Science fiction makes an interesting pact with its readers, [Robert Charles] Wilson said. “We often write about events and technologies that are implausible or even impossible. I don’t expect the Earth to be temporally dislocated by extraterrestrial forces, any more than H.G. Wells expected a basement tinkerer in 1896 to invent a time machine. But the time traveler in the Wells novel was immediately thrust into the forefront of what was known and could be imagined within the best (and most controversial) science of the time—evolution, the long-term geology of the Earth, the fate of the human species,” Wilson said. “People who describe SF as ‘limited only by the imagination’ may forget that we use scientific plausibility as an artistic constraint, like the five-seven-five syllable count of a haiku.”