HKU Bulletin November 2009 (Vol. 11 No .1)

19 November 2009 SEEING the light A new project highlights the city’s problem with light pollution. complaints about light pollution are on the increase which reflects changing attitudes. “However,” says Dr Pun, “There is no government agency to officially deal with this issue. In cities like Singapore and Taipei they have a lighting plan, which means that different areas have different usage. Heritage sights might be lit but other areas are not. We are way behind in that sense because anything and everything can be lit up in Hong Kong, even outside the heavy urbanized areas. “Fortunately, in his Policy Address this year the Chief Executive reiterated his intention to cut greenhouse gasses. But it’s not just about that, it’s about environmental protection too.” Finally, he says, “The fantastic night sky, and all the stories you can tell your kids about the stars, that is what we are losing. Why do people care about astronomy? It’s hard to explain, but a natural connection does exist. The night sky fascinates people, it is mysterious and inspirational. It’s part of our nature.” And for that reason alone, it should be cherished. comparing data from different nights – a Monday in Sai Kung versus a Wednesday in HKU which was not very satisfactory.” However, when that same student began studying for his MPhil they began to move in a new direction. “Previously we had been using a traditional astronomy technique which is very accurate but only very few people were capable of conducting it and the instruments were prohibitively expensive. Then we discovered the Sky Quality Meter which we now use, Now he says, “We are not proposing that we turn off all the lights but many of our lights shine up not down. This is wasted energy. We’re also concerned about the amount used – parks seem to use as much light as they possibly can. In some situations it’s understandable, but a lot of it is unnecessary. It’s extremely bad for the trees, wildlife and birdlife. “This improper usage of light is the fight we are up against,” he says. But the public appears to be catching on. The number of It has inspired generations of poets, philosophers and scientists. Indeed, the night sky, with its celestial patterns, has been a source of fascination since earliest times. But in Hong Kong new generations are missing out on this great natural wonder thanks to our love affair with neon. For many of the millions of tourists who visit this ‘City of Lights’ each year their lasting image is one of forests of neon signs, towers of incandescent colour, and a nightly laser show that blazes across the harbour. There was a time when these dazzling displays were confined to the city’s busiest districts. But, increasingly, this obsession with all things bright is spilling over to parks and rivers that ignite like Christmas trees as soon as the sun sets. But the backlash against such outrageously lavish displays has begun led, in part, by a physicist at HKU. Assistant Professor, Dr Jason Pun Chun-shing is passionate about astronomy and what it can teach us, and he is troubled by the fact that, thanks to increasing light pollution, more and more Hong Kong children fail to experience the wonder of the night sky. “As an astronomer I was disappointed that, compared to when I was younger, there are now no good places to see the stars in urban areas,” he explains. “That got me thinking about what to do.” So, in 2003 he began a project to measure the brightness of the night sky in both urban and rural areas. “At the same time a group of amateur astronomers met with the then Secretary for Home Affairs to propose ideas such as a night sky preservation zone, like the marine reserve. There are places around the world where these measures are in place, but to this day Hong Kong does not have any regulations governing the use of outdoor lighting.” That initial 2003 project was extended the following year with a final-year undergraduate student and together they established that the city night sky was 30 times brighter than that of the countryside. “This study was limited by many factors – the night sky changes nightly depending on weather condition and the position of the moon, the level of air pollution so we were Research it’s small and convenient and much easier for the general public to use.” So, in 2007, armed with a grant from the government’s Environmental Conservation Fund they bought 30 Meters and relaunched the project. “We tried to raise public awareness about the issue,” he explains. “But it was not popular at that time. In fact, even the press didn’t understand the concept. They understood air pollution and water pollution. But what is light pollution? There was this conviction that Hong Kong is supposed to be bright and that lights are a sign of prosperity.” It took a while to engage the public but when they understood the concept he found enthusiastic volunteers in secondary school students, amateur astronomers, and members of the Camping Association who helped gather data. He went on to develop a web page and create a public forum, increasing public understanding of the problem.