Quirks and Quarks - Humans and animals love the same sounds, and more...

Episode Date: June 5, 2026

150 years ago, Charles Darwin noticed that birds and humans were both drawn to bright plumage and elaborate display. He called this interspecies esthetic appreciation a “shared taste for the beautiful.” Now, in a recent study, an interdisciplinary team of scientists built an online game exploring the mating calls of 16 different species and discovered, to their surprise, that humans and animals agree on which sounds are more attractive.PLUS:How the brain can learn to truly multitaskFrom the archives: The Russian space mirror that flashed across Canadian skiesThe Matrix is real: birds, dragonflies and dogs see the world in slow motionCould the next giant particle collider unlock the mysteries of the universe?

I am an actor, fresh out of theater school with big dreams and an even bigger drug habit. But things are pretty good. That is until my best friend is set up on a date with David Lee Roth. Yeah, from Van Halen. If you know, you know. From CBC's personally, this is Discount Dave and the Fix. The true-ish story about how a fake rock star led me to a real trial that held up a mirror to me. And okay, let's just say that not everyone in this story is who you think they are.

Personally, discount Dave and the Fix. Available now on CBC Listen or wherever you get your podcasts. This is a CBC podcast. Hi, I'm Bob McDonald. Welcome to Quarks and Quarks. On this week's show, our brains can, in fact, learn to multitask. The new thing in our study is that we show, no, actually your brain can offload things that now you can do one thing with the front of your brain,

while another part of your brain does something else. And humans and animals agree on which animal sounds are most attractive. But when you look at the specific sounds where the animals really have a strong preference, those sounds are the ones where the humans really agree with the other species. Plus, an archival interview about a Russian space mirror, the next big thing in particle physics, and how time passes more slowly for fast-moving animals. All this today on Quarks and Quarks.

Here's a question for you. What are you doing right now? I mean, besides listening to our show. Are you writing an email? Driving? Maybe organizing your bills? This is the idea around multitasking, that our brains can work on two tasks at once.

It's a feat many scientists doubted was even possible. But in a new study, researchers have now mapped out how our brains can pull it off. Dr. Max Reasonhuber is a neuroscientist at Georgetown University School of Medicine in Washington, D.C., and the co-director of their Center for Neuroengineering. Hello and welcome to our program. Hey, Bob. Nice to be here.

Why do some scientists think the brain's not capable of true multitasking because we see people doing it all the time? Yeah, some better than the others. Normally when we do something, it's the front of your brain that kind of decides what to do. It's called the preformal cortex, and there's machinery there that keeps you on task. So usually you do you do one thing that you want to do

and a lot of other things that you don't want to do. And the prefront cortex is the one that orchestrates what gets done. And so people thought, if you're now going to do two things at the same time, then your brain can kind of do that by switching back and forth really fast. But that wouldn't be true multitasking. So you do one thing, then you do the other thing, and you switch back between the two. And the new thing in our study is that we show, no,

actually your brain can offload things that now, you can do one thing with the front of your brain, while another part of your brain does something else. Wow. Well, what did you do to figure out how our brains are able to do that to sort of dedicate two different parts of the brain to do two different things? We wanted to see how does your brain actually change

when you learn a new task and become really good at it? Because you probably had the experience, Bob, like when you were learning to drive, at least I had, that initially you really have to pay attention to everything, right? You have to look at the dashboard, all the traffic signs. And now after, while as he get better and better, you can start talking to someone and still drive. You can get

home and say, realize, oops, I'm home, right? I didn't even realize that I'm already here. And so it seems like we can learn to do things automatically, and that frees us to do other things in parallel. And so we wanted to see, is that really happening? And so, well, we couldn't, let's build, to drive in our study. So we tested them on this task where they had to sort these more of car images. And what we could do then is we could image their brains after they learned the task initially, it takes a few hours, and then you're pretty good at it. You're 90% correct or so. And then we imaged them again after they had done it for 30,000 trials. And then we could compare, okay, how does the way your brain do the task change? Okay. So you're saying that they were doing

this car morphing task 30,000 times? I mean, they must have been pretty good at it by that time. Well, pretty good and pretty bored. Yeah, really. So we had to kind of gamify it, right, to make it sticky. And of course, we paid people that it always helps. And so that way we get people to do this for a total of like 20 hours over a few weeks. Boy, well, take me through this task that they were learning. What were they actually doing?

