It could have all been so different. Join New Scientist (and Astronomer Royal Martin Rees) for an eye-opening journey through a series of alternative realities and forbidden experiments.Imagine the dinosaurs had survived or the Russians had got to the moon first. What would Earth be like without us or chickens (two very different scenarios)? How about if the world stopped spinning? What would happen if we all turned vegetarian (not the happy story you might think)? How could we see the future or learn how to talk to animals?