Listening to the Universe

Why is monitoring the sky so exciting and what changed that set the stage for these large-scale projects?
The night sky has always been a source of wonder and information to humans. Can you imagine how different history would be if we were not able to see the stars? Navigation would be a lot more difficult. Newton would not have been able to dream up his laws of universal gravitation. There would be no Galileo.

In modern physics, astronomy has walked hand-in-hand with particle accelerators, such as CERN in Switzerland. Particle accelerators cannot get up to the energies that you need to look at new physics—it’s just too expensive. Moreover, the accelerator experiments investigate something that you have already anticipated. The stars on the other hand don’t cost you anything and you find unpredictable things, phenomena at energies much, much higher than you could design an experiment for on the ground. There are a hundred billion stars in the Milky Way and each of those stars could represent an “experiment.”

The other game changer has been big data. Not only can you do these huge sky surveys, but you can analyze immense data sets—billions of stars. The reward is you are doing fundamental physics in a different way, and making discoveries, at a much lower cost.

What are the big targets?
How did the universe form and evolve, what dark matter is, what dark energy is—pretty fundamental questions. There is also the search for extraterrestrial life and extraterrestrial intelligence. For the first time, we are capable of looking at exo-planets, which orbit stars outside our solar and planetary system. By observing even distant planets, we can determine a lot about their chemical composition. For example, if a system is out of chemical equilibrium there is a chance that something is driving that. Of course it may well be an amoeba or whatever it is out there which is not intelligent. I would put my money on such “life forms” being discovered before signals from other civilizations.

What is so unique about radio array telescopes like MeerKAT and SKA?
Traditionally we think of telescopes as optical—you look up with your eyes. Radio telescopes just convey information. The beauty is that radio waves can be detected in daylight as well as at night. They can reveal the cosmos at greater distances, in finer detail and at lower cost than other means by synchronizing many dishes to simulate a single larger antenna. If you have one telescope, three meters across, your aperture is three meters. If you have two dishes and put them a kilometer apart, it turns out that your resolution is equivalent to that of an aperture of 1 kilometer. You are restricted not by the dimensions of the dishes themselves but by the dimensions of the array.

As a result, we’re making beautiful new discoveries, like black hole mergers where you can see one black hole gobbling another. There’s also been much excitement about the James Webb infrared telescope, which launched in December and will complement our findings here on earth. Also complementing our findings are the gravitation wave observatories, like LIGO (Laser Interferometer Gravitational-wave Observatory) in the US, which are picking up a type of signal that was not possible before.

Look at our MeerKAT pictures of the center of the Milky Way, 25,000 light years away—that is just in our backyard from an astronomical point of view. It’s so bright it’s almost like taking a photograph into the sun. The fact that you can pick up such contrast and detail is an indication of the enhanced new capabilities with regard to big data and imaging. We’ve also been able to learn more about pulsars—those rotating neutron stars, some of which rotate many times a second. Imagine a huge object zapping around and so you get this flash, flash, flash, flash, flash as it goes. Apart from the extreme regularity of those flashes, you can discover if there is a gravitational wave, which comes from a black hole merger or a neutron star merger—a huge shock wave that goes across the universe. You can get complementary data from different instruments; that's what the excitement is all about.

Already three decades ago, you had this vision of South Africa as part of a substantial global astronomy project. With all the country’s challenges, how were you able to hold on to this idea and motivate for such an ambitious project?
After apartheid, we had a system that was very isolated from the rest of the world. Roger Jardine and I—when he was Director General and I was Deputy Director General of the Department of Arts, Culture, Science and Technology—asked ourselves: What would drive significant science infrastructure investment in South Africa? Astronomy seemed like a good choice. We have large arid areas with low population densities, ideal from which to view the southern sky. If you are a northern hemisphere astronomer you need to look at the cosmos from both sides of the Earth.

We also wanted to build on South Africa’s long association with astronomy. This dates back to the 1820s with the founding of the country’s first observatory, through to the 1915 discovery of Proxima Centauri, the second star closest to the Earth. We worked on a strategy to attract big astronomy investments and develop human capital—at the time, you could count the number of radio astronomers in the country on one hand. We wanted to participate in a project of global scale. That’s why we decided to bid for SKA. In the early days, there were China, Argentina, Australia and us. In the end it boiled down to simply Australia and South Africa. 

Was there skepticism that this was too ambitious for a developing country with so many other socio-economic challenges?
This was a geopolitical statement. We wanted to prove that we could stand shoulder to shoulder with our global peers—and we are succeeding in this regard. Having made the initial investment in a world class project, we are attracting new investment. Just two hours ago I was in a meeting with my counterpart from the Italian astronomy institute, who was proposing installing numerous receivers in the Karoo at a cost of millions of Euros. The Germans did the same with their receivers. Ultimately South Africa will carry only a portion of the total cost of SKA, the rest being borne by other member countries. We will get more back than what we put in. There is a rate of return that comes from the operating budget being deployed for the next 50 years. And it keeps us at the cutting edge of a high-tech world.