Yeah, so they were looking at cars and had to learn that these cars go in two different categories. And so we had this morphing system where we can just take a bunch of different cars and then morph between them. And we think about like a Volkswagen Beetle and some kind of sedan, and then it goes smoothly from one to the other. And then we told them, okay, somewhere in the middle,

this now gets another label. And so we train people on these cars. And the nice thing is you can make it very easy in the beginning, and then you can make it harder and harder. Okay. So once they learned that car morphing task, what was the second task you gave them to see if they could multitask?

Yeah, no, that's exactly what you need to do, right? So we can do the car task, and we train people to get better, but then you want to have another task that we know requires your prefrontal cortex, right, requires your attention. And it's a disk that can be red on one side and green on the other,

or you flip it around, so you left green or right green, and people have to see which side it's green on. And so we flash that on the screen, on the side, while in the center we asked them to do the cars, and now we test them doing two things at once that we find initially, before they had all the experience,

they could sort of kind of do it, but they weren't great at it. And then we tested them again after the 20 hours, and we found that they were actually better now at doing the disk task than they were before in addition to the car task. And we could also show that the better they were, the less the cars were tying up their prefrontal cortex, but rather it went directly to another part of the brain. So what did you see happening in their brains while they were doing that?

After the initial training, we found, yeah, indeed, It's in front of your brain, your peripheral cortex that does the car categorization. And the individual cortex learns to tell the cars apart, but it can't label them. So it can't say this goes on one pot, this goes in the other. But now after 20 hours, we found that now in your visual cortex, actually, this part of the brain that before didn't care about the category labels, now all of a sudden could do the category labels and it also directly connected now not to prefrontal cortex, but to, a part of your motor system.

Oh, I see. So the pre-futnel cortex is dealing with the immediate stuff and your learn task. It's kind of like going on cruise control or autopilot. You just stuff it away and let it do it on its own. Exactly, right. How quickly can our brains take these different roots in the brain to transfer information like that? So, I mean, how long does it take? So here we just had the before and after, and we actually currently have a new study where we now do EEG while people are learning to automate it. And it turns out, at least in our current study, it can happen very quickly. As soon as you should be frontal cortex learns it, it starts talking to your temporal cortex,

to your visual cortex. And so if you anthropomorphize it, right, it tells it how to do the task. That's amazing. One part of the brain is teaching another part of the brain how to do something. Yeah, yeah, no, it's very nice. And this pathway now, we think then gets remodeled, right? So once you be frontal cortex has learned it, then it pushes down the information, into that temporal cortex, and the temporal cortex can then go directly to your motor cortex or

like a stage there to then determine the response, kind of bypassing that bottleneck, right? So we call it the frontal bottleneck because it can only do one thing at time, which usually is a good thing, right? You want to focus. We know we can do two things at a time, and so here's a circuitry then how that can work. But it's almost like it's, the information is taking a shortcut when it goes back there to the motor cortex, it's closer to the muscles. Right, right, right, right, right. Now, we know that an experienced driver can drive and eat at the same time, but not drive and text.

So what are the limitations in terms of how far our automatic system can go in multitasking? With the texting and driving, the problem is, unless you're like a chameleon, right, you can keep one eye on the road and one on your phone, you have to move your eyes. And that's the problem, right? So even if you could multitask, your eyes can't look at the road and at the point at the same time. So better keep the eyes on the road. But you can listen to the radio and drive at the same time.

