Welcome to STEMology – Show Notes

Season 1, Episode 6

Herding sheep, A breaking model, Yawning lions, fusion energy and blue dye

In this episode Dr Sophie Calabretto and Dr David Farmer talk about…

In today’s episode of STEMology, we’re going to talk to you about … 

A new way to herd sheep that is not as stressful on the sheep, the physics community are keeping a careful watch on some results which are coming out showing a foundational model is broken, yawning means more to lions than humans, we take a step closer to fusion technology and the discovery of a natural blue dye 

Correction from Mark in New Zealand… cow burps produce more methane than a cow fart

Herding Sheep

it turns out that our traditional herding methods, which are often using things like sheep dogs, really stress the sheep out in a way that’s maybe a little bit unkind.

A breaking physics model

physicists are not upset about this, they’re actually quite excited that it might be broken

Yawning lions

not only are the yawns contagious, but they provide some kind of important social cue for the lions to coordinate their behaviour.

Fusion energy progress

what they’ve managed to do using their physics and particle magic is create stable plasma at 50 million degrees Celsius.

Natural blue dye

what they wanted to do was create this natural blue. And in fact, they were still using the red cabbage

This is a “kind of, sort of, vaguely close” copy of the words that David & Sophie speak in this episode.

IT IS NOT 100% accurate.  We are very sorry if we have spelt something completely incorrectly.  If it means a lot to you to have it corrected, email us at stemology@ramaley.media

