Episode 14: Modeling Meerkats!

with Prof Romeel Dave, Prof Lerothodi Leeuw and Nicole Thomas

Welcome to Season 2 of The Cosmic Savannah!

This week we recap what we have been up to during the season break, including an exciting trip to the Kruger National Park in South Africa! We were in Kruger for a workshop to discuss how best to combine simulations and observations in astronomy.

We caught up with the organiser Prof Romeel Dave from the Royal Observatory Edinburgh and Episode 8. As well as Nicole Thomas from the University of the Western Cape and Episode 9. We got to see how they are doing and what the workshop aimed to achieve. Nicole also discusses her exciting trip to the 2019 Lindau Nobel Laureate Meeting!

We’re also joined by Prof Lerothodi Leeuw from the University of South Africa. Lerothodi talks with us about the challenging interface between theory and observations.

Finally, we also get to do some game viewing in the incredible 2 million hectare Kruger National Park!

This week’s guests:

Related Links:
Romeel’s Quora Profile: https://www.quora.com/profile/Romeel-Dav%C3%A9
UWC: http://astro.uwc.ac.za/
Royal Observatory Edinburgh: https://www.roe.ac.uk/
MeerKAT: https://www.ska.ac.za/science-engineering/meerkat/about-meerkat/
UNISA: https://www.unisa.ac.za/

Featured Image: Modeling Meerkats, a tessellation of the SARAO/MeerKAT image of the galactic centre

 

Transcript

Dan: [00:00:00] Welcome to The Cosmic Savannah with Dr. Daniel Cunnama

Jacinta: [00:00:08] and Dr. Jacinta Delhaize. Each episode we’ll be giving you a behind the scenes look at world-class astronomy and astrophysics happening under African skies.

Dan: [00:00:17] Let us introduce you to the people involved, the technology we use, the exciting work we do, and the fascinating discoveries we make.

Jacinta: [00:00:24] Sit back and relax as we take you on a safari through the skies.

Welcome back everyone.

Dan: [00:00:36] Yeah. Season two, episode 14, we made it back into the studio.

Jacinta: [00:00:40] We did. I’ve forgotten how to do this.

Dan: [00:00:42] me too

Jacinta: [00:00:43] Okay. All right. Well, before we start this episode, we have a small request for you our listeners. If you enjoy this podcast, we’d really appreciate it if you could leave us a review in iTunes, that’ll really help us reach other listeners who might also be interested.

Dan: [00:01:00] Thank you.

Jacinta: [00:01:02] Okay. On with the episode, yeah. Well, I guess we will start by telling you what we’ve been doing during our break, during our hiatus,

Dan: [00:01:09] a break from the podcast, but not from work.

Jacinta: [00:01:12] No, a lot of work. That’s why we took the break.

Dan: [00:01:14] Although we did do some travel.

Jacinta: [00:01:16] We did do some pretty awesome travel.

Yeah. All right, Dan. So tell us what have you been up to.

Dan: [00:01:21] Ah, what have I been up to? Well, we’ll talk a little bit more about our trip to Kruger. We’ve both been to a conference there and we’ll have some interviews from that, but I also took a trip to Europe. I visited Italy and I spent some time in Rome and at the Vatican observatory, and we’ll have more on that in a later episode.

 

Jacinta: [00:01:42] So, well, I went all over the place. I also went to Europe. After our Kruger conference, I went to the  University of Oxford where I was working with members of the MIGHTEE team, and we’re going to hear all about MIGHTEE today. It’s one of the MeerKAT survey projects. So it’s a big galaxy evolution survey with MeerKAT.

Dan: [00:02:06] Do you know what it stands for?

Jacinta: [00:02:07] Oh, okay. Let me, let me, let me try… No.

Dan: [00:02:13] Hahaha

Jacinta: [00:02:15] I think it’s the…

Dan: [00:02:16] MeerKAT intergalactic…

Jacinta: [00:02:18] Oh, yeah, yeah, yeah. Right. Oh, wait, wait, wait. I do know the MeerKAT International Giga-hertz Tiered Extra Galactic Exploration.

Dan: [00:02:32] Boom, I hope its right

Jacinta: [00:02:33] I hope its right too, yes. Okay. So I was working with members of my team and we were sort of having a little mini, what do you call it?

Busy week, busy week. Yeah. It was a busy week where we all sit together and we work on the data and we get everything started. And that was really useful because the following week was the, I don’t, I’m not sure how to pronounce it, but MIAPP- M I A P P a center of excellence conference or meeting in Munich in Germany.

So that was altogether a four-week workshop where all experts, all of the world’s experts in neutral hydrogen gas studies were there and talking about science and working together and collaborating. So I attended that and it was actually really useful. I wasn’t quite sure before I went how useful it was going to be.

I was there for two weeks, but actually it was a really good format. Because we, we could have some talks in the morning. So we knew what each other were working on and then we had the whole afternoon free to just work together and collaborate and that was extremely useful for me. So I got a lot of work done.

I got, I got a lot of projects started and yeah, that’s what I’m working on now.

Dan: [00:03:44] Yeah. Those busy weeks are wonderful for sort of focusing on something, getting a break from all of the administration and day to day stuff.

Jacinta: [00:03:53] Yeah. I guess it’s just getting away from your desk and as great as it is, people asking you to do things and other, you know, departmental chores and just focusing on, on that pure research for two weeks.

Yeah. It was really good. And then, I came on home.

Dan: [00:04:07] Lovely. Welcome back.

Jacinta: [00:04:09] Thank you. Yeah. So today’s episode is actually about the first part of our trip, which is where we went to the Kruger National Park in South Africa and well Dan, you were running a conference there. Tell us about that.

