I grew up in Cwmcarn, a small village in South Wales, UK. I moved to Bristol at the age of 19 to study an undergraduate masters-level course in Physics with Astrophysics, and continued on at Bristol for my PhD; 'The Multi-Wavelength Properties of High Redshift Star-forming Galaxies'. I briefly worked at the University of Portsmouth on a project making predictions for detecting high redshift galaxies using the Dark Energy Survey (DES) before returning to the University of Bristol as a postdoctoral researcher working on galaxy evolution.
Recently my wife and I moved to Perth, Australia for me to undertake a position as John Stocker fellow at the University of Western Australia, where I work on the Galaxy and Mass Assembly (GAMA) survey, with the aim of extending GAMA to high redshift. Upon arriving in Perth we welcomed a new member of our family, our White Swiss Shepard, Laika (named after the first dog in space). In my spare time I like to laugh at my wife, go to the dog beach and throw things in the sea for Laika to rescue, and occasionally play the guitar.
Q & A
What is your field of Expertise?
My research is focused on how galaxies have changed from the Big Bang to the present day and aims to answer key questions about the Universe such as, how did the first groups of stars come together to form galaxies, how do galaxies change as the Universe expands over time and how do we eventually form galaxies like our own Milky Way? In order to do this I use observations from some of the world’s most powerful telescopes to study the light emitted from young galaxies, which formed when the Universe was just a fraction of its current age. I then compare these galaxies with the more massive, more complicated and older galaxies, which reside in the Universe today and try piece together links between these seemingly unconnected types of galaxy.
What made you study this field?
I have always had an immense passion to study the unknown. Ever since I was young I’ve always wondered about the things that I couldn’t understand, questioning what I saw around me and trying to make sense of the things that seemed strange. I believe my father, who is also a Professor of astrophysics, started this curiosity. I remember him asking me when I was very young if I could prove that I wasn’t just a ‘brain in a jar’ somewhere and after days of thinking I came to the conclusion that I couldn’t. This bewildered me and I became intently curious about the other questions that as yet had no answer, such as why are we here, how do you know your reality exists and where did the Universe come from? Through multiple over dinner conversations and rained out camping trips with my father I became fascinated by the endeavours of humans to understand the Universe that they live in. A high school astronomy course followed by an undergraduate degree fuelled my desire to understand the unknown. So when the opportunity came to do a PhD in astrophysics and eventually pursue it as my career, I jumped at the chance. Now I get to work in a job each day that constantly fuels my curiosity. It’s a difficult feeling to describe; sitting at your desk looking at an image a galaxy that existed millions of miles away and billions of years ago and knowing I’m the first person to see it – you can’t beat that.
Why are you passionate about what you do?
Astrophysics asks some of the biggest questions that humanity can pose, trying to decipher the fundamental properties of the Universe in which we live, but also has the ability to inspire awe in anybody, no matter what their level of academic learning. Everybody can step outside on a dark night, look up and wonder in amazement at the vast scale of the Universe, question what the small points of light are, how they got there and how they work. As I child I looked up and did the same thing, and as I started learning about the Universe I was so immensely dumfounded by the sheer scale and wonder of it, it was all I wanted to study. The Universe has amazed me ever since and almost every day I still find out something new which fuels my excitement about the cosmos.
With respect to my specific area of research, I had a moment during my undergraduate degree where a Professor explained to me that the light we observed from these distant galaxies was emitted 12billion years ago and that the galaxy it came from had long died. I thought about this for a long time and decided that what it meant was that the light had been traveling through the Universe, unimpeded, for 12 billion years. It had been flying through space for, not only the whole of human history, but also the whole of the history of life on the earth. While the dinosaurs roamed the earth it was flying on its lonely path through space. In fact, that light had been traveling through space long before the Earth or even the Sun existed. Since that light left its home, the Sun, the solar system, the Earth, life as we know it and humanity have all popped into existence. The fact that humanity, that has lived for the blink of an eye on cosmological timescales, on a tiny little planet, in an unimportant place in space, can build a telescope, stop that light on it 12 billion year journey and use it to understand what was going on in a galaxy that ceased to exist billions of years ago, was just mind blowing to me.
The fact that we can understand a single thing about the immense far reaches of the Universe astounds me to this day and from then on I just had to study these galaxies and try to understand them better. People generally tell you about all the wondrous things that we know about the Universe and how much we have learned, but that’s not what excites me. It is the things we don’t know that inspire me. The questions yet unanswered and problems yet to be solved. Astrophysics has told us so much but we haven’t even scratched the surface in understanding the Universe and I want to be part of solving some of its mysteries.
What are your most cherished achievements through your work?
There are many quite technical achievements that I am very proud of in my work. To mention one key result, of which I am particularly proud, I managed to obtain the first detection of emission arising from dust in a particular class of distant galaxies. In astronomy terms dust is essentially small molecules in the galaxy which are produced as stars die. The reason dust is interesting to us is because it blocks out the light which is emitted by stars. One of the key things we wish to know about all galaxies is how many stars they contain and how quickly they are forming new stars. In order to work this out we must know how much light is being blocked by the dust. Detecting this dust in galaxies in the early Universe is very difficult as it’s extremely faint and hard to observe. In my work, I took observations of a large number of galaxies and combined them all together to measure the average amount of dust in each system. This allowed me to estimate the amount of stars that are forming in the galaxies that we do not directly see. The signatures of dust in these particular galaxies had never been observed before! I would also have to say that one of my most cherished achievements is playing a small part in helping my wife towards her PhD – also in astrophysics. While she was undertaking her PhD I had the pleasure of doing some work with her as part of her research into the effect of super-massive black holes on galaxies. Just playing a small part in helping her work gave me great pleasure and seeing her finally achieve her goals and obtain her PhD made me exceptionally proud.
