Turn down the lights, see more

One thing city-dwellers often do when they venture out into the countryside is gaze in awe at the night skies. Because the impact of lighting in urban streets and buildings usually means we rarely get to experience the vision of the stars.

According to an article published in the Science Advances magazine in 2016, increasing light pollution has meant that the Milky Way was hidden from more than one-third of humanity, including 60 per cent of Europeans and nearly 80 per cent of North Americans.

In an Australian first, street lighting is now being dimmed at certain times across Canberra, with the welcome result of both saving on carbon emissions and giving a clearer view of the night skies.

Researcher Danny Bettay told the ABC this week that for the last six months scientists from ANU have been controlling the intensity of around 30,000 streetlights in Canberra, using a laptop to reduce the brightness from 100 per cent to 70 per cent and even 50 per cent.

The changes are imperceptible to the human eye, yet dimming Canberra’s lights for six months saved 1000 tonnes of carbon emissions, while the reduction in light emissions was also measured.

Astro physicist Brad Tucker said that a darker night sky means a brighter celestial glow.

“For every 10 per cent the lights are dimmed, there is a 5 per cent change in the glow of the sky. So when we dim all the way to about 50 per cent, that means the sky is reduced by about 25 per cent in terms of brightness.

“As a result, we see more stars, the fainter stars will be even brighter, and some new stars will pop out”, Tucker told the ABC.

About a third of Canberra’s streets now have the technology installed, potentially reducing light pollution and offering residents a clearer view of our glorious night skies.