Unless it's your show and it's so engrossing that people just forget everything else and then you get in trouble. Dr. Reasonhuber, thank you so much for your time. Thanks so much for your interest. Dr. Max Reasonhuber is a professor of neuroscience at Georgetown University School of Medicine and the co-director of their Center for Neuroengineering in Washington, D.C. In nature, finding a maid is fundamental for the survival of most species, which is why animals put so much effort into it. From fancy plumage or elaborate songs to complicated dances,

across the animal kingdom, there are a number of ways that one might try and say, hey, look this way, over here, choose me over that other guy. Well, 150 years ago, Charles Darwin noticed that the elaborate displays that birds put on were also aesthetically pleasing to him, which he found a bit strange, considering they weren't meant for human appreciation. He called this a shared taste for the beautiful. Well, now a team of scientists have decided to put this notion to the test, seeing whether humans and animals are, in fact, drawn to the same sounds. Using a computer game and thousands of participants, the researchers found that indeed Darwin was right. We do seem to have a

shared taste for the beautiful. Producer Amanda Buckowitz spoke with the two lead authors to find out more. As I walk outside, I'm often struck by the beauty of nature, right? The colors of a butterfly or the sounds of the birds around me. These are all signals that were designed to attract other species, not me. And yet maybe because I share something fundamental in the way I process these with the other animals, I get to share in that sort of beauty and attraction as well. My name is Logan James. I'm a postdoctoral researcher at McGill University, and I'm also affiliated at the University of Texas at Austin. I'm really interested in the way that different animal communication systems evolve and are used to communicate different kinds of messages. I researched the Tungura Frog down to the

in Panama at the Smithsonian Tropical Research Institute. And this is a tiny little frog that's been studied for decades. And the males of this frog make a sound that we call a wine. It sounds like, er, er. But then they'll add sometimes what we call chucks, and so it'll sound like er-er-er-er-er-er. And it's those additional chucks that we study a lot because those make the call a lot more attractive to potential females.

And so I've sort of long been thinking about this notion that Darwin actually had about a taste for the beautiful. So Charles Darwin was observing animals and trying to understand how evolution acted to sort of produce the diversity of species that we see today. And one of the things that he noticed was that animals, in particular birds, have a lot of beautiful colors and sort of flashy displays that they do. And he noted that these displays are to attract. other birds. They're not meant for humans, and yet he found them to be attractive to himself as well. And this is a fairly peculiar in some ways, right? The idea that something that's meant to attract another bird could be attractive to a human. And he kind of coined this notion of a share to taste for the beautiful. So the project really, you know, we've been thinking about this idea of studying animal

preferences for a while, but we didn't really have the means or even the, you know, the expertise to conduct a psychological study with human participants. It's a really different sort of ballgame there than the animal studies we were used to. And so Sam happened to be coming to Montreal where I was based at the time. My name's Samuel Meir. I'm a faculty member at the Yale Child Study Center in the States and also here in New Zealand at the University of Auckland. My lab focuses on auditory perception mostly in humans. I come to Montreal to give a talk about some of our work on what people understand about the music that they hear from around the world.

And Logan saw this as a really nice opportunity to say, oh, well, we have a question about what people understand about animal sounds. You guys have the methods to figure out how to test that question. We should talk. And so we just started chatting about some ideas and some options, and we figured out that this was a really cool collaboration where we could, you know, utilize his ability to get lots of participants to answer these questions in order to get these really broad and sort of complete picture of the process. references across the globe. I mean, it sounded a little weird, to be honest. I think none of us really thought it would work, though, which is why it's kind of fun that it's turned out to be quite a compelling evidence base

for this idea that's been around for, you know, 150 years. So, I mean, the first thing that we really needed was basically any sets of sounds where animals had been used in some sort of study to assess their preferences for these different sounds. So we assembled a corpus of 110 pairs of sounds that came from 16 different species. This includes songbirds like the canary, the zebra finch, the song sparrow, the swamp sparrow. We have a number of species of frogs. We have sounds from two different mammal species other than humans. We have the gelada monkeys from Ethiopia, as well as the singing mice from Central America. And then we also have some insects, including these crickets from Hawaii, as well as some grasshoppers and even a fruit fly.

