It was an exciting day for the first day at ALAN2015. So exciting that compressed into half a day it was twice as exciting. The day started with Clifford Paul describing his traditional links to the land, the environment and the sky as a member of the Mikmaq nation. In a modern world it is often suggested that the activities of humans are of a new definition and are sure to become a replacement for tradition. It is difficult to accept the awe inspired by a dark night sky and a vault of brilliant shining stars and the luminous galaxy could be seen as a lesser alternative to city buildings at night. Possibly the glittering toothless facades of buildings can be seen as a placebo of the night sky.
Reducing the Blue Spectrum
The second talk was from Pierre Goulet and Sebastian Guigere, Piere Goulet was instrumental in establishing the first International Dark Sky Reserve that is located nearby to Sherbrooke at Mount-Megantic. The requirements for a day sky park can be difficult to meet and reducing the sky glow from neighbouring towns is of primary concern, there has been a considerable effort to reduce the amount of blue light emitted from street lighting. Their talk concentrated on the on-going battle to reduce the content of blue spectrum in local lighting and the efforts of dealing with lighting manufacturers to come to the party with suitable luminaries. Their approach was to not increase the amount of blue spectrum and to not reduce the current utility of existing lighting when compared to the existing high pressure sodium.
One of the solutions resulted in street lights at 1800K and PC-Amber lights in the low 2000's of K. Of course these luminaries have a lower efficacy than the blue rich LEDs and when the market is being driven by government sponsored energy reduction schemes the financial reward for choosing the high efficacy blue-rich LED is too great for most public utilities. This is a world-wide issue which is having far reaching effects.
The nature of the light emitted by blue-rich LEDs is seen as being cold and white and giving a high colour rendering. Many people would describe the light as harsh and stark, yet local utilities and councils argue that this a better light for safety and visibility.
The following talk by Scott Feierabend of the International Dark Sky Association fired us up to understand the power of numbers and the need for a collective change of mind to understand the consequences of light pollution and what will be lost if the trend to over lighting and irresponsible use of outdoor lighting continues.
I need to come back for a second instalment - as it's time to go into the second day of ALAN 2015.