As a young boy, Charles Adler - nowadays a physics professor at St. Mary's College of Maryland - read a lot of science fiction. He often wondered which parts of the fiction were physically possible and which were unrealistic. His book is intended in part for children like his younger self who are curious to have answers to such questions. His curiosity served one of the motives for his decision to become a physicist.
... no science fiction writer can be really esteemed accomplished unless he or she has a thorough knowledge of basic physics, chemistry, biology, astrophysics, history (ancient and modern), sociology, and military tactics ...
But of course every writer takes a literary license to expand the bounds of plausible. The book is about the extent of violation of the scientific laws science fiction and fantasy authors commit in their books.
For example, the Great Hall at Hogwarts impressed Harry Potter as being lit by myriads of candles floating in mid air, but Adler suspects that during the shooting of the Harry Potter movies the hall has been lit by concealed electric lamps. Why? One obvious reason is that candles burn in an upward position and thus block much of the emitted light from going downward. But more importantly, only 0.8% of the light emitted by a candle falls into the visible spectrum. For a tungsten bulb this number - the luminous efficacy - is close to 13%.
Is teleportation possible? Well, if just a little bit, like 1%, goes wrong, there maybe release of energy equivalent to an explosion of an H-bomb. But also take into account that the "to" and "from" systems may be fast moving relative to each other, so that if moment is indeed preserved the impact may be disastrous even for small bodies. Do not forget the Heisenberg uncertainty principle: teleporters will have to control both the location and the momentum at the destination.
These are just two examples of the problems that a reader of science fiction and fantasy books may want to ponder about. My presentation was simplistically descriptive, but the book goes into every imaginable detail, with graphs, formulas, equations, and all kinds of calculations. In fact, there is so much (mostly elementary) physics in the book, that it could be easily and profitably used as a source of entertaining exercises in high school or introductory college courses.
Truth be told, at the outset, when I realized what the book was about, I was a little annoyed. Science is science and fantasy is fantasy, and one may not want to know that there might be something wrong with the concepts in the book one is enjoying. Should everything be laid bare? That's literature we are talking about, for crying out loud, not textbooks or manuals! But Adler's writing is lucid and engaging and it sucks you in. There are so many whys and whats that I eventually developed a feeling that reality may be by far more interesting then any kind of fiction. This is an unusual and worthy book.