Episode 71: Dark Side of the Universe

with Renee Hložek

In this milestone episode of The Cosmic Savannah, hosts Tshiamiso, Jacinta and Dan celebrate the start of Season Six and the podcast’s fifth anniversary.

They engage in an enlightening discussion with Associate Professor Renée Hložek from the Dunlap Institute, focusing on her research in dark matter, dark energy, and the cosmic microwave background. Highlights include the significance of science communication, diversity in STEM, and Dr. Hložek’s involvement with the Vera C. Rubin Observatory.

Join us once again in this 6th Season of The Cosmic Savannah and let us take you on a safari through the skies!


Story Collider Podcast Episode: https://www.storycollider.org/stories/2016/1/1/renee-hlozek-who-looks-like-a-scientist


Podcast Manager and Show Notes: Francois Campher

Social Media Manager: Sumari Hatting

Transcripts: Abigail Thambiran

Audio Editing: Jacob Fine

And all of our volunteers!


Tshia: [00:00:00] Welcome to the Cosmic Savannah with Dr. Tshiamiso Makwela,

Jacinta: Dr. Jacinta Delhaize,

Dan: and Dr. Daniel Cunnama. Each episode we’ll be giving you a behind the scenes look at world class astronomy and astrophysics happening under African skies.

Tshia: Let us introduce you to the people involved, the technology we use, the exciting work we do and the fascinating discoveries we make.

Jacinta: Sit back and relax as we take you on a safari through the skies.

Dan: Welcome to this episode and to a new season,

Jacinta: Season six. Woohoo. Hopefully this is coming out on our fifth birthday of the Cosmic

Savannah. Oh yeah. But might be delayed slightly because somebody here got covid

Dan: and apparently in our small, you know, little studio. She’s not got Covid.

Jacinta: It was me.

Dan: We’ll report back in our next episode.

Jacinta: Yes, [00:01:00] I did. No, I did test negative. I’m being responsible everybody.

Dan: Okay. We appreciate it.

Jacinta: Anyway, how is everybody else?

Dan: Good, thank you. Yes. Looking forward to a little bit of leave coming up for me, which is exciting.

Tshia: No, that’s exciting. I think Dan deserves to leave.

Dan: Oh, I think we all deserve to leave.

Tshia: I mean, I deserve leave every day, but I. I’m, I’m good. I’m doing all right. And how are you Jacinta? Apart from Covid?

Jacinta: No, I’m feeling better. Thank you. And yeah, actually not too bad at the moment. So yeah, really excited to get into a new season and yeah, lots of exciting stuff planned for this season.

Some really cool people that we’re just speaking to.

Dan: And you spoke to our guest for today’s episode.

Jacinta: I did. So our guest on today’s episode, which I think is Episode 71, is Associate Professor Renée Hložek from the Dunlap Institute in Toronto. And Renée actually is South African and studied here in Cape Town.

Dan: Yes. Unfortunately I wasn’t able to join for the interview when you spoke with Renée, but I studied with Renée.

Jacinta: Right. She was your. Direct, what [00:02:00] colleagues?

Dan: She was my peer. Peer. Yeah, that’s, yeah. So,

It was during our Honours at UCT, Renée and I were in the same class. We both joined the National Astrophysics and Space Science Program, NASSP, at the same time, and did our Honours together.

We had a lot of fun together. She was definitely more nerdy than I was. I mean, it’s, I’m not sure there’s levels of nerds too, right? Like, you know, we’re all nerds and it’s just like, you know,

Jacinta: We’re all astrophysicists.

Dan: Exactly. But no, we had a lot of fun together and I really enjoyed Renée and we talked already about the National Astrophysics and Space Science Program at the 20 year anniversary of that.

Getting together to reminisce and celebrate the incredible achievements of the program. And it was wonderful to catch up with Renée. I didn’t catch up with her on the podcast, but I did manage to catch up with her separately and reminisce a little bit and just see how, how far she’s come and how far all of our fellow peers and students have come and where they’ve all ended up.

Because, you know, a lot of them didn’t end up in astronomy necessarily, but are still, you [00:03:00] know, doing great things,

Jacinta: killing it

Dan: in sort of various different fields around the world.

Tshia: I actually met some of Renée’s PhD students when I visited the Dunlap Institute.

Jacinta: Oh cool.

Tshia: So she’s kind of a big deal over there as well.

So we definitely have a powerhouse. Starting off season six with us, which is quite awesome. I didn’t manage to actually meet her or speak to her ’cause I was a little bit away during the, the NASSP 20th anniversary. But also just listening to the interview and realizing when she did her Honours and masters at UCT and I’m just like, I was definitely struggling with physics probably in grade 10.

Dan: Hey, I was with her. Just careful there.

Jacinta: I bet you could tell us some interesting stories, Dan.

Dan: What? About the eighties?

Jacinta: It’s a joke. I’m pretty sure it’s a joke.

Anyway, so well, let’s talk about science now.

Dan: Well, I think the other thing to talk about quickly is, I [00:04:00] mean, just Renée and the incredible things she’s achieved, talked about her being a bit of a powerhouse, but I think Renée has been a role model for many, many people. She’s, you know, she’s an individual and she’s not scared of saying it.

She’s incredibly confident. She’s a very good public speaker and is just wonderful to see. So, you know, not only is she incredibly bright and successful academically, but she’s also a, a real role model for scientists, women scientists in particular. And yeah, I think a huge amount of respect for her name, what she’s done.

Jacinta: Yeah. And we talk about it in the chat. But yeah, she’s, as you said, very passionate about being an individual and not conforming to what we think of stereotypically as a scientist and showing that. You don’t need to look like anything in particular to be a scientist. You can still be an excellent scientist no matter what you look like.

Dan: Yeah. And I think with your students and supervision and, you know, just encouraging people to, to follow their interests and dreams and yeah. Be themselves and, and there’s, there’s space for everyone in science,

Jacinta: [00:05:00] in, in space? It’s the kind of joke on me, mate. Oh, I know, but I was trying to be you.

Dan: Oh well flattery,

Jacinta: I feel like I nailed it.

Alright. Anyway, so Renée, sorry, go ahead.

Tshia: No, I don’t wanna say anything. I was just like, this is really a genuinely funny moment.

Jacinta: Well, at least we made Tshia laugh.

Anyway, getting onto the science. So Renée is of course a real rockstar scientist. So she is a cosmologist and she studies dark matter and dark energy. So very much the dark side of the universe.

Tshia: And isn’t the universe all dark though?

Dan: Well, no. Look at the, look at the star.

Jacinta: That’s light.

Tshia: No, but like, there’s just that light.

But actually. I think it’s all dark. But anyway,

Dan: We can talk about cosmology later. I’m gonna, I’m gonna let Renée handle it and then we can have deep discussions later. Yes. So, [00:06:00] so, but there’s something of a cosmologist myself. I’ll have a thing or two to say about you saying the whole universe is dark.

Okay. Okay.

Jacinta: Oh, Dan is getting very passionate.

Dan: I’m calm. Sounds fine.

I’m fine.

Tshia: You’re not fine.

Jacinta: Cosmology anyway is the study of the universe as a whole, how it began, how it’s gonna end, what it’s like, really universal parameters are, and part of that is no, it wasn’t a part of pure laugh.

Dan: A minute this morning

Jacinta: I’m on fire.

Dan’s shaking his head at me. And it’s like a large fraction of the universe we believe is dark energy. And after that, a large fraction is dark matter. And then a tiny little slice is everything else. You know, our sandwiches, our like planet, our sun, everything else light and matter. And

Dan: sometimes if you burn your toast, then it’s gets pretty dark too.


Jacinta: No! Too contrived. [00:07:00]

Dan: Okay.

Jacinta: You’re allowed to laugh out loud, Tshia..

Dan: In this case. We’re laugh. We’re laughing at me, not with me.

Jacinta: Tshiamiso is laughing quietly to herself here.

Dan: I think we should, I think we should pass the button to Renée.

Jacinta: Yeah.