Dan: [00:04:24] Yeah, so I organized the conference with my previous supervisor who we had previously on the show.

Jacinta: [00:04:32] Yeah. Episode eight

Dan: [00:04:34] Yeah, well remembered. And so we organized a kind of workshop to, with some talks and basically bringing a whole lot of people together from two different fields. So the simulation field, which is my field in terms of working on the theory and creating galaxies and, and then the observational field,

Jacinta: [00:04:55] which is my field.

Dan: [00:04:56] So, which is why we both attended. So we brought together these two different fields and we spent a week trying to talk about how we could best work together, so how the observations could help inform the simulations and vice versa, and how we can do better simulations and try and reach out to the observers and try and produce the things that we can easily compare.

It’s not an easy task.

Jacinta: [00:05:18] do you think we made some progress during the conference?

Dan: [00:05:20] I think so. I think there were some interesting discussions and some potential project ideas which came out of it. There were definitely some collaborations formed. It’s always good to meet some people you haven’t met before who are working in a similar field and some of their problems and just having those connections.

Somebody you can email when you have an idea, when you want to do something, you know who the expert is that you can email.

Jacinta: [00:05:42] Yeah, I guess that’s, that’s actually one of the most important parts of having a conference. It’s sort of why we have them. I spoke about the MIGHTEE survey that I mentioned earlier, and in particular, I’m looking at the data and there’s a particular galaxy I found or that we found that’s really interesting, but I don’t think I’m allowed to talk more about it yet.

Dan: [00:06:05] When is it getting published?

Jacinta: [00:06:06] when I publish it…

Dan: [00:06:07] back to work!

Jacinta: [00:06:09] don’t ask that question. And what, what do you think was the most important thing that we talked about?

Dan: [00:06:15] I think talking about the future, I think that a couple of people Romeel and others, Professor Jarvis who was there- Matt Jarvis.

There was a lot of talk about what’s going to happen now that MeerKAT is running and the SKA is on the way. For the last 10 years or so there’s been a lot of these sorts of workshops talking about how we can best work together, but now we really are getting data. MeerKAT has been running for over a year.

There’s a lot of data coming through, you know, observations such as yours and we’re learning a lot. It’s the most powerful radio telescope- we’re discovering things we’ve never discovered before and there really is a real opportunity to try and learn something, which can then inform simulations and push the simulations to try and do better, to try and explain some of the things which we are observing.

So I think that it’s a pretty golden time and I think that the excitement for this and for the future was wonderful to see.

Jacinta: [00:07:14] Yeah. I guess Matt and I were the only two who had actual MeerKAT data to show and I didn’t realize that until I got there. So actually it was quite an exciting role for me to play as… “Hi simulators, I don’t know any of the words you’re using, but here is what the data looks like, so let’s try and do something together. “

Dan: [00:07:30] Yeah and the simulators are like: Whoa, how did that happen? Okay, let me go back to my computer.

Jacinta: [00:07:37] Yeah. So, well we spoke to Romeel again when we were at the conference and he explained why we were running this and from his point of view. So shall we have a listen to what he has to say?

Dan: [00:07:41] Yeah, great.

Jacinta: [00:07:45] So we’re here at the Protea hotel on the outskirts of the Kruger Safari park and we’re here. Why are we here Dan?

Dan: [00:08:07] to do work?

Jacinta: [00:08:09] Are we?

Dan: [00:08:10] Well we’re here for a conference, the modeling MeerKATs conference and we’re talking about observations and simulations and how we can merge the two.

Jacinta: [00:08:21] And with us we have the organizer of the conference. Well, Dan is one of the organizers and we have the other one and you might recognize him from episode eight. It’s Professor Romeel Dave, welcome Romeel!

Romeel: [00:08:26] Yeah, it’s me again.

Jacinta: [00:08:21] So Romeel, why are we here and what are we doing and why did you create this conference?​

Romeel: [00:08:40] So as hopefully many of you know, the MeerKAT telescope is now online. It’s the largest science project ever done in South Africa and the MeerKAT telescope is of course a radio telescope. It’s gonna open up new windows into our view of the universe and one of the things that we’d like to be able to do is to take all that data and understand the physics of the objects out in the sky, the stars, galaxies, all the crazy things that are happening. The pulsars, the black holes, all these sorts of things. And these are all going to be probed in the radio using MeerKAT. Now at the same time, what we’d like to do is provide a context for all this stuff, all these data that we’re gonna have and we’d like to assemble it into a coherent picture of how it is these objects formed.

Where do these big giant black holes at the centers of galaxies come from? How does a supernovae, you know, shock heat up the gas and create the synchrotron emission that we can see as radio observations. And this is the job of us simulators, right? This is what we do as modelers, we try to take numerical simulations starting with the conditions shortly after the Big Bang and produce the kind of objects that we’re seeing in the real universe. And because now we have this new window on what the various phenomena are through the radio telescopes like MeerKAT, we’d like to be able to incorporate that information and inform our models of the universe and how things, how the universe is formed, and how we came to be.

Dan: [00:10:16] Why do we have these conferences and who, who comes, I mean, like, who do we have here?

Romeel: [00:10:21] So we have about 25 people in this particular meeting and it’s a relatively small group, but it’s a very focused group of people who work particularly. I said, these are scientists, everyone from we have, I think we have a MSc student all the way up to, you know, somewhat senior professors and we’re essentially trying to build a community who will be able to use models and observations together to try to understand the underlying physics of the things that’s going on. And so I think, these are, we have both a lot of simulators from South Africa as well as from various other places around the world. We have observers, people who are going to be using MeerKAT, but who are interested in talking to the simulators to try to, and the modelers to try to understand you know, how their data can be better used or better situated within the overall the picture of how we have of how galaxies form. So these are the kind of people that we’re trying to build a fledgling community here now that the data is kind of starting to come in- we want to have a community here in South Africa that’s also doing these sorts of things and synthesizing this information into sort of, the overall grand picture basically.