STEMology s1e6
[00:00:00] Sophie: [00:00:00] Welcome to episode six of STEMology
[00:00:02] David: [00:00:03] a podcast that is your one-stop podcast shop for the interesting fun, and sometimes just patently bizarre news in science, technology, engineering, or maths
[00:00:11] Your hosts are Dr. Sophie Calabretto and Dr. David Farmer
[00:00:14] On today’s episode, we’re going to be talking about herding sheep, a breaking model,
[00:00:19]Sophie: [00:00:19] yawning lions, fusion energy, and blue dye.
[00:00:25] Mel: [00:00:25] hi guys. It’s Mel here, the producer. Thanks for that intro, Dave and Sophie, I just have a slight correction to make. this correction is from Mark. . So shout out to Mark from New Zealand. And he wanted to make a little correction from episode three. So back there we were talking about farting cows and how the potential to change their diets is going to help climate change.
[00:00:51] Sophie: [00:00:51] It’s going to help stop releasing methane into the atmosphere, which is a contributing factor to climate change.
[00:00:59] Mel: [00:00:59] That’s all right. So, uh, the seaweed, the future food for everyone by the sounds of it. We did talk a little bit about how cow farts were the source of the methane, but Mark wanted to remind us that it’s not just from one end, it’s from both ends.
[00:01:15] So, uh, actually the burping of cows is one of the largest sources of methane. And I’m going to put a little source on our show notes page from NASA of all places where they’ve
[00:01:27] David: [00:01:27] check the facts. NASA.
[00:01:29] Mel: [00:01:29] yeah. They’ve checked the facts.
[00:01:30] David: [00:01:30] the facts yet.
[00:01:31]Sophie: [00:01:31] they’re into peer of you.
[00:01:33] Mel: [00:01:33] That’s right. So I’m going to hand it back over to you, but thank you again, Mark from New Zealand.
[00:01:38] David: [00:01:38] Thanks Mark.
Breaking Model
[00:01:39] sophie physics is broken or possibly breaking.
[00:01:52] Sophie: [00:01:52] I mean, well, that’s very disturbing for ,us and everyone on this planet that we live on that is governed by mostly rules of physics that we
[00:01:59] believe,
[00:02:01] David: [00:02:01] also my understanding.
[00:02:02] Sophie: [00:02:02] we don’t believe rules. Dave. We know rules.
[00:02:06] David: [00:02:06] We can show them to be true mathematically. And here’s a problem, which is that we’ve shown some things to be true mathematically in physics. And then now that we’re doing the experiment, it’s not coming out right. Is broken or it’s breaking.
[00:02:19] Sophie: [00:02:19] It’s breaking. Yeah. So this is in reference to the standard model. So we’re going to, I think we let’s, I think we backtrack Dave before we forward track. So we have our standard model and the standard model in physics, it’s basically the building blocks of matter and explains how they interact with each other and how the forces that we know in this universe work in terms of these, these building blocks, these fundamental particles. So we have four forces. We had the electromagnetic force, we have the weak force or the weak nuclear force. And so from my physics memory that has to do with radioactive decay of atoms and those kinds of things,
[00:02:57] David: [00:02:57] that too. Yep.
[00:02:58] Sophie: [00:02:58] we have the strong force or the strong nuclear force.
[00:03:00] And that’s really sort of the force that binds together those fundamental particles to form larger particles, and then we can make atoms and then yes, very handy. And then we have gravitation or gravity that is not included in the standard model. So that’s a little bit of a problem with the standard model already.
[00:03:17] But in the standard model, we basically have sets of particles. We’ve got matter particles, which are fermions. We have force and carrier particles, which are bozons. And you know, some of these force and carrier particles convey the different forces. We have infermions, we have quarks. Which make up protons and neutrons and they have different.
[00:03:36] My favorite thing that I ever learned at university was quarks come in different flavors, like up and down, charm and strange and top and bottom.
[00:03:47] David: [00:03:47] and blue raspberry
[00:03:48] Sophie: [00:03:48] and blue raspberry, which is relevant to something we’ll be talking about later. And yeah, so then we have leptons, which will include electrons and electron neutrinos, but also something called Muon’s and muon’s are the issue here.
[00:04:02] David: [00:04:02] neons are the issue we’ve reached the issue. Which is why physics is broken or breaking. so basically we’ve got this standard model and basically theoretical physics is so advanced that we’re now at the point where it takes experimental physics quite a long time to catch up. That’s right.
