Read more: "The night: The nocturnal journey of body and mind"
LOOK up at the sky tonight and count how many stars you can see. Ten? A couple of dozen? Then you're in good company. Several hundred thousand stars should be visible on a clear, moonless night. Yet 75 per cent of the world's population has never seen the majesty and wonder of the star-strewn Milky Way – and they never will.
That's because more of us than ever are living in cities that are getting bigger and brighter. All that light from buildings, street lamps and vehicles is scattered by dust and gas molecules in the lower atmosphere, producing a diffuse glare known as skyglow. On some nights, it can outshine moonlight.
And there's little respite. From dusk until dawn, 365 days a year, ...
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