Dan: [00:11:39] And hopefully we get some sort of firm collaborations forming out of this.

Romeel: [00:11:42] That’s the idea. I mean, ideally what I would like to have coming out of this meeting would be a several definitive projects on the various ways that we can use simulations to help with particularly the so called MeerKAT Large Survey Projects. So the Large Survey Projects are a set of essentially things that were competitively decided to be occupying the majority of MeerKAT’s time in its first five years.

We’re doing these sort of mega projects that would be very influential and very high profile to sort of set the MeerKAT apart as this fantastic new radio telescope here in South Africa that’s doing all these amazing things. So we again, we want to have a modeling component to those large survey projects that then allows us to interpret that data better and to do more stuff here in South Africa rather than, you know, just simply exporting the data and letting other people sort of take advantage of all the great things that we’re doing down here.

Jacinta: [00:12:42] Well thanks so much to both of you for organizing this. As an observer, it’s a bit of a steep learning curve to be at my first simulations conference, but I think it’s definitely worthwhile because it’s really important for us to bring simulations and observations together.

So thanks very much and I guess our session’s starting now, so we better head back in.

Romeel:[00:13:15] Thanks Jacinta

Jacinta: [00:13:18] So Dan, what I got out of the meeting was actually realizing that it’s not easy to compare observations and simulations. Somehow I thought that you know, the output of the simulation would just be, you know, you get the output and then you directly compare it to an observation. But that’s not actually actually how it works.

Dan: [00:13:28] No, it really isn’t. So the simulations certainly don’t have the same resolution as real life. We don’t resolve individual atoms. Which makes us very, it makes it very hard to compare exactly.

Jacinta: [00:13:40] How dare you not resolve individual atoms?

Dan: [00:13:41] Its coming! And the same goes for photons, right?

We don’t resolve all of the physics that goes into light, so we don’t we don’t include the path the light’s taken how what it’s interacted with on the way so to try and compare it to an observation which is this complex thing. A photon of light has traveled for billions of billions of large years and encountered a lot of different things along the way and changed. To try and account for that in a simulation is very, very difficult. So we have to make approximations and then try and reduce the observations to something we can compare, some sort of measurable which we can compare to a simulation where we have that measurable also. So, you know, we can do masses quite easily using the observations and the simulations, but to try and do more complex things is, it’s difficult.

Jacinta: [00:14:39] Yeah. And I guess you’re simulating kind of fundamental properties like masses and we can’t directly measure a mass. We can directly measure the amount of light that comes out and the rotation properties of objects in the galaxies and then from that, we have to estimate the masses. So yeah, it’s sort of, it’s comparing the same thing, but with an extra level of translational calculation on top of that.

Dan: [00:15:05] It’s like you’re looking from the outside and we are looking from the inside.

Jacinta: [00:15:08] Yeah, exactly. Yeah, that’s a great way to, to describe it. I also spoke to professor Lerothodi Leeuw at the conference and he was telling me about the dust component of galaxies and how he’s interested in looking at how to include dust into simulations because dust is really easy for us to observe. Sometimes it’s even annoying, but, uh, but it’s actually quite difficult to put into the simulation. So he’s interested to see kind of what impact that would have.

And that might help us to compare the simulations and the observations because what you get out of a simulation of stars, for example, may not be what we’re going to see because we’re gonna see stars blocked by dust and so if you can put the dust into the simulation then you can see how the dust blocks the stars, the simulated starlight, how it reddens it, how it scatters it and then maybe it’ll be easier to compare to observations. Would you agree with that?

Dan: Yeah.

Jacinta: So let’s hear what Lerothodi had to say on the topic.

I’m here at the modeling MeerKATs conference in the Kruger National Park and I’m here with professor Lerothodi Leeuw. Welcome Lerothodi.

Lerothodi: Hello. Thank you.

Jacinta: Can you tell us who you are, where you’re from, and what you do?

Lerothodi: [00:16:30] I’m Lerothodi Leeuw and I work for the university of South Africa as an astronomer. I started my career observing dust in galaxies, and at this particular meeting, I’m here because I started working in this new area, which is the interface really between observations and modeling.

Jacinta:  So we’ve talked before on this podcast about simulations, and we’ve talked about observations.

So you’re starting to work at the interface of the two of those, where those two come together. Why is that? Why is that important?

Lerothodi: It’s really important because in both observations and simulations, people tend to work on what’s easiest first and you know what will make a impact for them fastest, right?

This is like this concept of the low hanging fruit everybody usually goes for, but what is in simulations is not necessarily what’s easy in observations and the intersection of these low hanging fruits for the two communities is not always the same and so I think being able to actually find out how these two groups can find synergies is important.

Jacinta:  okay, so tell us more about your particular research. What are you doing?

Lerothodi:  So I mentioned dust. Dust is actually something familiar to a lot of us because observationally, it’s one of these low hanging fruit in terms of its impact and an example of this is the Milky way. If you’re in an area that has really, really dark skies where you can see the Milky Way in its beauty, you will notice that amongst the Milky way this path of stars, there are dark patches and where these dark patches are, it’s actually where the dust obscures stellar light from the Milkyway because the Milkyway itself is this disc galaxy.

