Marcus Chown is an award-winning science writer and broadcaster. Formerly a radio astronomer at the California Institute of Technology in Pasadena, his books include Solar System for iPad, which won a Bookseller Award for Digital Innovation. His acclaimed books include What a Wonderful World, Quantum Theory Cannot Hurt You, We Need to Talk about Kelvin and The Ascent of Gravity, which was a Sunday Times Science Book of the Year. He lives in London. www.marcuschown.com @marcuschown