Professor Yin-Zhe Ma, who also holds the Chair in Computational Astronomy at Stellenbosch University, spoke to the University’s news team about how he uses innovative observational methods and computational tools to help deepen our understanding of the fundamental laws of the Universe and to unravel its mysteries.
Q: Tell us more about your research and why you became interested in this specific field.
A: My research is about the Big Bang Theory of the Universe and its observational tests. The Big Bang Theory is the idea that the universe started from a very hot and dense beginning about 13,8 billion years ago and has been expanding ever since. I became interested in this topic when I was a second year undergraduate student at Nanjing University in Jiangsu, China while listening to a very interesting seminar given by Professor Tan Lu on neutrinos (tiny, electrically neutral particles produced in various process, such as the sun’s energy production, and during radioactive decay), dark matter (invisible stuff in space that doesn’t emit light or energy, but helps hold galaxies together because of its gravity), and dark energy (a mysterious force/energy that accelerated the expanding of the universe over time).
I immediately knew from then on that this was the subject for me, because the Universe is the biggest thing you can ever work on. I eventually did my PhD in astronomy (the scientific study of everything in the Universe beyond Earth’s atmosphere, including stars, planets, galaxies and other celestial objects and phenomena) at the Institute of Astronomy at Cambridge University.
Q: How would you describe the relevance of your work?
A: I would say that my work is relevant as far as our curiosity about the sky, nature, the fundamental laws of the Universe, and the nature of dark energy and dark matter is concerned. After all, we are possibly just one of many species in the cosmos. There could be tons of other intelligent species out there but too far away to connect with us. Astronomy is the knowledge about all these intelligent species. For example, if they live in our Milky Way, they can also realize that we are orbiting around the centre of a bulge of all stars where a supermassive black hole resides. So, in that sense, it is very relevant to all intelligences in the cosmos.
Q: To what extent do innovative observational methods and computational tools help us unravel the mysteries of the Universe?
A: They help a lot. We get most of our information about the cosmos through observations. So, observational tools and the computational capacity to analyse the data are key to advance this subject.
Based on your research, why is it so important to invest in astronomy and astrophysics research and infrastructure?
Investing in such a high-end subject can push the boundary of human knowledge and make people ask unimaginable questions. It can also and drive new technologies and innovations in such a way that they benefit people’s lives.
We’ve all heard about the Big Bang Theory. What are some of the remarkable achievements and unique challenges encountered in this area?
There are many achievements indeed. These include the accurate prediction of primordial abundance of light elements, the prediction of the microwave background radiation which has been verified in high precision, and the prediction of galaxy formation and clustering on large scales to name a few.
Of course, there are also unique challenges. The nature of dark matter, dark energy, neutrino mass hierarchy, primordial lithium abundance, and the physical nature of inflation etc, are still mysteries of the Universe. But as observations are improving, we are gradually unravelling these mysteries.
What are some of the observational explorations planned for the next decade at the forefront of cosmology?
Several frontiers can be foreseen. One is about the nature of dark matter because there are many probes, and direct and indirect detections in many dimensions in our search for dark matter. My research group is working on using South Africa’s MeerKAT telescope to search for Axion dark matter and Axion-Like dark matter, and also weakly interacting massive particles (WIMP), which are candidates of dark matter with different masses. Stellenbosch University is also investing in the PaarlAfrica Underground Laboratory (PAUL) that will also search for the dark matter decay signal.
The other frontier is the Epoch of Reionization, which is the critical period (roughly 150 million to 1 billion years after the Big Bang) when the first stars and galaxies formed and emitted radiation that ionized the surrounding hydrogen gas, making the universe transparent to light. My team is heavily involved in Hydrogen Epoch Reionization Array (HERA) which is an experiment aiming to measure the signal of this epoch.
Q: You have spent many years in the challenging environment of higher education. What keeps you motivated when things get tough?
A: I don’t think it is tough at all, it is quite fun to be honest! There are many students in this country who have great potential and worthy of being educated and cultivated intellectually. The important thing when we select students, is to look at intellectual merit and capabilities, irrespective of other factors. Because we are a developing country, we cannot afford to lose talented minds. I believe every talented person is an asset to this country.
Q: What aspects of your work do you enjoy the most?
A: If I derive some equations for the first time or run my computer code to get some new results, I would be very happy. I feel that some of nature’s secrets are only revealed to me at that point, which is astonishing, exciting and fulfilling. What I usually do, is to take a long walk outside, often into the park, contemplate the results I just found while I am surrounded by the birds singing, fresh air and tranquillity of the forests, and give my subconsciousness an opportunity to think. Then I return to my room, open my book or computer, and check whether the results are “still there” (verify my results). I enjoy this process — the “power” to comprehend nature is something that really fascinates me.
Q: Tell us something exciting about yourself that people would not expect.
A: I am fortunate to have travelled to 26 countries, including many countries people don’t usually visit. If you want to know some exotic locations, you are welcome to talk to me.
Q: How do you spend your free time?
A: I don’t have much free time actually! But I do intend to slow down a bit and enjoy a bit of Stellenbosch’s social life. I actually plan to start learning Afrikaans soon so that I can hold my own when I’m in the company of Afrikaans speakers.