This is a book of alternate history short stories. One thing I really liked was at the end of each tale they discussed the revision point, the point at which the story timeline diverged from the one we learned in history class. This is good, because apparently the editors tried to pick stories that avoided the two most popular points of alternate history: the civil war and WWII. On this they succeeded whole-heartedly—I couldn’t begin to tell you what would have had to happen differently to have our world occupied by an army of cloned Albert Einsteins! As with most collected fiction, this set is hit-and-miss. Several of these sagas are pretty good (Unwirer by Doctorow and Stross tells the tale of an America that had outlawed the Internet was my favorite), others not so much (When the Morning Stars Sang Together by Szpindel wonders what would have happened if Galileo healed his rift with the Catholic church). Some of the stories aren’t even alternate history in my opinion but straight sci-fi because they postulate changes in a history that hasn’t happened yet, such as practical cold fusion being discovered today or a completed Human Genome Project. Doesn’t make the adventures less interesting, but I was geared for something else and found this a bit disappointing.
George Santayana, the Spanish-American philosopher and novelist, is famous for having penned the oft-quoted statement, “Those who cannot remember the past are condemned to repeat it.”