| We usually think of pollution as a
harmful waste substance that threatens the air and water. {{U}}(1)
{{/U}}some people have become{{U}} (2) {{/U}}about another kind of
pollution. It can be everywhere, depending on the time of day. {{U}}(3)
{{/U}}it is not thought of as a{{U}} (4) {{/U}}. It is
light. The idea of light pollution has{{U}} (5) {{/U}}with the increase of{{U}} (6) {{/U}}in cities. In many areas, this light makes it{{U}} (7) {{/U}}to observe stars and planets in the night sky. In 1922, the International Dark-Sky Association formed. This organization wants to reduce light pollution in the{{U}} (8) {{/U}}sky. It also{{U}} (9) {{/U}}the effective use of electric lighting. Light pollution is the{{U}} (10) {{/U}}of wasted energy. Bright light that shines into the sky is not being used to provide light{{U}} (11) {{/U}}it is needed on Earth. {{U}}(12) {{/U}}designed{{U}} (13) {{/U}}causes a great deal of light pollution. Lights that are brighter than{{U}} (14) {{/U}}also cause light pollution. Most people in America are{{U}} (15) {{/U}}to find out that they are not able to see our own galaxy, The Milky Way, with their own eyes. {{U}}(16) {{/U}}about three-fourths of Americans cannot see the Milky Way because of{{U}} (17) {{/U}}light. Objects in the night sky are{{U}} (18) {{/U}}that provide everyone{{U}} (19) {{/U}}wonder. But light pollution threatens to prevent those wonderful sights{{U}} (20) {{/U}}being seen. |