Meat and drink to scientists

Stephen Hawking was told, when writing A Brief History of Time , that each equation would halve sales. He risked one, E=mc². Graham Woan risks 2,000.

His book is for diving into and jumping out. No one sits down and just reads equation after equation. But all physicists need equations, just like animals need meals. And when the equation hunger arises, and you want to satisfy it quickly, efficiently and satisfactorily, Woan's book is what is required.

The Cambridge Handbook of Physics Formulas is just the ticket for the efficient undergraduate physicist and engineer. The expected chapters on dynamics, mechanics, quantum physics, thermodynamics, solid-state physics, electromagnetism and optics are enlivened by a collection of units, constants and conversions, as well as chapters on mathematics and astrophysics.

What I like especially is the clarity of the format. The equations have been corralled into boxes, with labels such as gas laws, electron scattering processes, inverse hyperbolic functions and stellar theory. All the variables are defined. The index is comprehensive, and you are not just guided to a specific page, but also to the relevant line. Many small, clear diagrams are included, so you are not left guessing as to such things as the form of the Poincare sphere, the ordering of the emissions from your Fabry-Perot etalon or the shape difference between a Bose-Einstein and a Fermi-Dirac distribution.

Woan has worked very hard to get the correct balance between length and depth. I am not sure when I will need to know 9 to a thousand decimal places or that the volume of a US tablespoon is 14.78676 x 10-6 m³, but I now know where to look. If you are in a hurry to check that you have correctly applied the Condon-Shortley sign convention to your Wigner coefficients, can distinguish between your rest mass and your relativistic mass, and really do know how far your Brillouin zone extends along your Burgers vector, this is just the book for you.

David Hughes is reader in astronomy, University of Sheffield.