You can't see the beautiful way when you're burning so bright, sung The Whitlams, and when it comes to our planet, they could be right.
Since American inventor Thomas Edison produced the world’s first light bulb in 1879, earth has become an ever-lighter place, with humans determined to destroy any limitations placed on us by darkness.
The result is our encroaching inability to see into true blackness. Of our planet’s 7.6 billion people, one third of us can no longer see the Milky Way when we look up at the night sky.
This light pollution has serious impacts that we are only just beginning to understand, but they are surprisingly broad, says Dr Richard McDermid, an astronomer and ARC future fellow and senior lecturer at Macquarie University. “It touches on our planet’s ecology, marine biology, human health, urban development, cultural heritage, as well as astronomy.”
Ironically, the recent shift towards more energy efficient LED lighting has made things worse, he says. Because LED is cheaper, people tend to keep lights on for longer. Also, most newer, whiter LED street lighting uses a blue light that diffuses more broadly through the atmosphere than conventional, orange-coloured, low-pressure sodium lights.
For us humans, this light pollution could be disrupting our sleep patterns – it interferes with subconscious signalling to the brain, keeping us awake and alert. Disrupting the circadian rhythms of people has been linked to diseases such as cancer.
For animals, the light can play havoc with ecosystems. Some creatures use the darkness for camouflage so the light pollution makes them more vulnerable to predators. Migratory birds’ transcontinental navigation systems get confused by the light concentrations of cities, and baby turtles hatching on Queensland’s beaches scuttle towards the artificial light of coastal development instead of the celestial reflections upon the ocean. Plants also rely on regular intervals of light and dark.
A growing number of Dark Sky Parks around the world are, through their darkness, throwing light on the problem. “They’re a growing phenomenon showing people are starting to care more,” says McDermid.
Dark Sky Parks are private or public spaces that enjoy exceptional starry skies and a thriving nocturnal environment. Their accreditation ensures they keep it that way through restrictions and guidelines for lighting in the surrounding areas – and a complete ban on street lighting.
Australia’s first Dark Sky Park and the only one in the Southern Hemisphere follows the boundaries of the Warrumbungle National Park in central western NSW. Its crystal clear night skies allow visitors and astronomers to gaze into exceptional darkness.
Awareness of the impacts of light pollution is crucial, and controlled studies are necessary to assess how the creep of urban areas is affecting ecology.
Furthermore, households and industries need to be more conscious of their lighting practices, says McDermid. This means only using lights at night when necessary (or using a timer), using downward lights and fitting them with shields.
“Just paying attention to those small things can end up having a big effect,” he says.
Another sky-friendly tip is to get out of the city at night, look up and enjoy the stars, and remember why the splendour of true darkness has inspired us for millennia.
“People are fascinated by what’s out there,” says McDermid. “I think looking up and wondering what our position in the universe is is an important part of being human.
“If you cant see all of that, you’ll just spend your life looking down.”