In conversation with Kat Phillips

Bethany Clarke and Ellen Jolley talk research, raids, and rugby with the Twitch streamer


Many undergraduates at some point consider doing a PhD after their degree—but it can be confusing when trying to work out what a PhD is really like, or even how to apply. That’s why Kat Phillips, a PhD student in fluid dynamics at the University of Bath, has taken it upon herself to demystify the whole experience. We sat down with Kat to talk about her outreach projects, Twitch streaming her PhD work, and how her local stadium came to be named after her.

Kat first became interested in doing a PhD during her undergrad degree at Cardiff University: “I think it was probably third year when I realised more concretely what direction I wanted to go in. I had a lecturer who taught me fluid dynamics, and she was incredible, just the way that she delivered a lecture was very clear. She was such a big inspiration and I thought: `that is what I want to do.'” This sparked her interest not only in fluid mechanics, but also in outreach. “It’s not just the research that I like. It’s the learning, and the teaching, and the communication. My dream job at the minute is something that lets me keep doing all my outreach stuff while letting me muck around at a university, sitting at a blackboard not talking to anyone.”

So what exactly is Kat researching? “I would say that I sit in classical fluid dynamics, on the bridge between analytical and numerical. The system that I’m looking at is bouncing droplets on a deep bath.” Droplets impacting onto liquid surfaces are seen all the time in nature (eg when it rains), and this has a number of important industrial applications too. In aerodynamics, their impact with wet surfaces can cause large ice accretions on aircraft surfaces. In industrial spray painting or inkjet printing, it is important to understand droplet impacts to achieve an even coverage.

“Historically, when people have looked at impacting droplets, they say: the droplet falls. There is some pressure transfer that is possible, because there is an air layer keeping the droplet and the bath separate. The bath acts as a trampoline and kicks the droplet back up, and then it flies away.” We can see something like this happening in the picture below this paragraph: this is the droplet after impact, having been launched back from the liquid surface. “What I’m doing is looking at a single impact and trying to compute the air layer between the droplet and the liquid surface dynamically. The goal is, throughout the evolution, to constantly update what that pressure transfer does. And we do that using lubrication theory. So it’s a really cool coupled system between this droplet, which is deformable, and a deep liquid bath with an impacting point. And you’ve got a thin film that’s technically being deformed at both boundaries. All of that’s happening in one big Matlab code.”

A water droplet after impact

A water droplet after impact. Image: Davide Restivo, CC BY-SA 2.0

A photo of a desk, with a laptop, headphones, and graphics tablet.

Kat’s first ever streaming setup

Stream big

Alongside her research, Kat has a Twitch channel where she livestreams about her PhD experiences, and about maths more generally. She started her channel in lockdown, inspired by the move to online learning.

While teaching undergraduate classes over Zoom, Kat encouraged her students to communicate with her however they felt most comfortable: “I think I told one of my kids that they could send a carrier pigeon if they could figure out how to do that—I will accept any form of communication.” This seemed to work for Kat’s students, who preferred to leave comments using the chat function rather than turning on their mic. For Kat, this sparked an idea: “in my spare time I was watching a lot of Twitch, and I realised that the way that I was teaching was exactly how I was watching my entertainment with streaming. So I had this mad idea: if I can do it in a Zoom call, I can do it on Twitch.” And so, Kat’s Twitch channel, KatDoesMaths, was born.

Kat’s livestreams are split into three categories: pomodoros, maths office hours, and gaming. For Chalkdust readers who are unfamiliar with the concept of pomodoro, this is a productivity technique developed in the 1980s by a (then) university student, Francesco Cirillo. Armed with a tomato-shaped timer from his kitchen, he would do 25-minute bursts of uninterrupted focused work, with five-minute breaks between them. This technique of splitting a period of time into several productive intervals, interspersed with short breaks to minimise distractions, is still a popular time management method used by students and workers around the world today.

Kat uses the pomodoro technique often, and livestreams some of these sessions. “During the sessions I am completely quiet. I share my screen, but it will be slightly blurred, so people can usually tell if I’ve got Matlab open, or if I’m writing in Overleaf, or just what sort of software I’m using.” The audience can work alongside Kat, and chat during the breaks: “I find that during the breaks is a good chance to chat, because you have a dedicated topic. You can explain what you were just doing, and a lot of people do like asking about what I’m up to.”