So this path, the Milky way should be all just the concentration of stars. In reality, when we look at it, we don’t just find this big concentration. We find these dark patches and this is the cosmic dust that I work on and it’s actually apparent to the naked eye itself. However, physically understanding the properties of this dust isn’t so easy because its composition, its nature is quite different from that of the stars and so observationally its this simple thing that can be picked up, but it’s also this thing that has a huge impact on stellar light, right? You know, it would block it out or absorb it or even scatter it. Now, modeling, a lot of the simulations will leave the dust part out in their work because it’s a harder thing to simulate.

So this has taken my interest now, as in, you know, join the community working in this interface, particularly the community trying to solve that particular problem- where we try and introduce the effects of the dust into the simulations and then produce these mock images of the simulations that can be compared with the observations better.

Jacinta: Okay. So when we make a simulation of the universe, of galaxies, we have to put a lot of different ingredients into the recipe that we use to make the galaxy. So you’re saying that stars are already one of the ingredients and now we’re trying to work to put an extra ingredient in, which is dust, is that correct?

Lerothodi: Yes, that is exactly correct.

Jacinta: Okay, so, now you mentioned that dust in blocks the star light so that we can’t see it, but what other role does it play in a galaxy? Why is it so important for us to include this into the simulations?

Lerothodi:  Well, it turns out that dust is also responsible for the formation of the stars themselves.

So there’s quite a big role there and indeed, I mentioned at the beginning the dust in the Milky way where you see those patches is actually where the new stars would be forming. So indeed, dust is a really, really critical aspect in the evolution of galaxies in this way, It turns out that the stars themselves also refine that dust to more evolved material.

So you’ve probably heard of the phrase we are made from, by the stars or from dust. Dust also has this big fundamental aspect in terms of the evolution and in this case I’m just talking about solving the problem of the effect of dust on stellar light in these simulations or work.

Jacinta:  Yeah, so I mean, making these simulations is super complicated because what are we trying to do? We’re trying to recreate the universe with all of its complex aspects and components which is just insane. And it’s amazing that our simulations can even reproduce some of the things that we observe in the universe.

Not all, but, but some and quite a good, good part of it. So, the reason the simulations work is because the vast majority of our universe is actually stuff we can’t see dark energy and indeed dark matter and we think we’ve got that pretty much right, right enough that we can reproduce galaxies and so even though we’re trying to go to more and more complicated stages where we’re including baryonic matter- meaning stuff like stars, gas, and in the future dust- it almost doesn’t matter on the larger scales to study the bulk of the physics. It matters when we’re trying to reproduce more complicated, higher level stuff, but as you said, we’ve picked the low hanging fruit first. They’re the easiest things to reproduce and they’re the most important things to reproduce. Would that be an accurate, summary?

Lerothodi: Yeah, that’s an accurate summary. So for example, where the simulations are having trouble is in what we call morphology of galaxies, or basically how galaxies look when we observe them.

Like that means things like those spiral arms and this thing I called patches of dust. Exactly how, you know, you see it in the Milky way, how it should appear in all these different galaxies. So when you start to go to such details, this is where, you know, the simulations don’t work well at the moment and that’s where the kind of work I’m talking about comes in. If you start to really want to look at those finer details, then you really need to be doing this.

Jacinta: Yeah. I think this work is really important. Unfortunately, we don’t have more time to discuss it cause our session is about to start and we mustn’t miss it.

But, is there any last messages you’d like to share with our listeners?

Lerothodi: Just that it’s good actually to try these different aspects of research and I mean, it’s been great for me to do something I haven’t done at all before in my career as an astronomer. So, it’s just nice that actually one can envolve in this way, even in their own career and I like that and I encourage everyone as well to look at how they can evolve in their own lives or careers.

Jacinta: That’s really wonderful. Thank you so much for speaking with us today Lerothodi.  

Lerothodi: Thank you and thanks for having me.

Jacinta: So Dan, what is it about the dust that makes it difficult to put it in the simulations?

Dan: [00:24:01] So generally the dust is a result of staff formation dying stars sort of getting distributed throughout the galaxy but it’s essentially a gas, so it’s a very small particles spread throughout the galaxy.

Certainly not resolved with our simulations, but also we don’t really know the strength that stars blow out winds, that supernova blow out wins and how far this dust should be traveling, how much of it is formed in terms of a simulation, it’s really hard to try and reproduce what’s observed in terms of the amount of dust we see.

So as Lerothodi said, the Milky way is beautiful especially on a very dark, if you look at the at the center, you can see the dust which is blocking the stars at the center of the galaxy. You can see it with your own eyes. To reproduce that in a simulation is incredibly complex.

The amount of detail that is in that dust and all the sort of turbulence and things going on there are essentially impossible to reproduce. Whereas again in observation, it’s there, right? it’s there all the time. You can’t avoid it. It blocks some of the stars. You have to deal with it.

Your photons are passing through it or getting blocked by it so to try and compare a simulation, which is fairly clean in terms of that to an observation, which is full of dust. It’s really quite tricky.

Jacinta: [00:25:29] Yeah, absolutely. It sounds very complicated.

Dan: [00:25:32] We also had the opportunity to catch up with Nicole Thomas again, who we’ve previously spoken to when she was in Edinburgh.

We spoke to over skype, but now we’ve got to speak to in person because she is still working with Romeel Dave and was visiting for the conference after an exciting trip which we’ll ask her about.

Jacinta: [00:25:52] Yeah. Nicole was in episode nine. I looked that up in advance

Dan:  its almost like you have something written down.

Jacinta: [00:26:00] I would never. Let’s hear from Nicole.

Okay, so the conferences just finished the modeling MeerKATs. How did you find it Dan?

Dan: [00:26:15] Yeah. Fun, that was great. I think it went really, really well and I think everyone enjoyed it and hopefully we’re going to have some cool projects coming out of it.

