[Darksky] Light pollution definition and quantification

[Jan Hollan]

Dear friends,

I realized that even a short definition of light pollution, as formulated
(discovered, not invented, as it follows from what the words light and
pollution mean) by Pierantonio Cinzano, may be not enough for those, who'd
like to include anti-pollution rules to any legislation or standards (as
we'd like recently to a directive on streetlighting products, to make it
work at all).

So I wrote a quantities-oriented text
                       What is light pollution?
 available as
                 http://amper/light/lp_what_is.htm

It grew a bit too long, but offers more than my previous attempt from Dec
21,  http://www.astro.cz/darksky/#LP, containing now a simple sentence
   ``is the increase of light levels in the outdoor environment (over
     those present naturally) due to man-made sources of light''

I'm much in favour that we begin 2007 having a true LP definition on our
websites! Not just some misleading remark that it's ``increased skyglow''
or something like that. Such descriptions have been fine ten years ago,
but they are a major obstacle now (I think even skyglow itself is a vague
or misleading term, but perhaps I don't understand English well enough).
A vaguely or very variously defined term won't be considered seriously.
Light pollution will not be taken as a true pollution, by environmental
agencies, with the existing mess of notions what it is at all.

After we will put a true definition to our articles and presentations, we
may urge IDA once more to do it on its main site too (I did twice). Maybe,
the definition might be shortened, where really necessary, even to
something like
      ``light added artificially by people to environment''
 -- but I'm not sure if such too simple formulations would not be
confusing (the above sentence might be read as concerning just emissions,
not the imissions, e.g. imissions to countryside which is hundred
kilometres distant from the source of emissions).i

I've also added my new text as a link to the end of the wikipedia article
Light_pollution. I did not edit the article, as due to the definition,
the changes might be complicated. If you are among the wiki article
editors, please think about the proper inclusion of it.

best regards,
 jenik