A cosmologist answers 12 questions about his profession

by Mukosi Fulufhelo

Thinking about a career in the cosmos? Here is what Cosmologist Dr Julien Larena had to say about his field. Find out everything from his typical workday, where to find funding opportunities, and how he answers some deep space questions.

Our latest issue of African Science Stars has an array of careers and a guide tailored to help you find your place in the cosmos. It’s free, read it here.

Q: Please tell us a bit about yourself and your chosen career path. What’s your regular day at work like as a Cosmologist?

A: Mostly, when I am doing research, I spend time reading papers, doing calculations with pens and paper or using a computer, and writing documents to summarise and present my results. I am naturally inclined to collaborate with other people, so most of my research happens in small teams of 2 or 3 people. Therefore, I also spend quite some time talking to colleagues over Skype or Zoom to share ideas and advance common projects. The rest of the time, I spend preparing courses for university students, undergraduates, and postgraduates, and contributing to the administration of my department.

Q: What excites you about your job?

A: The constant questioning of the world; figuring out how nature works; solving problems; sharing ideas. 

Q: Where do I find jobs in the field in South Africa? Can I only work at universities and research institutions?

A: Yes. This is pure research, without any direct application, so it is done in public institutions.

Q: Do you think there are enough job opportunities in the field in South Africa? What about Africa? If not, what are the chances of a career abroad?

A: This is an internationally oriented activity so you can practice almost anywhere in the world. It has developed tremendously in South Africa (and to a lesser extent in Africa) over the past decade or so.

Q: Where can one find funding for such fields?

A: Most funding is governmental. So, in SA, it would come from the National Research Foundation or institutes such as the National Institute for Theoretical Physics. Recently, on the observational side of things, the Square Kilometre Array has provided many funding opportunities.

Q: How do you measure your success in your career?

A: Success is a matter of personal satisfaction and peer recognition.

 Q: Do I need to have a certain level of understanding of programming to be able to get a job in Astronomy, Cosmology, and space science?

A: Nowadays definitely, yes.

Q: Many think there is a thin line between Astronomy and Cosmology, some are unable to differentiate between the two.  How are they related and how are they different?

A: They are very close sisters indeed. Astronomy is usually reserved for the detailed studies of specific objects in the universe, such as galaxies, stars, or planets. It consists of understanding all their details, what they are, how they form, how they evolve, what they are made of. Cosmology, on the other hand, is the study of the Universe as a whole, on its largest scales and throughout its entire history. So it usually does not worry too much about the minute properties of individual objects and rather focuses on their collective properties. For example, while an astronomer may want to understand everything about a particular class of galaxies, a cosmologist would be more interested in how the hundreds of billions of similar galaxies formed and interacted with each other.

Both activities are very close and talk to each other constantly, of course.

Q: According to you, what’s the significance of the study of Cosmology?. What can we achieve by understanding how the universe came to be and its evolution?

A: ‘Pour l’honneur de l’esprit humain’ (J. Dieudonne)

 ‘For the honour of the human spirit.

Q: Is our solar system expanding, if not, why?

A: Our solar system is not expanding: as part of our galaxy, the Milky way, it is (mostly) isolated from the rest of the Universe. The forces responsible for the expansion of the universe on very large scales are very very small on the scales of the solar system, compared to the forces that hold the solar system together. So the solar system is holding up!

Q: What do you wish people knew about cosmology?

A: It is a very exciting topic in which much seems very strongly established today, but with many dark, unexplored corners remaining. Our generation(s) will be creating the largest and most detailed maps of our observable universe over the next 3 decades. What we will discover could be stupendous! 

Q: Any advice and tips for aspiring Cosmologists?

A: Work hard, keep asking questions and keep dreaming.