Why Does E=mc2?: by Brian Cox and Jeff Forshaw

Why Does E=mc2?: by Brian Cox


My rating: 5 of 5 stars
This is probably the best known equation in science but knowing how it is derived and what it actually means is a whole different story.

In this book Professors Brian Cox and Jeff Forshaw start with Galileo's profound insight into the nature of relative motion which led him to the inescapable conclusion that the Earth was not the centre of the Universe. They then progress to the observations of Faraday and Maxwell on the curious link between electricity and magnetism describing simple experiments that everybody has probably tried at some point in their life. They show how Maxwell was able to accurately predict the speed of electromagnetic waves with his equations establishing the importance of experimental evidence as well as elegant theories.

Using maths no more complex than Pythagoras' Theorem and a little bit of algebra they lead the reader along the same paths of reasoning that Einstein followed to develop his theory of special relativity, examining the strange consequences of the speed of light having a fixed value. Almost without realising it, you are in a strange world where space and time become a single entity dependent on the observer. Again, the effects that are predicted by the theory have been demonstrated in practical ways, and indeed how things like GPS satellites have to account for the warping of spacetime and the time dilation effect to correct their internal clocks compared to Earthbound timekeeping.

The final chapters take the boldest leap of all, talking about the standard model - an equation for describing how all subatomic particles and forces interact with each other with just a handful of symbols. Most importantly they stress how any theory, no matter how elegant, is absolutely dependant on experimental proof which is why the LHC experiment at CERN is so important and interesting - it will either find the elusive Higgs Boson to complete the standard model or it will open the way to a new and more complete description of the nature of matter.

This is certainly not a dry book - there are plenty of wry observations and humour along the way, including an description of the link between mass and energy by comparing the mass of a hot meat pie purchased at half time at Oldham Athletic on a wet Saturday afternoon with the same cold pie at the end of the match. This book should be accessible to just about everybody - the areas where the maths gets a little tricky are clearly sign posted and the reader is encouraged to follow the working so that they can appreciate the lightbulb moments as the conclusions fall into place.

Read it and wonder at the sheer strangeness and charm of our universe.

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