Learning Objective: This is a discussion class. At the end of the session, the participants are expected to be able to develop their critical thinking skills and express their opinions freely.



Introduction: Our Vanishing Night

Most city skies have become virtually empty of stars.

By Verlyn Klinkenborg Photograph by Jim Richardson

If humans were truly at home under the light of the moon and stars, we would go in darkness happily, the midnight world as visible to us as it is to the vast number of nocturnal species on this planet. Instead, we are diurnal creatures, with eyes adapted to living in the sun's light. This is a basic evolutionary fact, even though most of us don't think of ourselves as diurnal beings any more than we think of ourselves as primates or mammals or Earthlings. Yet it's the only way to explain what we've done to the night: We've engineered it to receive us by filling it with light.



What is Light Pollution?


All that light ruins the night sky

Termed 'light pollution' , all those lights wash out the night sky ruining the beauty of the cosmos for all. It's particularly bad in larger cities. One avid astrophotographer who lives in Hong Kong refers to his city as 'a city without stars'.

From Wikipedia- Light pollution, also known as photopollution or luminous pollution is the excessive or obtrusive artificial light.



Brightest Cities of the World




Vocabularies

1. diurnal

2. artificial

3. nocturnal

4. primates

5. Earthlings



Discussion Questions

1. Do you think light pollution is a serious problem?

2. Which is more beautiful? The night lighted by bright cities or with stars and moon?

3. Where do you want to live? In the city or in the countryside?