[00:04:17] Isn’t it? Because the energies involved to do these things are so big. So basically we’re now still doing experiments to test the standard model. And one of the things that’s been tested at Fermilab, which is a place where they test these things, it’s a comparatively low energy physics, but still high energy place.
[00:04:34]They’ve been measuring the magnetic moment of the muon, which is the strength of the magnetic field when it decays, I think
[00:04:41] Sophie: [00:04:41] Yes, I also think that’s true. So yeah, about 20 years ago, they came up with something called the muon anomaly where they did these first tests of this anomalous magnetic moment. And they found that what they were measuring was not the same value as what the standard model told us it should be.
[00:04:59]David: [00:04:59] And that’s alarming because the standard model is pretty good so far.
[00:05:04]Sophie: [00:05:04] Yeah. So if this value is different, that seems to suggest there’s an issue with the standard model. And so the issue was that I think back when they measured this thing 20 years ago, they determined that experimentally we had about 3.7 Sigma in difference. Dave, do you want to tell us about statistical significance and Sigma?
[00:05:25]David: [00:05:25] Basically the bigger Sigma is, the less likely it is that what you’re observing is happening completely by chance or by accident. And so as your Sigma value gets bigger, your statistical significance gets bigger. And so you have more and more faith in your results.
[00:05:42] So 3.7 Sigma, you’re not as sure as you would be for say five Sigma. And five Sigma is actually what the physics community take to be as okay, now it’s five Sigma there’s only a one in 3.5 million chance that what we’re observing is a spurious or an accidental finding. So now we believe our experiments or results.
[00:06:03] So it sometimes takes a long time to build up these datasets then to become convinced that what we’re observing is real. And so we’ve had this value sitting at 3.7 Sigma and this latest finding takes it to 4.2 Sigma. So now basically what’s happened is it seems like it’s, it seemed like it was breaking 20 years ago and now it seems slightly more likely that it’s breaking now.
[00:06:27] And I read that they generated all this data in 2018 and 2019. And this 4.2 Sigma value is based on, they’ve measured 8 billion muons, and their latest analysis constitutes only 6% of those. So they’ve still got lots of data to analyze, so they might actually figure it out. They might actually, with this data, we’ll be able to come over the five Sigma threshold and say, Hey, physics is not just breaking, but no broken.
[00:06:51]Sophie: [00:06:51] I was going to say, my most recent memory of five Sigma being significant was when they found the Higgs boson. Right? So. Higgs boson is another thing in the standard model. And I think it was about 2012. I can’t remember, but they basically found the Higgs boson, we had our five Sigma value, which meant that as you said, there was one in 3.5 million was the likelihood of finding this false positives.
[00:07:14] They went. Okay. So the Higgs Boson exists. And so now if we hit five Sigma with this Muon anomalous magnetic moment, it means that the standard model is not right in terms of that. What else does it not right about Dave and will the universe collapse?
[00:07:30] David: [00:07:30] And that’s what’s cool about this, right? Cause it’s not just upsetting, like physicists are not upset about this, they’re actually quite excited that it might be broken, because if the experiment comes out a different way to what the model predicts, it means we can go back into the model with real data and recalculate and get to a more fundamental and more correct understanding of how the universe works.
[00:07:49] And that’s great.
[00:07:50]Sophie: [00:07:50] Except gravity is still not involved, but that’s a problem for another day. I
[00:07:55] David: [00:07:55] that’s a minor, that’s a different, that’s different thing. That’s different than we’re just talking about muons
[00:07:59] Sophie: [00:07:59] And so everyone stay tuned. Uh, we’ll let you know when we hit five Sigma.
Sheep Herding
[00:08:03] David: [00:08:12] From the breaking of physics to the fixing of sheep herding practices. UNSW Canberra researcher, Kate Yaxley and more specifically squadron leader, Kate Yaxley, which has to be one of the coolest honorifics that you can have, right behind weapons expert and Jedi Knight squadron leader kate Yaxley is using unmanned aerial vehicles to heard sheep.
[00:08:34] Sophie: [00:08:34] I’d like to think of them as unpersonal aerial vehicles. I write that down on my piece of paper. I think we need to change the language slightly, but yeah, so
[00:08:41] David: [00:08:41] absolutely not wrong.
[00:08:43] Sophie: [00:08:43] Yeah. So, we need to heard sheep to get them from paddock to paddock because sometimes there’s food, we put food out in some paddocks and they’re in a different one, et cetera.
