The universe is packed full of mysteries, but one of them has to be the question asked by Surendra Verma’s book – why aren’t they here? “They” in this case, is little green men, or at least aliens of some kind. Given the scale of the universe, it seems to some people that it’s inevitable that there are aliens out there somewhere… only you’d think they would be more obvious than they are. Of course, UFO fans would say they are pretty obvious – yet we aren’t exactly overwhelmed with aliens landing on the White House lawn, science fiction movie style. Surendra Verma sets out to show just what the chances are of aliens being out there, whether they are like to visit us, and what we can make of claims that they already have. Along the way, Verma neatly brings in snippets of information, giving historical context to some of the science behind the discussion of aliens existing, whether it’s Aristotle’s ideas of just what the universe is, or Gauss’s idea to use banks of mirrors to signal