GUARDIAN SCIENCE BOOK OF THE YEAR 2017 Popular science at its best Mail on Sunday Eminently accessible and enjoyable Observer With every breath you literally inhale the history of the world. On the ides of March 44 BC Julius Caesar died of stab wounds in the Roman Senate but the story of his last breath is still unfolding. In fact youre probably inhaling some of it now. Of the sextillions of molecules entering or leaving your lungs at this moment some might also bear traces of Cleopatras perfu