Marcus Chown is an award-winning writer and broadcaster. Formerly a radio astronomer at the California Institute of Technology in Pasadena, he is cosmology consultant of New Scientist.

His books include The Ascent of Gravity, What A Wonderful World, Quantum Theory Cannot Hurt You, Felicity Frobisher and the Three-Headed Aldebaran Dust Devil, and We Need to Talk to Kelvin, which was short-listed for the 2010 Royal Society Book Prize.

Marcus has also tried his hand at Apps and won The Bookseller Digital Innovation of the Year for Solar System for iPad. Marcus was a regular guest on the BBC4 comedy-science show, It's Only A Theory, with Andy Hamilton and Reginald D. Hunter, and often appears on Channel 4's Sunday Brunch.

Marcus lives in London with his wife, a Macmillan nurse. Whereas she does a very socially useful job, Marcus writes about things that are of absolutely no use to man or beast! Can time run backwards? Are there an infinity of universes playing out all possible histories? Was our Universe made as a DIY experiment by extraterrestrials in another universe?