Tshia: I, I also agree

Jacinta: This is going well. Hi everyone. Welcome back. I’m sure you missed us. All right. I think we’ll hear from Renée now.

With us now we have Dr. Renée Hložek from the Dunlap Institute of Astrophysics and Astronomy, University of Toronto in Canada. Welcome to the Cosmic Savannah, Renée.

Renee: Thank you so much for having me.

Jacinta: Renée, you are actually from South Africa originally, but after a long journey are now working in Canada. Can you tell our listeners a little bit about who you are, where you are from, what you do?

Renee: Sure. I was born in Pretoria and I did my undergrad degree there, and then I heard of this amazing program [00:08:00] called NASSP that brought me down to Cape Town to do my Honours degree. And then I did a master’s degree also with the SKA here. And then I started my PhD in the UK in 2008. So I’ve had like a whole journey.

I went from there to the US and now I found myself in, in Toronto, Canada.

Jacinta: Wow, okay. That’s like all over the world. Well, all over that part of the world. Okay. So first of all, you mentioned NASSP now that’s the National Astrophysics and Space Science Program, right?

Renee: Yes, yes.

Jacinta: And that is what actually brings you here.

At the moment.

Renee: Yes. So the fellowship was started 20 years ago, which is to me bizarre, like it’s time passes. But one of the goals was actually to train South Africans and other people from other African countries to be skilled in astronomy, astronomy skills, science literacy, and to basically make the next generation of scientists.

So in my class we had the, the first Ethiopian Cosmologist. We had some of the first Gabonese and Rwandan scientists. It was really, really great. And then of course, just that community [00:09:00] coming together is exciting now.

Jacinta: Awesome. And I believe Daniel, one of our Cosmic Savannah hosts was also a, a colleague of yours in Honours.

Renee: He was, this is really great and great to see how amazing things he’s doing as well.

Jacinta: Unfortunately he couldn’t be here to chat with you today, but I’m sure you’ll catch up in the next couple of days. So we are having the 20th anniversary celebration conference of NASSP and you and I will be there and we’ll hopefully see a whole bunch of people doing really interesting things in astronomy and outside of astronomy as well.

Renee: Absolutely. It’s amazing to see what happens when you, (give) a bunch of people skills in astronomy and then set them loose on the world, which is exciting.

Jacinta: Yeah. And, and our skills are really quite transferable. So, you know, critical thinking and analysis and all of these things. Anyway, getting back to you. So you mentioned you did your Honours here.

Was that the University of Cape Town?

Renee: Yes.

Jacinta: Yeah. And then you went to the UK tell us what you did there.

Renee: So, as part of my PhD or DPhil in the UK, I was working on mainly the cosmic microwave background, which is, you know, light that’s been traveling for [00:10:00] billions of years. Basically, the first light that we can really see that comes after about the universe was about 400,000 years old.

And during my PhD I was studying that light. And observations of that light made with a new telescope in the Atacama Desert. It was called the Atacama Cosmology Telescope. And we used it to really understand the first moments of the universe, what the universe is made of. And also the ACT telescope was able to measure this light with quite fine angular resolution.

And the resolution that your telescope has tells you you can sort of access different physics. And so in this case, we were able to learn a little bit about massive neutrinos and what the universe was made of on small scales, which is really fun.

Jacinta: Okay. So just the, the small questions of the universe there, which is how it all began.

Awesome. And that was at the University of Oxford, right?

Renee: Yes.

Jacinta: And that’s actually where we met. All the way back in, I think 2009, 2010, where I was doing part of my PhD there. So it’s great to kind of come full circle and see back here in Cape Town, [00:11:00] both of us here in Cape Town now. Alright, so you did your research on using this ACT telescope Atacama Cosmology Telesope, and then you finished up your PhD and then you headed off to the US.

What happened then?

Renee: So in the US I did a sort of a combination of some of the work that I had done during my PhD, and then actually some work that had started during my time in NASSP. So, as a cosmologist, I’m interested in those big questions as you said. And that also means that I study a range of things in the, in the universe, cosmic components.

And one of those is dark matter. So I care about matter that we can’t see with our eyes, but that has gravitational impacts on the universe. And then I also care about dark energy, which tells us about how the universe is changing, how it’s expanding with time. And some of my first projects in NASSP were to actually see or predict or forecast how well we will be able to use telescopes in the future. At the time it was in the future, and now it’s almost in the [00:12:00] present, which is crazy how we can use those telescopes to understand how dark energy is changing with time. And so during my postdoc at Princeton, I had a little bit of both pieces of that work.

Some of it was CMB analysis and some other parts were kind of taking that, the theory of how we would use this new data to help us understand dark energy and doing a little bit of both at the same time. That I continued, I also wanted to further my goals of communicating science to everybody to give talks in public.

And also talking about what it means to be a scientist and who sort of challenging the idea of what does a scientist look like? Who are they, what do they do to try and encourage everyone, but my focus initially was women and girls to think about themselves as scientists and people that were much more diverse in all sorts of aspects.

Both in their job and who they are and their ethnicity and where they come from, et cetera.

Jacinta: I remember when I first saw a photo of you kind of giving one of your talks and you had bright red hair and [00:13:00] yeah some tattoos, and I just thought that it was so refreshing to see. Someone just genuinely being themselves on stage and being celebrated for that.

So yeah. Thank you for doing that.

Renee: Yeah, always. In fact, that’s something that I wrote a little there’s a, there’s a podcast called Story Collider, which if folks are interested in science related podcasts, like I’m sure the listeners are, Story Collider is an opportunity for people to give talks in public in IRL.

And the stories are normally about science and I gave one of the talks, the Story Collider, about who looks like a scientist, what does it mean? Because actually you’re right, I have a lot of tattoos. My hair is often weird colors and red and, and whatever. And a lot of the time people said to me while I was a student, if you look too different from what people’s idea of a scientist is, they won’t take you seriously.

They’ll think that you aren’t a good scientist..

Jacinta: Yeah, I know. Exactly. And then you did a couple of talks on the, on the big conference stage in [00:14:00] California. Right. How was that experience?

Renee: It’s, you know, it’s very strange for a few reasons. The first is like, it was the first time I’d spoken to 800 people at once.

And the weird thing is you can’t see any of them. So, because it’s, ’cause the spotlight is on you. And so,

Jacinta: and the audience is dark.

Renee: The audience is dark. And, but one of the things that was interesting is, so when I was much younger I did a lot of singing performance. And it’s sort of similar that you can’t see the audience.

So when I got on the stage, I was like, oh, this is fine. And my favorite moment is. Just before you speak because it’s like nothing, anything can happen. It’s like the quantum physics of talk, like it’s gonna go well or it’s gonna go badly. Nobody knows. And that was always my favorite. But the other thing that’s strange is when you give a talk, you have a little remote control and you press a button and that button flashes a light away from you at the person who’s controlling your slides. Because the reason why they they control your slides is because if anything goes wrong, then they can handle it and fix it. And you don’t sit there like, yeah, scratching around on a computer. [00:15:00] But the weird thing is there’s like a tiny, tiny delay between you pressing the button and them doing the thing.

And so you have to really calm yourself. ’cause if you get stressed and then you start pressing a ton of buttons, then the slides go very fast. And so there’s this moment where you have to like chill out.

Jacinta: Oh wow. Yeah. Wow. That’s amazing. So a couple of years ago I did a talk, I think I spoke about how astronomy can help humanity in terms of achieving the the sustainable development goals.

And I worked so hard on preparing my talk and everything and it was actually in my hometown of Mandurah because long story short, I got stuck there for visa reasons, for ages, and I had the same experience as you. I was like quite nervous and like ramped up with energy beforehand. And as soon as I stepped onto the stage, I grew up on that stage with ballet and I was like, “I’m home!”. And then I was like, “I’m here! Everybody listen to me.”. It does help you relax if you think like, yeah, yeah, yeah. It’s just interesting that very different skills from our childhood, [00:16:00] which had nothing to do with academia, can actually help you move forward in your career. So it’s good to, to value all of your skills.

Renee: Absolutely. So when I was a postdoc, I did a course in improvisational comedy and like improv comedy, kind of, whose line is it anyway, kind of stuff. It’s very weird and very scary and it’s like, I dunno, walking in traffic, it’s very weird. But I found that it helped my talks as well. Because particularly helped my science talks because no matter what happens in the world of improv, you kind of roll with it and you relax.

And that sort of really helped me realize if I get, if I get a difficult question that I’m not sure of the answer to. I have skills to help me go ahead and move forward and relax as opposed to feeling like, Ooh, I’ve got no skills at all. So yeah, you’re right, definitely.

Jacinta: Exactly. And that can also almost help with the imposter syndrome as well.

Renee: Totally.

Jacinta: Yeah. Awesome. Cool. And then, so one of the key things that you did was to make a video about heat death, which I believe is very, very popular. So give us a little taste of what is heat [00:17:00] death?

Renee: So the heat death of the universe is basically what we describe as the end of the universe. It’s not that you die on a fireball, it’s sort of the opposite, that the universe gets bigger and bigger and bigger and colder and colder and colder until there’s basically no more heat, which could be sad.

And in fact, the talk is animated, so it’s really cool. The animation crew were amazing, and so you see the sad universe when it’s really cold. It’s really very, very cute.

Jacinta: Oh, okay. I can’t wait to go and watch this now. Awesome. And so overall, how would you say the experience was?

Renee: It was great. I mean, I love challenging myself to think about when you’re communicating science, obviously you wanna get the details right.

You wanna make sure that everyone understands every single thing of what you say, but you realize that people sometimes come to something in a cycle. Like they’ll hear your talk the first time and then they get a little bit and then they’ll listen again and then they hear something else. And that’s how we learn.

And so now when I meet other people that give talks or I listen to talks, I always try to think of that like if, [00:18:00] imagine if this is the first time you’re listening to me, what am I gonna learn now? And then I think, okay, are there any nuggets for the second time? Yeah. And just to think that it’s always a journey rather than wanting to be super technical right away, because you can get quite dry when you’re speaking like that.

Jacinta: Yes, that’s a really good point that I’ve never thought of before. That’s awesome. And that can obviously help in science presentations in lectures and all of these sorts of things. Okay. So then after Princeton, what happened next?

Renee: So I was applying for jobs. So in academia there are not that many jobs at universities because if you think that there’s a finite number of universities in the world and each of those have a finite number of professors, and normally you wait for someone to retire before there’s a new job.

So I was looking all around the world for different jobs and one of the jobs was in Toronto, in Canada. Which I had known about and I had been to before, but I didn’t know as a South African, I did not know it was possible to live in a country where the outside temperature was sometimes minus 35 degrees Celsius.

Jacinta: Is it [00:19:00] possible?

Renee: Well, so so I interviewed for the job in February of 2015, and that week it was minus 35. And I remember thinking like, oh, I thought I would be dead. Like I just didn’t understand how, I mean, minus two or three, I understand, but minus 35, and you know, for the Americans on the phone, that’s the same temperature, right?

Minus 35 is basically the same in, in Celsius or Fahrenheit. So we walked to dinner and I remember telling someone that, that we were with, I said to them, I can’t tell you how, but I know what the inside of my skull looks like. ’cause I can feel it, like it’s so cold that I could actually like draw you a map of my skull.

It was so cold. But that’s, I took the job anyway.

Jacinta: Wow. But like how do you, like genuinely, how do you survive in that?

Renee: So the way you survive is actually, it’s all about clothes. So I have a coat that if it’s warmer than minus 20, I sweat in it. So it’s like very, very warm and you basically have as little of your face out as possible.

So it has a hood that comes quite far down and then it zips around. So it’s like just your little [00:20:00] eyes peeking out and you don’t ever leave the house with wet hair. I learned that. So in South Africa, never drop my hair with a hair dryer in Canada. I always have to do that. Otherwise it snaps.

Jacinta: What?

Renee: Yeah, you can just snap.

You can just snap your hair. It’s really quite amazing.

Jacinta: Wow. Okay. So that’s a whole different new world, which I’m not sure I need to know that, but it’s good to know that it is livable.

And how do you enjoy it now?

Renee: It’s fun. I, what I really enjoy is that I have a wide range of students. I have Canadian students, I have Nigerian students, I have, you know, encounter a lot of different people and also that I get to work in a lot of different areas.

So one of the cool things as a professor is with time you build a research group and so you have different people work on different things that you think are interesting and need to be worked on. And I’ve enjoyed defining those goals. It’s very scary in the beginning because you think. I don’t know if I have enough ideas in my head for, for five people to work on them. Yeah. And then with time you realize, oh, I get to [00:21:00] watch these scientists become their own independent people and then they don’t even need you for ideas anymore and they’re doing different things and that is really great.

Jacinta: Awesome.

That’s. So exciting. So, well, I mean, first of all, congratulations.

That’s awesome.

Renee: Thank you.

Jacinta: And I’m so glad we have someone like you in that position and helping younger scientists and more junior scientists to grow and to find their own feet. So what do you do as part of your role? So explain to us how it works in Canada. What does it mean to be a professor there?

More about that.

Renee: So professors in Canada, basically, I do a few things. So on one hand I teach classes. So I teach, in fact, one of my classes has 1,500 students in it.

Jacinta: Oh, what?

Renee: And we teach them all at the same time. So if I thought the TED stage was scary. Now imagine you have you know, 1,500 students, like on two or three levels all around you in this.

Jacinta: Oh, they’re in person.

Renee: They’re in person. Whoa. I have an amazing picture, actually. So the start of my class in January of 2020, I always take a [00:22:00] selfie on the first day of class because I’m basically 12 years old in my head. And so I took a photo and you can just see all these students behind me. And then of course, the pandemic started during the course.

And so my last lecture, I’m in the same room, but there’s no one and I, it’s just completely empty.

Jacinta: Oh, and you took another selfie?

Renee: I took another selfie to be like, oh, okay. Oh. So yeah, I mean it’s very strange. Like if you ask, so one of the things we do to check understanding is you have like a little, everyone has a little clicker and you ask a question where it’s like an A, B, or C answer, and then they press the right, you know, whatever they think is the right answer.

It’s quite amazing when you do this and you say, go and then you see 1000 people answer your question. It’s like, it’s very strange, but very fun.

Jacinta: Ah, I’m gonna talk to you more about that afterwards. That’s an interesting teaching strategy.

Renee: So I teach, so part of what I do is teach, and then the other part of what I do, I obviously do my own research and I write my own code and I write papers.

But then what I also do is I supervise the research of my students. So I work with undergrads doing research and Masters students and PhD students. And [00:23:00] then normally what happens is we define a research question together, but with some direction from me. And then they go ahead and they get data or they start making a theory and they start working through things.

And then as they struggle, as things are going right or wrong, we sit and talk about it every week. And then by the end of their Masters or their PhD, they have become these completely independent scientists that are defining their own questions, which is pretty fun.

Jacinta: Wow. Awesome. So how many students have you had already?

Renee: At the moment I have six students which is really fun. Yeah. And I have graduated three PhD students, which is exciting.

Jacinta: Oh, that’s big.

Renee: Yeah, as a, as a professor, but then I, even as a postdoc, I managed to supervise some students and that was great. So over my whole kind of career, even though I was working with other people, I’ve worked with about 60 students, which is really fun at all levels.

Jacinta: That’s awesome.

Okay, so now what is your research about now?

Renee: So I still have multiple strands and I, one of the things I always wanna tell young people doing science is they always say you have to become an expert in one thing. [00:24:00] And I never wanted to do that. So I have lots of different interests and I keep working in all of those areas.

So. So the, basically as a cosmologist, it’s all in the big picture of dark energy, dark matter, and the earliest moments of the universe. And so I study dark matter particles or, or predicted dark matter particles. One of them is called the axion which has a really fun name. And these axions have very specific properties.