[00:08:50]But it turns out that our traditional herding methods, which are often using things like sheep dogs, really stress the sheep out in a way that’s maybe a little bit unkind. And so, I mean, I know that there are already some countries that have been using drones. So our unpersoned aerial vehicles, to herd sheep around, but they haven’t actually looked at the effect that the drones have on the sheep compared to say a sheep dog or a motorcycle or something similar.
[00:09:17] So what they did, Dave, which is my favorite thing is they used a non-invasive method to measure the stress experienced by the sheep. And that was a strapped on heart rate monitors to these little sheepsies. And then they tried to drone them around and they measured the stress or the increased heart rate.
[00:09:34] So just a few, baseline facts for everyone who’s going to try this at home. So you’re unstressed sheep should have a resting heart rate of about 80 beats per minute.
[00:09:44] David: [00:09:44] Yep. Not that dissimilar from a person they’re kind of the same size people. So
[00:09:49] roughly a little bit higher, but
[00:09:50] Sophie: [00:09:50] Yeah. Unless you’re a super athlete and it’s a little bit lower, but so your athletic sheep, maybe. I don’t know, 40 to 60, I wonder if that’s a thing.
[00:09:57] Um, and then when you’re vigorously driving your sheep, we’re looking at something like 163 beats per minute, but 262, that is our threshold. So we can’t have more than 262 beats per minute , because that’s the maximum acceptable stress in the presence of working dog
[00:10:16] David: [00:10:16] and you can tell that that’s stress, because, presumably if they’re running as fast as they are, when they’re being driven hard, then you can see the, if it’s from like 150 ish, up to 250 ish, then that difference in heart rate is accountable to the animal being upset and stressed about what’s happening.
[00:10:31] Because it was a dog and it’s presumably a predator as in their eyes. And they’re like, I don’t like this. I’ll go over there, but I’m not happy about it.
[00:10:38] Sophie: [00:10:38] Yeah, exactly. And so what they did is they took 12 dorpa sheep. And they did 18 test runs and they repeated each of these things three times over a two week data collection period. We need to know lots of different things. And so there are different approaches to using these drones.
[00:10:53] So they had them playing sounds sometimes. And so the different sounds that they had the drones playing, I love was drone only, alert siren, border Collie, motorbike, and then music. But I don’t know if you could find anything, david. I could not find specifics about the music that the drones played and I would love to think it was show tunes.
[00:11:10] David: [00:11:10] that would, yeah. Or I don’t know, run baby run
[00:11:14] Sophie: [00:11:14] Oh, I
[00:11:15] David: [00:11:15] than stopping the name of love, for
[00:11:17] Sophie: [00:11:17] That’s true. Yeah. Okay. So they’re yeah, themed music. They also vary the height and speed of the drones, and also the maneuvering tactics. So you had your classic, straight and level approach to the sheep. We also had zigzag and swooping, and then they also changed the flock size as well.
[00:11:33] And what they found was that the peak heart rate. So they w when they were measuring the heart rates as well, they weren’t average, they could measure instantaneous heart rate of the sheep. And so throughout that drone testing, the peak heart rates were consistently less than the peak inplacement heartrate when they use the dogs and the motorbikes to even move the sheep into the testing arena. So there were super stressed out in being moved into these testing arena. They let them calm down and then they use these drones and it was always lower.
[00:12:01]David: [00:12:01] Yeah, it’s impressive. Isn’t it? And like they went into real detail. So they did two signals with the two audio signals. They did an alert signal and a drive signals. So one just to let them know that the drone was there. And when that happened during the drive and they tried every different combination and apparently the best combination was a siren at the alert and then a dog bark during the drive.
[00:12:23] And they say it was best to, because it had the best combination of causing the least stress, while enabling the drone to be far away. Cause obviously if you’ve got spinning propellers near a woolly hide, that’s a problem. So they want the drones to be far away, but effectively driving the sheep.
[00:12:39] And that was the most effective way. It’s a really in depth and rigorous paper.
[00:12:43] Like I was really, I had such a nice time
[00:12:45] reading it.
[00:12:46]Sophie: [00:12:46] I was really impressed.
Yawning Lions
[00:12:54] David: [00:12:54] so. From sheep being moved by drones to lions moving themselves because they’re pal yawned. Sophie.
