|
 In
the 1990s cosmologists started muttering that they had discovered a
puzzling fact. (So what’s new?) Their new fact implied that the universe
was actually younger than some of its oldest stars. Which is absurd, as
Euclid used to say.
Not
to fret. As you probably know, the universe’s age partly depends on that
magic number, the Hubble constant, which is the rate of expansion of the
universe. But what is its value? For those who really care, it’s been
measured as 70 kilometres per second per megaparsecond, give or take
10%. (I don’t need to remind you that a megaparsecond is 3.26 million
light years.)
With
that figure under their astral belts, together with measurements of how
far away certain extremely distant supernovae are, astronomers have been
able to calculate that our dear universe is 12 billion to 15 billion
years old, plus or minus about 1.5 billion years
Bear
in mind, of course, they’ve now also discovered that the rate at which
the universe is flying apart is speeding up, propelled by a
mysterious force called “dark energy”. This means that
the cosmos will expand forever, and never cease to exist. Quite
reassuring, really.
But
let’s face it: the age of the cosmos isn’t quite as important as the age
of you and me, and how we feel about it. Take the case of the comedian
George Burns who, once he reached eighty, felt so positive that he made
a point of peppering his stand-up routines with self-deprecatory old-age
jokes. A favourite of mine is the one that appeared in the QQQ of
Issue 31 of Bikwil (May 2002):
You
know you’re getting old when you stoop to tie your shoes and wonder what
else you can do while you’re down there.
How
old is “old”, anyway, in human terms?
Me,
I’ve always believed that the word applies to people born twenty-plus
years before I was — although as I expand towards 70 (with ever
increasing Hubble speed, it seems), that “twenty” is having to be
whittled away a little each year.
Now,
I had intended to include something here on early-onset Alzheimer’s, but
I’ve forgotten what it was. |
