Skywatch: ‘Light Pollution is becoming a serious problem’
Skywatch: ‘Light Pollution is becoming a serious problem’
By: by Dale Hawkins, Tehachapi News Columnist
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Posted by editor Tue Nov 30, 1999 00:00:00 PST
Viewed 236 times
0 responses 1 comment Tehachapi has some of the darkest skies in all of civilized California (which I define as a place where you can enjoy the stars and still use your cell phone to order pizza). The ability to clearly see the Milky Way is a spectacle that few Californians enjoy and a natural resource that we should protect.
However, our dark skies are being threatened by rapid growth. When I arrived three years ago, I couldn't see my hand in front of my face on a dark night from my backyard in Golden Hills. This is no longer true. As new malls and Wal-Mart are constructed, huge lights are being installed that stay on all night. Tract housing is bringing in many new street lights. Seeing the Milky Way is getting much more difficult from the city. There was talk of building an observatory at the Tehachapi High School. However, because of light pollution, an outlying site is now being sought.
Lighting is considered essential to proper security. However, it's actually a double-edged sword. Our eyes are capable of extreme sensitivity, able to see the slightest movement in very dark situations. In fact, our eyes have a sensitivity range of nearly one million times! However, artificial lighting is making it impossible to allow our eyes to properly adjust to the dark. We should not be afraid of the dark, but what is in the dark that we can't see because our eyes can't see into it properly. Bright lights in fact are an asset to “evil-doers,” for they create the dark shadows in which they can lurk.
An excellent example is the new vertical lights that surround the corner of “F” and Green Streets near the Hitching Post Theater, as well as other intersections. They are truly dazzling - so dazzling that as a pedestrian, I find it hard to discern the curb (yes, I know that it's actually a slope, but I can't even see that!). As a driver, the lights blind me so as to make it difficult to be sure that there are no pedestrians, especially if I want to turn a corner where my headlights are of no help.
The same is true of house lights in areas where there is no street lighting. They provide the illusion of security, but in fact make it easier for one to remain out of sight in the shadows.
This is a problem all over the world. It was only about a century ago that everyone on the planet had a great view of the sky. The situation got so bad in San Diego that the famous Mount Palomar Observatory made plans to close and move the equipment to South America. Only a strong county ordinance to control lighting saved this American landmark institution.
The International Dark-Sky Association (IDA) is dedicated to curbing this increasing threat to astronomy for professional, amateur, and casual astronomers alike. They have created model legislation for use by all municipalities. It includes simple measures like shielding light to ensure that it doesn't project above the horizon and lights only what is intended. It's also important not to make lights any brighter than they need to be and to turn them off when they are no longer needed. Most lighting need not be on any later than 11 p.m., which is the beginning of the prime astronomy hours. Some lights are more astronomer friendly than others and carry the IDA Fixture Seal of Approval. For more information about the efforts of the IDA and how you can help, visit their website at www.darksky.org.
Bear Valley Springs has a strong lighting ordinance that is considered to be very effective. Supervisor Don Maben has introduced a similar ordinance for the unincorporated areas of the county. As building permits continue to be issued for more homes and businesses, the Tehachapi City Council needs to enact such an ordinance to protect our beautiful night sky.
Manned Space Watch
With Discovery's safe return after attaching Node 2 to Space Station Alpha, Atlantis is on the pad preparing for a Dec. 6 launch to deliver the European Space Agency's Columbus laboratory module.
Night Sky Watch
Comet 17P/Holmes is still bursting forth at second magnitude as of Nov. 11 and is still located in Perseus.
The moon reaches first quarter on Saturday, Nov. 17. Therefore, the evening sky will be bright.
Jupiter is now low in the southwest, with Mars in the east in the early evening.
Venus is still a dazzling jewel in the eastern morning sky.
Sunrise/Sunset (PST)
6:35 a.m. /4:45 p.m.
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Tue Nov 20, 2007 07:05:10 PST
A much needed, and long overdue, article.
However, if you want to single out some offensive lights, meaning that they spill excessive light into the night sky, there are far worse offenders than the corner "pole lights" downtown.
Among these would be the decorative "gas lamps" the city has installed all along the downtown corridor. Implemented correctly, with right fixture, these could have been wonderful. One small change in design, wherein the glare producing lamps were recessed into the hood, and not visible, would have made these night sky friendly. As they are, with exposed lamps and apparently either mercury vapor of metal halide, they spill broad spectrum light and glare and are extremely environmentally unfriendly.
Other offenders are the hundreds of "drop lens cobra" street lights employed all over the residential and business districts of the City of Tehachapi. These are still being allowed, and installed, in new housing tracts. This is an archaic design that is being phased out by progressive, light friendly, communities all over the world. The City of Tehachapi should not allow further installation of these lights and should begin replacing them with the modern, night sky friendly alternative, a "flat lens cobra" or "zero cutoff" design.
http://www.skykeepers.org/g...
Finally, the absolute worst, and least environmentally friendly lights downtown, both in terms of broad spectrum light pollution and electrical inefficiency, is the row of mercury vapor "yard lights" above the shed in the Techachapi Lumber Co. yard. Come on folks, lets get some high or low pressure sodium, shielded fixtures in there. Many progressive, night sky friendly, municipalities have prohibited the use or sale of mercury vapor fixtures (except perhaps in sports venues). The City of Tehachapi should do the same and require that local hardware and home improvement stores remove them from their shelves.
Just a few steps that would go a long way toward preserving our night sky.
