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28 January 2021 | Story Igno van Niekerk | Photo Supplied
Pictured from the left: Lucas Erasmus from the Department of Physics, Piet le Roux from the Astronomical Society of SA – Bloemfontein, Quinton Kaplan from the Department of Physics, Thinus van der Merwe from the Astronomical Society of SA – Bloemfontein. Front: Prof Matie Hoffman

In his book, The World is Flat, Thomas Friedman mentions how at first countries, then companies, and eventually communities went global. In true flat-world fashion, a combined team of the University of the Free State (UFS) and the Astronomical Society of South Africa – led by Prof Matie Hoffman, Associate Professor in the Department of Physics – participated in a once-in-a-lifetime event with their counterparts from the Ellinogermaniki Agogi School and the Skinakas Observatory in Greece.

On 21 December 2020, Earth was treated to the Jupiter-Saturn conjunction, when the two planets were only 0.1 degrees apart in the sky. Although conjunctions are regular phenomena, NASA mentions that the great conjunction of Jupiter and Saturn in 2020 was the closest since 1623 and the closest observable since 1226! A pinkie finger at arm’s length could cover both planets – although they were still millions of kilometres apart in space.

Planning started months ahead of the event, with the Ellinogermaniki Agogi Observatory in Greece and the Boyden Observatory in Bloemfontein chosen as the two selected vantage points. From both the Southern and Northern Hemisphere, the conjunction would be broadcast live on YouTube. As with any other technical project on an international scale, challenges arose. For example, in the Northern Hemisphere, it was already dark at 17:45 while the South African astronomers were still basking in sunlight until after 19:00. The conjunction would only be visible from South Africa after 19:30, almost two hours after it would be visible in Athens. The time was well used, with the event including a word of welcome by the Consul General of Greece in South Africa, Ioannis Chatzantonakis, presentations on Saturn and Jupiter, as well as a virtual tour of the Boyden Observatory, emphasising its connection with Greece through its first Director, Stefanos Paraskevopoulos. 

On Saturday, 19 December, the teams ‘gathered’ on opposite sides of planet Earth to do a dry run. One could sense the urgency and tension as both teams realised that they would have a huge captive audience on YouTube, and plans had to be made in case of connectivity challenges and if the weather did not allow the conjunction. As preparations progressed, Prof Hoffman was talking to his Greek counterparts and was simultaneously walking around with his laptop to share the landscape and activities via his webcam with colleagues in Greece. 

Monday 21 December 2020 – the weather prediction was correct. Clouds covered the Free State sky and scattered raindrops started to fall. Revert to Plan B. A recording made on Saturday evening was shared via the YouTube link, while a live feed of the conjunction from elsewhere in South Africa was arranged. From both sides of the world, information was shared about the history of the venues, as well as the marvel of what was happening in space. Fortunately, expert planetary photographer Clyde Foster was able to share a live feed just after 19:30 from the observatory at his home in Centurion, Gauteng. Those attending the event where visuals and speakers were together on one screen – yet thousands of kilometres apart – watching an event in outer space, will indeed agree with Thomas Friedman: the world is flat. The live-stream event of the conjunction was a catalyst that will result in continued collaboration between the UFS and colleagues in Greece in the field of astronomy. 

By the time of this writing, the livestream has reached more than 50 000 people.


News Archive

Einstein's gravitational waves as creative as Bach's music, says UFS physicist
2016-02-19

Description: Gravitational waves  Tags: Gravitational waves

Profile of the gravitational waves of the colliding black holes.

Prof Pieter Meintjes, Affiliated Researcher in the Department of Physics at the University of the Free State, welcomed the work done by the Laser Interferometer Gravitational-Wave Observatory (LIGO) science team.
 
For the first time, researchers from two of the American Ligo centres, in Washington and Louisiana respectively, observed gravitational waves directly, 100 years after Albert Einstein said they existed. "My study field in astrophysics involves relativistic systems. Therefore, Einstein's view of gravity is crucial to me. I consider the theory as the highest form of human creativity - just like the music of JS Bach. Over the past 100 years, the theory has been tested through various experiments and in different ways.
 
“The discovery of gravitational waves was the last hurdle to overcome in making this absolutely unfaltering. I am therefore thrilled by the discovery. It is absolutely astounding to imagine that the equations used to make the predictions about the gravitational-wave emissions when two gravitational whirlpools collide - as discovered on 14 September 2015 by LIGO - are basically Einstein's original equations that were published way back in 1916 - in other words, 100 years ago.
 
“The LIGO detectors have been operational since the early 1990s, but they had to undergo several stages of upgrades before being sensitive enough to make detections. LIGO is currently in its final stage, and is expected to function at optimal sensitivity only within a year or two. To be able to conduct the measurements at this stage is therefore a fantastic achievement, since much more funding will certainly be deposited in the project,” Prof Meintjes says.

Description: Prof Pieter Meintjes Tags: Prof Pieter Meintjes

Prof Pieter Meintjes
Photo: Charl Devenish

The search for gravitational waves by means of the Square Kilometre Array (SKA) is one of the focus points in research by both Prof Meintjes and PhD student, Jacques Maritz. This involves the study of radio signals from pulsars that might show signs of effects by gravitational waves. They are looking for signs of gravitational waves. The gravitational waves discovered and studied in this manner would naturally vary much more slowly than the signal discovered from the two colliding gravitational waves.
 
The discovery will definitely provide renewed impetus to the Square Kilometre Array (SKA) Project to use the dispersion of pulsar signals, and to search for the impact of gravitational waves on signals as they travel through the universe. According to Prof Meintjes, the SKA will definitely contribute fundamentally to the Frontier research, which will provide a good deal of publicity for the UFS and South Africa, if significant contributions are made by local researchers in this field.

Video clip explaining gravitational waves

 

  • The Department of Physics will present a general, non-technical talk concerning the recent detection of gravitational waves by the 2 Laser Interferometer Gravitational Wave Observatories (LIGO):

Wednesday 24 February 2016
11:00-12:00
New lecture auditorium, Department of Physics

 

 

 

 

 

 

 

 

 

 

 

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