And some of my research with my students is we ask the question, if the universe had axions in it, what would the CMB look like? The cosmic microwave background, or what would galaxies look like? And so we come up with a bunch of different sort of predictions for what our observations would be. That’s one strand.

Another strand is using the same cosmic microwave background, but to ask and answer different questions about how do the first stars form and how is gas distributed in the universe and how do we understand all of those properties. And then I also think about dark energy and dark energy models when [00:25:00] I use and plan for data from the Vera C. Rubin Observatory, which is being built right now in Chile.

So I have those different kind of strands, but in general I say to my students, any problem you want to ask in cosmology, if it concerns what the universe is made of and how it’s changing with time and how it’s started and how it’s gonna end, any of those questions are allowed and we do anything in that area.

Jacinta: Oh, awesome. Okay. Again, everything, the whole universe. Alright, so first of all, what is the difference between astronomy and cosmology?

Renee: I don’t see a huge difference. So in general, if I think of what an astronomer does, is, they look at the sky and they try to understand it. Depending on what they look at, they might be classified as, you know, an astronomer that uses optical light, an astronomer that uses radio waves.

As a cosmologist, I’m like a subset of an astronomy like group, but I’m interested in not just anything, but specifically questions that relate to those que, you know, fundamental like [00:26:00] origin of the universe, dark matter, dark energy, et cetera. I don’t really mind what wavelength I use. So I use radio waves, microwaves, optical light.

That doesn’t matter to me as much. As long as the stuff that I’m doing is gonna teach me about the building blocks of the universe, I’m happy.

Jacinta: Okay. So it’s all about how the universe began and how it’s gonna end. And like this really big picture like. On the larger scale possible.

Renee: Yeah. One of the things I like to tell people is if you study galaxies, often you care about the galaxies.

So someone will say, they study a certain class of galaxies or how those galaxies operate. Just like if I know you, I really care about you and who you are and you know all the things about you. But if you imagine someone taking a census of the whole country, they don’t really care how your day went.

They just care where you live, what languages to speak, blah, blah, blah. And so as a cosmologist, I often do what we call survey astronomy. Where I’m not actually interested in any individual galaxy and how it’s behaving and its properties. But I’m interested in the statistics [00:27:00] of all the galaxies on the sky.

Where do they live? How are they distributed? What is the space between them? Because those statistics tell me like the, those big questions, just like the census tells me broad things about South Africans.

Jacinta: Right. And you also mentioned, so part of that is overall what is the universe made of? So some fraction of that is, what we call baryonic matter, which is what we are made of atoms and protons and electrons and anything that you can sort of touch. But then there is this other even much bigger fraction of the universe, which is stuff that we don’t really know what it is. Right? So as you, you were mentioning dark matter, even a larger fraction of the universe is dark energy.

What are they and what is the difference between them?

Renee: Great. Yeah, so I always tell people from in my classes, if there’s one thing I want to remember, it’s the difference between dark matter and dark energy because we are silly. We gave them dark as the first name in both of them, which confuses everybody.

But dark [00:28:00] matter. Can be understood as, I like to think of it more as semi-invisible matter. So it acts the same way that normal matter does. In other words, I can bump into it gravitationally, we would be bound in the same way. So if the sun was made of dark matter, it wouldn’t shine, but we would still orbit the sun.

But the not shining part is a big deal, obviously, because it means it’s hard to see dark matter. So it doesn’t, we say that it’s weakly interacting with light. You can’t, light isn’t gonna bounce off the surface of dark matter and it’s not gonna make its own light, and that’s why it’s hard to see. But in every other way, we think it behaves mostly like normal matter in the sense that it interacts with gravity.

Dark energy is totally different. It’s much easier to think of it as like an anti-gravity force in your head rather than a thing like dark matter, because it sort of is acting against the way we would think gravity works normally. So the analogy I like to give is anyone who’s over [00:29:00] about 1-year-old, if you throw a ball in the air, they will know what to expect.

They will expect the ball to fall on the ground. Actually, you can do this game even with dogs. Dogs get very scared if they don’t see the ball fall down, they get really freaked out. But imagine I threw a ball up in the air right now, and it started to float away. Like instantly you’d think, well, maybe there’s air on the ground, like pushing it up.

But that’s sort of what we see. The analogy in the universe is. If we can measure the distance to certain objects, then we know how big the universe would be if we had normal gravity, normal, just normal things in it. And in fact, we can predict that the universe would get bigger. And then eventually, if there was enough stuff in the universe, it would sort of collapse on itself because gravity sucks.

Gravity pulls everything together. And then about 15 years ago, what we noticed was that the distances were bigger than they should be. So the universe appears to have started accelerating. And so. Something must be pushing against the gravity collapse that we expect and [00:30:00] actually making the universe get bigger, faster, and faster and faster.

And so we call it dark energy because it’s a misunderstood energy or something we don’t know. But it’s much better to think of it as like the anti-gravity push. That means the universe is behaving weirdly. And so we don’t know what it is. We don’t think it could necessarily just be like a particle, but we, it’s something that’s acting against gravity on the biggest scale.

So like you and me aren’t affected by dark energy because you and me-the distance between us is small, but on the biggest cosmic scales, we see this dark energy taking effect.

Jacinta: So for example. The gravity between the earth and the sun is enough to overcome this dark energy. So we, we aren’t getting pulled away from the sun because gravity is, is stronger than this dark energy on that scale.

But then on big, big, big scales like between the Milky Way and some very distant galaxy, then dark energy is kind of essentially pushing us away, from that galaxy.

Renee: [00:31:00] Exactly. So the analogy I like to make there is gravity is really important to you. You think it’s the most important thing to you. Although as a human, the most important forces are really the ones keeping your body from flying apart.

So your kind of atomic forces between the parts of your body. So it’s always important to think of like the scale, and similarly, at the scale of you and me and the earth and the sun, gravity is the only thing that really matters. And so it’s keeping us all together. But on those largest system scales, you really see dark energy come, come into its own, as they say.

Jacinta: And this is where if the universe just keeps expanding and everything keeps getting pushed away from everything else, eventually the idea is that of this heat death that you were mentioning before where the universe just dies of the cold.

Renee: Well, the nice thing is that it’ll actually continue. It’ll be very large and very empty forever.

So that’s, there’s like a real beauty in it. So the, the reason why this is a big problem is one of the things we do in cosmology is we like to say, I want to know, imagine the total energy pie of the universe. How much of that energy is in the individual component? So it’s sort of like [00:32:00] I’m doing an accounting of the cosmos and I can measure how the relative fractions change with time.

So in the early universe it was very hot. Everything was radiation. So the radiation fraction was very high. Right now, most of the universe is not made of radiation, and so most of the universe, you know, was made of dark matter. If we take the dark energy and we think about this dark energy, one of the weird properties about it is that as the universe gets bigger, the dark energy density relative to the volume stays constant, which is something completely opposite to how our brains think.

Because if you take a glass of Oros, ’cause I’m South African and you put in a little bit of Oros in water, and then you increase the size of your container, the density is going to decrease. But of course that doesn’t happen in the universe with cosmology. So with dark energy, as you make the universe bigger, the energy density is constant, which means there must be more dark energy being made with time.

So eventually, if I look at my cosmic pie, [00:33:00] all of the universe will be made up of dark energy. There’ll be very little of any of the other stuff in it. And so it’s this cold, empty, dark, energy filled wasteland, which is sad, but beautiful.

Jacinta: Okay. Two questions there. What is Oros?

Renee: Oh my goodness. You don’t know Oros?

Jacinta: No!

Renee: Oh my, it’s, it’s, if you’re over the age of 12, I think people don’t drink it anymore, but it’s an orange, like an orange squash. I can even sing you the ad.

Jacinta: Please do.

Renee: From when I was a child. So it’s like, oh, we love living in an Oros world with Oros boys and Oros girls. When you’ve got a thirst, who do you call first?

Oh, oh, oh, oh Oros!.

Jacinta: Okay. I’ve lived here for five years and I haven’t tried Oros so I think I’m gonna have to do that.

