Science Fiction: Characteristics

Obviously, the most prominent feature of the science fiction genre is the science—after all, this is science fiction. So common characteristics of the science fiction genre would include:

• A fast-paced plot
• Advanced technology, like genetic manipulation, cloning, robots, artificial intelligence, and spaceships
• Complex scientific theories, such as those dealing with time travel, multiple dimensions, and string theory 
• Unusual characters, such as aliens, genetically modified beings, cyborgs (humans with a strong machine component), and androids (sentient robots)
• Boundary pushing, whether physically (e.g. space exploration), theoretically (e.g. time travel), or ethically (e.g. do androids deserve the rights of humanity?)