Light pollution: as we lose sight of the stars, we lose a sense of ourselves

Technological advancement means the world is more illuminated than ever – at the expense of seeing stars.

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For millennia, humans have gazed up at the night sky as an act of transcendence. It has long been a natural instinct to peer up into the unknown, pondering how we got here, and what more there is out there. Seeing stars sprayed across the black canvas above has always induced vertigo of cosmic proportions.

Western astronomy found its beginnings in ancient Mesopotamia – the birthplace of civilisation where Sumerians looked at constellations as if they were cathedrals, turning to the structures of the night sky for religious guidance and spiritual ecstasy. The practice was passed on to the Babylonians and Assyrians, who later occupied the region and evolved primitive astronomy into something a little more representative of science.

Over the years, however, a significant rise in artificial lighting has meant the once routinely seen light of the stars and planets has been dimmed down. Lampposts, car headlamps, billboards – all of these contribute to light pollution. Estimations place a third of the global population in regions where the Milky Way galaxy can’t be seen, making it increasingly difficult for curious-minded individuals to ask the same questions of space as civilisations past.  

A common measure of the night sky's darkness is the Bortle Scale – a nine-stage scale grading the brightness of the skies. A nine on the scale indicates inner-city glow – a sky far too bright to spot the stars. A one, on the other hand, means conditions are as good as they can be to see the cosmos. Most westerners live under skies of grade six or seven.

Filmmaker Sriram Murali depicts the dramatic contrast between the two ends of the Bortle Scale using timelapse, travelling to eight different locations in North America to show us “what we lose when we can’t see the stars”:

The burgeoning interest in astronomy has meant the issue of light pollution has become a crucial one. Nasa announcements on the discovery of new exoplanets – planets beyond our Solar System that could potentially harbour life – seem to be an almost weekly occurrence. As the search for life in the Milky Way heats up, the brightening of the skies is obscuring the view for all those in city areas who are curious to know what lies beyond.

To combat light pollution amateur astronomers take to city streets to give passersby the chance to see what populates the night sky, how far away certain planets are, and how long it takes for their light to reach us.

In a video for the New Yorker, astronomer Joe Delfausse ruminates on why he takes to the streets of a city like New York, telescope in hand. “I like to take my telescope to places where people are, and show them the heavens, and let them commune with nature,” he explains. It takes time for light to travel from space, and so looking through telescopes gives people the chance to look into the past.

The development of LED lights, cost-effective, energy saving, brighter alternatives to regular light bulbs, has meant that they have been widely adopted. The issue in the rise of their use, however, is that around half the light projected from these bulbs is wasted, glaring up towards the sky unnecessarily.

Satellite images over the most populous regions of the world have photographically documented the raging glow of LED lights, highlighting a significant brightness over their tungsten counterparts. Many argue that the change to LED lighting has been a necessary one in order to ensure energy expenditure is minimised, while maximising the efficiency of the tools and energy we use.

The push for LED lighting is scientifically grounded, and anything which gives society a chance to preserve energy in a world where burning fossil fuels damage the climate and run the risk of being depleted, should rapidly be adopted. If there is, however, a way of doing this while clearing the night skies, it should take priority. Circadian rhythms can be disrupted, and nocturnal animals may find night brightness causing unnatural changes to their sleeping patterns and habitats.

In a world stifled with political anxieties and economic inequality, torn in regions by oppressive regimes, the chance to see the Milky Way once again, as previous civilisations have always done, may renew an age-old solution to tackling our most pressing issues. In his Meditations, Roman emperor Marcus Aurelius said, “Dwell on the beauty of life. Watch the stars, and see yourself running with them.”

The detriments of light pollution are severely underestimated. But if dealt with, humanity could find its Freudian ego dissolved, its insignificance in the face of the universe’s infinitude understood, and a forgotten unity rediscovered by standing under the stars.