Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
18 April 2022 | Story Leonie Bolleurs | Photo Stephen Collett
Prof Ted Kroon
Prof Ted Kroon from the Department of Physics recently delivered his inaugural lecture on the topic What’s the use of a rainbow on the UFS Bloemfontein Campus.

“A rainbow is a natural phenomenon, the result of the refraction and reflection of the sun’s rays in drops of rain. As far as mankind is concerned, it’s a perfectly useless object and won’t make anyone money. Yet the poet who said, My heart leaps up when I behold a rainbow in the sky, only put into word the feeling of wonder and excitement we all have when we see a rainbow.”

“Every day I see a rainbow in my work; I do not need to wait to see one in the sky,” says Prof Ted Kroon, Professor in the Department of Physics at the University of the Free State (UFS), who used this phenomenon to introduce the topic of his inaugural lecture: What’s the use of a rainbow. 

“Far from being only a colourful spectacle with no practical value, rainbows are useful – and lead to useful things,” he believes. 

According to Prof Kroon, one can find examples of real rainbows and rainbow analogies used not only in everyday life, but also in physics. “Besides it being familiar devices in literature, culture, and even marketing, studies of rainbows can yield practical engineering information and may even help us to find new habitable planets,” he says.

Inspired by the many uses of a rainbow

In his lecture, he discussed the basic features of natural rainbows and how they come about. He also explored how the rainbow gives meaning to colour, and how this relates to the temperature of objects. He looked at an array of instances where the rainbow is used; from depicting the life of a star to indicating that we are sick (a thermometer) or when we need to refill a gas cylinder.
Moreover, Prof Kroon pointed out that rainbows are used in computer chips, stress identification, and to transmit internet data through underwater cables of glass fibre. He also referred to how the rainbow was harnessed as an engineering tool to measure refractive index and characterise fine droplet sprays used in industry. 

He continues, “Remarkably, the science developed to understand the natural rainbow can be redirected and applied to the optical properties of metallic nanoparticles, allowing the development of nanotechnology. Knowing how the natural rainbow works and its limitations, better systems have been developed to produce rainbows. Such rainbows have been used to discover new elements and to determine the age of the universe.”

As a member of an international community of phosphor researchers who are privileged to work with rainbows every day, he has used them to study the light-emitting properties of materials doped with bismuth. With this project – an initiative with the African Laser Centre taking place between 2016 and 2021 – he collaborated with the University of Khartoum in Sudan and trained a number of its postgraduate students. “My role included the guidance of students and the measurement and interpretation of the light-emitting properties of the materials. Our research during this time, considering more than a dozen materials, was summarised in 34 scientific publications that contributed to a greater understanding of bismuth ions as light-emitting materials,” he explains. 

Developing new materials, efficient in emitting blue light

He has been developing luminescent materials since 2006, primarily for general lighting (fluorescent tubes and LEDs) and displays (television, computer, and cellphone screens), as well as niche applications in medical and forensic science. 

As part of his current research, he is examining the effect of plasmonic metal nanoparticles on phosphor light emission. He is also exploring materials that absorb infrared light but emit visible light. “For this, I would like to consider the long-term stability of such materials and develop new materials that are more efficient in emitting particularly blue light,” he says. 

Prof Kroon holds a C2 rating from the National Research Foundation and has published more than 150 articles and book chapters, obtaining a Scopus h-index of 26.

News Archive

Tswelopele hosts first LGBTQI panel discussion
2016-10-05

Description: LGBTQI  Tags: LGBTQI

Tshepang Mahlatsi, Zane Thela, Dionne van
Reenen, Dr Thierry Luescher and Galeletsang
Soato, at the Brotherhood with no Limit panel
discussion held at Tswelopele residence on
the Bloemfontein Campus.
Photo: Supplied

Ignorance about issues relating to the Lesbian, Gay, Bisexual, Transgender, Queer and Intersex (LGBTQI) community is a threat to mankind. This is according to Tshepang Mahlatsi, former Prime of Tswelopele residence, regarding LGBTQI concerns at University of the Free State (UFS).

House Tswelopele on the Bloemfontein Campus hosted a panel discussion, Brotherhood with no Limit, on 19 September 2016 to discuss issues affecting the LGBTQI community, which has often been on the receiving end of criticism, hate speech and bigotry.

Academics take stance at LGBTQI discussion

The panel, which consisted of staff members and students, opened the discussion to everyone on campus. The panel comprised Zane Thela, Programme Coordinator: Gender and Sexual Equity Office: Student Affairs; Dionne van Reenen, Assistant Researcher; Dr Thierry Luescher, Assistant Director, Directorate for Institutional Research and Academic Planning, and Mahlatsi.

Creating a safer environment for LQBTQI dialogue

“The message that we were putting across was simple. We as a house cannot allow society to define our own brothers for us,” Mahlatsi said. The responsibility of students and student leaders was to stand in solidarity. He said it was not fair that in the 21st century people were still fighting to be recognised for who they were and what they identified themselves as. This issue had been discussed at Tswelopele before and it was not that much of an issue, Mahlatsi said. “However, this was the first formal one [discussion] where we had speakers who are more informed on the topic.”

The panel discussion also aimed to challenge other residences that still do not allow such talks to take place in a safe environment.

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept