Last week, from 7 to 9 October, the Pretoria Centre of the Astronomical Society of South Africa (ASSA) hosted the 8th biennial symposium at the Council for Geoscience Silverton campus. Although the theme of the symposium was light and spectrum pollution, a wide range of papers were presented across topics as diverse as mining in space and the problems facing science journalism in South Africa.
The first day opened with a tour of the Council for Geoscience. We were introduced to the seismology department, and briefly discussed the seismic readings picked up from the massive fireball which streaked across Southern African skies late last year. We were then herded to the other side of the building where the geologists showed us their laboratories, boasting some very impressive equipment.
After an introductory speech by Andrie van der Linde, professor Phil Charles (Director of the SAAO) took the podium to deliver the first paper. Although his topic was the repair status of SALT and progress at Sutherland, he is a very enthusiastic speaker and covered a wide range of topics related to astronomy in South Africa. He exceeded his allotted time, but spoke with such passion and knowledge that nobody seemed to mind!
Prof Charles was followed by Dr Hubrecht Ribbens, who spoke on Techniques to Observe and Analyse Celestial Objects and Phenomena. This turned out to be a very large and ambitious topic and even though he spoke for a full hour, there was only time to cover the topic lightly. Hopefully he will have more opportunities to explore the subject more deeply at future conferences.
The final speaker for the morning was Hendrik van Heerden, of the University of the Free State. Hendrik is involved with a project to build a museum at the site of the historic Boyden Observatory, which has continuously produced valuable astronomical observations for over a century. The Boyden Observatory was originally built in Chile by the Harvard College Observatory in 1890, and was moved to South Africa in 1927. Boyden has continuously produced valuable astronomical work ever since. In the 1950s, Harvard announced that they could no longer afford to run the observatory, so Boyden became the world’s first international joint venture observatory.
After providing a brief history of the observatory, Hendrik showed the intended plans of the new museum, and gave a photographic tour of the facilities.
After lunch, the afternoon session was opened by Johan Smit, chairman of the Pretoria Centre. He presented a very entertaining talk on The Dark Side of Light – Light and Spectrum Pollution. While active campaigners against light pollution would have been familiar with much of what Johan had to say, he managed to present the material in a compelling way, and made excellent use of photographs to demonstrate the negative effects of light pollution. He was also able to illustrate such counter-intuitive aspects of light pollution: for example, security lights are more likely to aid criminals by providing conveniently located shadows in which to hide while dazzling the eyes of home-owners and security staff! He finished off by giving some pointers on how to raise the subject with local government and neighbours who insist on directing high-powered lights into our gardens and bedroom windows at night.
Next on the agenda was Michael Poll, president of ASSA. His talk on Astronomy in Cartoons was very casual and light-hearted and composed entirely of syndicated cartoons containing astronomical references. The point of the discussion was that the basics of astronomy are generally poorly understood, and popular representations generally repeat the same basic mistakes. By pointing out these mistakes we can raise public awareness and educate our audience (although he noted that it’s very easy to come across as an irritating know-it-all in the process!)
The final session for the afternoon was supposed to be a workshop on laser safety and regulation in South Africa. Powerful green laser pointers have recently become freely available on the market and are often sold with no regard to licensing requirements – any visible wavelength laser with a power output of more than 5mW is dangerous enough to require registration with the Department of Health (DoH) and must be licensed. The licenses are easy to obtain, but the DoH lacks the knowledge to be able to evaluate applications for “Astronomy Use”, which is the standard justification for a high-powered green laser.
The workshop was supposed to allow members of ASSA to discuss the situation with a DoH representative and present guidelines on what type of laser the ASSA considers suitable for astronomy work. Unfortunately the representative experienced had problems with his travel arrangements and was stranded in Cape Town. He sent his apologies. In his absence, we discussed the situation and compared experiences. The general consensus seemed to be that any laser with an output exceeding 50mW is excessive and can actually interfere with astronomy by ruining an observer’s dark adaptation! Andrie van der Linde proposed a set of guidelines requiring an authorised astronomical organisation (such as ASSA, universities, astro-tourism companies) to provide motivation for individual operators to be permitted use of any green laser over 5mW.
The day was concluded with a formal dinner at Mohka Restaurant at the Pretoria Botanical Gardens.
And that is enough for this update – come visit tomorrow for the summary of the second half of the Symposium.