What might have been - Gregory Benford

What would have happened if history had been different - if the major events that shaped our times had occurred in a different way...or not at all?
In this intriguing volume, fifteen of science fiction's most imaginative minds alter the past to create a present of startling posibilities. From a Confederacy that won the Civil War to a Europe converted to Viking paganism, from Albert Einstein as a frustrated violin teacher to a Christian Genghis Khan, these bold excursions in time depict bizarre new worlds - oddly familiar, yet disturbingly different.