Renee: It’s delicious.

Jacinta: The second question, very similar is what is causing the extra dark energy to grow?

Renee: Really good question. And in fact, I think when we figure out what dark energy is, that’s definitely Nobel Prize winning stuff.

So maybe I brushed over it a little bit too. So it’s good that we can go back [00:34:00] and, and sort of re-explain, but one of the suggestions for this dark energy or, or really for this making-space-bigger-effect, this acceleration of space. One of the suggestions for what that could be is what we call vacuum energy.

So right now we just see ourselves in, you know, macroscopically. But if you zoomed into space smaller and smaller and smaller and smaller and smaller, like very smaller than any microscope could see, you see that there’s like this quantum frothing of everything, right? This very exciting quantum scale universe.

And there is sort of a prediction that even the energy of empty space, so of a vacuum, that there is actually this energy, quantum energy associated with empty space with vacuum space. And so one of the suggestions was, oh, maybe the dark energy is actually this vacuum energy, the energy of kind of empty space.

And that’s why, so I should say, that’s why as you make space bigger, you would get more of this energy because if it’s associated with empty space, [00:35:00] the more empty space, the more dark energy. If it was this vacuum energy, the problem is, and one of the biggest challenges in cosmology is that if you, you can actually do a quantum calculation to figure out how much of the dark energy there is from your kind of calculations.

You can also compute how much of the dark energy there is based on observations. And those two numbers differ hugely. Huge, huge, hugely, which means the theory prediction doesn’t quite match what we see. And that’s where a lot of folks who work, like really in the theory modeling, are trying to come up with other models of what dark energy could be that actually match what we see.

Jacinta: Okay, so based on the model of our best guess about what dark energy is related to this vacuum energy and the observations, they don’t match. So it’s kind of like either the model is wrong or this vacuum energy concept is wrong. So how are we gonna progress? What are we gonna do now to figure it out?

Renee: Yeah. So that’s sort of where I come in, in the sense that myself and other [00:36:00] colleagues, we approach it from a bunch of different areas. On one hand we say, okay, there are a ton of creative people coming up with models of what the dark energy could be. Maybe it’s a scale of field, maybe it’s something like the axion I just mentioned earlier when we were talking about dark matter.

But with different properties, maybe, you know, sort of, can I think of the model? And then there’s this concept which we call phenomenology, which is a fun word, but basically you say. What are the predictions of my theoretical model in terms of concrete observables? So like if my model of dark energy is x, y, z, what do supernovae look like?

What does the cosmic microwave background look like? What, how, how do galaxies cluster? And then we play a matching game between the theory and the model. Now you, in order to do that, you need to make the error bars on your data better and better and better, which is why we build new telescopes. But if you’re a theorist, you constant, it’s like a little guessing game.

Like, you know, if you’re, if you’re trying to figure out who done it in the, in a murder mystery, it’s like, is it this? Is it [00:37:00] this? And so there’s this tension and there’s balance between theory and observation, which is why I love cosmology actually. And right now we haven’t quite solved things, but there are an infinity of really creative people that continue to think of these models and predict what we might see.

Jacinta: When I was younger and I had very stereotypical ideas about what an astronomer was or what a theoretician was, I would think of someone probably a, a man with a big beard kind of sitting with pencil and paper and like solving equations and trying to figure out this like theory, this model of dark energy in the universe.

And being very kind of take it very personally. Like my model is right. I have made this one, but surely now that can’t really be right because surely you have to come up with a whole bunch of different models and then go and test which one is right and not like truly believe that you’ve solved it and yours is right.

Would that, would that be correct?

Renee: Well, yeah. I mean, I tell people my [00:38:00] job as a cosmologist is not figuring out what the universe is, but figuring out what the universe isn’t. Because mostly I’m trying to kill models, trying to kill ideas. That being said, I think sometimes there is a tension because someone will come up with a model that solves one observation, so.

Listeners may have heard of modified gravity. So some people say, I don’t like the idea of dark energy. It seems really bizarre. So what if gravity is just behaving differently in a way that, you know, I can predict maybe there’s a something else going on. And so in that case and allowed, you can say that, but then what I require as an observational cosmologist is you have to make predictions that match all the observations we already have.

And sometimes people will make an observation, sorry, a prediction that matches one kind of data. Like maybe they can reproduce these expansion of the distances of, of supernovae but they can’t reproduce, say the cosmic microwave background. By my books, that theory [00:39:00] is not acceptable because you have to be able to predict everything we see or explain everything we see in your model.

But there are still some people who are very, very certain that their model is right. So your image is maybe needs to be revised, but maybe not as fast as you might like. There’s still some people who believe their model is right and they won’t listen to anything else.. But that’s just the way the cookie crumbles.

Jacinta: That’s just humans, I guess. Yeah. Awesome. I was gonna say you’re a model murderer, but then I realized how that sounds. Theoretical model. Okay, so that’s dark energy, which is super weird and almost as weird as we mentioned dark matter. And you were talking about axions. So tell us more about that. You, you were mentioning what dark matter is that you can detect it by gravity, but not by light.

It doesn’t interact with light. It doesn’t emit light. It doesn’t reflect light. Well, something else that we know of that doesn’t emit light is black holes. So could dark matter be black holes? [00:40:00] And if not, why not?

Renee: Yeah. So some folks do have models where dark matter is made of black holes. So there were, there were two historically I must, preemptively apologize. astronomers love acronyms. They’re not always very good. And so historically, initially people said, what if dark matter is just made of big heavy things we can’t see? And they, they named them MACHOs or massive compact halo objects. So MACHOs. MACHOs, exactly. And the reason why they named them MACHOs is because a little bit before someone had said, what if all the dark matter is made up of weekly interacting massive particles, really big particles that don’t interact?

Those are the acronym for that is WIMPs. And so they were wimps and MACHOs.

Jacinta: WIMPs and MACHOs. It’s really silly. Oh, no.

Renee: So, so sometimes so people, some people think, okay, what if the dark matter is a WIMP? So you’ve heard of the Large Hadron Collider. So this is a big collider in Europe. Where you basically take particles protons, et cetera, and you accelerate them and then smash [00:41:00] them into each other.

And when you smash them into each other at that very high energies or speeds very close to the speed of light, you get a scattering of lots of energy, lots of particles being produced. So you’re sort of recreating moments that are similar to the early universe, right? Very hot, very dense, lots of things happening.

And you can look at the products that come out of those collisions and see, are we making, are we making these rare particles that are maybe decaying or that we could find? And this, this led to the discovery of the Higgs boson which is this predicted part of the particle physics, the physics of atoms, and, and how everything works, subatomic particles.

But one of the expectations was, or the hope was that we would detect some of these weekly interacting massive particles or WIMPs that would explain the dark matter. Unfortunately, as time has progressed, the allowed region of like how massive the particles are and how weekly they’re going to interact, sort of [00:42:00] is becoming harder and harder for dark matter if it exists in those kinds of particles to be hiding.

Because we’ve been smashing together, we’ve been, we’ve been doing the experiments that would have found a lot of these weekly interacting massive particles, which is why we sort of cut to astronomy, because astronomy, unlike a particle accelerator, is able to detect only kind of gravitational effects and maybe sometimes gravitational waves, et cetera.

But we have this huge canvas of the sky, and so we’re sensitive to different scales. And some theorists have suggested, okay, if, if it isn’t one of these weekly interacting massive particles, could it be an axion? But now your original question was, why is it not black holes? And the problem is, if you make enough dark matter out of black holes to match the kinds of densities that we know we need to see, you just have so many black holes that there’s just, there just too many of them. But I would say that there are still folks who think maybe there were really big, massive black holes really early on in the universe.

And so those folks still [00:43:00] predict like, these are the kinds of signals we should see from gravitational wave detectors, et cetera. So all of those theories continue to kind of move around, but the simplest thing we could have written down doesn’t seem to be happening. And so that’s why one of the alternatives that has been proposed is these axions.