I didn't know that fruit flies make noises before we did this research. We developed this online platform where participants could volunteer to listen to these sounds, and then we simply ask them, which sound did you like more? You know, the question is not how nice is this, right? The question is for each pair of sounds. You know, here are two pretty weird sounding gelata monkeys. Which one is the better one? And then here are two really beautiful bird songs of those two, which is the, which do you like more? And then we just repeat that process for, you know, a handful of times to get a set of results from each participant. Across 4,000 participants, we found that on average, we do see that humans are more likely to agree with the animals themselves more than chance.

It's not a knockout result. It's not like 100% of the time they do. But when you look at the specific sounds where the animals really have a strong preference, you know, the Tungara frogs, you know, nine times out of ten, they prefer sound A over sound B. Those sounds are the ones where the humans really agree with the other species. One of the clearest findings that we had was for what we call acoustic adornments. So these are extra bits of sounds. We can call them chucks or clicks or trills or other sorts of little bits that animals add on to their calls.

and we do find that other animals really seem to like these additions to the calls, and so do the participants. So I really like a lot of the bird songs, and people who go online and play the game will have their own intuitions about this, but when I play it myself, I find the bird songs are the ones that I have the really strongest intuitions for. Like for pretty much all of them, you know, I hear them like, oh yeah, that one's nicer. So certainly we did not always agree with the animals, and there were cases where we really actually had opposite preferences.

So one of those examples is actually the zebra finch. And in this case, the human participants actually had the opposite preferences, the birds, for whatever reason. And then we also really didn't seem to agree in general with the gelata monkeys, which is interesting because that is the closest relative that we have in this study. And yet it was not one of the ones where we found we really agreed. To be fair, the gelata monkeys sound really, weird. They really do. They sound like somebody's like in pain or something. It's like, it's like, whew, like they don't sound. It's not something anybody really wants to listen to.

We were curious to know whether or not aspects of the sounds themselves are like an acoustic difference within the pair, the pitch or the frequency of the sounds could predict the preference in the animals. We didn't find that there was any sort of finding there. And that, that accords quite nicely with what we know about human preferences for other nice sounds. So it would be silly to make a claim that, oh, well, when you listen to a song, if it's lower in pitch, you're going to like it more. Like, obviously, some music is sung by people with lower voices, other music is sung by people with higher voices. There's no relation between these things at all. Complexity is a good example as well. You know, some of the animal sounds sound more complicated than others, and that in some cases makes

humans like them more and also makes the animals like them more. Some of the nicest music in the world is totally not complex at all. You know, lullabies are very calming and soothing and really nice, and they tend to be quite simple. It would be useful to know a bit more about how that works, about, you know, what is it that makes, you know, the song calm you down or the song excite you? Because it's not so simple as just play it faster or play something more complicated. It's got to be more complicated than that. So I think this is a step in that direction. I don't think any of us really knew whether or not this was really, really going to pan out. You ask 10 people what their favorite song is, you're going to get 10

answers, right? So the idea that even for a single stimulus pair that humans might generally have the same opinion was honestly pretty exciting for us. And so then to see the actual results really panning out was really cool. And I'm, yeah, really grateful for all these collaborators and mentors that have helped bring this project together. That was Dr. Logan James, a postdoctoral researcher in the Department of Biology at McGill University and University of Texas at Austin, and Dr. Samuel Mayer, a cognitive scientist at the Yale Child Study Center in New Haven, Connecticut,

and the University of Auckland in New Zealand. Their game is still online, so if you want to see if you too share a taste for the beautiful, we'll have a link to the study on our website. The sun is always shining somewhere, but it's not always where you want it or need it. What if you could use a large space mirror to turn night into day? Well, 33 years ago, Russian cosmonauts tried to do just that.

To celebrate 50 years of Quarks and Quarks, we're bringing back some of our most interesting interviews, including this one from February 6, 1993, when I spoke to one of the Russian scientists working on an experimental reflector program. The Russians wanted to reflect sunlight from space onto agricultural, fields to extend the growing day or illuminate northern Siberia during the long polar nights. The experiment garnered a lot of attention across Canada. People could watch from the ground and see the experiment in action and be part of it. Here at Quirks and Quarks, we set up an answering machine for listeners to call in.