Through these sessions, Kat can interact with her audience, while also having time to work on her PhD: “it’s really good for me as well. I find that I do my best work when I’m streaming, because it forces me to get off Twitter and actually do work.” As she enters the final year of her PhD, her livestreams are mostly pomodoro sessions: “I do pomos the most, because work is a bit manic right now as I’m going into my final year. They also require the least amount of prep from me.”

Not all of Kat’s sessions follow this format. “The other streams that I do—I call them maths office hours—are more going through maths problems. A few times I’ve given talks on Twitch, depending on how much time I have to prep.” The audience can request topics for these office hours, and Kat will answer questions live. “Typically, I’ll be going through past exam questions or teaching a topic. But the goal is not to have a lesson: the whole point is that it’s a conversation.” The topic of the streams isn’t rigid: “it’s normally a war of attention with me going through a topic and then getting sidetracked by something like ‘hey, have you seen this cool way to divide by nine really quickly?'” And it’s not just maths students who join these streams: “oftentimes, I’ll get people from all different stages of careers and with different background experiences chatting.”

Kat also streams herself gaming, usually puzzle-related games, though these happen the least of the three. “Ideally, I aim for about one office hour a week, and then a game stream every now and then, when I’d want to or when I have something to play. Then I do pomodoros whenever I’m at my desk back at home and doing work.”

Through these streams, Kat has developed an audience of regular viewers. “I think one of the really nice things about Twitch is that it encourages that community. I have a Discord as well, where followers can chat to each other, as well as to me.” Although these conversations often centre around maths, most of Kat’s audience are not, in fact, currently engaged in formal maths education. “A lot of the people that will engage with me on my streams are people who are already in the workforce, but maybe were either interested in maths as a kid, or are doing something in a tangential field. Generally speaking, I kind of assume that the person that I’m talking to on the other end is just someone that kind of has a vague interest in maths, but not studying maths.” And this audience engages with the different streams in different ways: “I think there’s definitely a Venn diagram somewhere of my whole community, and different people enjoy different parts of it. The ones that are coming to the pomodoros typically will be studying something, or they’ll be working on a project.” While some of the audience may have initially been attracted to Kat’s Twitch because of one type of livestream, they often stay for the others. “The people that come to the game streams, I’ll normally end up trying to lure them into the office hours. Most of the audience are used to seeing games, and then you slowly move them into thinking about maths.” This has worked for Kat, with more people coming to view her streams: “it’s a nice growing community, I’d say.”

A screenshot of Kat's Twitch profile, showing thumbnails for two recent streams.

Some different streaming highlights

This community of viewers follow Kat’s journey through her PhD, gaining an insight to the highs and lows of the process. “I think it’s good for people to see a version of a PhD that isn’t just ‘we get it right all of the time’. My community have been with me for the last two years of my PhD, and it has been ups and downs.” One thing she has shared with her audience is her experiences with navigating the process of writing a paper: “something that keeps coming up is the PhD dream of writing a paper. Every time that gets knocked back, I’ll tell my audience why and how, because it’s easy to feel like that’s a really bad thing. But it is what it is, and you just have to work with that.” Kat hopes that talking about this online will help destigmatise the PhD process, saying “especially if you’re far away from academia, you have this idea of what it’s supposed to be, but it’s different for everyone.”

A particular highlight of Kat’s streaming happened during an office hour, where Kat ran into a bit of a surprise. “There’s this functionality in Twitch where at the end of a stream, you can send all of your viewers on to watch someone else.” During an office hour where she was teaching herself hypothesis testing, a popular streamer sent his audience over to KatDoesMaths. “I’m not a statistician by trade. I was trying to teach myself, making an absolute mess of it… when he raided my channel with 1800 people. So not only was I fangirling over this big celebrity suddenly watching me do maths, but there were also 1800 people there watching me trying to do hypothesis testing. That is still one of the highlights of streaming this far.”

Behind the research

Outside of Twitch, Kat is heavily involved in several initiatives revolving around demystifying academia—from PhD applications to showcasing what day-to-day research actually looks like. “I think anyone that wants to get into academia should have the opportunity to. I think it’s a dangerous game we play when we say that everyone should have a certain level of qualification. I think that the ability to get the qualifications should not be the limiting factor. If you want to do a PhD, just because you really like learning, I think that’s a good enough reason to. Often people miss out on opportunities because they don’t know what’s available to them, or what’s possible for them. I think that’s such a shame because it favours people that don’t need the extra help already.” One thing Kat mentioned in particular was the lack of awareness that most students have about funding when applying for PhDs: “I think, at the bare minimum, everyone should be aware that there are funding opportunities and scholarships. The idea of paying for a PhD put me off, and I didn’t realise it was standard to get funding until I applied.”