Jacinta: [00:26:23] Yeah and we have one of the attendees here with us, and you may recognize her. We’ve got Nicole Thomas back, welcome Nicole.

Nicole:  Hi. Thank you again for having me.

Jacinta: So we spoke to Nicole on episode nine and she’s been off on several adventures around the world since then. So Nicole tell us where you’ve been

Nicole: [00:26:41] Oh, well, so I’ve been in Edinburgh for the last about five months, which is where you interviewed me from via Skype the last time on episode nine. I then attended the Lindau Nobel Laureate meeting in Munich in the end of June to early July where we got to meet with about 600 young scientists, got to meet about 40 Nobel Laureate in physics where we learned about the research they did and the research we do as young scientists in hopes of networking and collaborating and now I’m back in Cape Town I arrived a few days ago, so I’m very happy to be back.

 Jacinta: Well, we’re not in Cape town yet.

Nicole: Oh, yes. No, we’re not in Cape Town yet. Tomorrow we’ll be in Cape Town! Yeah, so I basically got in and flew straight up to Nelspruit so I’m not 100% with things at the moment, but yeah still happy to be back in South Africa.

Dan: [00:27:37] And how did you find the conference? Have you got some cool projects coming out of it?

Nicole: [00:27:40] Yes, there were quite a few actually to come out that I’ll be included in mostly I’m working on the AGN continuum projects with MIGHTEE so I’ll be working with quite a few people and I’m very excited for it.

Jacinta:  So you mentioned you went to the Lindau meeting. Can you tell us what Lindau meetings are? I know you mentioned that it was a meeting between 600 students and 14 Nobel laureates in physics, I think you said. Forty? Four-zero gosh, that’s a lot. Nicole just mimed four zero to me.

Dan: [00:28:12] Didn’t you go to one of those Lindau meetings?

Jacinta: [00:28:14] Yes, I did. I went in 2012 and I think it’s every four years.

Nicole: Every four I think yeah. the physics part of the Nobel prize hosts a meeting every four years.

Jacinta: Great and so what was the most standout occasion for you? Was it really cool meeting the laureates or was it more significant to you to meet your colleagues, the younger scientists?

Nicole: So it was quite interesting meeting the Nobel laureates, of course. I mean, you have these people that do all these amazing things and you want to know whether they’re just ridiculously smart or whether they’re just human as well and you do see quite the human part of it, but more significant to me was meeting other young scientists because these are the people that you will end up collaborating and working with in future or just being perhaps in the same department or working in the same fields. So I did connect with some other young scientists. Luckily, we did have quite the cohort of South Africans, which is amazing. But also there were other young scientists that I met that I might in future be doing some collaborative work with.

Jacinta: I think South Africa was one of the hosts of the meeting this year. I mean, I know Lindau is in Germany, but a different country hosts part of the meeting there each year. Well, what was that about?

Nicole: Yeah so every year a country hosts an international day, this year it was South Africa’s turn and basically what happens is the country will host a breakfast and talk about the science that is occurring in the country at the time- SKA was a big topic, which was brilliant and then we have a traditional sort of dinner, where traditional South African food is served and we had some cultural performances and we had quite a good few people on the dance floor which is a first for the Nobel Laureate had meetings, but it was very well received and it was a good time.

Dan: [00:30:13] Well, thank you very much for joining us again, Nicole and great to catch up and I’m sure we’ll catch up with you again soon.

Jacinta: [00:30:18] Yeah, we’ve got to go on safari again now.

Nicole: Brilliant, I look forward to it

Dan: [00:30:31] Sounds like an incredible experience. You didn’t really elaborate on your experience with Lindau

Jacinta: [00:30:37] Yeah, so I went to Lindau in 2012 that was the 62nd Lindau meeting and it was it was a really big experience. There was about 500 young researchers like myself there. I was doing my PhD at the time and there was I think 27 Nobel laureates winners of mostly winners of the physics prize, but also from some of the other science prizes so chemistry and physiology and medicine. It was really incredible though, it was a big spread of research fields of the laureates and it was really great to meet them and I guess to realize that they’re just people. You know, they’re really just people like us and of course, they were very intelligent and they did really great work, but they were also lucky. You know, sometimes you’ve just kind of got to be lucky and it was a it was a great year because in 2011, so the year before the meeting, Brian Schmidt and some others had won the Nobel prize for the discovery of the accelerating expansion of the universe and so, Brian professor Brian Schmidt he’s an Australian astronomer who we all knew quite well in the astronomy community.

So it was great to hang out with him and he could tell us sort of like the behind the scenes of what the laureates were doing while we were doing our own things at the meeting so that was a really great insight.

Dan: [00:31:57] And of course, just this week we had the Nobel prizes.

Jacinta: [00:32:00] That’s right. Yeah, so speaking of Nobel prizes again, the 2019 Nobel prize in physics again went to astronomers.

Dan: [00:32:06] Yeah. Astronomy. We’re killing it.

Jacinta: [00:32:07] Well, it’s kind of the final frontier of human exploration in a way, so,

Dan: [00:32:13] well don’t tell the CERN people that.

Jacinta: [00:32:15] No, I mean I’m not saying it’s the only frontier

Dan: [00:32:17] Yeah but you are certainly, there’s a lot, I mean, there’s a lot of work there’s a lot of new instruments and a lot to be discovered. So certainly we expect a lot of discoveries to be coming out of astronomy and Nobel prize winning astronomy too.

Jacinta: [00:32:32] Yeah, so who won the prize this time and what was it for?

Dan: [00:32:35] Yeah so as always, it seems these days the prize was split between Professor Jim Peebles and two people whose names I’m not quite sure how to pronounce, I’ll give it a try: Michel Mayor and Didier Queloz. So for Jim Peebles, anybody who studied cosmology will know Jim Peebles, he kind of wrote the book, and that’s what he got the Nobel prize for.