And boy, did we get a lot of calls. Here's an excerpt from that show. Hi, Bob. This is Michelle and Don Gardner calling from Marion Bridge, Cape Breton. We witnessed the mere station orbiting overhead between 635 and 640 this Friday morning. As it passed, it became brighter for a second than it slowly faded away into the morning. We are watching a piece of space technology in its infancy, and it was nice to be an eyewitness with a ringside seat. That was an eyewitness report of the Russian space experiment that was visible over Canada this week.

For the first time ever, an experiment being conducted in space was visible from the ground. Cosmonauts aboard the Space Station mirror unfurled a large rotating reflector made of thin, illuminated plastic, and used it to direct sunlight onto the dark side of the earth. The 30-meter diameter reflector, called Znamia, which means banner, was unfolded from an unmanned progress spacecraft flying in front of the Mir space station. Cosmonauts positioned the reflector, then looked down on the surface of the earth to see a spot of light five kilometers wide shining on the ground below them. Five hours after the experiment began,

it abruptly ended when the reflector was jettisoned. By the time the two spacecraft passed over Canada on Thursday, the reflector was tumbling freely in space but had not yet burned up in the atmosphere. Terry Dickinson, Quirks and Quarks's Eye on the Sky, was one of the people who spotted the spacecraft as it passed over. Terry, we've received many calls from people across Canada who saw the Russian experiment,

but there's quite a difference in what people reported. some spotted two objects and others saw three. Why do you think there's such a discrepancy? Well, the discrepancies would be due to the fact that people across the country where there would be different angles of view and with free to tumble completely different levels of brightness to the third object. I've never seen three spacecraft following in the same orbit in a train like that, and those two close together forming that gorgeous, moving, brilliant, double...

Terry Dickinson, thank you very much. Thank you, Bob. Our phone machine has been working overtime over the last few days, recording dozens of reported sightings of the Russian spacecraft. To find out more about just what went on in space, we contacted Professor Vladimir Sera Miatnikov, technical director of the Russian Solar Reflector Project. We've reached him at his home in Moscow.

Professor Sira Miatnikov, you must be pretty excited about this experiment. Well, we certainly saw it here in Canada, and we've had many false. calls from people across our country, including myself, who saw the spacecraft pass overhead, and it was quite spectacular from the ground. We have a tape now from one of our listeners who called us in from Rabbit Lake in Northern Ontario, which is sort of in the center of our country. There we go.

My wife and I just walked out on the lake, like it's frozen hard on this gadoo track. And we were more or less just gawking around when all of a sudden we saw this bright, light coming from the west at about 45 degrees above the western horizon, and there it was coming right at us. My neighbor across the lake said it just looked as if the big flashing thing was towing these other two right behind it. Dr. Sero-Myotnikov, how did you feel about that description? Oh, yeah. It's very, very interesting. If we send you the reports of our listeners across Canada who spotted the Russian space station and the reflector, how will that help you in your scientific work?

Thank you very much for speaking with us. We appreciate your time. Thank you for calling and for very valuable information. I will be waiting. That was me on February 6, 1993. We didn't expect our telephone answering machine to become part of the Russian space experiment, but if you called in with your observation, your report was sent to Moscow. I'm Bob McDonald and you're listening to Quarks and Quarks on CBC Radio 1 and streaming live on the CBC News app. Just go to the local tab and press play wherever you are. Coming up later in the program, how animals living in the fast lane perceive time more slowly than those that dawdle. If you think about the eagle chasing a mouse, then these very fine-scale movements that the mouse is trying to make in order to escape.

The eagle is very aware of all of that and has a lot of time. to respond accordingly. I am an actor, fresh out of theater school with big dreams and an even bigger drug habit. But things are pretty good. That is until my best friend is set up on a date with David Lee Roth. Yeah, from Van Halen. If you know, you know. From CBC's personally, this is Discount Dave in the Fix.

