far more than I thought I would. The idea is to cover 125 topics with infographics. On the internet these tend to be long pages with lots of numbers and supposedly interesting factoids. Thankfully, here the term is used in a more eclectic fashion. Each topic gets a large (circa A4) page (a few get two) with a couple of paragraphs of text and a chunky graphic. Sometimes these do consist of many small parts - for example 'the limits of the human body' features nine graphs - three on sporting achievements, three on biometrics (e.g. height by date of birth) and three rather random items (GNP per person, agricultural yields of various crops and consumption of coal). Others have a single illustration, such as a map of the sewers of Paris. (Because, why wouldn't you want to see that?) Just those two s...
Post a Comment
Read more

Against the Odds - John Gribbin and Mary Gribbin ****

The number of women working in STEM subjects has expanded dramatically, but as John and Mary Gribbin make clear, in the history of science this is a very recent occurrence. Here, they bring us the stories of 12 women, from Eunice Newton Foote, born in 1819, to Vera Rubin, born in 1928 - effectively covering nearly 200 years in that Rubin died as recently as 2016. There are some names that will already be familiar from popular science histories (and deservedly so). You will find, for instance, Dorothy Hodgkin and Rosalind Franklin represented. But there are plenty like Foote that few will have come across, including Inge Lehmann, Chien-Sung Wu and Lucy Slater. While arguably Foote is there primarily to demonstrate the difficulties she faced (her discovery of an aspect of greenhouse gas behaviour was independently bettered within weeks), the rest have all made significant discoveries or developments against the odds and often missed out the recognition the deserved. The most prominent ob...
Post a Comment
Read more