Light Pollution: Beacon in Chicago

pease1 writes: "The owners of Chicago's Palmolive Building decided it would be cool to recreate the famous 'Lindbergh Beacon' that was used for aviation navigation for many years. Except, to compete with the modern glarey lights of downtown Chicago, they increased the candle power to 7 billion, up from the original 2 billion candle power. During a recent test, they appeared surprised by the backlash described in this recent Chicago Tribune article. Residents of nearby high rise buildings were surprised when a really huge flashlight started to shine in their apartments!

This is an interesting example what those of us involved in the fight for quality outdoor lighting call racheting. The most common form of racheting can be seen where two or more gas/service stations have each increased lighting levels in order to compete/attract business. At least one person has started an online petition regarding the beacon.

Projects like this needlessly contribute to worldwide light pollution, as highlighted in this recent Slashdot thread."

Comments

International Dark-Sky Association

[FreeMath]

For those interested, the IDA provides information on what the problem is, how to help, and has some pictures that illustrate the problem well.

Light Trespass

[mgarraha]

Shining your lights into someone else's windows is called light trespass. Some recent lighting ordinances codify it as exceeding a certain illumination level, e.g. 0.1 foot-candles, at the property boundary. If a 7 billion candlepower source puts 10 percent of its light outside the beam, it illuminates surfaces a mile away with 2 foot-candles, or 20 times more light than the full moon. If the beam is 10 degrees wide, at 1 mile it gives 10,000 foot-candles, about the same as the sun. Maybe a vandal sniper can convince the developers that this little Art Deco restoration project is not worth the cost of perpetual replacement.