Two master science writers answer 140 of the biggest questions in physics, distilling the essence of each subject into tweets of 140 characters. Marcus Chown and Govert Schilling take us on a unique tour of the universe, covering everything, from the most basic question - 'Why is the sky dark at night?' and 'Why do stars twinkle?' - to the most challenging - 'What are quasars?' and 'What happened before the big bang?' .Some of the questions in this brilliantly informative book are as surprising as the answers. 'Is it possible that all the galaxies we see in our telescopes are nothing but an optical illusion?'. 'Could you swim on Saturn's moon, Titan?'. 'Why doesn't the Moon fall down?' (Not a stupid question, it turns out). And 'would Saturn float in a big enough bath of water?'