So tell us more about the axion. Yeah, so the axion, it has a strange name and that actually comes from, it has an origin that isn’t directly related to dark matter studies. I study a very particular kind of axion that can solve cosmology problems, but it’s a theoretical s scaler field, which I’ll explain what that is in a second.

That was proposed to solve a kind of particle physics problem of symmetries Now. The word s scaler field is always pretty scary because it, it’s hard to understand what it is, but a nice analogy and it’s good ’cause we’re sitting in a room in the middle of summer in, in South Africa. So the word scalor just means that I only need to give you one.

Property to describe the particle fully. In this case, its value, right? If we think of temperature, [00:44:00] I just need to tell you the value of the temperature, numerical value, and you know what the temperature is, as opposed to like a vector. I need to tell you the speed of the particle and in which direction it’s moving.

But a scaler, I only need to tell you one thing, one number, and then it’s a field because in this room that we’re sitting in, I could record the temperature at each position in 3D space. So around me, above me, below me, and that defines the kind of 3D temperature in a 3D lattice in this room. Now we think about that scale, a field concept, but instead of having an A temperature, we talk about the kind of expectation value or the mass or the energy of the particle.

And so the axion is a field like that in 3D space that has different properties. Now, the cool thing. Is that the axions are ultra ultra light. So when we measure things in, like humans, we measure kilograms. When we eventually get down to very, very small particles, we don’t measure them in in grams or kilograms anymore because you just have like zero with a ton of [00:45:00] decimal places.

We start to measure them in units of electron volt. Mm. And the electron volt comes from the connection between mass and energy. And so e equals mc square, the equation that everybody knows, tells you the connection between energy and mass. And so I can actually start talking about the like energy unit of a field or a tiny particle instead of grams because I know this conversion.

And so the axions are super, super, super, super light. They’re 10 to the minus 22 electron volts, which is basically vanishingly small. But the key thing is that these fields, they kind of act like. Quantum particles on a macroscopic scale, which sounds crazy because, you know, I just said earlier, quantum is when you zoom, zoom, zoom, zoom in.

But the key thing to take away from an axion is it stops a galaxy from clumping in the normal way because it sort of has like a, a pressure that we normally associate with quantum pressure, but it’s kind of macroscopic manifestation. So these axions as a field, they kind of like, [00:46:00] if you go to a party and there’s someone that has a very big dress on, you can’t actually get close to whisper in their ear.

Mm. They’re just sort of blocking you. And so axion kind of do that. They suppress the clumping of things on a certain scale and normally those scales would be very small, but in axions they’re big enough that they actually affect how galaxies clump together. And so that’s what makes us able to see them.

Whereas other wimps may not have the same impact and so they could hide from us basically.

Wow. I think my mind just blew. So first of all, I now know what a s scaler field is, so thank you, Renée. That’s exciting. And couple of questions. So the axions, they are bigger than electrons. They’re much, much, much lighter than electrons.

Much, much, much lighter. Okay. So they’re much lighter and we’ve. Never detected one, right?

No. So the, so the axions, well, first of all, the axions are predicted to be in a range of masses because they haven’t, you’re right, they haven’t been detected. I should [00:47:00] note, as a shout out to all people who are interested in detections of particles, they are these really cool experiments to try and detect axions directly.

So. We talk about direct detection or indirect detection, astronomy observations are indirect detection. So in other words, I’m claiming or or suggesting that the axion is changing a galaxy. And so I look for it by looking for those changes in the galaxy. But direct detection is like, can I see a particle being produced?

So like those kalli experiments or like direct detection, the axions. So I told you that dark matter is weekly interacting with light. What we mean is that I say that it’s semi invisible because it does interact a little bit. And the axions have this cool property that if they are around a very strong magnetic field, they do interact with light.

And in fact, photons can become axions and axions can become photons. And so there are these experiments called light shining through a wall where they have a very strong magnetic field. They shine a light at [00:48:00] a wall. The theory is that the photon gets turned into an axion, which is very weakly interacting.

So it can go through the wall and then the axion would turn back into a photon on the other side. So they’re basically trying to find axions by seeing if they can shine a light through a wall. It’s really cool. It’s really fun. So do we definitely know that Axions exist? We don’t know that axions exist, they still are sort of hypothetical particle.

They do solve this other un sort of semi unrelated problem in particle physics, but a lot of these experiments to detect them are still ongoing. So that’s why I think if we do detect an axion in one of these kinds of experiments, that will then help, you know, my case, my cosmological case. ’cause we, we might expect there to be axions with a bunch of different masses having lots of different axions, but they haven’t been detected yet,


Okay. The jury is still out. Wow. Alright, so this conversation could go on forever, but I better wrap it up. One last kind of area that I want to talk about is that the Vera Creen telescope that you mentioned, which is [00:49:00] being built now. So first of all, who is

Vera Rubin? So, Vera Rubin actually was an observational astronomer who pioneered studies of dark matter.

So the original worry. When people looked at galaxies and how galaxies rotated is they didn’t seem to be rotating correctly. You sort of would imagine, like if you’re on a roundabout, you sort of would imagine that they would be flung apart, but they seemed to be rotating as if they were embedded in some stuff and it was named Dark matter.

And Vera Rubin was one of the pioneers and pushing these observations and kind of nudging people to say, Hey, there’s something here. Something is behaving that isn’t just light that we can see and we need to understand it. And so the telescope was named in her honor because one of the things that we’ll study is dark energy, of course, but also it’ll study dark matter because it’s gonna make this survey of all the galaxies in the sky that we can see optically.

And that’s the LSST, isn’t it? The large sea. Survey of space and time, the Legacy, legacy Survey, survey of space and Time almost. Got it. [00:50:00] Right.

And are you going to be using that for your work? Absolutely. So I’m actually the spokesperson of one of the science collaborations that will use Ruben. So we called Dark Energy Science Collaboration, which is fun.

So I’m the chair of the Dark Energy Science Collaboration, which makes me sound like I’m some That’s awesome. Florida. Yes, I was gonna say the same, but this is an international collaboration of about a thousand people, and we are interested in a lot of different ways. You can understand dark energy with observations from Reuben.

So sometimes you can see. How galaxies are kind of wobbling and wobbling because of dark matter and dark energy. And you can use that to, to constrain those models. You can also use kind of lens transient, like Lens super Novi to find this. And so there are lots of different prongs that we’re using to observationally try to constrain dark energy.

And one of my roles as the spokesperson of the Dark Energy Science collaboration is looking at the big picture and bringing together all the different scientists to [00:51:00] answer these questions and develop pipelines. And so it’s very, very, very exciting. Mm. And also very scary because, you know, the Reen Observatory was, I knew about when I was an A student, my first paper was in predicting how well we could use some of the data.

And now we’re, you know, a few months away from the commissioning of the telescope and it’s so daunting ’cause we’ve gone from no telescope to basically on sky, which is really exciting. Wow.

So cool. The future. Almost the present is gonna be so exciting. We’ve mentioned this before as kind of like the optical revolution in astronomy that’s happening as the kind of analogy to the, the SKA and the, the revolution in radio astronomy.

That’s, that’s coming. It’s gonna be so exciting. It already is. Okay. So I would like to keep you forever, but obviously I can’t. So thank you so much for spending all of this time with us. Renée, before you go, do you have any final messages for listeners?

Yes. I think when I was starting research, I thought to myself like, the universe is too hard.

I’m never gonna understand this. But what I realized [00:52:00] is with time, the reason why this is such a fun job is that. All we do is solve puzzles day in and day out. And sometimes it’s easier and sometimes it’s harder, but for everyone who’s starting to think about science and stem and they’re worried if it’s too hard or if they’re too stupid, I would tell you, like if you’re curious and you’re passionate, keep going because the universe is this wonderful, wondrous place.

And you know, the fact that it’s hard to understand is kind of the point. Yeah. And so if you see that as the challenge and not as something holding you back, you’ll really enjoy it. Oh, that’s awesome advice. Thank you, Renée. Where can listeners find you? So they can find me on threads and also on Instagram.