The true-ish story about how a fake rock star led me to a real trial that held up a mirror to me. And okay, let's just say that not everyone in this story is. who you think they are. Personally, discount Dave and the Fix. Available now on CBC Listen or wherever you get your podcasts. You know how dogs get so excited when their humans get home? It's because they perceive time differently than we do. Ten minutes feels a lot longer for your puppy than it does for you. Dogs take in visual information at least 25% faster than we do.

Picture Neo in the Matrix, dodging bullets as they drift past in slow motion. It's the same reason mosquitoes can avoid your slapping hand. Well, in a recent study, scientists wanted to see how an animal's way of life and the environment they live in affects their visual processing speed. They scoured data from more than 200 species across the animal kingdom to compare how quickly they process the world. And they found that the pace that animals perceive the world is fundamentally shaped by their lifestyle, and environment. Dr. Clinton Harlem is a neuroscientist at Trinity College, Dublin, and he's the lead author of this study. Dr. Harlam, welcome to Quarks and Quarks. Thank you very much. Thank you for

having me. First of all, what does visual processing speed have to do with how animals perceive time? It's indirectly related. We can't, unfortunately, directly measure how animals experience time overall. But what we can do is measure how much information animals have to deal with per time frame. And visual information is one of those things that we can measure. But from the animal's point of view, how does that change how they see the world compared to the way we do? So it's a little bit similar to how the refresh rate of a computer monitor works. So there's a certain maximum number of images that you get shown per second. And visual systems work a little bit like that as well. So there's a maximum amount of visual information that you can be aware of. And that

varies across different animal species. So some animals can see more per time frame than others. Well, walk me through what you were looking for in the study. So we know from previous studies already that this measure for how fast we see things varies from animal to animal. And what we looked at is how the environment and how different lifestyles are related to that. and so we looked at how different animals hunt for food, for instance, and what types of habitat they live in and how they move through their habitat to see if there are any links with how they visually perceive the world.

Well, how do you go about measuring the speed at which animals can perceive the world? Yeah. Luckily, we didn't have to do any of that ourselves because a lot of this information is already available in the scientific literature. But generally how it's done is with a little of... flickering light and you make an animal look at the light which can flicker at a lot of different frequencies and at a certain frequency the light will be flickering so fast that the animal can't tell that it's flickering anymore and that's that measure for the maximum number of flashes that it can see per second is the measure for how fast it can process visual information wow well how do you

know when the animals reach that threshold so in some animals you can do this behaviorally so dogs, for instance, and certain birds can be trained to respond to a flickering light, and then they get a food reward when they get it right. And at the point where they can't see that the light is flickering anymore, they stop responding. But not all animals can do that. So in animals that are a little bit less cognitively developed, you can do this with an electrode as well. You put an electrode directly on the eye, and then you measure the responses coming off the retina

as it processes the flickering light. What kind of different animals did you include in your study? About 237 different animals, and they span the entire animal kingdom. So we had not only mammals like cats and dogs, but also different types of fish and insects and arthropods, even invertebrates like worms and jellyfish, birds, so a little bit of everything. Wow. Well, what would be the evolutionary advantage? of experiencing time more quickly or more slowly than other animals?

Well, what we found is that animals who live very fast-paced lifestyles, they tend to also see things very fast. And intuitively, that makes a lot of sense, of course. So in an evolutionary sense, it's animals that need to hunt at a fast pace. They also need to see at a fast pace, so they can see exactly where their prey is going and how they need to maneuver through the environment. But we also see the same thing in animals that are very maneuverable in general.

So animals that can fly and that move around in this 3D world where they need to react to the environment very fast. Is there a cost for an animal to see the world more quickly? Yes, there's definitely a cost. So sensory processing in general is quite expensive on a metabolic level. So being able to see fast means that you're not. neurons have to fire at incredible rates and that they have to be very interconnected as well, and that costs a lot of energy. So generally what we see across the animal kingdom is that really only animals that really

depend on high visual processing rates have the ability. So it gets lost very easily in animals that don't really depend on it, such as animals that don't move around much or animals that live at night. Well, take me inside the mind of animals, you can to explain what it means to experience time differently. I mean, let's say you're an eagle hunting for a mouse. Right. Yeah, unfortunately, we don't exactly know what goes through the mind of the animal.