How we succeeded was by coming in with a pitch to be part of the biggest scientific instrument ever built. If we had decided to build a smaller telescope, nobody would’ve been interested. You’ve got to be globally excellent. You can’t just be locally excellent.

What about the involvement of other African partner countries?
We work with African astronomy institutes and universities and fund their post-doctoral fellows. We have also just finished refurbishing an old telecoms dish in Ghana and turned that that into a telescope. We have a vision of doing similar things for all of the African partner countries.

What other spin-offs have there been?
We employ 414 people, have created several thousand broader job opportunities, and have provided about 1,400 bursaries since inception and will add on about 100 a year. We have created a pipeline of astronomers, physicists, mathematicians and engineers that feed into this whole enterprise. The project already involves hundreds of foreign and domestic businesses, dozens of countries, a steady stream of international researchers and the expansion of an active scientific network among South Africa’s universities, all of which put necessary resources back into the economy. Not all of the clever people that will come out of our programs will stay in astronomy. In fact, most will go into the rest of the economy and do great things there. 

This is consistent with large projects elsewhere in the world. Without the Apollo program you would not have Silicon Valley. Without CERN, you would not have the Web. The http protocol, which is the basis of the Web, came out of CERN, devised for people to communicate with one another across the accelerator, which has a 22-kilometer diameter. WiFi is a spinoff of Australian radio astronomy. While you will not be able to predict exactly what the spinoff will be, if you put some really bright people together looking at cutting-edge problems and you fund them well, other things will happen. We have a commercialization division that looks specifically at that.

Do you have any examples of how the skills learned in building this complex astronomy system have been transferred into other disciplines?
Let me tell you about the call I received from the Minister of Trade, Industry and Competition, Ebrahim Patel, at the height of the coronavirus pandemic, when hospitals were under severe logistical stress. He said: “With the engineers that you’ve had and success that you’ve delivered, would you take on the design and project manage the manufacture of ventilators?” I said “yes” without thinking about it. We immediately engaged with clinicians to understand their needs, were able to get some funding from the Solidarity Fund (established to support the national health response in the fight against COVID-19), and together with government’s Council for Scientific and Industrial Research (CSIR) produced 20,000 ventilators which were donated to hospitals. 

Has the SKA project helped diversify the local economy of the Karoo?
Yes. We bought 135,000 hectares of farmland in the Karoo as we needed a large buffer against radio frequency interference from phones, vehicles and so on. This effectively meant removing 16,000 sheep, or about R20 million per annum, from the local sheep farming economy. But we have put back far more through directly providing employment to over 100 locals,  technical skills training and new opportunities in areas like construction. We absorbed laborers who from the farms we bought into SARAO. Our presence has led to the diversification of the local economy, mitigating an over-dependence on agriculture during a long period of drought. It is much easier to train local people, who are used to living in remote and difficult conditions, for example in splicing fibre, than it is to bring in people from cities like Cape Town or Johannesburg. Furthermore, we have placed mathematics and science teachers at the high schools in the surrounding rural towns and also provided students with bursaries and equipment.

We’ve now also got the MeerKAT National Park. I didn’t know how to manage 135,000 hectares of land, so we brought in the South Africa National Parks to create one of the biggest, new national parks in the country. So, there are environmental benefits too with farmland being managed back to its natural state.

We’ve seen the Webb space telescope project confront a systemic lack of diversity in the pool of scientists who have access to it. Has there been any similar concern at SARAO and the SKA?
Absolutely. Our original pool of engineers were largely white males coming from the defense industry. We’re tapering off from that legacy now as people leave by natural attrition and we can fill those positions. In five years’ time MeerKAT will be integrated with SKA—which requires an organizational shift. So we’re negotiating a kind of a transfer of key staff out of SARAO, my organization, and into the international observatory of the SKA. We’ll need fewer engineers and more in the data field. So the structure is changing and we’re introducing more diversity in the process.

How do you feel about private business in general getting into space exploration?
It pulls in resources you wouldn’t otherwise have, but it does also lead to conflicts. Elon Musk wants to put up 12,000 satellites to give comprehensive internet connectivity to everybody on the planet—his Starlink project. While we applaud this goal, these satellites are going to be noise for us as their signals are much stronger than what's produced by bodies millions of light years away. We’re working with private operators so when they fly over the so-called astronomy geographic advantage area, they avert their beams. Starlink’s very cooperative, but some of the others aren’t. Fortunately, it’s the biggest one.

Are there any lessons here on how society should be thinking about overcoming other big challenges, such as climate change, for instance?
You’ve got to think big and forge a common vision. You also need people who initiate contact across boundaries; people who are able to look at it from the other discipline’s perspective. How could they benefit? They’ve got to be able to see how this collaboration is going to improve their situation too.

If you had all the resources at your disposal that you could imagine, what would be another sort of moonshot project you'd like to do?
It would be a project in energy, or energy storage. Something that always attracted me as a nuclear guy is the catalytic cracking of water to produce hydrogen as a byproduct of the waste heat from high temperature nuclear reactors. Effectively you get hydrogen for nothing. This was one of the value propositions of South Africa’s Pebble Bed Modular Reactor. However there are significant regulatory hurdles to clear before this can become a reality.

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