[00:13:03] Sophie: [00:13:03] That was, that was beautiful. Yeah. So, um, I really liked this paper and I know you did too, because this was an accidental discovery and we love an accidental discovery here STEMology. So there were some researchers from the university of Peyser and there were hanging out in Africa and they were looking at the play behavior of spotted hyenas, but they could also watch lions when they were there, because there was some lions hanging around.
[00:13:25] And what they noticed very quickly was that, not only do lions yawn very frequently, they seem to be concentrated in short periods of time. And they went, that’s interesting, let’s check out these lions. So they just filmed these lions over a long period of time and they looked at the data and it turned out the yawning did something.
[00:13:45] Dave, what did it do?
[00:13:46] David: [00:13:46] Yeah, that’s right. So yawning as y’all know, is a ubiquitous behavior, which we do and it’s contagious and there’s lots of posited reasons why we might do it. It might be blood flow to the skull. It might kill the brain. It might aid alertness. It might, especially when transitioning in and out of rest, that kind of thing.
[00:14:00] Nobody really knows what it does, but we do know that it’s contagious. And someone had actually shown that Yoni was contagious in lines before, but here. They saw something else they saw, not only would one lion, if it saw another lion be more likely to yawn itself, the original yawning lion would yawn and then get up or sit down or do something in order to change his behavior.
[00:14:22] And what they would find was. If the second lion seeing the first line yawn also yawned itself, it was then 11 times more likely to engage in the same behavior as the first lion suggesting that not only are the yawns contagious, but they provide some kind of important social cue for the lions to coordinate their behavior.
[00:14:43]Sophie: [00:14:43] Yeah. So just back to the contagious yawning. So this is just, you know, I love numbers. I love to throw a number in there. So it was, if a member of the pride saw another lion yawn, it was 139 times as likely to yawn themselves in the next three minutes. And then as you said, if a lion caught a yarn from another lion, then there were 11 times more likely to mirror those movements.
[00:15:05] And so they talked about this in terms of motor synchrony , and so basically they could synchronize their behavior by prefacing that with a yawn. And so I just, I did want to digress a little bit about yawns, cause I find this young contagious very interesting. Cause I was always, you know, I have a bit of a thing about serial killers. And I was always told that if you yawn and someone else yawns, um, that person is highly empathetic. And if they’re highly empathetic, they’re less likely to be a sociopath or psychopath. And hence less likely to be a serial killer.
[00:15:34] Turns out there was a study done in 2018 that does say contagious yearning was related to empathy. So what they did is they use something called the interpersonal reactivity index, which is just a way to quantify empathy. And people who are more highly empathetic were more likely to catch a yawn, but there was no evidence that suggested that the susceptibility to contagious yawning is directly related to pro-social behavior. So just because you’re highly empathetic and catch a yawn, you’re no more likely to go kill a person then as someone who doesn’t catch a yawn.
[00:16:09] David: [00:16:09] It says nothing about how cool you are. Basically it
[00:16:12] Sophie: [00:16:12] no. And then they actually, they did something with dogs and they found that at least in non-human animals, contagious yawning is not a signal of empathy.
[00:16:20] And again, this is one study, but it is a peer reviewed study. It was quite interesting. So when people. You’re going to catch you on if you’re more empathetic, but you’re just because you’re more empathetic and not in on this scale, your I’m not less likely to go kill someone. And then, dogs just, they don’t care.
[00:16:37] David: [00:16:37] so. Yeah. I don’t know how you would begin to study empathy in lions, but this seems to be saying that it’s got a very functional social role, which presumably it does for humans as well. So one of the things you read about contagious yawning is that it has to do with increasing alertness when you’re tired, which seems a bit counterintuitive since you often do it, when you’re transitioning from being awake to being sleepy. But presumably if you yawn and you see someone else yawn, it increases your alertness in the sense that you are now aware that other people in the group are tired. And that maybe group vigilance is going down as a whole. And maybe you need to be a bit more alert because everyone’s a bit sleepy.
[00:17:14] I’m so alert in that sense versus the kind of, I’m not more awake, but more aware that you’re not awake. If that makes sense.
