光污染研究及短片製作比賽
Public Education Campaign to Conduct Research and Visualize Impacts of Light Pollution
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光污染小資訊
Light Pollution
Knowledge

甚麼是光害?

What is Light Pollution?

「光害」(又稱光污染)是一種因過度使用人為室外照明,而對自然環境和生態等引起的負面影響。人為室外照明包括街燈、霓虹招牌、廣告版照明等。設計不良的室外照明將光線直接照射或反射上天空,大氣中的雲、霧、懸浮粒子等污染物會將這些光線散射開,導致夜空被照亮,可見星星的數目因夜空的對比下降而減少。
“Light Pollution” is a form of environmental degradation in which excessive artificial outdoor lightings, such as street lamps, neon signs, and illuminated signboards, affect the natural environment and the ecosystem. The wasteful light emitted directly upwards or reflected upwards from poorly-designed artificial light sources can be scattered by clouds, fog, and pollutants like suspended particulates in the atmosphere. The night sky is thus brightened, leading to a reduced number of stars visible in the sky due to a decrease of the light contrast.

嚴重的香港光害問題

The Seriousness of Light Pollution in Hong Kong

在人煙稠密的香港鬧市,數之不盡的街燈和大型室外廣告招牌,做成嚴重的光害問題。根據香港大學物理系2003年起的研究統計,香港市區的夜空,比起人口稀少的郊野地區,已被光害嚴重污染了超過三十倍!
In a crowded metropolitan like Hong Kong, the urban streets are dotted with countless street lamps and huge neon signs. These contributed to the serious light pollution in the city. According to the data collected by the HKU Department of Physics since 2003, the brightness of the Hong Kong urban night sky is at least 30 times higher than that in the less-populated countrysides.

(Credit: NASA)

晚上由國際太空站在太空拍攝的香港及鄰近珠江三角洲夜景。
Nighttime picture of Hong Kong and Pearl River Delta Region nearby taken from the International Space Station in space.

人們的生活經常依賴燈光,人口稠密的地區,室外照明便愈多愈密,光害便愈嚴重。所以在鬧市我們不能見到星星,但在一些較偏遠的新界地區,光害的影響較少,我們仍可在這些僅存的地方觀星。不過隨著城市的急速發展,現時可觀星的地區在不久的將來亦會被光害一一「污染」,到時繁星點點的景象將會在香港的夜空永遠消失,無可代替的星空便白白地被摧毀了!
As almost all human activities in the evening rely heavily on lightings, we expect that the higher the population density, the denser is the outdoor lighting, leading to more serious light pollution at that area. Therefore nowadays even on some of the clearest evenings, only a few stars can be seen regularly in the urban areas while astronomy enthusiasts can still have a fulfilling night of star-grazing in selected remote countryside sites where the light pollution is less severe. With the continuous urbanization of Hong Kong, these few remaining good sites are under the heavy threat of light pollution. If this problem is left unattended, the precious starry night in Hong Kong could forever disappear.