YOU R AG
120 Australian Geographic
MONEY: TORSTEN BLACKWOOD/GETTYWITH DR KARL KRUSZELNICKIE
VOLUTION happens not
just in the field of biology,
but also in the field of
‘ Money-ology’, and Australia
played a major role in the latest
evolutionary step of the currencies.
Early on, durable metals such as
copper, silver or gold were used
as money. In early China, the units
of exchange were copper coins- but a bunch of coins was heavy.
So a pragmatic merchant might
leave his coins with a trusted
person, who would give him a slip
of paper denoting the value of the
coins. By the seventh century, this
practice had evolved into actual
paper money – but usable only in
local areas, and with a limited
lifespan. By 1274 AD, the Southern
Song government made paper
money the national currency – a
world first. Marco Polo returned
from Kublai Khan’s court and
described with astonishment how
notes of paper money were treated
as if “they were coins of pure gold”.
It took until 1666 for Swedish
bank Stockholms Banco to issue
the first paper money in Europe.
‘Paper’ in banknote terms
usually means cotton paper, often
mixed with linen or other textile
fibres. But over the years, bank-
notes have been made from silk,
leather, sealskin, wood, and even
playing cards. Paper banknotes
usually last only three years before
they have deteriorated too much
to be usable. Furthermore, with
the advent of scanning and colour
printing, the risk of counterfeiting
has increased.
So fragility and counterfeiting
kick-started the shift to polymer
banknotes – made from biaxially
oriented polypropylene (BOPP).
They are tougher – more resistant
to wear and tear, and can even
survive a trip through your
washing machine. Thanks to
the polymer, and various security
features (security threads, water-
marks, hologram, etc.), they are
very difficult to counterfeit.
The first prototype ‘plastic’
banknotes were introduced in the
early 1980s. However, they weren’t
perfect – the plastic was fragile,
and the ink smudged. It was
Australia, in 1988, that issued the
first widely used successful
polymer banknote – the com-
memorative $10 banknote. In 1996
we became the first country to
have the complete set of circulat-
ing polymer banknotes in every
denomination, from $5 to $100.DR KARL is a prolifi c broadcaster,
author and University of Sydney physicist.
His new book, House of Karls, is
published by Pan Macmillan. Follow him
on Twitter at: twitter.com/DoctorKarlPOLYMER BANKNOTES
NEED TO KNOW
On the money. The fi rst widely used
polymer banknote was Australia’s com-
memorative $10 note, introduced in 1988.LIGHT POLLUTION
We have been subscribers since AG 1
and always enjoy the magazine. In
AG 126 there are two articles that are
intimately connected – Take a stand for
the poles by Tim Jarvis and The end of
darkness by Peter Meredith.
Most electricity is produced by
burning fossil fuel. Reducing
electricity consumption would reduce
light pollution and also the rate at
which we are filling the atmosphere
with greenhouse gases, which are
warming the planet and destroying
the polar regions.
Pictures taken from space of Earth
at night show how much light is being
wasted. Most lights (and electronic
equipment, such as computers) in
cities and towns do not need to be on
all night and a huge amount of
electricity – and pollution – could be
saved by simply turning them off.
We wonder when humans are
going to realise that the amount
of fossil fuel is finite and, therefore,
not going to last forever.
VALERIE & DOUGLAS BROOKER, SYDNEY, NSW
Continued page 122ECHIDNA
SPOTTED
My family and
I live in the
Kimberley and
were recently on
the Gibb River
Road, at Windjana
Gorge, when we spotted this freshwa-
ter crocodile eating what looked like
an echidna. In light of your article
Lost and found (AG 122) on the western
long-beaked echidna, we thought this
picture, above, may be of interest.
AARON MCSORLEY, THE KIMBERLEY, WA
62 62 63Story by Peter MeredithArtificial light is overwhelming the night sky; it eclipses our view of the stars and hinders the work of
astronomers. But a battle to save the dark has begun.The end of darknessviews are increasingly threat-Way arcs over Murphy’s Galaxy quest. ened by light pollution. Haystacks in SA; such The Milky^