“There’s nothing mutually exclusive about being a scientist”

All About Space talks to the astrophysicist and YouTube sensation about life, the universe and everything

How would you describe your research to somebody outside your field?

The job of a researcher is to answer the questions that no one knows the answers to. To do that you obviously have to think of the question first. My specific research is all to do with the connection between galaxies and the supermassive black holes that we find at the centre of every single one. Something that massive has a big effect on everything around it, and my job is to work out whether feeding this black hole has a negative impact on the galaxy.

I notice you use data to infer quenching histories. Can anything be done to improve these inferences in the future?

What I’m trying to do is model how many stars a galaxy is forming based on how much light I’m getting from that galaxy, so that’s the inference bit. You observe one thing, but you want to know another thing. We can use different data to improve this inference. Instead of just looking at how much light there is, we look for what’s called emission-specific wavelengths due to elements that are there.

Hydrogen is fuel for star formation, so if there’s lots of it you know you’re forming lots of stars. We can use those kinds of fingerprints that are much more precise to improve our inference, but it also comes with improving computational models and statistical methods. Research that’s going on right now in computer science and maths will eventually improve that kind of inference as well.

‘Understanding the physical processes that have shaped our universe is the fundamental goal of astrophysics’ – so begins your PhD thesis. How close are we to achieving this goal?

I think that there is so much more that we don’t know than we do know, and I think it would be arrogant of us to assume that we’re even close to figuring out the properties of the entire universe. We are so small, and the universe is so big. It’s fantastic what we’ve done so far. The fact that we can measure black hole masses and figure out how massive galaxies are and how they’ve evolved is incredible, but I don’t think we’re anywhere near to being done. And I don’t think any astrophysicist would ever want to be – we’d be out of a job, and knowing everything is boring.

Galaxies have supermassive black holes at their centres

And you’re always disagreeing…

But the disagreeing is part of the process, right? Eventually the evidence piles up in favour of one interpretation, and that’s why in current science it can seem we don’t know what we’re talking about. I was blown away that they managed to come up with a vaccine for COVID-19 in nine months, for example.

And your university was at the forefront…

It was, yeah! The physics department was involved in some of the diagnostics, using machine learning techniques that have been developed for a physics application for diagnostic tests instead.

You applied to use the Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT) to study bulgeless galaxies. What do you hope to discover, and was your application successful?

One of the questions distracting me was how black holes grow in galaxies that have not merged with other galaxies.

When galaxies merge, they grow in mass, and you tend to ruin these nice spiral shapes and just end up with a big blob. What about galaxies that haven’t had a merger, but still have a supermassive black hole? Are they piddly black holes or have they managed to grow at the same rate but in a different way?

What I wanted to do was see if galaxies without bulges were somehow feeding their black holes by themselves, perhaps by funnelling gas down their spiral arms. Unfortunately, it wasn’t successful, but I will try again.

What would you say is your biggest frustration within astrophysics?

Two things. The first is how long a project takes. From start to finish it can be over a year, and it’s very difficult to stay focused in that time, especially for someone like me who really enjoys the gratification of scratching things off a to-do list. The second thing is more about the culture of astrophysics and academia as a whole. I am a junior research fellow, so I’m sort of halfway between being a PhD student and a permanent member of staff at a university. That’s great because you have the freedom to get jobs around the world, but in a few months you’re going to be applying for new jobs because of the way the academic job cycle works. You lose yourself in the science and then realise, ‘oh my gosh, someone could take this away from me.’ That’s what’s scary about it.

As a consumer of science media, what is your biggest frustration with the way your field is communicated?

The assumption that we are all geniuses. You have to work at it. Not everyone is a musical prodigy, and it’s the same thing with physics. If someone is massively interested in space and astronomy but they’re not good at maths, practise and you’ll get better at it. It’s also frustrating that everyone looks like Einstein. There is a huge, diverse range of people that do astrophysics. If you’re interested in it, don’t let anyone tell you it’s too hard, because only you can make that decision. One assumption I want people to get away from is that you can’t like science and maths because you have to stop liking something else. There’s nothing mutually exclusive about being a scientist.

How can science communication build bridges between the public and the research you’re involved with?

A lot of science communication is done by fantastic people, but they’re often removed from what we call the frontline of research. By having more academics on YouTube who are in that field and staying up to date, it’s possible to relay that information back to the public without middle people. Middle people do fantastic work, but I think there’s something to be gained by getting it straight from the people who are fully immersed in it. One way that can really help kids learn science is teaching them the history of how we figured stuff out. If more scientists taught like that, I think it would resonate more.

“It’s arrogant of us to assume that we’re close to figuring out the properties of the entire universe”

How has your research impacted your outlook on the world?

That’s a difficult one. It’s changed my perspective on the change that someone can bring about. When you’re doing research like that and you’re asking such specific questions, it makes you realise how important it is to step back and see the bigger picture. You’re more aware of how something small can affect things in a big way. A lot of people say when they look at the night sky they get freaked out by the scale of it. By doing the research, you realise something that seems small can have a big impact. I don’t feel weird when I look at the night sky. The scale of it actually makes me very hopeful, which is nice.

You uploaded a video of you watching Star Trek: The Next Generation for the first time. Is it realistic for young people growing up now to want to be a starship captain one day?

It’s realistic for kids growing up now to want to be an astronaut. The space industry is growing, so those opportunities are becoming more common, but starship captain I think is still a long way off. Our nearest star system is four light years away. Voyager 1, which is the furthest spacecraft from us at the minute, would still take around 70,000 years to get there. And I don’t think any form of warp drive is coming any time soon.