But as you said earlier, I really liked your analogy with Neo from the Matrix. So we think it might be that an animal that gets a lot of visual information and has a very fine-tuned resolution. in that sense, it might see things in a little bit more of a slow motion compared to how we see things, for instance, and that they have a lot more time to make decisions based on how their prey is moving. For instance, if you think about the eagle chasing a mouse, then these very fine-scale movements that the mouse is trying to make in order to escape. The eagle is very aware of all of that and has a lot of time to respond accordingly. So the eagle would see motion that would go beyond what we would see. Yes, exactly.

I'm thinking about things like fluorescent lights that flicker. We don't see that flicker very much, but other animals might see that if they were flying through a room. They would, yes. And that's kind of an interesting finding as well in this study. Now we know that there are a lot of species out there that can actually see flickering lights at a rate. above what we can see and a lot of our man-made lights they tend to flicker and we intentionally made them to flicker above our own perceptual rate or our own perceptual threshold but animals can still see that and we think that might have a lot

of negative consequences especially now that we found these links with their foraging success and the way they move through the habitat that they can be very negatively affected by constantly being exposed to flickering lights. Well, how can a better understanding of how animals process time and visual information help us with conservation work? Well, for us, it's very important to be able to get a good sense of how an animal experiences the world so that we can help either the animal adapt to the world better or have us adapt the environment so it suits the animal better.

So just knowing how an animal senses work in general is always very helpful in that sense. Dr. Harlam, thank you so much for your time. You're very welcome. Dr. Clinton Harlem is a neuroscientist at Trinity College Dublin in Ireland. Think back to the summer of 2012. Barack Obama was campaigning to get re-elected going up against challenger Mitt Romney. London was getting ready to host the Olympics and the K-pop hit Gangnam style was on its way to becoming a cultural phenomenon. And in the world of physics,

well, let's see if you remember this. Today in Geneva, a team of scientists announced that it has finally discovered the Higgs boson particle, sometimes referred to as the god particle. Scientists believe it plays a critical role in the creation of everything in the universe. It's been sought for decades. That's right. The big physics story of 2012 was the discovery of the Higgs boson. using the world's largest particle accelerator known as the Large Hadron Collider, or LHC. Now, the LHC, which opened in 2008, took 10 years to build and cost over $5 billion. It's housed in an underground circular tunnel 27 kilometers long underneath the border between France and Switzerland near Geneva. Thousands of scientists from all over the world collaborated on the project, including many Canadian researchers,

all with the goal of tackling some of the most fundamental questions in physics, one of which was the existence of this Higgs particle. And while the LHC is still up and running, physicists are already thinking about the next big experiment as they look ahead to addressing puzzles beyond the Higgs. And joining us now to help us make sense of the various proposals that have been put forward is science journalist Dan Fogg. Hi, Dan, welcome back to Quirx.

I'm delighted to be here. Now, I remember that announcement back in the summer of 2012. It was a pretty big deal. So what's been going on with the large head-drawn collider since then? Well, finding the Higgs was certainly the high point. Of course, research has continued. Physicists were hoping they might find other particles apart from just the Higgs, maybe something that might shed light on the nature of dark matter,

or the question of why the universe is made up of matter rather than antimatter, but no luck yet on that front. Meanwhile, the LHC has gone through a series of upgrades, which involved having the facility shut down, often for several years at a time, and it's going to shut down again for another four-year upgrade process. That will result in what they call the high luminosity LHC, basically aimed at boosting the rate of particle collisions even further. But yes, finding the Higgs was the main motivation for building the LHC, and pinning it

down was certainly its greatest achievement so far. Well, take me back. I mean, why was finding the Higgs boson such a big deal? Well, it was an incredible accomplishment because it confirms the existence of the so-called Higgs field, which is what physicists believe is responsible for giving particles mass. But the thing is, physicists knew the Higgs was there, or at least that it was very likely to be there.

