Humanity is under threat - from storms that seem to get ever fiercer, earthquakes that seem ever more deadly, and killer viruses that are engulfing the globe. Some scientists think it's time for us to fight back. Can we - should we -hack the planet?
Questions of good and evil, right and wrong are commonly thought unanswerable by science. But Sam Harris argues that science can -- and should -- be an authority on moral issues, shaping human values and setting out what constitutes a good life.