Where has your work taken you?
I have travelled to many places during my research to attend conferences and meetings with collaborators, as well as to observe at some of the world’s foremost telescopes. To mention a few key places, I have taken observations the Australia Telescope Compact Array (ATCA) in Narrabri, NSW, the Anglo-Australian Telescope in Siding Spring, NSW, the 30m telescope in Granada, Spain and the Isaac Newton Telescope on La Palma, Canary Islands. I have attended multiple conferences across the UK, in France and Chile. I am originally from the South Wales in the UK and now work in Perth, so have travelled quite far from home!
What would you most like to achieve though your work?
The thing I would most like to achieve is leaving a lasting impression on the world of science that will live on long after I have gone. I believe that the success with which you can measure you career (and in fact your life in general) is the things you leave behind. I would hope to discover something that changes the way we view the Universe, and filters on into the legacy of future scientific discoveries to come. This doesn’t necessarily mean proving (or disproving!) a fundamental idea in astronomy, but simply adding to our current understanding of the Universe and building the foundations for future major discoveries yet to come. I hope that my published scientific research stands the test of time and provides insights for future, much more talented, scientists to build upon. Science is an ongoing immense jigsaw puzzle which stated with our earliest ancestors and will extend way off into the future of humanity, with each person trying to find correct pieces in their brief life. What I would like to achieve is to be able to lay a few key pieces of the puzzle and for future generations to at least remember that I played the game.
How would the average person view your work?
I think that as astronomers we are in a rather unique situation in science where the general public are relatively well informed about the basics of what we do. Most people have taken a look out at the night sky, or even just the moon, and questioned what is out there. The subject of astronomy seems to capture people’s imagination and inspire awe in the wonder of the unknown, in a way that many science disciplines don’t. Especially over the recent years with great public communicators such as Brian Cox, Neil deGrasse Tyson and the resurgence of the work of Carl Sagan, the public understanding of the wonders of astronomy is rapidly increasing all the time. I have found this in the many public outreach events I have been involved in. Talking to non-scientists about astronomy, most people have a pretty good idea of the major questions that astronomy is attempting to answer and a large fraction can hold a good discussion about the way in which we are trying to address these problems. I do feel that the average person has a rather idealized view of the day to day work of an astronomer, thinking that we spend all of our days (or nights!) looking through telescopes out into space and not sat in front of a computer screen, which is my normal working day. However, they are very enthused about the job that we are doing and feel that our work is extremely beneficial to forwarding humanities understanding of the Universe.
How would you explain your work to the average person?
I would firstly ask them if they had ever looked up at the night sky (the reply would have to be yes!) and then tell them that although most of the points of light that they can see are stars, like our sun, some of them are in fact galaxies that contain billions of stars all within the tiny point of light they can see. I would say that we are sat in one of those galaxies, called the Milky Way, and as astronomers we wish to understand how these galaxies, including our own, work. How they move, how they make stars and, most importantly to me, how they change over time. I would say that we now have the technology through massive telescopes, such as Hubble, to see many thousands of galaxies right across to the far reaches of the Universe, and the further we look out into space the further we are looking back in time. This would illicit some strange looks, but I would continue and say that, this is because light has a speed limit. I would explain and say this…. Imagine that I take a picture of myself, in the center of Perth and send it to a friend in the Sydney. It takes 3 days for the post to reach them, so when they look at the picture they don’t see me as I am today, but me how I was 3 days ago. This is because the postal service has a speed limit! If I have also sent the picture to a friend in the UK, which takes 2 weeks to arrive, this friend then sees me as I was 2 weeks ago. Essentially, the photo is just the imprint of light reflected from me, so the further the light travels, the further into my past my friends see me. In the extreme, imagine I was going to send the picture to an astronaut on an imaginary space station near Pluto and it takes 100yrs for the postal service to reach her. She would see the photo of me as a young man, where as I would be long dead and gone. Not only that, but she would see a snap-shot of how Perth was 100yrs ago.
This is how it is with light from a distant galaxy. The galaxy emits its light when the Universe was young, near to the big bang, and it takes billions of years for the picture of the galaxy to travel through space before we see it. When we see that galaxy, we don’t see how it is now, but how it was when the light was emitted from it – when the Universe (our cosmic Perth) was much younger. This galaxy probably no longer exists but the `picture’ of it has been traveling through space for billions of years. Following this idea, the more distant the galaxy, the further the light has to travel, the longer it takes and the further we are looking into the past. Using this we can look at galaxies at different distances away from us and see how they are different form the galaxies which we see nearby. This allows us to piece together how galaxies have changed over the age of the Universe and helps us understand how galaxies first form and eventually turn into things like our own Milky Way.