In the world of words the imagination is one of the forces of nature.
The witnessing of titanic events is always dangerous, usually painful, and often fatal.
Ethics change with technology.
The brightest minds in our field have been trying to find a definition of science fiction for these past seventy years. The short answer is, science fiction stories are given as possible, not necessarily here and now, but somewhere, sometime.
Never tell a computer to forget it.
The reader has certain rights. He bought your story. Think of this as an implicit contract. He's entitled to be entertained, instructed, amused; maybe all three. If he quits in the middle, or puts the book down feeling his time has been wasted, you're in violation.