A selfie of Kat and three of her colleagues, with their backs to the stage in a theatre

The Behind the research team

One of the initiatives Kat is involved with is Behind the research, based at the University of Bath. This is a toolkit for students in the maths department with the primary goal of equipping them with the skills and knowledge necessary to do outreach. This toolkit comprises of both a physical kit (laptops, cameras and other technical equipment) as well as information (for instance, which software works well to edit outreach videos). “If anyone in the university department wants to do some outreach using online or video audio visual stuff, I want them to be able to do it. I don’t want the limiting factor to be ‘I can’t afford a camera’. You don’t need high tech equipment to do that sort of thing, but I think it’s nice that they don’t have to do it alone”. The tagline for the initiative is “meet the real people behind the research”, which the team do by producing YouTube videos and blog posts of their experiences.

Kat and the other organisers of Si Mon Sci Comm Con

Kat also co-organises PhD Your Way—a national open day focusing on maths PhDs, bringing together institutions from all over the UK to inform prospective PhD candidates about the process. “It’s independent of any one institution. The idea is that we bring all of the universities to one place, so that you know the information you have to get isn’t hidden on different websites under different names.”Current PhD students also come along, so attendees can ask them questions about their experiences: “you can actually ask them, not only all the admin stuff, but what is it actually like living there? What’s the social life like? Is there support if I have dependants? Or if I’m part time, how does that work? Is the mental health support good? All of that information.” This event has been successful in the past: “I met someone the other day that decided to do a PhD because of this event, so we have influenced at least one person. I’m very proud of that.”

Kat is also beginning to take a step into in-person outreach talks. Later this year, she will be touring with Education in Action, giving a series of talks for their Physics in Action sessions. “The goal is to show that fluids are everywhere, and that one set of equations can describe everything.” This is Kat’s first solo outreach in-person lecture experience, and we spoke about the jump from online outreach to in-person talks: “I think a lot of people are trying to go the other way, starting with doing more traditional maths communication, like talks and going into schools, and then working outwards to online content. Whereas I’m trying to jump the other way.” But Kat told us that “going this way has worked really well for me in terms of my public speaking skills”, and she’s really excited for the talks. “The talks in public, when you give a big lecture, are really cool. You get the energy off the crowd.”

Katie Phillips Stadium

Before saying goodbye to Kat, there was one more thing we wanted to chat to her about. Everyone knows the sudden pang of fear that comes when someone asks the dreaded icebreaker question: “so—what is a fun fact about yourself?” Everyone except for Kat, that is. How many people can say they had a rugby stadium named after themselves? Kat told us: “I’m from South Wales, and I have been a big fan of the Ospreys since I was a child—in part by choice, and in part because in South Wales, you get disowned if you don’t like rugby”. Kat was joking about being disowned of course: what reasonable person could disown someone for simply betraying their entire culture. Kat had been a season ticket holder from the start of the rugby club, and so on their tenth anniversary, she was entered into a celebratory raffle they were holding. “It just so happened that I won the raffle. So, when I was 17, they called me up and said ‘for one game against Glasgow Warriors, we’re changing absolutely everything in the stadium’.” And so on that fateful day, Kat arrived to watch the Osprey v Glasgow Warriors game at the newly-named Katie Phillips Stadium. “They printed fake temporary boards—saying the Katie Phillips Stadium—and they put them up. The programme said Katie Phillips. All of the commentators had to go along with it. It was a really, really surreal experience.”

The future

So what will KatDoNext? In the immediate future, she plans to continue with her PhD and livestream the process: “a lot of my time is spent doing pomodoro sessions, especially coming into the final year of my PhD. As soon as I go into writing up status, I’m definitely going to be streaming for hours, I think.” But for the distant future, she hopes to stay within academia: “I want to keep going as far as I can. I’m still in love with my research, fundamentally, fluid dynamics is just really cool, and I will never not have that opinion. I think so. Getting to study fluids is pretty dope. So yeah, I’ll keep doing that for at least a little bit longer.”

Bethany is a PhD student at Imperial, researching swimming cells and fluids. You can often find her putting bugs in her code or fuelling her caffeine addiction.

Ellen is a PhD student at UCL studying fluid mechanics. She specialises in the flow around droplets and ice particles.

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