[00:17:22] Sophie: [00:17:22] but Dave, did you know that fetuses has yawn in utero?
[00:17:25]David: [00:17:25] Well that, yeah. But, but, but presumably it’s not something you do intentionally, so there must be a bit of the brain devoted to just producing the motor pattern. So that
[00:17:33] Sophie: [00:17:33] Yeah. So yeah, they’re just practice. They’re practicing for the big show when they’re out and they need to yeah. Be more alert, but yeah. So I thought that was really interesting, but yeah. Great study. And lions yawn to tell each other to stand up and sit down. This is what I learned today.
[00:17:48] David: [00:17:53] from the greater makelele game reserve in Africa to the TAE technologies fusion machine, which whisks up hydrogen plasma, Sophie thoughts on this?
[00:18:05] Sophie: [00:18:05] Yeah, so, um, I’m a big fan of nuclear fusion in the sense that if we were able to harness nuclear fusion we could create really clean energy. In a way that we don’t get the sort of byproducts of nuclear efficiency. Obviously we already use nuclear energy around the world.
[00:18:22] And the issue with fusion is what we’re doing is we’re doing big atoms and we’re splitting them and we’re taking the energy from that. But then you get all these radioactive byproducts. It takes a long time for these things to decay. Where do we put them also, then we have, you know, dangerous things happen when we build these fusion reactors on unstable areas of the world, but if we had fusions, a fusion is what happens in the sun, Dave.. So what we have is these lighter elements. And what we want to do is we want to convince them to merge with each other and in doing so we have this sort of excess of energy because there’s, you know, we talked about the standard model before, so there’s energy holding each of these atoms together.
[00:18:59] And then when you fuse them into a new atom. The idea is if you pick the right elements, you get this excess of energy. And if we could harness that energy, we could then use it to power our things. The problem is we need extreme temperatures. And often a lot of pressure to coax nuclei to overcome their natural repulsive forces.
[00:19:18] And so we’ve managed to make fusion happen a lot of times, but we always have to put in more energy than we get out, which means it’s not a super efficient way of producing energy on a global scale that people can use.
[00:19:30] David: [00:19:30] Yes. And there seem to be a couple of different approaches to doing those things that you just described. So, one is a thing called a Tokamak, which uses a powerful magnetic field to imprison ionize gas in a donut shaped vessel, which I think is hence the name.
[00:19:44] Sophie: [00:19:44] Yeah, so that’s a sort of magnetic confinement fusion just to get technical about it. Yeah.
[00:19:50] David: [00:19:50] Okay. And there’s that kind. And then there’s another kind where other labs, such as the U S national ignition facility, they crushed tiny pellets of fuel with powerful laser pulses to spark a burst of fusion, which is presumably what you observe in the documentary film, spider-Man 2 starring Toby Maguire. Thoughts?.
[00:20:07]Sophie: [00:20:07] Uh, yeah. And so that’s a, that’s a sort of inertia to confinement fusion. So my understanding there’s five different kinds. So what we basically want is plasma, right? So plasma is, think of a box of gas, but we’ve put enough energy into this box of gas and everything in there has absorbed enough energy that the electrons have separated from the nuclei.
[00:20:25] So we essentially have charged gas.
[00:20:27] David: [00:20:27] It’s what’s passed gas, right? You have like solid to liquid and then liquid to gas. And then if you keep going, you get gas to plasma.
[00:20:32] Sophie: [00:20:32] Gas to plasma. So what we want is a lot of plasma. And if you have a lot of plasma at high temperatures and high pressure, you can cause fusion. so basically what we’re describing all the different ways to contain plasma and make the plasma like the stuff in the plasma fuse with each other.
[00:20:47] but, the new story is that we have TAE technologies. They uses a process called field reverse configuration. And what they do is, as you said, at the very beginning, is they spin this plasma around.
[00:21:01] So they make a little whirly of plasma. And because plasma is made of charged particles, when you spin charged particles around, or when you make the move, you get a magnetic field. So what they’ve actually done is it’s the magnetic field that it creates itself that basically keeps the plasma in position.
[00:21:20]The problem with the plasma is just like, it’s not super stable and so you can create plasma quite easily, but it just disappears sort of, you know, close to instantaneously. And so what they’ve found is they’ve come up with a way to sort of keep this vortex of plasma to hang around for long enough to cause fusion to then harness its energy.
