Přístupnostní navigace

Přejít k obsahu | Přejít k hlavnímu menu

VUT

Menu
  • Life at BUT Submenu
    • BUT Ambience
    • Spaces
    • Dormitories
    • Refectories
    • Sport
    • Brno
    • Practical guide
  • Study Options Submenu
    • Join BUT
    • Short-term studies
    • Degree studies in English
    • Degree studies in Czech

    E-application

  • Students Submenu
    • Courses
    • Study programmes
    • Study Regulations
    • Going Abroad
    • Scholarships
    • Social Safety
    • Admission Office
    • Welcome week
    • Final theses
    • Recognition of Foreign Education
    • Personal Data Protection
    • Entrepreneurship Support
  • Research & Development Submenu
    • Research & Development
      at BUT
    • Excellence support
    • International Scientific Advisory Board
    • Research quality assurance system
    • Research infrastructures
    • Knowledge Transfer
    • Open Science
    • Projects
    • Projects from Structural Funds
    • Specific University Research
  • Cooperation Submenu
    • Cooperation with corporate sector
    • Welcome Service
    • International Staff Week
    • International Agreements
    • University Networks
  • University Submenu
    • University profile
    • News
    • Organization Structure
    • Alumni
    • Sustainable university
    • Safe University
    • Entrepreneurial University / ContriBUTe
    • Official notice board
    • Career at BUT
    • Social Safety
    • Support and Development of Employees and Students / HR Award
    • Media
    • Personal Data Protection
    • Contacts

    Faculties

    • Faculty of Civil Engineering
    • Faculty of Mechanical Engineering
    • Faculty of Electrical Engineering and Communication
    • Faculty of Architecture
    • Faculty of Chemistry
    • Faculty of Business and Management
    • Faculty of Fine Arts
    • Faculty of Information Technology

    University Institutes

    • Institute of Forensic Engineering
    • Centre of Sports Activities
    • Central European Institute of Technology (CEITEC BUT)

    Parts

    • Centre of Information Services
    • Continuing Education and Counselling Centre
    • Halls of Residence and Dining Services
    • VUTIUM Press
    • Central Library
    • Rectorate
  • CS
  • Log in

    Log in

    • BUT Web
    • Intraportal
    • Studis
    • Teacher
    • Elearning
  • Search
  • CS

Close

  1. Home
  2. University
  3. News
  4. Turned off Brno showed experts the sources of light smog

Turned off Brno showed experts the sources of light smog

On Saturday night, April 10, 2021, the public lighting in the whole of Brno was turned off for several hours. The aim of the event was to find out how much Brno suffers from light smog. In addition to aerial photography, Petr Baxant from the Faculty of Electrical Engineering and Communication Technologies at BUT also took part in the observation. The first results show that although public lighting creates light pollution, the regulation of lighting in private buildings and premises could have a much greater result.
Experts found the background at the Brno Observatory | Author: Jan Prokopius

"By turning off the streetlights, the brightness was reduced by about 45 %. It is not much, but we must also consider that public lighting is regulated and at night it was no longer at 100 % of the evening maximum. It turned out that the level of the night light is more influenced by entities outside the Brno city administration. We will be interested in how many of them are dominant and which they are. We would then like to focus on these in the next measurement," Petr Baxant summarizes some of the data.
The resulting images are coloured in the so-called pseudo-colours, which is a colour scale of brightness. The human eye is sensitive to brightness and perceives contrasts in particular. The brightness of a computer monitor or telephone display is in the order of hundreds of candelas per square metre (candelas is a unit of the luminosity of the source), while the surface of the full moon has a brightness of about 3500 cd/m2, which is a thousand times greater than the brightness of Spilberk Castle under architectural lighting. The artificial illumination of such a façade is about twenty times greater than the natural illumination of the Moon.
Images showing light pollution | Author: Petr Baxant

"Round fisheye images show us a view of the zenith, and therefore the entire upper hemisphere. Here we have very interesting numbers from the calculation of illuminance caused by a low clear sky. At the measurement site, there was only 0.008 lx of light intensity when the public lighting was off. This is a value about thirty times smaller than we would measure with a very bright full moon," Baxant points out that even a bright moon can interfere with the measurement. His team's research is aided by a brightness analyser they build, which allows the Moon and its brightness to be read and replaced by background. A conventional lux meter does not allow such a measurement. At the time of Saturday's measurement, however, the Moon was not visible.

"Saturday's attempt was truly unique. We were ready and we managed it. Thanks to this, we will start the next stage of research. The public might think that these are small numbers and we may not be interested in the topic. We will probably look in vain for a truly zero light background, or rather what the stars and natural light from the planet's atmosphere create for us. However, we would like to at least get closer to it and find out how we are doing in the conditions of the Czech Republic and towards other places on the planet," Petr Baxant concludes with a positive outlook.
Among other things, FEEC scientists are working with their own brightness analyser, which can read the brightness of the Moon | Author: Jan Prokopius
  • View of the Špilberk fortress after the turn off | Author: Petr Baxant
  • View of the Špilberk fortress before the turn off | Author: Petr Baxant
  • View of Brno before the turn off | Author: Petr Baxant
  • View of Brno after the turn off | Author: Petr Baxant
    Show gallery

Published 2021-05-09
Link https://www.vut.cz/en/but/f19528/d212533

Life at BUT

  • BUT Ambience
  • Spaces
  • Dormitories
  • Refectories
  • Sport
  • Brno
  • Practical guide

Study options

  • Join BUT
  • Short-term studies
  • Degree studies in English
  • Degree studies in Czech
  • E-application

Students

  • Courses
  • Study programmes
  • Study Regulations
  • Going Abroad
  • Scholarships
  • Social Safety
  • Admission Office
  • Welcome week
  • Final theses
  • Recognition of Foreign Education
  • Personal Data Protection
  • Entrepreneurship Support

Research & Development

  • Research & Development
    at BUT
  • Excellence support
  • International Scientific Advisory Board
  • Research quality assurance system
  • Research infrastructures
  • Knowledge Transfer
  • Open Science
  • Projects
  • Projects from Structural Funds
  • Specific University Research

Cooperation

  • Cooperation with corporate sector
  • Welcome Service
  • International Staff Week
  • International Agreements
  • University Networks

University

  • University profile
  • News
  • Organization Structure
  • Alumni
  • Sustainable university
  • Safe University
  • Entrepreneurial University / ContriBUTe
  • Official notice board
  • Career at BUT
  • Social Safety
  • Support and Development of Employees and Students / HR Award
  • Media
  • Personal Data Protection
  • Contacts

Brno University of Technology

Brno University of Technology

Antonínská 548/1
602 00 Brno
Czech Republic

www.vut.cz
vut@vutbr.cz

  • Facebook
  • Twitter logo Twitter
  • YouTube
  • Instagram
  • LinkedIn
  • Spotify logo LinkedIn

Copyright © 2025 VUT

Accessibility Statement
Cookies Policy

  • HR Award logo HR Award
Nahoru