Tomorrow marks the end of the 13th cycle of the ancient Mayan calendar, giving rise to rumors about the end of the world. Worries about a looming apocalypse are nothing new in human history, but 21st century reactions to the possible destruction of the planet (or human civilization) vary widely, from “preppers” who cultivate self-sufficiency, to groups offering prayerful wishes, to entrepreneurs who have found a growing market for their survival gear.
