Living inside our cities we are increasingly unaware of our place
in the cosmos - as the views of our home galaxy the Milky Way are
drowned out by the glare of street lights. Without making a trek to
a dark part of the countryside the only way to glimpse the spectacle
of our nearest five thousand stellar neighbours glittering against a
deep black sky is to take a trip to a planetarium.
Traditional planetaria projected the light of a powerful bulb
through tiny pin pricked holes in a cover, but the trouble with
these designs is that 99% of the light would stay inside the cover -
and only 1% would leak out to simulate the night sky. "It is often
just too dim," says Mario Di Maggio, a planetarium astronomer at the
Glasgow Science centre. "If we wanted to make the stars brighter we
could only make the holes bigger," he explains, "and that would
result in big discs of light on the walls - rather than tiny points
of light - like the stars appear to us."
In Glasgow things are changing. They've just taken delivery of a
planetarium projector which uses optical fibres inside the
projector, to control the individual colour and brightness of each
star. "It's a great advance for us," says Mario. "We can even make
the stars twinkle realistically."
Scotland's Astronomer Royal, Professor John Brown is a big fan.
He believes it's as good as stepping out under a really clear, dark
night sky in the countryside.