[00:21:38] So apparently if you leave this plasma alone, it will disintegrate in a fraction of a millisecond. I’m not quite sure how this works,
[00:21:46] David: [00:21:46] Oh, I know, I know how it works. It says in the article it says in the article, it gets very technical. It says its machines whisk up the hydrogen plasma. Um, it doesn’t tell us anything about how it works. Yeah. That makes it spin very much the most flamboyant and poached eggy of the approaches to fusion.
[00:22:02] But that’s
[00:22:02] Sophie: [00:22:02] they. No. So then what they do is they fire beams of particles tangentially into the edge of the ring, which stiffens it and makes it spin faster. And from what I can tell, what that basically means is they’re sort of injecting a fuel source. So what is either going to be, it’s either going to cause a reaction when you shoot these things out or it’s going to be captured into the ring and it’s going to create that additional fuel you need for future fusion reactions.
[00:22:27]So Dave, but what they’ve managed to do using their physics and particle magic is create stable plasma at 50 million degrees Celsius.
[00:22:35] David: [00:22:35] So very hot, hotter than the sun,
[00:22:37] Sophie: [00:22:37] Which is hot to, and then the next step would be creating stable plasma at a hundred million degrees Celsius.
[00:22:43]David: [00:22:43] Which is very much hotter than the sun. And that’s what you actually need for traditional deuterium and tritium fusion.
[00:22:49]So Norman is 60 million degrees. Copernicus is a hundred million degrees, which will actually allow them to try fusion, with traditional fuels. And then their next like stretch goal, which is not even beginning to be funded is hydrogen and boron, which requires billions of degrees.,
[00:23:06] Sophie: [00:23:06] right, and billions of degrees seems like too much, but if we can get to the point where we can use traditional fuels and we can create fusion energy, then what we have is an infinite source of clean energy that we can use forever until people don’t exist.
[00:23:22]David: [00:23:22] I just feel the person I feel bad for is Norman. I mean, Norman is already like four or five times hotter than the sun. He’s 50 million degrees. The next machine is going to be called Copernicus. I mean, Copernicus, like who’s the guy who said that the sun’s at the center of the solar system, which is a bit more prestigious than just Norman.
[00:23:42] And I think Norman’s already doing a really good job. So I just, I feel a bit bad for Norman. Um, and I can only hope that Copernicus is superseded in a similar way.
[00:23:51] Sophie: [00:23:51] But like Norman knows he paved the way. And I think that’s the main thing.
[00:23:55] David: [00:23:55] Norman
blue dye
[00:23:56] Sophie: [00:24:07] dave, how do you feel about brightly colored foodstuffs?
[00:24:11] David: [00:24:11] I, um, I I’m keen. Like, I mean, I, um, I really don’t mind it. I feel there’s something kind of invigorating about a particularly red tomato or, you know, a particularly orange, orange, or I don’t know, a particularly yellow lemon. why do you ask?
[00:24:32] Sophie: [00:24:32] Well, so you’ve just talked about naturally colored, bright foodstuffs, but I would really like to talk to you about trying to create weird colors with natural color. And so blue, for example, is not a color that we, I would like you to name a blue fruit or vegetable right now that isn’t a blueberry, because those are like a bit purple. I want a cyan. What is a natural food that is sort of cyan’ish is what
[00:24:57] David: [00:24:57] I am. Um, uh, I can’t think of one now that you’ve taken blueberries off my plate.
[00:25:03] Sophie: [00:25:03] well, do you know? No one can say, so this is the issue. So we’re moving into sort of an arena where we’re more interested in sort of natural foods. We don’t like the idea of putting these like wierd synthetic food dyes in the things that we eat. There has been a lot of researchers to, you know, sometime maybe they’re bad or maybe they’re not.
[00:25:20] And, uh, I think it’s still maybe, but. What they’ve tended to do when they’ve made natural blue food coloring is, you can use a red cabbage and other things that are sort of red and purple. So apparently this was a thing that kids did, and I never did it, but if you take red cabbage, Yeah, you cut it into pieces.
[00:25:36] You boil it, you get a purple-ish broth that when you add baking powder to it, it turns bright blue. All right. So that is a way to make bright blue, natural food coloring. However, it’s not particularly stable and it also has slightly purple undertones. And the issue is they use blue as a mixer. And so if you want to create green, for example, you’d mix blue and yellow.
