Armageddon looms thanks to increasing longevity, according to this fretful jeremiad. Fishman (China, Inc.) visits a number of locales--luxury retirement communities in Sarasota, Fla.; the rust-belt city of Rockford, Ill.; a village in Spain; Beijing--and everywhere finds a skyrocketing population over 65 with attendant problems: soaring medical costs, overwhelmed caretakers and government pension systems, and oldsters who feel sad and neglected. Fishman weaves these findings with all manner of demographic, economic, and cultural discontents, including plummeting birth rates, environmental degradation, underpaid immigrants, American industrial decline, globalization, and outlandish teen fashions. Unfortunately, conflating all this under the rubric of aging's "shockwave" obscures more than it reveals; while focusing on an unsolvable existential predicament--you can't keep people from aging--Fishman avoids investigating solutions to specific problems he raises, which are mainly issues of trade, industrial policy, and economic inequality, not necessarily longevity. (Oct.)