每日一学(4月26日）LIGHT POLLUTION. POLLUTION, LIGHT

vicandy

Light pollution-光污染

Light pollution, also known as photopollution or luminous pollution, is excess or obtrusive light created by humans.


This time exposure photo of New York City at night shows sky glow, one form of light pollution

Types of Light Pollution：

1.Light trespass-（光入侵）

Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbor's fence.

Example of a light pollution source using a broad spectrum metal halide lamp pointing upward.


2.Over-illumination（过度照明）

Over-illumination is the excessive use of light. Specifically within the United States，  over-illumination is responsible for approximately two million barrels of oil per day in energy wasted.

Office building illuminated by high pressure sodium (HPS) lamps shining upward, of which much light goes into the sky and neighboring apartment blocks and causes light pollution.



3.Clutter（混光or 彩光污染）

Clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents.


4.Glare（眩光）

Glare is often the result of excessive contrast between bright and dark areas in the field of view.


5.Sky glow（人工白昼现象）

Sky glow refers to the "glow" effect that can be seen over populated areas.

[ 本帖最后由 vicandy 于 2008-5-3 20:21 编辑 ]