LONDON -- Novels that explore historical injustices, the nature of consciousness and the dizzying impact of the internet are among six finalists for the prestigious Booker Prize for fiction.Three books by American authors are on the shortlist announced Tuesday for the 50,000-pound ($69,000) prize: Patricia Lockwood’s social media-steeped novel “No One is Talking About This;” Maggie Shipstead’s aviator saga “Great Circle;” and Richard Powers’ “Bewilderment,” the story of an astrobiologist and his