We straying a little from physics here and our field of
expertise but it is an interesting and useful subject and,
dare I say it, something of a dilemma.
A century is a collection of one hundred (consecutive)
years. Similarly a decade is a group of ten years.
Starting from the year 1 A.D. we have a series of centuries
called the First Century, the Second Century, ......the
Nineteenth Century. These Centuries start at the beginning
of the year 1 (or 101, or 202,....1901) and end at the end
of year 100 (or200, or 300, ...0r 2000). That's all right
and proper and those using the argument to claim that the
present century (and, by extension, the present millennium)
doesn't end until the end of 2001 are on strong ground.
Yet....
(1) When we refer to decades such as the sixties or the
seventies, we mean from 1960 to 1969 and 1970 to 1979. I
don't hear people saying "At the end of the eights in 1990".
Why do we use a different yard-stick here?
(2) As far as the person in the street is concerned, the
main argument above is pedantic and arcane. He or she
"knows" that the year 2000 is the start of a new century;
that knowledge is reinforced by the point I raise in (1).
This is much more immediate than thinking about the first
century sarting in the year 1 A.D. rather than 0 A.D.
It going to be interesting to see which set of
new-century-and-millennium-celebrations are the more
popular, those on Jan 1 2000 or those on Jan 1 2001. I
intend to celebrate both.
Brian McInnes