Science fiction is "a realistic speculation about possible future events, solidly based on adequate knowledge of the real world, past and present, and on a thorough understanding of the nature and significance of the scientific method." Fantasy is the impossible made probable; science fiction is the improbable made possible but sometimes it is difficult to discern science from science fiction. During the first year at Barcelona University, in a biochemistry teamwork activity, students have to analyse the difference between science and fiction. They have to explain why certain facts apparently possible in chemistry and biochemistry fiction, are actually impossible in reality. The topics of these science-fiction presentations and discussions are: a) Comic superheroes who are not bound by the laws of chemistry such as Sandman, Iceman, the Human Torch and Spiderman. b) Cinema and television contents, the possibility of time travel and travelling forward into the future or Jurassic Park are examples discussed by students and c) Imaginary interviews. Students, hypothetically, address ten questions to the chosen (bio-) chemist. In the context of (bio-) chemistry education this science-fiction activity could be useful to ensure that students acquire scientific thinking.
