[Darksky]Re: Help for Article in National Geographic Magazine

Jan Hollan
Tue, 28 May 2002 20:35:11 +0200 (CEST)

> Dear Mr. Hollan:
> I am writer for National Geographic Magazine. We have long been
> interested in the subject of dark skies, and we were excited to hear
> about the Protection of Atmosphere act in your country. I am hoping
> you can tell me more about it for a short feature I am writing for our
> "Geographica" section in the magazine.

Dear Maggie,

 with a pleasure.
> I understand that the law goes into effect on June 1, but that cities
> such as Brno are already employing fully shielded light fixtures. Are
> you already seeing the benefits of this at the Copernicus Observatory?  
> How near to the city lights of Brno is your observatory? How do you
> expect things to improve even more after June 1?

I could not say there is any improvement visible when looking to the sky
at the observatory. The number of the fully shielded lamps is still low,
they are far below the hill and the nearest ones are not of this type at
all (we are deep inside Brno). The improvement is mainly in the streets
themselves, everything is visible much better with a vastly reduced glare.

The June 1 will make little difference probably. There are no explicit
measures yet, and when they will exist, it would take years to implement
them. But still, there are some possibilities to avoid some worst cases of
obtrusive light, like that ones mentioned in the last letters inside the
http://amper.ped.muni.cz/darksky archive for the very evening of June 1.
(Hope it's no problem putting this letter there as well.)

We plan with the local lighting utility to begin replacing the polluting
prismatic refractors below the lamps around the observatory with flat
glasses soon. There is no problem with that, they are the GE M250 ones,
which could be fitted with flat glass from the beginning already -- just
the lighting people have not been aware of it before. It should help a
lot, at least excluding glare to our visitor's eyes completely. To achieve
darker sky as well, we should discard several thousand non-flat refractors
(there are some thirty thousand street lamps in Brno).
> What other sorts of measures are being taken, besides use of the new
> light fixtures, to combat light pollution in the Czech Republic? Are
> the problems of light pollution mostly caused by businesses or the
> city governments? Are private citizens affected by this law, too?

Better aiming the light is the most important goal, reducing its total
amount is another one. Brno has a priority in this programme, as it
successfully installs dimming systems managed from a single centre. Some
streets are dimmed later in the evening, according to the intensity of
traffic there, beginning sometimes at 8 p.m. already. Unfortunately, none
of these new capabilities is working near our observatory yet. 

However, there is one interesting feature of our site: from the beginning
in the mid fifties, there is no lighting at all in the park around us. So,
our visitors have traditionally the best place here to view the stars
inside the city, in spite not being even two kilometres from its
centre. The park is considered a very safe one, compared to another, lit
ones... so says my experience as well, I'm going here for more than thirty

There are some horrible examples of skybeamers, rare in Brno but very
polluting at some places, like the border to Austria near a southern
Czechia town Znojmo. And the Czech railways spoiled almost completely
their old excellent (Austro-Hungarian) tradition by installing towers full
of reflectors shining not just to the rails but on the whole city and the
universe above it... Something excluded both in Austria or Hungary itself,
they adhere to the use of fully shielded lamps completely.
> I have read that you were instrumental in drafting this law. Is it
> possible for me to get a copy of the law's text in English?

Just see http://www.astro.cz/darksky and the links from there. 
> Thanks very much for your help. I hope to hear from you soon!
> Sincerely,
> Maggie Zackowitz
> Senior Writer
> National Geographic Magazine

So perhaps for the beginning, I'm honoured to work with the NG!

best regards,