So other than the R15 billion price tag what is the Square Kilometre Array (SKA), and why the interest? SKA is a very large telescope, and as the name implies, it will be one square kilometre in size. But take note of the word ‘Array’. The rule of thumb is that the wider a telescope is, the further it can see. It would be impossible to build a telescope of 1km2, as one single unit, so it is being built as an array of smaller telescopes, all operating together as one.
This telescope also does not “see” using light in the conventional understanding of a telescope. SKA will be a radio telescope. Such a telescope monitors radio waves rather than light. People are used to seeing astronomical pictures created from light images, but few realise that astronomers can generate accurate pictures built up from radio waves.
The radio waves that astronomers want to view have been travelling through space since the birth of the universe, so when they get a snapshot of these waves, astronomers will actually see a picture that was created at the beginning of time.
Major astronomical events, such as exploding stars, do not just emit light; they emit energy covering the whole electromagnetic spectrum including radio waves, x-rays and gamma rays. Radio waves travel much further, with fewer disturbances than does light. So to see back to the beginning of time, it is best to use radio waves.
Not only will SKA be able to see far into space, it will also be able to see back into time. When the universe was born out of a huge explosion, the radio waves that were formed at the time have been travelling through space ever since. SKA will be able to detect these radio waves and produce images of what the beginning of time looked like.
SKA will be so sensitive that if there are alien beings living on another planet orbiting a nearby star we will be able to detect their TV broadcasts. So why would we build a R20bn device to detect the TV broadcasts of aliens? Well, it would be exciting if we did find aliens but that is not the purpose of SKA. It will be used to probe deep space to unravel more mysteries of the universe.
We know that galaxies in the universe are flying away from each other at a great rate, but we don’t know why. SKA will be able to measure these motions so accurately that it will add to knowledge, leading to the solution of the mystery.
There are also possibly gravitational waves in space. SKA should be able to detect them if they exist. Can all of this be beneficial to mankind? Well yes, it expands knowledge and understanding of mankind’s existence, but it also may lead to economic benefit.
For example, when nuclear physicists wanted to move huge amounts of nuclear experimental data, very rapidly, from research groups in one laboratory to another over long distances the world-wide-web of the internet was created to do just that. Look at what the internet has become commercially. Maybe SKA knowledge will follow the same path.
South Africa has been working on a precursor to SKA for some years now – this is the MeerKAT project, which has constructed radio telescope dishes in the Northern Cape. There is an array of radio dishes already operating, all controlled from Cape Town. To drive these dishes in sync from Cape Town is a major technological achievement.
To achieve this, a local team worked with the University of California and the US National Radio Astronomy Laboratory on developing “reconfigurable computing hardware and architecture”. The result is that they developed Roach boards – Reconfigurable Open Architecture Computer Hardware boards. This technology uses very fast hardware to carry out specialised computing applications in parallel.
South Africa is now building Roach boards for India and Australia. The team has also started getting inquiries from the local telecoms industry. So this big science, aimed at looking back in time, will also produce valuable technology for business applications.
SKA will also attract a constant stream of local and foreign visitors, mainly scientists and astronomers, adding to South Africa’s prestige. This has been demonstrated by the successful SALT telescope (SA Large Telescope) at Sutherland.
SALT is the largest optical telescope in the southern hemisphere and it attracts a constant stream of international astronomers. Furthermore it operates 24 hours a day, because during the daylight hours it streams the night’s information internationally via the internet.
SKA will now add even more stars to South Africa’s international scientific radiance.
Dr Kelvin Kemm is a nuclear physicist and Business Strategy Consultant based in Pretoria.