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HOW CONVENIENT it would be for amateur astronomers if the night sky
was miraculously ``labelled'' with the outlines of the constellations!
No effort would be needed to find the Great Square of Pegasus. One could
just look up into the sky and find a quadrilateral of stars marked PEG.
It has taken some 4,000 years to create the current
officially recognised 88 constellations in the northern and southern
hemispheres, and a great deal of chaos has gone into it. They today
consist of 14 real and mythical men and women, nine birds, two insects,
19 land animals, 10 water creatures, two centaurs, one head of hair, a
serpent, a dragon, a flying horse, a river, and 29 inanimate objects.
Nor is it remotely easy to recognise these shapes by
staring at them. The only one I can make out is the Sword and Belt of
Orion, and even that task stretches my imagination to its modest limits.
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What if the night sky was labelled?
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It wasn't always like this. Until the International
Astronomical Union fixed the present constellations in 1930, shapes in
the sky would often have been completely unfamiliar, except of course
for the stars which are always in the same places.
Ptolemy, in his Almagest in the 2nd century
AD, fixed the number of constellations at 48, including some of the
present ones.
But Ptolemy's constellations were much too big to be
useful. He had one huge one called Argo, the Ship of Jason. But this
vessel later had to be cut into four - Carina the Keel, Vela the Sail,
Puppis the Stern, and Pyxis the Compass (although I don't think it
likely that Jason had a compass.)
In 1627 a cleric named Julius Schiller, in his Coelum
Stellatom Christianum, proposed a ``religiously correct'' night sky.
The name of Cassiopeia was to be changed to Mary Magdalen, Perseus to St
Paul, and the zodiacal constellations to the 12 Apostles. Not
surprisingly, Renaissance-minded scientists ignored him.
A century later, the English naturalist and satirist
John Hall invented 13 constellations with deliberately ugly names,
including that of a toad, a leech, a spider, a worm and a slug. His
ideas also failed to find acceptance.
And the independent MP A.P. Herbert, in his 1944 book
A Better Sky, proposed renaming no less than 270 stars. Some were
to given the names of famous aviators and aircraft, such as Bleriot,
Wright, Clipper and Spitfire. The five brightest stars of Draco,
originally named after a tyrant of ancient Greece, were to be given the
names of later tyrants, Attila, Hitler, Mussolini, Robespierre and Kubla
Kahn.
All this disagreement about shapes in the sky is
perhaps not surprising. People just see things differently. The seven
bright stars of Ursa Major the Great Bear that we call the Plough, the
Americans call the Big Dipper, the ancient Chinese saw as a chariot for
a senior bureaucrat, and runaway slaves of the southern American states
saw as a symbol of freedom that pointed to the north.
But one can sometimes look up into the sky and
see the constellations conveniently labelled! A transparent umbrella
known as an ``Astrobella'' enables us to do just this. The names and
shapes are printed on it.
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