[00:25:57] But if your blue is a bit purpley, if you mix purple and yellow, you get Brown. So you’re not going
[00:26:02] David: [00:26:02] Which is not very appealing.
[00:26:04] Sophie: [00:26:04] No. I mean, if I want a, you know, a lime colored candy. If it’s a Brown, it makes me a little bit worried. And so we currently use sort of two main synthetic blue dyes in our foods. One of them has been linked to cancer, but then it sort of got a bit unlinked to cancer as well.
[00:26:21] But what they wanted to do was create this natural blue. And in fact, they were still using the red cabbage because apparently it’s something called an anthocyanin
[00:26:33] David: [00:26:33] I read about these. So these are, these are bluish purpley compounds. And an interesting thing about them is that they are the compounds that become increasingly present in autumnal leaves as the, the season of autumn comes on. And that’s why the leaves become more orangy, yellowy red, because it mixes with the other colors.
[00:26:52] Sophie: [00:26:52] Oh, that’s beautiful. Yeah. So they want to take these things, and they want them to hold onto their true blue color. And so apparently they’ve concentrated on a specific anthocyanin that they’ve just called P2. And apparently if you mix that molecule with Aluminium ions and create complexes of three of the P2 molecules arranged around one, aliminum ion like spokes on a wheel.
[00:27:16] You make the complex stronger, and it’s a more stable blue color, which is fine, except that only about 5% of the anthocyanins in red cabbage are P2. Which means that process is terribly inefficient because 5% is not a lot of percent.
[00:27:31] David: [00:27:31] So that did something quite clever. Didn’t they, they took an enzyme that converts some of the anthocyanins to the other form of anthocyanins, which can be stabilized with the aluminium, meaning that their yield went from 5% to like 50%. So now they have a yield of 50% of these things that turned things blue and are stable for a long time instead of five, which is good.
[00:27:52] Sophie: [00:27:52] except my favorite part was it has yet to be determined whether these metal complexes are safe for human consumption.
[00:28:01] David: [00:28:01] Yeah, it’s naturally derived. We’re just going to add a whole bunch of aluminium to it and as enzymes and it’s going to be great and that’s going to be really natural.
[00:28:11] Sophie: [00:28:11] that’s good. Yeah. So I think, you know, this is on the quest for natural colors, as I said. So one of the blues that we use was linked to brain tumors in mice, and then another effect said, actually that has no adverse effects. There has been lots of studies done on hyperactivity, although no tenable link has being established between high productivity and artificial food dyes, but they’re just things that we use. And we might find out in 50 years time, like DDT, it was a really bad idea to have these things around us. So if we can use more natural food colors, it’s maybe not a bad thing. And just hopefully they manage to work out whether or not we should be consuming high
[00:28:45] David: [00:28:45] but. But so we think, I mean, they, they save themselves like these are it’s yet to be determined, but these metal complexes are safe for human consumption. So if these are naturally derived, like what do we really mean by naturally derived? Like synthetic is made by human beings and human beings that are derived from nature.
[00:29:00]I feel like it’s, it’s, it’s what they call a false dichotomy. It’s it’s not really a true distinction to make between things.
[00:29:06] Sophie: [00:29:06] No, I think you’re right. And to be honest, if I can get some bright blue ungodly drink at this stage, I still probably will drink that because it makes me very excited
[00:29:17] David: [00:29:17] Possibly hyper.
[00:29:19] Sophie: [00:29:19] maybe, but just from enthusiasm, not necessarily because of the artificial food dyes.
[00:29:25] David: [00:29:25] Yes, because of the, well, the vibrancy and the way that it makes you feel when you look at it.
[00:29:30] Sophie: [00:29:30] Yeah.
[00:29:39]David: [00:29:40] thank you for listening to another fun episode of STEMology. Be sure to check out the links to all these great stories on our show notes.
[00:29:45]Sophie: [00:29:45] Go visit www.stemology.com.au.
[00:29:49]If you have any news that you think is STEMology worthy, drop us an email at STEMology@remedy.Media. We’d love to give you a mention.
[00:29:56]David: [00:29:56] Your hosts have been Dr. Sophie Calabretto and Dr. David Farmer.
[00:30:00] This is a podcast from Ramaley Media.
[00:30:01] Our executive producer is Melanie De Gioia and our music is by Elizabeth Maniscalco.
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[00:30:11]David: [00:30:11] We look forward to sharing the latest in all things, science, technology, engineering, and maths with you next week, and be sure to bring your friends.