When it comes to big science, very few things are conclusively known. From Quantum Mechanics to Natural Selection, what we have instead are theories - ideas explain why things happen the way they do. We don't know for certain these are correct - no one ever saw the Big Bang - but with them we can paint beautiful, breathtaking pictures of everything from human behaviour to what the future may hold. Profiling the key scientists behind each theory, "30-Second Theories" presents each entry in a unique, eye-catching full-colour design, with thought-provoking extras and stylish illustrations. It is essential for anyone keen on expanding their mind with science's most thrilling ideas.

Paul Parsons is former editor of BBC Focus magazine. He has written for publications from the Telegraph to FHM. His The Science of Doctor Who (Icon) was longlisted for the 2007 Royal Society Prize. Martin Rees is Astronomer Royal, President of the Royal Society, and Professor of Cosmology and Astrophysics at Cambridge.