Jacinta: [00:33:01] Yes. You would have used his cosmology a lot in your simulations.

Dan: [00:33:04] Yeah. So what Jim did was he put together the theory around the initial sort of fluctuations in the early universe and how using that we can predict how much matter there is, how much dark matter and dark energy and then that was subsequently observed by the, by observing the cosmic microwave background and those observations matched uncannily well with with Jim’s predictions. So he kind of, he did the theoretical framework on which our cosmology still stands.

Jacinta: [00:33:35] Right. So he predicted that before the observations confirmed he was right.

Dan: [00:33:38] Yeah and it really matches it and like incredibly well, the prediction to the observations not the other way around. We’re not making a fit to the observations.

The prediction was so bang on that the observations came up bang on it.

Jacinta: [00:33:52] And the other half of the prize?

Dan: [00:33:55] and the other half of the prize went to two scientists who discovered the first planet around a solar-type star. So, an exoplanet. So they discovered the first exoplanet around a solar type star.

So not a neutron star or something like that. And that basically set off a cascade of exoplanet science. We’re sitting at over 4,000 exoplanets discovered now since 1995 and there’s more and more each day so it really has opened up a whole new avenue of science and astronomy and then also other fields.

So like astrobiology has had seen a massive resurgence because of this. There’s a lot of interest into what, what makes life, how can life form, where can life form. We’ve observed all of these other planets. They’re all different sizes and masses and you know, different atmospheres.

So we want to know what’s suitable for life. It may be a bit more complex than just us and just carbon based life that we have.

Jacinta: [00:34:59] Yeah. And I, I think we should probably do another episode on exoplanets cause this is so interesting. There’s so much happening at the moment.

Dan: [00:35:06] Yeah, we certainly should. It’s, it’s a very exciting field at the moment as evidenced by the Nobel prize.

Jacinta: [00:35:11] Yeah, definitely. It’s interesting that the, the Nobel prizes are still awarded to individuals because a lot of science these days is happening in big teams and groups of people. So I wonder how that’s gonna change in the future because as we get bigger and bigger data sets. You know, you have to work as a team. You can’t really, it’s sort of very different to in the times of Einstein and other famous scientists like that where you could just sort of almost sit in an office by yourself and do the work yourself. Like now we have so much data that we have to work in teams, so I wonder how that’s going to change.

Dan: [00:35:48] Yeah. I mean, I think they’re going to have to rethink their philosophy a bit the Nobel committee. As you know there’s the Breakthrough prize which gets awarded every year,

Jacinta: [00:35:55] so, is that breakthrough, Is that for physics?

Dan: [00:35:57] So that’s for fundamental physics, yeah. So, so basically the, the breakthrough prize gets awarded every year, but it isn’t specific to a single person. This year we spoke about the Event Horizon Telescope and of the first image of a black hole

Jacinta: [00:36:12] special episode five,

Dan: [00:36:13] special episode five, and I was actually in Rome with Heino Falcke who was one of the lead authors on that paper on those papers when the breakthrough prize was awarded, but that breakthrough prize was awarded and split amongst the 350 team members which kind of makes sense because everybody contributed. Everybody did something to make this discovery happen and I think that the more we advanced with astronomy the more that’s going to happen.

Work like Jim’s is going to be less and less frequent any sort of big theoretical work even is done in a team these days. So I think that we will see the Nobel committee moving towards a more team-based Nobel prize. It’s complex. Very. I’m sure they’re discussing it too. Yeah. We aren’t the first to have this idea at all, but then something does need to be done.

Jacinta: [00:37:16] Yeah,  definitely. Yeah. The the whole way we approach science now is quite different, so yeah, it’s always good to rethink the status quo. Yeah. All right, so that’s the end of our science part of our episode.

Dan: [00:37:32] but we did have a little bit of fun.

Jacinta: [00:37:34] Oh, we did. Yeah. We had, we had a lot of fun while we were in the Kruger.

Of course, you can’t go to the Kruger without going on Safari on a Safari drive or two, which we did.

Dan: [00:37:42] Yeah. As a South African, I call them game drives.

Jacinta: [00:37:45] Sorry. Okay. Let me start that again.

Dan: [00:37:47] No no, it’s fine. It makes more sense for our international listeners.

Jacinta: [00:37:52] Yeah. Okay, and so this was my first time going on a game drive in the Kruger and it did not disappoint. Tell us more about the Kruger Dan.

Dan: [00:38:03] Yeah. So the Kruger national park is, it’s a massive tract of land in the North East of South Africa. It was established a long time ago now, I don’t know exactly, but probably over a hundred years ago and since then has been largely untouched. So, it’s massive.

It’s, you know, bigger than some European countries, bigger than Switzerland and all that exists inside of it, other than a few roads for tourists are animals living in their natural environment of every shape and form it’s really quite a special place. When you drive in, you can drive in for 40 Ks, drive up to the top of a hill. You’ll notice, I keep saying drive because you can’t get out of your car in Kruger, there are big animals and they will eat you

Jacinta: [00:38:55] yeah, there are big cats.

Dan: [00:38:57] but yeah, you can sort of drive to the top of a hill and look around and sort of in true lion King fashion, everything the light touches has not been touched by man. It’s really quite an incredible place and yeah, I love it. Obviously, listen to me, but yeah, it was wonderful to go on a game drive. It always is. It never disappoints and I mean, even if you see three little birds, I still think it’s wonderful. So just being in that environment.