I am at Renée Logic. I’m the only person with this combination of names, so it’s very easy to find me and then they can find me@Renéelogic.com. Awesome. Thanks so much, Renée. Thank you.

Dan: That was great. Thank you. Jacinta full for interviewing [00:53:00] Renée. Wonderful to hear what, what she’s been doing and you know, a very different conversation to what I had personally with her, but I’m sure what nothing but, but yeah, like, you know, as we said at the start of the show, she’s. She’s really a rock star.

She’s done some amazing stuff and across the field of astronomy. So in terms of her public engagement, her sciences is really cutting edge and some exciting things coming out of that. But then her, her lecturing and her supervision, you know, across the board, she’s really excelled and, and just wonderful to hear her speak.

She’s remarkably good at explaining concepts too. Yep. So, agreed.

Jacinta: Her analogies and, you know, I mean, I’m not a cosmologist and I very rarely understand anything that Dan or the other cosmologists talk about, but that made perfect sense.

Renee: She’s

Jacinta: absolutely brilliant. In a way, she explains things, so I really love that chat.

It was really, really awesome to talk to her.

Tshia: Yeah, and I think so much of her science communication also comes through into her teaching because, you know, she explained how she’s teaching, [00:54:00] acquired. Big class. Yeah, massive. That is a huge class. That’s crazy. I’ve actually seen the venue too while I was there.

Really? And I just could not believe they teach that many students because I’m mean at GCT. How many students do you have? Jata? Oh, I mean, I’ve got 24.

Jacinta: It’s too big for me.

Dan: I’m amazed at many students show up. Well, it’s compulsory.

Tshia: Yeah. So I think we, we see how that science, communication and science education just kind of filters into the way she does things.

Yeah. And it’s quite amazing to have. A lecturer who can actually come back into your level as a student. And you, you actually want to go to that class no matter how big it is. And even though you know that, you know the lecturer’s not gonna actually see you, you feel seen because of how she explains the concept and how she interacts with you generally.


Dan: Yeah, she gave an excellent talk at the NASP conference too. Mm. Which was also, which was also really, really impressive.

Jacinta: Yeah. Unfortunately I missed it, but I did get to chat with her, so I think there’s

Dan: a recording online so even the listeners [00:55:00] can find it. Oh, excellent. We,

Jacinta: we can link to that in our show notes.

Yeah. Actually cme. So can you tell us more about the Dunlap Institute you, you said you visited, what’s that like?

Tshia: Oh, my word. She, she actually alludes to this when she speaks about the diversity of students that she actually has. And if there was one thing that I experienced while I was there is just the amount of diversity really that exists, like.

People from everywhere in the world are just like, right, that’s wonderful there in Toronto. That’s so cool. And it, it was quite awesome being there. Some of the masters and honor students had just developed some card game, which it’s almost like, not Pictionary, but something similar to Pictionary, where you have this card game with different concepts and you try to put them together to explain to the other people what kind of image you have.

Renee: Mm-Hmm.

Tshia: And so they, they do. And make all of these development just to make science more interesting and engaging for the public. So that was really cool. What else did I see? I mean, it was a year ago [00:56:00] now since I was there, but it was, it was a lot to do and I was only there for a week and I quite enjoyed myself.

I quite enjoy myself. Yeah. Nice. It wasn’t cold at the time. No, it wasn’t. No. Oh, I’m so glad it wasn’t cold because, oh gosh. I can’t even imagine. I would never, I would never, I would never, it wasn’t that cold. It was just. Spring. Yeah, so it was just there when spring was starting out. So it was a bit long, slightly above zero.

I still had like a pollac on, so I still had a pollac on, although the sun was out. I was just not gonna, I’m so South African that I do not play at all the,

so just since how long have you been in South Africa?

Dan: I think I know where this is going.

Jacinta: Oh, I think it’s five and a half years now. Why and how have United ours? Well,

Dan: well, because she’s more than 12, right.

Jacinta: I feel like this is not on me. I feel like this is on my South African friends and colleagues.

Not, we are all more [00:57:00] than

Dan: 12 too. I mean, no, I’ve never even heard of it. Renée is, is not wrong. You know, it’s, it’s like, it’s a children’s drink. It’s a, you know, I don’t even know. It’s just sugar essentially. And some, yeah, it’s true. Some orange coloring. Okay. But

Tshia: Al is a hack. There’s a hack to a nice, so you pour a bit of No.

Oh, sorry. There we, Daniel, the convention, but like you pour a little bit of a and sparkling water. Oh, taste amazing. Alright. Okay. Good to know. So I’m not 12 anymore, but I, you know, sometimes I do Can cup

Jacinta: take

Tshia: a cocktails?

Jacinta: Interesting. There we go. So do you guys know the, the jingle that she sang?

Dan: You know, I wouldn’t, if you had asked me in a quiz night, I would never have been able to pull that out of my head.

But the moment she started singing it, yeah, it came flooding back.

Tshia: So that is the, the jingle of like pre eighties Oh, the ancient jingle. This is the eighties.

Dan: We were talking about the,

Tshia: because I know a totally different jingle from the nineties. Yeah. When, [00:58:00] when Aris was introducing the, the other flavors.

So the Aris is an orange flavored drink. Yeah. But then like somewhere in the 2000, then it has different flavors. So then they had another jingle for the different

Dan: flavors. Go on,

Tshia: come on. No, no, but it goes like, okay, I’m gonna sing it. Yeah. So it goes Mango. So the mango is the other one.

Dan: Okay.

Tshia: And then like, so it was as if the Aous man, so there’s an Aous man as well.

Of course there’s a, the aous man. Okay. So

Dan: if for for international listeners, he essentially looks like the Michelin man.

Renee: Oh yeah, he does. I, I’m looking at a picture of him right now. Okay.

Dan: We don’t, we, it’s, it’s not confirmed. Two came first, or if they the same person. Oh.

Tshia: And then it’s, he’s playing marimba, you know, marimba.


Jacinta: do. It’s like the, it’s like the, what would you call it? Kind of like the wooden xylophone, but the A African version. Mm. Yeah.

Tshia: And then those are the flavors. So of the S Okay. So every single time the S man,

Dan: this is coming back, there’s one of

Tshia: them. Then you can see, you know, manga [00:59:00] Lemon Manga. Art at Eva, the thing and then goes Oh, oh, oh, oh Ros.


Dan: we’ve still got the O Ros.

Tshia: Yeah, you get the O

Jacinta: applause. I loved it.

Dan: Good digression. Okay. Anyway, so this is a podcast about science and so probably sponsored

Jacinta: by Aros. Im joking.

Dan: The end of the heat, death of the university. There’ll still be a bottle of error.

Jacinta: Well, it’s plastics will last forever. Right. Charming.

Dan: Be and inside and out.

Jacinta: Probably not sponsored by OS I guess. Nope, not at all. Okay. Anyway, I did think it was getting back to science just for the end here. I thought it was really interesting how she was explaining all about the different candidates for dark matter and particularly the axion because you know, I, I, I guess I’ve been talking about the axion.

I sort of know what it is, but I didn’t really know what it, what it was. And I thought it was awesome how she was talking about [01:00:00] the, like, one of the experiments to detect it is like shining light through a wall. Mm-Hmm. Yeah. That’s really cool.

Dan: Yeah. I thank you once again just for that interview before we wrap up a quick round the room.

Jacinta: Yeah. Okay. Well Dan, how are you? I know that you are going on a big holiday soon. Mm-Hmm. I’m

Dan: going on a big holiday. I’ve got a two and a half weeks off. I’m going to a different continent. I’m not taking my laptop. So vacation responder on, can we know which continent? That sounds awesome. Yeah. I’m going to South America.

I’m going to Argentina. Wow. So, yeah, taking the family should be fun and yeah, exciting. So looking. No, that is exciting. Looking forward to that. Exciting. And hopefully I’ll come back refreshed and renewed and excited. Wow.

Jacinta: Traveling. Not for work. That’s exciting. Can you believe it? Oh no, I can’t.

