Questioning the Millennium by Stephen Jay Gould, Cape, 190pp, £12.99 in UK
The original millennium talked about in the Book of Revelations was the thousand years of bliss that would follow the Apocalypse. Archbishop James Ussher, Anglican Primate of All Ireland in the 1600s, helped to give the word its modern meaning, in which earthly time is counted in units of 1,000 years, with each millennial transition being marked by some big gig - the finishing of Solomon's temple, the new Dome at Greenwich, or whatever.
He was also the man, as Stephen Jay Gould reminds us, who fixed the creation of the world at exactly noon on October 23rd, 4004BC The extra four years are because the sixth-century monk who invented the BCAD system made the mistake of setting Jesus's birth-date at the hinge of human time. But Herod died in 4BC, so if 4,000 years had to pass between the creation and the birth of Jesus, then . . . What is Stephen Jay Gould, the world's most gifted scientific essayist, doing with this stuff? To trust the man, as one always does, to work up to some important insight, is to travel rather deeper into calendrical calculations than one might normally care to go.
Gould has always loved calendrical questions because they show humanity exercising its wit and eccentricity in bending nature to some semblance of order. There are no thousand-year cycles in nature, nor nearly as much mathematical regularity of any kind as science itself has taught us to expect.
Indeed, nature seems to act almost perversely in denying us the means of convenient calculation for so many basic activities: farming, fishing, navigation. We need to keep track of three great natural cycles involving sun, moon and earth. If any of them worked as an even multiple of any other, the calendar could be so straightforward. But the day and the solar year fail to mesh by just under a quarter of a day, the moon takes an aggravating 29.53059 days to circle the earth. Human cultures have devised some fairly arbitrary means of tidying up all the odd bits left over, such as the "reform" by which Pope Gregory dumped a pile-up of ten days to bring the calendar back into sync (October 4th, 1582, was thus followed by October 15th).
Gould's fascination with cal endrics extends to the history of apocalyptic movements, and millennial yearnings and hysterics. Last November, he wandered down from Harvard, where he is professor of zoology and geology, to attend a historians' conference at Boston University on "The Apocalyptic Year 1000". He went as a sceptic, doubting that enough people even knew then what year it was, to produce a proletarian panic. But he came away convinced that the BC-AD chronologies of England's Venerable Bede had spread through enough ecclesiastical timekeepers to account for the millennial stirrings.
Those who panicked were led by a Christian view of the world which believed that six thousand years would elapse between the Creation and the Second Coming, and that five of these millennia had already gone by. When 1000 came and nothing happened, the creation was moved forward by one millennium, to 4000BC - now everything ends in 2000 AD. It's all right - "millennial expectations always fail," Gould promises.
As a cheerful humanist, he is perfectly happy for the western world to ring out the millennial bells on New Year's Day, 2000. It is true that Dennis the Short - Dionysius Exiguus - started his calendar at Year One (6th-century mathematics not having gone very far with the concept of zero) and thus chained every year ending with 00 to the end of its century. Logically, we should wait until January 1st, 2001 for the start of the new millennium. But this time pop culture is right, says Gould, "because most people so feel it in their bones".
Calendrics is, as he says, a strange little subject, and one not usually seen as the province of grand or expansive thinkers. Some aspects of packaging of this little book raise thoughts of Longitude by Dava Sobel, last year's great success in the field of scientific history. But Gould's personal interest is as exuberant and authentic as ever, and one good reason for it is offered by an epilogue which both fascinates and touches, and is best left as a surprise.
Michael Viney is author of A Year's Turning and an Irish Times columnist