Skip to main content

Mass - Jim Baggott *****

Jim Baggott is one of the UK's best popular science writers and never disappoints. As the book's name suggests, Mass is about what seems at first sight a straightforward and ordinary aspect of matter. It's just a property that stuff has that makes it behave in a certain way. But the further we get into the book, the less obvious the nature of mass becomes - as a reader, it can feel a little like following Alice down the rabbit hole.

We begin with a run through the history of our growing understanding of what matter is, and the nature of mass. Apart from repeating the myth that Giordano Bruno was burned at the stake for supporting a heliocentric cosmology, this is fairly straightforward stuff, but then Baggott makes the interesting step of not just making the transition from a philosophical view to a scientific one, but continuing with the philosophy to include, for example, Kant's 'Ding an sich' or 'thing-in-itself' concept that underlines the way that we can't actually know reality, only our sensory responses and the models we build. There was a time when scientists were on the attack as far as philosophy is concerned (Stephen Hawking infamously declared philosophy to be 'dead' in The Grand Design), but in practice, with a concept like mass, that philosophical consideration is important and useful.

As he continues, Baggott takes us through relativity and its implications for mass to be dependent on frame of reference and quantum theory to underline our growing understanding of what stuff is, before coming to his coup de grace, where we find that mass is not that fundamental aspect of stuff that it appears to be, but is rather a combination of the interaction of quantum fields and an effect produced by energy. It's a neat inversion of our usual way of looking at mass and matter - beautifully well presented. Along the way, Baggott manages his usual trick of going into the physics to a slightly deeper level than is common in popular science coverage - for example, in his description of what is involved in the renormalisation used to get rid of infinities from quantum electrodynamics - while keeping the text mostly approachable.

If I have any criticism, I felt the skip through relativity didn't quite do the subject justice. It was too summary to really get a feel for it, but too detailed to be scene setting, making it one of the less interesting parts of the book, particularly if you've read anything on relativity before. That balance seemed to be handled better with quantum theory. I'd also say that towards the end, where we get into abstruse matters, there isn't quite enough explanation, so the reader is occasionally left thinking 'I don't see how you make that leap.' This seemed particularly true when talking about spontaneous symmetry breaking. There's a diagram showing how ice has lower symmetry than water that confuses rather than helps, and we are told that for spontaneous symmetry breaking to occur when water freezes 'we need to add something (impurities or inhomogeneities, in this case) to encourage it to happen.' A very reasonable reader response is 'If you have to add something, it certainly isn't spontaneous' - a problem that isn't addressed.

Despite a few points like this towards the end, for me the book was interesting throughout (I liked the business book style 'five things we learned' at the end of each chapter) and it encourages the reader to really think about the nature of matter and how something as apparently straightforward as mass is not what it seems. That delight in revealing the unexpected typifies, for me, the joy of physics.

Hardback:  

Kindle 
Review by Brian Clegg

Comments

Popular posts from this blog

Quantum Space: Jim Baggott *****

There's no doubt that Jim Baggott is one of the best popular science writers currently active. He specialises in taking really difficult topics and giving a more in-depth look at them than most of his peers. The majority of the time he achieves with a fluid writing style that remains easily readable, though inevitably there are some aspects that are difficult for the readers to get their heads around - and this is certainly true of his latest title Quantum Space, which takes on loop quantum gravity.

As Baggott points out, you could easily think that string theory was the only game in town when it comes to the ultimate challenge in physics, finding a way to unify the currently incompatible general theory of relativity and quantum theory. Between them, these two behemoths of twentieth century physics underlie the vast bulk of physics very well - but they simply can't be put together. String theory (and its big brother M-theory, which as Baggott points out, is not actually a the…

Beyond Weird - Philip Ball *****

It would be easy to think 'Surely we don't need another book on quantum physics.' There are loads of them. Anyone should be happy with The Quantum Age on applications and the basics, Cracking Quantum Physics for an illustrated introduction or In Search of Schrödinger's Cat for classic history of science coverage. Don't be fooled, though - because in Beyond Weird, Philip Ball has done something rare in my experience until Quantum Sense and Nonsense came along. It makes an attempt not to describe quantum physics, but to explain why it is the way it is.

Historically this has rarely happened. It's true that physicists have come up with various interpretations of quantum physics, but these are designed as technical mechanisms to bridge the gap between theory and the world as we see it, rather than explanations that would make sense to the ordinary reader.

Ball does not ignore the interpretations, though he clearly isn't happy with any of them. He seems to come clo…

Everything You Know About Planet Earth is Wrong - Matt Brown ****

This is the latest of a series of 'Everything You Know About... is Wrong' books from Matt Brown. Although I always feel slightly hard done by as a result of the assertion in the title, as there are certainly things here I know that aren't wrong (I mean, come on, the first corrected piece of 'knowledge' is that 'The Earth is only 6,000 years old' and I can't imagine many readers will 'know' that), it's a handy format to provide what are often surprisingly little snippets of information that are very handy for 'did you know' conversations down the pub (or showing up your parents if you're a younger reader).

Some of the incorrect statements that head each article are well-covered, if often still believed (for example, people thought that world was flat before Columbus), some are a little tricksy in the wording (such as seas have to wash up against land) and some are just pleasantly surprising (countering the idea that gold is a rar…