Explosion of LightIt happened so slowly that we didn''t really even notice it. It''s been a part of our lives for so long that we''ve taken it for granted. Little by little, light by light, we have virtually eliminated the night from large portions of the globe. Light at night is a part of who we are, our 7x24 society craves more and more of it, as if it were the driving force in our economy and even our evolution.
Yet, in our effort to light everything we do, we''ve not taken notice of a simple fact. Too much of a good thing can be bad. In the case of outdoor lighting, it turns out that it''s a really bad thing. You may be scratching your head in amazement. Light at night allows us to accomplish so much. How could this possibly be bad? How could something that provides so much value have a downside?
Light at night does indeed provide us with so many benefits that we''ve come to depend on. It allows us to work and play and shop virtually round the clock. The benefits of light at night in general and outdoor lighting in particular are well known. What is not so well known by the vast majority of people is that light at night has a dark side; a side that most are completely unaware of, or at least not fully appreciated. By changing night into day, we have disrupted a cycle which has been a constant throughout time; a cycle which has shaped the evolution of virtually every living creature on this planet.
So, what''s wrong with a little light at night? Nothing is wrong with a little light at night. Unfortunately, we''re not talking about a little light at night. We''re talking about an explosion of light which prevents large segments of the developed world from truly experiencing the night. But, 6:00pm is generally considered the beginning of night and that still arrives every single night. And, just as the sun rises in the east every morning, it sets in the west every night. Well, this much is still true. But, and this is a key point. It no longer gets dark at night in many areas. Sure, its not as bright as daytime. Not even by a long shot. But, it doesn''t really get dark anymore. It may seem dark to you, but so many people have not actually been in the dark in such a long time that they no longer even remember what its like.
Step outside on any clear, moonless night and look up into the sky. How many stars do you see? Can you count them up pretty quickly? Most likely, you can. Most likely, you see no more than a few dozen to a couple of hundred. A typical American would see perhaps 50 stars if they took a few moments to count. Some more, some less. Unfortunately, if those very same people were alive 100 or more years ago, they''d have seen more like 3000 stars in the night sky. Where''d they all go? Well, they''ve been obscured by an ever increasing amount of outdoor lighting. Porch lights, garage lights, parking lot lights, building lights, security lights, accent lights, emergency lights, runway lights, flag lights, wall lights, architectural lights, area lights, spot lights, flood lights, pathway lights, deck lights, decorative lights, holiday lights, street lights, traffic lights, car headlights. Lights on factories, lights on oil refineries, lights on fishing vessels. You name it, we''ve found a way to mount a light on it. Typically, more than one. Typically brighter than was used in the same situation just a few years ago. Where 100 watts sufficed for years, we now have 250. Where 400 watts sufficed, we now have 1000. Where we had incandescent bulbs, we''ve now switched to metal halide.
The use of light at night has been growing at an exponential rate for quite some time now. We''ll discuss the implications of this Light Pollution in a future post.
Anthony Arrigo is an avid astronomer and night sky activist. His company, Starry Night Lights, specializes in night sky friendly outdoor light fixtures that reduce light pollution. Please tag or bookmark this article.