Jacinta: [00:39:27] Yeah. So we though since the name of our podcast is The Cosmic Savannah that we would record part of this episode under the cosmos in the Savannah,

Dan: [00:39:35] and we take you on little drive through the Kruger.

Jacinta: [00:39:37] Yeah. So you can hear, you can hear us going on that drive now and you can also hear me losing my absolute mind when I see one particular animal so, let’s have a listen.

Hello from the Kruger national park, putting the Savannah into cosmic Savannah

Dan: [00:40:00]  Welcome to the Savannah, the cosmic Savannah,

Jacinta: [00:40:06] so we are here. Why we are Dan?

Dan: [00:40:08] We are here for work which is in air quotes, which you can’t see. We are here for a conference for a few days, but we are also going to be doing some game drives which is what we’ve just started.

Jacinta: [00:40:20] Yes, we are on a, what’s this vehicle called? It’s

Dan: [00:40:22] a game drive vehicle that’s basically like an open top back vehicle. So you’re kind of in the open-air.

Jacinta: [00:40:31] Yeah, and it’s packed full of astronomers, which is pulling onto the road out from the resort now and what happens next?

Dan: [00:40:40] Oh, we’ll cross the bridge and look in the river for crocodiles and hippos.

Jacinta: [00:40:43] Alright Crocodiles. Okay. Here’s the river. I don’t see any crocodiles

Dan: [00:40:47] I don’t see any crocodiles either.

Jacinta: [00:40:50] Oooh there’s a warthog! Yay! All right, so we’re through the gate now and we’re in Kruger proper right?

Dan: [00:40:56] Now we’re in Kruger.

Jacinta: [00:40:57] Yeah, Dan’s got these binoculars. Oh, that’s prepared.

Dan: [00:41:03] Obviously, come one. It’s serious business. We’re looking now. We are looking for big game. It’s not easy. We’re not in a zoo. We’re not guaranteed to see anything except for maybe an impala.

 I take this very seriously.

Jacinta: [00:41:18]  Okay. I’m understanding that now. All right. And we missed what our expert guide told us before, but his name is Abel and he said he’s very excited to have a truck full of astronomers on board cause he was talking to us before and he said he’s a avid stargazer.

Dan: [00:41:35] Yeah and he’s got a certification from the Field Guides Association of South Africa for stargazing so he’s not just an avid stargazer, he’s an “Abel” stargazer.

Jacinta: [00:41:47] Fantastic. He probably knows more about the stars than we do

Dan: [00:41:51] speak for yourself

Jacinta: [00:41:52] about the night sky. Do you know about the night sky?

Dan: [00:41:54] I know a fair amount about the night sky, particularly the South African night sky.

Jacinta: [00:41:59] Well, I can’t really say the same, but actually every time I’ve been outside in nature since I moved here to South Africa, it’s been a full moon

Dan: [00:42:10] and it was a full moon last night. So you’re going to have the same thing again.

Jacinta: [00:42:13]

And there was an eclipse last night actually, I wasn’t awake to see. Did you see it?

Dan: [00:42:17] No. I also was not awake, but it was, it was fairly late. The maximum eclipse was 11:30pm or something, but it was a partial lunar eclipse, which the red sort of moon goes quite red.

Jacinta: [00:42:31] Abel said that he saw it actually.

Dan: [00:42:34] Yeah. He was doing a night drive, so he got back from their night drive at about 10pm and the moon was red and must’ve been pretty magic.

Jacinta: [00:42:42] Amazing. Seeing the lunar eclipse from the Kruger.

Dan: [00:42:45] Yeah. Shivers. There – there’s a baby!

Abel: Look, look guys. Look at the small one. That’s a baby hyena!

Jacinta: [00:42:54] Oh my gosh it’s a baby hyena! Oh my gosh! Argh! It’s so cute! We can see the mom behind it.

Dan: [00:43:08] There’s a rhino! Rhino! Rhino! Guys, a rhino!

Abel: Well-spotted well-spotted well-spotted

Dan: [00:43:14] We’ve hit a road block

Jacinta: [00:43:14] there’s elephants on the road blocking our way.

Abel: [00:43:18] There’s a breeding herd of elephants with a newly born baby just between them. So they are very much protective when they have a newly born baby so we give them all the time with them.

We don’t have to rush them out of the road so the matriarch will decide if she has to give the way now or not.

Jacinta: So night is starting to set in on the savannah,

Dan: [00:43:50] We’ve turned off the lights. We’ve got big game light to scan the bush for eyes so that we can try and find which animal owns those eyes.

Jacinta: [00:44:03] So I guess the light is reflecting off the retina. We saw quite a spectacular sunset. It was very red,

Dan: [00:44:13] orange perhaps.

Jacinta: Okay. I’m sorry.

Dan: It was beautiful. So now we’re looking for the nocturnal animals. So there’s like a day and night switch where the whole different group of animals come out at night. They live in the dark and hunt the dark and so we are looking for those. Now, still some orange in the sky. And a bat!

Jacinta: [00:44:35] A bat! Look, I can see the first star

Dan: [00:44:42] It’s actually a planet, Jupiter

Jacinta: [00:44:43] it’s Jupiter? You see, this is why I need stargazing lessons. So we’ve seen so far a warthog, hyena baby and mother, elephants, zebra, impala,

Dan: [00:45:00] giraffe, a rhino

Jacinta: [00:45:01] guess a rhino. White rhino, a kudu. No, we didn’t see a Kudu. Oh yes, we did see a Kudu, a bush buck, and the little one. A steenbock.

Wow. We’ve just turned off the lights and the moon is rising and its orange, bright orange. It’s incredibly beautiful. This is the real cosmic Savannah, hey Dan?

Dan: [00:45:25] Uh huh, take a photo.

