On the night of 9-10 April 2021, Brno plunged into semi-darkness. The intention to switch off the public lighting in Brno, including architectural lighting, was to find out how the operation of lighting in the administration of the city of Brno affects the surrounding environment and what is the effect especially on light pollution. Since the team of lighting engineers from the Institute of Electrical Power Engineering actively participated in the experiment, we publish here relevant information and outputs from this night event. The media coverage took place just after the event and we would like this content to keep the data up-to-date and possibly a source for further reports and reporters who will be able to find verified facts here (Continue with czech version).
The author team consists of:
Assoc prof. Ing. Petr Baxant, Ph.D.
Ing. Jan Škoda, Ph.D.
Ing. Martin Motyčka, Ph.D.
Ing. Filip Novák
As a thank you for our work, we received a photo image by Brno photographer Pavel Gabzdyl, who also took visual photographs of the lit and darkened Brno during the experiment and created a very interesting composition from them. In the left part of the picture Brno is extinguished and in the right part it is lit up. The images are composed into one even though they were shifted in time by a few minutes, maybe tens of minutes. Pavel Gabzdyl has a very distinctive way of photographing Brno and you can find other very interesting images on his website. The original painting and its "birth certificate" can be seen in the premises of the Institute of Electrical Power Engineering on the 7th floor of Building A, Technical 12, Brno.
It is a limited edition, only five pieces were produced. We are glad that our work has such an outreach and that we can be present at unique projects that address not only scientists and experts, but touch practically the whole population and in this case we dare say that they touch life as a whole.
We discussed the experiment of the extinguished Brno with the director of the Brno Observatory and Planetarium, Mgr. Jiří Dušek and his colleague Jiří Kokmotos, the head of the programme of the Czech Radio Brno in the programme Daisies online. In the end, two episodes were produced and there will probably be a sequel.
Sedmikrásky online | 39 - about light with Petr Baxant - Part 1 https://youtu.be/O8BcnAa0JSM
Sedmikrásky online | 42 - about light with Petr Baxant - part 2 https://youtu.be/bMgoP1eAnVs
The experiment with the extinguished Brno was of further interest to several media outlets. No wonder. The switching off of nearly 43,000 lights in the second largest city in the Czech Republic will spark public interest. Here is a list of the most interesting reports.
Currently
Czech Television 22.6.2022, About Science and Scientists: dazzle
https://www.youtube.com/watch?v=u-14pGhO55U
Czech Television, 30.4. Events in the regions CT24
https://www.ceskatelevize.cz/porady/12094108610-regiony-ct24/322281381960430/
Brněnský deník.cz: Brno's fight against light smog: the aim is to see the stars in the city, 21.4.2022
Czech Radio Brno: One year since Brno's lights out: BUT scientists develop device to measure light pollution, 11 April 2022
ČT: Week in the Regions (Brno) About Science and Scientists: dazzle 2.4.2022
https://www.ceskatelevize.cz/porady/1181680258-tyden-v-regionech-brno/322281381890402/cast/903786/
Older posts
Czech Radio Brno, programme Apetýt 25.5.2021
Where there is light, there is safety? It doesn't have to be, thinks the scientist who let Brno go out
Light pollution 14.4.2021
Brno experiment: https://svetelneznecisteni.cz/brnensky-experiment/
Český rozhlas Brno, 12.4.2021
Dark as Brno. Thousands of lamps went out in the city, scientists from BUT investigated the sources of light pollution: https://brno.rozhlas.cz/tma-jak-brno-ve-meste-zhasly-tisice-lamp-vedci-z-vut-zkoumali-zdroje-svetelneho-8466354
Autonabíječka.cz
The experiment has also attracted the attention of electric motorists, as dark Brno could evoke blackout drills. The editorial team of the web server writes about energy savings and night lighting autonabijecka.cz, author: Petr Beneš.
Ten, kdo zhasl Brno
How much energy is wasted and how many kilometres would electric cars travel on this energy?
And since the night lighting affects mainly traffic, the attempt to turn off the public lighting "bubbled up" to the Brno "shalina".
Brno zhaslo: odborníci hledali zdroje světelného smogu - článek v časopise Šalina
The full magazine can be found here: https://dpmb.cz/cs/download-section/4 – May 2021 and there is also an article on electromobility.
And other bits and pieces describing experiments with nighttime non-illumination
Light pollution in Brno
A problem that doesn't just end with "you can't see the stars at night".
Miriam Zedníčková, Michael Varga, Dušan Vala and Martin Fiša
26 November 2021
https://storymaps.arcgis.com/stories/7729fd4932da4f218def7edb1e04de6a
If you find other articles on this topic, please email us.
Workshop of the Ministry of the Environment 14.5.2021
We also had the opportunity to discuss the results of the experiment at an international seminar. A recording of the EU Green Week 2021 seminar on light pollution can be found on this page: https://www.mzp.cz/cz/ligh_pollution_webinar_prezentace It contains a number of other contributions by other authors, including those from abroad, who are professionally involved in similar topics.
This particular deliverable of ours provides an expert lecture and presentation of the measurement results, the first validated data processed from this experiment.
What are our next plans?
We did a similar experiment in autumn - but in the opposite polarity - this time everything was shining, including the full moon. TopGis took another aerial photo of Brno at night, this time with public lighting on. We have taken further measurements with a brightness analyser and will be looking at how the images look from above and below and how we can get relevant photometric data from them.
For these two experiments - spring and autumn - two unique mapy nočních snímků.
An event has been announced for spring 2022 Hodina Země. 26.3.2022 at 20:30 - 21:30 and we measured the effect of extinction on the brightness of the night sky in Brno. The conditions were not ideal and in the city of Brno, the Brno City Council took part in the event with only a few monuments being extinguished, so it was not visible in the measurements.
We received support from the Czech Technology Agency for the project Research and development in the field of measurement and evaluation of artificial light in the night environment and its impact on living organisms and the environment as a whole. This project aims to develop a methodology for the objective measurement and assessment of light pollution from arbitrary sources.
Photogalery
Links to other interesting sites
- For more information about the measuring equipment developed in our light laboratory, please visit www.lumidisp.eu.
- The phenomenon of light pollution is the subject of a website www.svetelneznecisteni.cz.
- A website about light, where you can find more links to other sources of information not only about night lighting: 555.lighting
- Website of the Czech Society for Lighting, Brno branch association, under whose auspices we are able to influence legislation, companies or connect people of similar interest and focus: www.cso-brno.lighting
- Earth Hour 2022 - an event to help reduce emissions on planet Earth: www.hodinazeme.cz
- Solar eclipse measurements 2022: https://www.fekt.vut.cz/o_fakulte/aktualita/232845
If you have any questions and suggestions for extending this page, please contact us via email info(at)lumidisp.eu.