Dan: Me neither.

Really? Well,

Jacinta: you have to pay for your own flight. Oh, well

Dan: yes,

Tshia: I

Dan: believe that.

Tshia: Yeah. I hope you really enjoy your break and Thank you. We look forward to hearing about it on the podcast. Yeah. And seeing some photos, hopefully, and

Jacinta: see

Tshia: me soon. Ooh, [01:01:00] nothing is happening from myself. But that’s good because you’re, that’s a good thing.

You’re usually overwhelmed and overworked. So yeah. But I think it’s really just the same things right at the moment. So the call for the teacher training program is out, so I coordinate that whole program. So finally the call is out. So we hope that people who are really interested in, especially astronomyists, interested in going back into teacher development programs and making sure that, you know, the science is accurate, the astronomyists accurate that teachers actually teach.

Renee: Mm.

Tshia: So that is kind of the main thing that I had to make sure that it goes out. So everything has been out the press release, all of

Jacinta: that. Well done. So is this a training program for teachers? Mm.

Tshia: Yeah. Yeah. But it is organized, you know, in collaboration with an astronomer, a national astronomy education coordinator.

So each country has one of those

Renee: Mm-Hmm.

Tshia: And a teacher because I think the model is, is [01:02:00] quite important to teacher development programs. Mm. Because while astronomyists have the knowledge of astronomy, they do not necessarily have the knowledge of teaching. And sometimes we need the teachers who have the knowledge of teaching to Right.

To kind of bring the two together and ensuring that it is actually a good program that teachers can actually take forward into their classrooms. Oh, cool. So that is open and applications closed, I think on the 15th of April. So yeah. astronomers who might listen and you’re interested, please do.

Dan: Oh, wow.

Cool. Yeah. How many teachers are you planning to hit?

Tshia: So we are running it from the I-A-U-O-A-E. Mm-Hmm. So International, national, astronomyical Union offers of astronomy for education. Education. Okay. So we have at least about 36,000 euros and we will allocate this to Okay. The number of proposals we get basically.

Cool. So in the previous years we’ve, last year we supported like 22 projects in 2021, about 23 [01:03:00] projects. Okay. So it’s so globally. Yeah.

Jacinta: Wow. So it’s for teachers teaching them how to teach astronomy and also astronomyists, teaching them how to teach. So

Tshia: it’s like a, a collaboration between the astronomer, the teacher, and the national astronomy education coordinator.

Because the thing is teachers want to teach astronomy, but they’re always not confident in how to teach astronomy. But so while this is about, well, astronomyists at the center of the teacher trainings, I think it’s important to highlight something that then mentioned earlier on that although there are many people who have gone through NASP doing master’s, Honours, and PhDs, not all of them are actually in astronomy right now, showing the multidisciplinary nature that astronomy is.

Renee: Mm-Hmm.

Tshia: And so we are hoping that through this training, the teachers are inspired to teach certain concepts in mathematics and physics using astronomy as a, as a tool. Oh, awesome. Basically. Cool. Yeah, because

Jacinta: astronomy’s interesting. And it makes everything

Tshia: more interesting. Yeah. And it is. It is really, I [01:04:00] think this is for me and quite biased, it is more than a hobby of just looking at stars.

Dan: Hmm. Yeah. Absolutely.

Tshia: astronomy is more than stars. Yeah. Galaxies

Dan: and dog matter. And dog energy. Yeah.

And you Jacinta, how are you?

Jacinta: Yeah, I’m good. You know, things took a little bit of a step back. Sort of two weeks of unplanned, so kind of sick leave, but that’s okay. And before that, things were quite crazy ’cause we had a series of conferences related to the Meir Cat telescope. So it was Meia Kat’s fifth birthday.

So we had a special conference called Mia Cat at five, where astronomers from all over the world, about 200 astronomers were 250 I think even astronomers and, and astronomy students. I met together in Stellenbosch, which is a beautiful kind of little town, about an hour away from Cape Town. I. Yeah. And we had a very intense week of, you know, hearing all about meerkat’s biggest discoveries from pulsars to fast radio bursts to [01:05:00] galaxy evolution and a whole bunch of different things.

And even searching for extra terrestrial intelligence. The breakthrough listen. Yeah. Team were there. So that was really cool. Very, very varied. And then after that there were two other conferences, or three other conferences, I think in the same venue about astronomy. And I went to two of them. One was modeling Meca two which is run by, well actually Dan’s your previous postdoc for advisor.

I went to modeling MCA one. You did? Yeah. I organized and we did an episode from there. Actually, that’s where we I dunno if you remember back in season. Woo. Two must have been one or two. Yeah. Yeah. We’re almost

Dan: as old as Meka

Jacinta: almost. Yeah, actually, yeah. Yeah. Actually we’re the podcast. Yeah. So we, we had a episode back then of like you and I going for Game Drive in the Kruger.

That was very cool at you. Yeah. Nice. Yeah. These are the adventures you get to go on. And our and our guard was

Dan: an amateur astronomer. Yes. That was cool. And then he turned around and started talking about the stars. Didn’t realize there were 16 astronomers. Yeah. Was now talking to, [01:06:00]

Jacinta: but to be fair, but it was amazing.

Yeah. We didn’t know any of the things that he was saying. astronomers.

Dan: astronomers are notoriously bad at stargazing. Yes. Yeah.

Jacinta: So we’ll put a link to that in the show notes. I don’t actually remember off the top of my head what episode number that it was. Yeah. Was a great one though. I feel like it was episode 11, but I’m not sure.

Goodness’s me. No,

Renee: you’re guessing.

Jacinta: Yeah. And so this was kind of like the. Second version of that conference, not as an exciting location, but still pretty cool. So that was really cool, like trying to look at how simulations of the universe and galaxies are comparing to observations. So getting both observational astronomers and simulators in the room together.

And then another meeting collaborations between the Meca telescope and Lofa, which is a, a radio telescope in the Netherlands. And kind of which stretches across all of Europe. And I actually helped to build one of the stations in the UK when I was a PhD student at Oxford, actually same year that I met Rene.

So full circle. And now just focusing on research, which is nice, having a little break from all the other duties and doing [01:07:00] some research with my students. So, yeah. That is exciting.

Tshia: Yeah, just having time for research. Yes. Dan, when was the last time.

Dan: More than five years ago.

Jacinta: Oh, cool. All right. I think we’ve prattled on for long enough, so let’s wrap it up there. Thank you everyone for listening, and we hope you’ll join us for the next episode of the Cosmic Savanna.

Dan: You can visit our website, the cosmic savannah.com, where we’ll have the transcript, links, pictures, and other stuff related to today’s episode.

Tshia: You can follow us on X Facebook and Instagram at cosmic savanna. That’s savanna spelled S-A-V-A-N-N-A-H. You can also find us on YouTube where audio only episodes are uploaded with those captions which can be auto translated into many different languages, including Afrikaans and ulu. Special

Jacinta: thanks today to Associate Professor Renée Ekk for speaking with us.

Thanks to our new podcast manager, Francois Kfa. Our social media manager, Sumie Hatting, and our audio editor Jacob, fine.

Dan: Also to [01:08:00] mark all that for music production. Miha, we check for photography. Carl Jones for Astro Photography. Susie Car for graphic design. Thanks to Emil Mankey for video creation. Moses Mungo and Abigail Tamran for transcription.

Tshia: We gratefully acknowledge the support from the South African National Research Foundation, the Square Kilometer Rail Observatory, the South African Agency for Science and Technology Advancement, the South African astronomyical Observatory and the University of Cape Town astronomy department.

Jacinta: You can subscribe on Apple Podcasts, Spotify, or wherever you get your podcasts and we’d really appreciate it if you could rate and review us and recommend us to a friend.

Dan: We’ll speak to you next time in the cosmic Savannah.

Tshia: Oh, good

Jacinta: salad.

Dan: Where do we go from here?

Jacinta: I thought I just said I was gonna ask something else, but I was, and I, I drew a blank.