In Conversation With… Dávid Puskás, Scholar of the P.C. Ho PhD Studentship at the University of Cambridge

June 2024

When you look at a star or a galaxy, you’re looking into the past, because the light takes a finite time to reach us, so we are looking at the history of the universe. It’s a bit like archaeology but instead of digging up something from the past, we are directly observing it through telescopes.”

Dávid’s interest in science sparked in his childhood as he created his own experiments and built various machines. “As far as I can remember I was always interested in the sciences and technology from very early on.” Although Hungarian by ethnicity, Dávid grew up in Romania and exceled at maths and physics: “The level of the state schools is quite restricted so the only real opportunity to push the boundaries was to attend competitions and Olympiads at a national and international level where teachers would give us extra classes and personal training.” Dávid’s interest in Physics and Astronomy grew but with little access to expertise at the school level, he joined the national team of Hungary for the International Olympiad on Astronomy and Astrophysics. He describes his teenage years competing as an exciting and eye-opening experience: “We travelled to Thailand and China and competed against 50 other countries but also made lots of friends.” Dávid continued his adventures abroad and aged 19, he moved to London to study Physics at University College London.  

When asked about his time at university, he notes: “I really enjoyed my time at UCL. Pre-Brexit it was very diverse; 70% of the students were international. My day-to-day courses were focused on Physics, but I was still interested in Astronomy, so I joined the Space Society and organised events in my spare time.” Unfortunately, his time on campus was cut short due to the pandemic which he spent back at home with his family. Upon his return, he conducted his first Astrophysics research project supervised by Professor Richard Ellis, inspiring him to pursue a PhD in Astrophysics. He applied to 15 programmes but his sights were set on the University of Cambridge’s Cavendish Laboratory: “When I joined the PhD programme, the James Webb Space Telescope (JWST) had just been launched, so my research is focused on galaxy formation and evolution, one of the most exciting topics the telescope could shed light on. I’m looking to answer the question: How did the small galaxies we observe at early times become the large galaxies we see today, such as the Milky Way? One explanation is that they grow their mass gradually by funnelling the nearby gas and converting it into stars. Another explanation is that smaller galaxies merge to form large and heavier ones. We don’t know which channel is more important, therefore I’m looking at different epochs in the universe to identify the number of merging galaxies.

James Webb Space Telescope © NASA, ESA, CSA, Northrop Grumman

At Cambridge, Dávid also joined the JWST Advanced Deep Extragalactic Survey (JADES) team, one of whose main leaders is his supervisor, Dr Sandro Tacchella. It is a joint collaboration between the two main instrument teams of the telescope, gathering about 100 scientists mostly from the US and Europe. On the JWST, Dávid adds: “The diameter of the main mirror of the telescope is 6.5 meters in diameter, but the whole instrument including the sunshield is about the size of a tennis pitch. It currently resides at 1.5 million km away from us, beyond the orbit of the Moon. It is kept away from the atmospheric effects and light pollution present on Earth, but if anything goes wrong, we’re unable to repair it at this great distance.” Much of David’s time with JADES is spent cleaning up the data and analysing it. He also attends their bi-annual meetings at institutions such as Harvard, Oxford, and the Cosmic Dawn Centre in Copenhagen.

With three and half years of academic funding, David highlights how crucial it has been to his academic journey: “I’m very grateful for this funding because otherwise I wouldn’t be able to do my PhD. In addition to the academic costs, the funding also allows me to attend conferences and workshops. Last year, I attended and presented at a conference on the formation of the early galaxies in Marseille and the annual European Astronomical Society conference held in Poland. This summer I will be attending a summer school in Greece focusing on theoretical and data analysis skills and then a conference in Stockholm.

He hopes to stay in academia and apply for a post-doctorate and fellowship opportunities. He also enjoys community and outreach work having led his group’s efforts for the Cambridge Festival Open Day, giving lectures to GCSE students, and organising stargazing events as a committee member of the Hungarian Society: “It’s always very exciting to see kids who are fascinated by the universe. If one of 100 kids wants to pursue science later, then I think it’s a great success.

In 2019, the Huo Family Foundation donated £3 million to Cambridge University to endow the P.C. Ho PhD Studentships in Physics.