Alternate Histories ~ Counterfactual Uchronias

Excellent to see Paul Di Filippo spotlight in the WSJournal Worlds That Never Were about alternate histories, a fascinating sub-genre of science fiction...

"Alternate history is a staple of popular culture, providing premises for countless films, novels and comic books. Such counterfactual worlds are known as uchronias -- a variant of the word utopia (Greek for "no land"), substituting chronos ("time") for topos ("land"). Despite their superficial similarity to the thought-exercises occasionally conducted by professional historians, uchronias are really a species of science fiction: Like stories set on other worlds or in the future, those placed in skewed versions of the past allow authors to assemble realities similar to ours but telling in their differences. In the right hands, alternate history can be an agile and entertaining tool for examining our assumptions. Recent months have brought us intriguing works from two authors known for their endeavors in this area: Harry Turtledove and Connie Willis. They take different tacks in their conjectures, with Mr. Turtledove radically remaking our world and Ms. Willis opting for more subtle tinkering."