Women in Science 2019: Dr Becky Smethurst - Part 1
This is the first of two interviews with Dr Becky Smethurst, Junior Research Fellow in Astrophysics at Christ Church. She also has a successful YouTube channel, which we’ll be chatting more about in part 2 tomorrow… But to start with, I asked her about her research:
ELEANOR: Could you start off by explaining your research?
BECKY: My research focuses on galaxies. Obviously our own galaxy is the Milky Way, which is sort of like an island of a billion stars in the Universe, and I look at all the other galaxies that we see when we look outside the Milky Way. I particularly focus on the supermassive black hole that we think lives at the centre of every galaxy.
Theorists have been saying that supermassive black holes are responsible for stopping galaxies from forming stars, and if that doesn’t happen then our best theory of the Universe is wrong. I’m an observer, so I use telescopes to try and prove that we see that happening – that supermassive black holes are taking away the fuel that you would need to form more stars in a galaxy. So the same stuff that you make stars out of, hydrogen gas, is the same thing that fuels the black hole and makes it grow as well. So I’m trying to actually observe that happening in the Universe, across all the galaxies that we can see.
ELEANOR: Are galaxies and black holes something that you’ve always been interested in?
BECKY: When I was an undergraduate an online citizen science project called Galaxy Zoo was launched – it’s an Oxford-based project, and basically they had a survey telescope that surveyed the sky every night and took millions of images of the sky, and they’d ended up with about a million images of galaxies that they wanted to know the shapes of. Because the shape kind of tells you how it’s lived its life, basically – if it’s a beautiful spiral galaxy it’s probably been left alone, and if it’s this big blob it probably hasn’t, it’s probably merged with other things. So you want to look at this statistically, across all these million galaxies, but to do that you actually have to look at the images, and there’s just not enough astronomers in the world.
They came up with the idea of a website where the public could do it – you get shown an image, and you’re asked whether it’s spiral shaped or not. So this launched when I was an undergrad, and I remember classifying it and being like, this is really cool, I feel like I’m contributing to science! When I had to choose a six-month research project in my final year I decided to do something on galaxies, and then when it came to picking my PhD project I noticed that Oxford had a project with Galaxy Zoo – and I got the position, and ever since then I’ve been involved in galaxies. So I guess I kind of fell into it in a way! But it was really nice sort of coming full circle, to work on the project and work with the data that I’d probably even contributed to.
ELEANOR: What’s the most exciting thing you’ve discovered as part of your research so far?
BECKY: There was this one result that I did as part of my thesis with my group, which I was really excited about because it sort of changed our view of how black holes grow. For the past twenty years or so the main hypothesis was that two galaxies come together, they merge and they grow, and the two black holes in the centre of them also merge and grow. And there are very tight correlations between the mass of the galaxy and the mass of the black hole.
Also, when you merge those things together you redistribute a lot of the stars, and you end up forming a sort of big blob in the centre, like the yolk of an egg surrounding the black hole, and the mass of that big yolk is proportional to the mass of the black hole. We were looking at galaxies that had no yolk, and looking into what happens in these galaxies that haven’t had a merger, so their black holes haven’t had a merger.
People have always said that they have tiny black holes, but we measured them and found that they were actually two orders of magnitude, so a hundred times bigger than what people had thought. And there was no way that you could have formed them in a merger because you had this beautiful, pristine, yolkless galaxy, and the black hole had still grown as massive as in one that had had a merger. So it sort of broke that viewpoint, and we think that actually the mergers are only about 30% responsible for the growth, and that a calm accretion of hydrogen gas into the centre is responsible for the rest of it. So I was really proud of that, because it might not have made the news but it’s slowly becoming accepted. It might not have been a eureka moment, but it was definitely a slow burn to acceptance.
ELEANOR: Tell us more about Astronomy at Christ Church.
BECKY: Christ Church has an amazing Astronomy group, which many people might not know. There’s about fourteen of us now, and it’s thanks to a generous donation from a couple of the alumni, Sir Michael Hintze and Philip Wetton, and there’s also a Hintze Centre for Astrophysical Surveys. So that means we can hire more people, and I think it means that people like myself who aren’t necessarily funded by them have people to talk to at Christ Church about different results and different fields – you have people to run ideas by, and they know a lot of other people in the field so you get to meet people through them. It’s just a really good community that we’re building at Christ Church in terms of Astronomy.
ELEANOR: What are your plans for the future?
BECKY: I can’t imagine not doing academia, and I can’t imagine not communicating in some way, so really I want to carve my own path through academia, where I’m not necessarily doing something traditional that includes teaching in a university, but it might be something where I can engage with people through the outreach that I do.
I hope that in the future, say in five years’ time, I’ll just be doing the same thing! I just love it. Maybe with a group of people to help do the research, because I find that I have so many ideas for YouTube videos, but I also have so many ideas for research off the back of it. But I don’t always have the research time to do that because I’m already working on 3 or 4 projects, so having people to help with that would be good.
ELEANOR: Do you have any particular career goals?
BECKY: My research goal would probably be proving that this feedback from supermassive black holes is happening in galaxies – that would be the cherry on the cake. And then when people think ‘we need to get someone who knows about this feedback process’, that the first person they think of is me. That would be cool. And obviously to be a Professor someday would be incredible.
In terms of science communication, I always think that the ultimate is the Royal Society Christmas Lectures. That would be amazing, to do that one year. To stand in that arena, where so many have come before you – it really is standing on the shoulders of giants. You’re very aware that, whatever you’re talking about in the lecture, you wouldn’t be able to give the talk because the knowledge wouldn’t be there if it wasn’t for all of the people that had previously given the lecture.
ELEANOR: Has anyone been particularly inspirational for you, both in terms of YouTube and your research career?
BECKY: Well people always talk about the ‘Brian Cox effect’, and I like to think of myself as being in the first generation of that, because Wonders of the Universe really started when I was in high school, which is sort of when he came onto the scene. And that probably did have some influence in also changing your parents’ perspective of what the subject is and what it could lead to in terms of a career. In terms of research, people always ask me this but I never know what to say, because I feel like I was just such a stubborn child that I was like ‘I’m just going to do it anyway, no matter what anybody else says!’, so I didn’t really need anybody’s footsteps to follow in because I wanted to do something different and do my own thing.
I think Vera Rubin is amazing. She looked at the rotation curves of galaxies and found that they must be missing matter – dark matter. And that was in the 50s. And the same with Jocelyn Bell Burnell when she discovered pulsars – again, that was in the 60s, and they were obviously working in a time when socially it might not have been acceptable for a woman to do that, so I really admire the fact that they were able to make such leaps forward with all the social pressures that were on them as well. I think they’re great role models in that sense. Plus Stephen Hawking as well, you’ve got to admire his courage, as well as his brain.
ELEANOR: What advice do you have for girls considering studying science?
BECKY: Don’t let anybody tell you that it’s difficult. Just go in and decide whether you like it and whether you think it’s difficult. Listen to yourself, and not to anybody that’s telling you that you can’t do something.
And it’s ok to make mistakes; I think you learn more from a mistake than you do from not making it. Let those mistakes guide you and teach you and make you realise what you want to do. Practice makes perfect – I didn’t know straight off half the things I need to know to do my job, it came through learning, and picking up stuff on the job. So it’s ok not to be good at it straight away and not to let that put you off – if you like it and you think it’s fascinating, keep at it, because practice makes perfect. If you’re interested, then go for it!
Follow Becky on Twitter @drbecky_ and find her on YouTube at www.youtube.com/drbecky.
