Scifest Africa was established in 1996 to promote the public awareness, understanding and appreciation of science, technology and innovation. The project is supported by South Africa's National Department of Science and Technology and other sponsors.
For more details, RFI spoke to Anya Fourie, the festival's director.
1. Tell us about this year's fair – what can visitors find there?
"We have 650 events for the next seven days, 80 exhibitions, all of which will be celebrating the theme of time because this year is our 20th year of the National Science Festival. We have exhibitions which are free, we have about 42 workshop titles repeated daily, we have fun events like sunset shows, science olympics. It's a wide range of activites open to people from the ages of 5 to 105."
Some other things you might find at the fair include :
*The Square Kilometre Array (SKA) project, which is an international effort to build the world’s largest and most sensitive radio telescope ever built.
*The StarLab inflatable planetarium.
*The Phedisanang PCP, which looks at the indigenous people in Africa and Asia and how they have utilized the Moringa tree for medicinal purposes.
*South Africa's latest and most fabulous fossil finds, including Homo naledi, to give learners a better understanding of the significance of palaeontology to everyday life on the continent.
2. What can visitors see at the 'Great South African Inventions' exhibition?
"Very few people know that there are inventions that come from South Africa that really are significant landmarks. We look at the Dolos, which is used in land reclamation along our coasts and to protect our coasts.
There's also the Pratley Putty, and the Kreepy Krauly, which was invested in South Africa. And the CAT scan which of course was a very important medical breakthrough. We also have traditional medicines like the use of aloe vera. These are all things that have come out of South Africa."
South Africa's National Space Agency is also present at the fair, letting visitors roleplay as Albert Einstein, to demonstrate theories of special and general relativity in Perfect Timing. This to show how speed and gravity affects space and time, by looking at the Global Positioning System (GPS).
"SANSA this year will be looking at earth observations, satellites that circumnavigate the globe and how we use those to watch changes. Changes not only in our landscape, but also our weather. We can also use these satellites to monitor natural disasters, such as the drought which South Africa has had recently."