15 May 2014
How Light Affects Light
Bob Crelin came to our class to talk about light and light pollution, and its affect on the night sky. What I liked most about Bob was that he was a realist, and spoke to the class on a level that we could all relate to. He posed the question of who enjoyed looking at the night sky, I mean really, who doesn’t? Bob is a songwriter, inventor, helps design drum hardware, and works for Ovation and Takamine.
From the start, I noticed Bob’s uncanny ability to look outside the box. He started to show us photos of car dealerships and gas stations, to prove his point that these were the major light producers. Bob explained that the reason that these places were emitting so much light was because they were able to capture the attention of people passing by this way. People have a natural attraction to light, especially when the surroundings are a lot darker in comparison. Next, Bob did a demonstration with a light bulb that he had, where he turned off the lights and asked us how well we could see him. After talking for a while and letting our eyes adjust, we could see him fairly well, being able to make out some small details here and there. Next, Bob turned on the light bulb that he had, and just about all of the detail that we could see pretty much vanished. Also, when Bob started to move the light around, it was hard not to focus on the light, kind of like an automatic reaction.
The presentation went on to explain that this is exactly what light pollution was all about. It is light that is emitted that really has no purpose, other than to capture the attention of the passer-by. In effect, this is light pollution because it is leaving its original property and causing a nuisance on another person’s property. Bob explained that there are special lights that can be used to battle this, that basically aim the light on only what they are trying to illuminate, as well as shield the light from going strait up into the sky. Bob had actually invented one of these lights to help aid in this movement. Also, on the ‘bright’ side, these new lights used much less energy than the traditional style lights. In one example, Bob had helped a car dealership transform to these new style lights. He showed us a picture of the dealership, with every light pole using 9,000 watts (there were about 40 light poles in the picture). The new style lights ended up using only a third of this, at 3,000 watts, basically cutting the dealerships energy use by roughly 2/3rd.
Personally, I find the Bob’s mission to battle against light pollution fascinating. Some of the other affects of light pollution that Bob mentioned were that cancer rates were related to lighting, that crime is not directly related to lighting, and that environmentally light can be detrimental to the natural cycle of trees, causing them to loose their leaves later than they normally would. Overall, I don’t think that there was ever a downside to any of the things that Bob was trying to do. He even got the town of Branford on his side, which ended up passing local regulations on light pollution and setting limits to the intensities and angles that light can be emitted. I think that these regulations are a step in the right path, and that hopefully Bobs fight will be recognized by the rest of the world, so that we can put an end to light pollution and all of its dark sides.
Milky Way Picture, "Milky Way", 15MAY24, http://www.universetoday.com/21563/milky-way/
United States Picture, "AAAP Light Pollution Pages", 15MAY24, http://www.3ap.org/lightPollution.shtml
Gas Station Pictures, "Light Pollution Wastes Money and Energy", 15MAY24, http://physics.fau.edu/observatory/lightpol-econ.html