[malclocke (Malc)]

Just finished this, and thought I would just capture my impressions here.
Not strictly an astronomy book, but hopefully relevant enough to be of
interest.

First off, I think the authors are probably listed in the incorrect order on
this book. My gut feeling is that the main author is probably the relatively
unknown Forshaw, with the dishy poster boy of particle physics Cox taking his
cut in return for increased sales. But maybe I'm too cynical.

I thoroughly enjoyed this book. It hit the sweet spot for me in terms of my
existing understanding of the subject matter. The approach of this book is to
keep the mathematics to a bare minimum, but it does not shy away from it
completely. However, the authors mostly live up to their promise of not doing
any more complicated mathematics than Pythagoras' theorem. The price the
authors pay for this is an occasional admission that you'll 'just have to take
their word for it' on the more complicated mathematical issues.

The book is split into 8 chapters. The first, 'Space and Time', deals with how
we have historically come to the realisation that we do not occupy the central
position in the universe, and that in fact it is impossible to define a
universal set of coordinates for charting space. We can only measure the
relative positions of objects, there is no absolute frame of reference.

The second chapter, 'The Speed of Light', deals with the 19th and early 20th
century work of Faraday and Maxwell on the unification of the electricity and
magnetism, and the eventual experimental discovery by Mickelson and Morley,
while attempting to measure tiny changes in the speed of the light as the Earth
orbits the sun, that the speed of light is constant in all directions.

The third chapter, 'Special Relativity', shows that armed with the experimental
evidence of a constant value for the speed of light, that we must except that
time must pass differently for two observers moving at different relative
speeds. This was one of my favourite chapters, and explained this concept
brilliantly.

Chapter four, 'Spacetime', deals with the problem posed to science by having
absolute space or time that all observers can agree on. The authors then go on
to explain how combining space and time into a single entity can solve this
problem. This is one of the more challenging chapters, and deals with what I
find some fairly difficult topics. I'm ashamed to say I had to read this
chapter twice, but did 'get it' on the second read, and it was well worth
persisting with.

Chapter five, 'Why does E=mc^2', is unsurprisingly another difficult chapter,
as it brings together the prior chapters to unveil the meaning of Einstein's
famous equation. Once again, I had to read this chapter twice. I would not
say I felt as enlightened by this chapter as some of the others, but did
definitely gain an understanding of the meaning of the equation in the context
of the topics covered prior.

Chapter six, 'And why should we care?', deals with some of the interesting
consequences of the knowledge gained so far. For example, a bucket of primed
mousetraps weighs more than a bucket of unloaded ones. This chapter also
covers the impact of relativity on the atomic and stellar level.

Chapter seven, 'The Origin of Mass', covers some basics of quantum theory and
the standard model of particle physics. This felt like the sloppiest chapter
of the book, trying to shoehorn too much into too short a space and a little
disconnected from the rest of the book.

The final chapter, 'Warping Spacetime', gives an overview of how gravity fits
into the picture, and the dilemma presented by our inability to align the
force of gravity with the standard model.

Overall, the book has provided me with a deeper insight into what is a fairly
difficult topic than any other work I have read. I'd recommend it to any
layperson reader looking to gain a slightly deeper understanding of relativity.
I would say the book does take a few shortcuts on the mathematics, but it is
refreshing that it does not shy away completely from presenting some equations.
Steven Hawking apparently once said that every equation in a popular science
book will half it sales. It's good that the authors didn't shy away from
including some maths, the book is a lot better for it.