IT IS not only wild-eyed prognosticators, in lonely towers with an owl for company, who predict the exact date of the end of the world. It has been marked in the diaries of popes, preachers and reformers. It has shivered the blood of a navigator nearing the edge of the globe, a delicate painter of the rites of spring, a serial killer, and the great brooding scientist who uncovered the secrets of gravity and light. It has been calculated from the alignment of planets, the track of comets, the birth of Antichrist (variously identified), the rate of global warming, nuclear build-up, intriguing palindromes or symmetries in dates, or the ever-gathering entropy of wickedness in the world. Some forecasters place it safely in the far future; others expect it imminently. Some, forgetful of the old tale about crying wolf, put out a prediction regularly. The most terrifying give no date exactly, like the hen in Leeds, in northern England, whose owner wrote “Christ is coming” on her eggs and pushed them back up again. The date to squawk about? 1806.