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 Laws of Thought - Tom Griffiths *****

In giving us a history of attempts to explain our thinking abilities, Tom Griffiths demonstrates an excellent ability to pitch information just right for the informed general reader.  We begin with Aristotelian logic and the way Boole and others transformed it into a kind of arithmetic before a first introduction of computing and theories of language. Griffiths covers a surprising amount of ground - we don't just get, for instance, the obvious figures of Turing, von Neumann and Shannon, but the interaction between the computing pioneers and those concerned with trying to understand the way we think - for example in the work of Jerome Bruner, of whom I confess I'd never heard.  This would prove to be the case with a whole host of people who have made interesting contributions to the understanding of human thought processes. Sometimes their theories were contradictory - this isn't an easy field to successfully observe - but always they were interesting. But for me, at least, ...
Post a Comment
Read more

The Infinity Machine - Sebastian Mallaby ****

It's very quickly clear that Sebastian Mallaby is a huge Demis Hassabis fan - writing about the only child prodigy and teen genius ever who was also a nice, rounded personality. After a few chapters, though, things settle down (I'm reminded of Douglas Adams' description of the Hitchhiker's Guide to the Galaxy ) and we get a good, solid trip through the journey that gave us DeepMind, their AlphaGo and AlphaFold programs, the sudden explosion of competition on the AI front and thoughts on artificial general intelligence. Although Mallaby does occasionally still go into fan mode - reading this you would think that AlphaFold had successfully perfectly predicted the structure of every protein, where it is usually not sufficiently accurate for its results to have direct practical application - we get a real feel for the way this relatively unusual company was swiftly and successfully developed away from Silicon Valley. It's readable and gives an important understanding of...
Post a Comment
Read more

Nanotechnology - Rahul Rao ****

There was a time when nanotechnology was both going to transform the world and wipe us out - a similar position to our view of AI today. On the positive transformation side there was K. Eric Drexler's visions in the 1986 Engines of Creation. Arguably as much science fiction as engineering possibilities, it predicted the ability to use vast armies of assemblers to put objects together from individual atoms.  On the negative side was the vision of grey goo, out of control nanotechnology consuming all in its path as it made more and more copies of itself. In 2003, for instance, the then Prince Charles made the headlines  when newspapers reported ‘The prince has raised the spectre of the “grey goo” catastrophe in which sub-microscopic machines designed to share intelligence and replicate themselves take over and devour the planet.’ These days the expectations have been eased down a notch or two. Where nanotechnology has succeeded, it has been with the likes of atom-thick mat...
Post a Comment
Read more