News: Globe at Night runs Mar 16-28, crowned by Earth Hour, when all lighting, if possible, should be switched off on Saturday evening 8:30 PM. As a sign that we are aware that just a year or two remain for starting effective prevention of a catastrophic climate change, and a sign that a real night should be brought back to Earth again. For Globe at Night, click here to see detailed star maps.

Night Environment Pollution and the Remedies through Legislation and Technology, in Czechia and in general

The main principle is simple,
  1. don't use artificial lighting outdoors when and where it's not necessary
  2. let the light go just the right direction: down (and steep enough).

Lighting fixtures with no down-protruding belly (a flat glass instead) do the job, (if lighting is really needed) like these in central Europe:
Kassel/Germany Gleisdorf-Solarstrasse/Austria Brno/Czechia Gleisdorf (boxes)
eco-settlement in Kassel Strasse der Solarenergie in Gleisdorf in front of Brno railway station parking lot in front of the museum in Gleisdorf

The best possibility ever to learn the best exiting knowledge at this field is the conference Light Pollution and Global Warming, at lake Bled, Slovenia, October 5-6, 2007. See more in the outstanding conference brochure at

The rules for minimizing adverse effects of lighting are well known. A draft template for the EU legislation is available in the eu_law directory. (The International Dark Sky Association submitted an incompatible template Model Lighting Ordinance to public discussion, an ad-hoc activity with serious concerns about it formed as Fix the Model Lighting Ordinance, A proposed introduction to some study on streetlighting (not included by that study's authors) explains the problem further (a pdf version is better to print and read).

Most information at this site is in Czech only (see, or, as a novelty, a huge research report within, just a couple of things is in English as well (a non-local one is on lighting and crime).

Czech Republic included light pollution in its newly coined Clean Air Act in 2002, a step much appreciated throughout the world. However, the Act contained a declaration only, the government had to issue the very rules. It had never happened, due to efforts of ... and unconcern of ... (you can guess, I have to be diplomatic). However, our effort to formulate simple and still effective set of such rules led to a draft submitted to the House of Representatives (it has not been accepted, as e.g. there was no support from the Ministry of Environment, unlike in 2001), which may be of interest to everybody. I'd appreciate any advice what should be changed in this set to fit legislation of most countries. I have to stress that the limits contained in documents below are the most liberal ones as possible, it's a really minimum set. Even a lighting system which obeys these limits may still be a significantly polluting one. Still, adhering to these limits would ensure that pollution of night environment would decline in the next decades, a profound change from its rise over the last century.

The report mentioned above is a result of a research grant given by the Czech Ministry of Environment, Mapping the light pollution and negative influences of artificial lighting on the living nature. Most of the research has been done within several autumn 2003 weeks. Let's hope the report will change the attitude of the Ministry toward light-at-night. The text is in Czech only, I'll try to write some English summaries. All the stuff (one full CD) is within directory -- there may be occasional English comments in some subdirectories.

Some other links:

If you just came across this page, I stress that the best source of information on the light pollution are the new pages Traditional sources of information were The International Dark Sky Association, and the LiteLynx (TM) by Cliff Haas. My favourite European links are

and some highly relevant links in America

Prevention of light pollution is a major environmental issue, not at all just an astronomical one as it may seem. Astronomers are just among the first ones who have realized how a quality outdoor lighting should look like. However, mentioning light pollution inside a basic environmental law in Czechia has something to do with the position astronomy traditionally has there (as regards the history from Tycho's times, the competent person is Zdislav Sima, contact is available here).

Jan Hollan, +420 (5) 43 23 90 96 (home, when not at:)
N. Copernicus Observatory and Planetarium in Brno, +420 (5) 41 32 12 87
hollan (At) ped. muni. cz

Light pollution definition: alteration of light levels in the outdoor environment (from those present naturally) due to man-made sources of light.

See more at What is light pollution.

Examples of adverse manifestations of such pollution

Glare (and therefore decreased visibility at night), light trespass, light clutter, energy waste, bad sleep for many million people, damaged habitats for wildlife, perceptible or even vast increase of sky luminance over its natural values (of cloudless sky, what reduces or wipes out the beauty and glory of heavens, but also of overcast sky, what can diminish the original ratio between day and night light levels more than thousand times). View of the night landscape changed into a mess of light points, hindering to see the landscape itself.