Jacinta: [00:45:28] I see a hippopotamus

Dan: [00:45:30] They are nocturnal grazers, so they come out of the water.

Jacinta: [00:45:37] The constellations are coming out.

Abel: Okay. I think overhead there is Scorpio and Jupiter is just next to it, that’s what I know. Tt’s above us and that is Mars just before Jupiter.

Jacinta: Oh I can see Scorpio. It’s huge!

Abel: There is Sagittarius

Passenger: We’d need radio eyes to really see Sagittarius.

Abel: That’s Mars, this is Taurus, and that’s Bootes, and that’s corona borealis.

Jacinta: Oh, it was such a good experience that Safari, sorry. That game drive. I did miss your joke about Abel being an abled stargazer. I listened to it, now that I listened to it again, I appreciate it. It was genius.

Dan: [00:46:30] Yeah, I mean, that was a super fun drive and we saw quite a bit, but you went on another drive the next morning. And saw something even cooler.

Jacinta: [00:46:38] I went on a sunrise drive and I didn’t take the recorder with me, which I really regret because it was so incredible.

We saw about 10 to 15 lions who had caught a giraffe. So they were sort of feeding on the carcass of this giraffe and there were hyena and vultures everywhere around the area waiting for the lions to finish so that they could also feed. And then later we saw a leopard which is extremely rare, one of the most elusive animals to see. And then we saw another leopard and this time it was up a tree and it had, it had a kill. It had killed a buck an impala and it was trying to find a branch to drape it over cause you know, this impala is heavy and it couldn’t find one, so it came down out of the tree and then a hyena ran in and stole the impala from it and then the leopard had to just run away and escape cause otherwise the hyena would attack it. It was incredible.

Dan: [00:47:40] It does sound incredible and I wasn’t at all jealous.

Jacinta: Oh, I’m sorry.

Dan: I mean, it’s those sorts of sightings and I’ve had them before. It really is an incredibly special thing, not something you can capture with a recorder or even with a camera- it’s something you have to come here and experience and it’s very, very special. Well next time we’ll have some more stories from our travels and in particular my trip to the Vatican observatory, which was very interesting.

Jacinta: [00:48:08] Yeah. You spoke to someone very interesting there.

Dan: [00:48:10] Yeah. The director so we’ll save that for next time. Yeah, but that’s it for today. Thanks very much for listening again and we hope you’ll join us on the next episode of The Cosmic Savannah.

Jacinta: [00:48:22] You can visit our website, thecosmicsavannah.com where we’ll have links related to today’s episode and you can also follow us on Twitter, Facebook, and Instagram @cosmicsavannah. That’s Savannah, spelled S. a. V. a. N. N. a. H.

Dan: [00:48:38] Special thanks today to Professor Romeel Dave, Professor Lerothodi Leeuw and Nicole Thomas for speaking with us.

Jacinta: [00:48:45] Thanks to Mark Allnut for music production. Janas Brink for the astro-photography, Lana Ceraj for graphic design, and Thabisa Fikelepi for social media support.

Dan: [00:48:55] We gratefully acknowledge support from the South African national research foundation and the South African astronomical observatory to help keep the podcast running.

Jacinta: [00:49:02] You can subscribe on Apple podcasts, Spotify, or wherever you get your podcasts, and if you’d like to help us out, please recommend us to a friend.

Dan: We’ll speak to you next time on The Cosmic Savannah.

Episode 9: Simulating the Universe – Part 2

with Nicole Thomas and Dr Nathan Deg

We continue our discussion from Episode 8 on simulating the Universe, this week focusing on the simulation of actual galaxies.

Nicole explains the SIMBA suite of simulations she is working on. SIMBA is a set of simulations which look at how the super-massive black holes at the centre of galaxies affect the galaxy they live in. She also talks about her experience growing up and studying in Cape Town, and some of the challenges she’s faced.

A simulated galaxy from the SIMBA suite of simulations

Nathan chats with us about his work creating individual galaxies within a computer using a new code he has just published. Using this we can learn more about how galaxies change over time and interact with their environments.

Two colliding galaxies built in GalactICS by Dr Nathan Deg.

Episode Links:
UWC: http://astro.uwc.ac.za/
Royal Observatory Edinburgh: https://www.roe.ac.uk/
UCT Astronomy: http://www.ast.uct.ac.za/
Nathan’s Blog post about his code: https://nathandeg.com/2019/06/04/galactics-for-the-non-astronomers/
Nathan’s GalactICS paper: https://arxiv.org/abs/1904.12700

Featured Image:
Looking at two colliding galaxies built in GalactICS in virtual reality. Video by Dr Nathan Deg, generated in collaboration with Mr Sivitilli, Dr Comrie, and Prof Jarrett in the IDIA visualization laboratory.

This week’s guests:

Episode 8: Simulating the Universe

with Prof Romeel Davé 

Prof Romeel Davé, from the Royal Observatory Edinburgh, and who spent 5 years working in Cape Town, introduces us to simulations! He explains how we can use simulations to perform experiments to test our understanding of the physics of the Universe.

Romeel also talks about his time here in South Africa, and his involvement in the MeerKAT radio telescope and the general development of astronomy on the African continent.

This week’s guest:

Prof Romeel Davé

Episode Links:

Romeel’s Quora Profile: https://www.quora.com/profile/Romeel-Dav%C3%A9
SARAO: https://www.ska.ac.za/about/sarao/
UWC: http://astro.uwc.ac.za/
Royal Observatory Edinburgh: https://www.roe.ac.uk/
MeerKAT: https://www.ska.ac.za/science-engineering/meerkat/about-meerkat/

Featured Image: A Simulated Galaxy courtesy of Romeel Dave.