That's because it's a prediction of what they call this standard model of particle physics. You can think of the standard model as being sort of like the periodic table, of the elements that you remember from the wall of your chemistry classroom. But in some ways it's simpler because instead of 90 plus elements, the standard model only contains a couple of dozen fundamental particles. But for physicists, finding the Higgs, even though they were thrilled about it, felt like it was actually just the beginning. Here's Dr. Max Svelowski, a physicist at Triumph,

that's Canada's National Particle Accelerator Laboratory, located on the campus of the University of British Columbia. The Higgs itself, discovering the boson, completed this beautiful story about the fundamental theory that explains how to standard model fits together, how the forces fit together, how the masses of particles emerge. So there's this really beautiful, complete picture that we have of standard model itself from this. But we also know there's so many questions that are still out there, things that we fundamentally don't understand. So as Dr. Sweetlowski says, there are a lot of answered questions. For example, why does the Higgs have the particular mass that it has?

And on top of that, there are the puzzles that I mentioned earlier about dark matter and the issue of matter versus antimatter. The standard model doesn't answer those questions, so physicists want to push further. Okay. So there's still a lot we don't know about the fundamental nature of the universe, but the large Hadron Collider was huge and it was really expensive. So if it didn't answer all of our questions, then what? We need a bigger Collider? Well, that's one idea, and in fact it's sort of the default plan. So a few years ago, CERN, the organization behind the LHC, unveiled its proposal for what it calls the Future Circular Collider, or FCC. Here's Dr. Tova Holmes. She's a physicist at the University of Tennessee in Knoxville.

The first thing you do in the FCC program is you dig a 90-kilometer ring. So it's a huge ring. It actually is about as big as you can possibly make it in the valley that Geneva's in. You basically run into mountains on either side. And the first thing you're going to do is put electrons and positrons in that ring and collide those at fairly low energies. But the unique thing is that they can annihilate into very clean collisions and you can target specific energies so that you can make tons and tons of higgs's. So they're going to make what we call a Higgs factory. And then once they've run that program and they've made all of these precision measurements of the Higgs boson, they'll take all of that infrastructure out of that tunnel, and they'll put in extremely advanced magnets that we have not

figured out how to make yet, but we have a great R&D program to get there. And they'll put in now a proton proton-proton-colider, so something that looks a lot more like what the LHC does, but at much higher energy. It's basically almost an order of magnitude higher than the LHC's energy. Okay. Now, is the physics community? on board with the idea of this bigger and more powerful particle collider? Well, naturally there are concerns. An obvious one is the cost, pegged at around $30 billion U.S. dollars, which would be divided up among the 25 CERN member countries.

And there are fears that it would siphon off talent and resources away from other projects. And, of course, there's the sheer length of time that it would take to get this thing up and running, especially because it would be built in phases, as Dr. Holmes explained, with that initial phase focused on making lots of Higgs particles, they call that the Higgs factory, which might happen around 2050, and then that second phase, smashing protons together and finally pushing up into the energy frontier, as they call it, that might not happen until around the 2070s or even the 2080s.

Well, 2080, even you'll be dead by that time, Dan. Oh, thanks, Bob. Okay, so what other options are on the table? Well, a number of alternative proposals have been put forward. One of the more interesting ideas is something called a muon collider. Now, a muon is a kind of a heavier cousin of the electron, and there are certain advantages to smashing muons together as compared with traditional particle accelerators

that smash either electrons or protons. Professor Holmes has been a huge supporter of this idea, so I'll let her explain. So muons are basically just heavy electrons. They're basically identical, but with 200 times the mass of an electron. And so far when it comes to colliders, we've built colliders out of much more familiar particles, electrons, and protons.

But as we reach for higher energies, those particles each have fundamental properties that limit how useful they are to us. So for the proton, it's composite, so it's made up of quarks and gluons. And that means that when you collide them together, you get lower energies because we're really colliding those quarks and gluons, and the collisions are very messy to reconstruct.

And for an electron, actually, its very tiny mass is a problem. Because of that tiny mass, it radiates away all of its energy as we accelerate it. So essentially what we need is a heavier electron, and nature has provided us one. That's the muon. Okay, so I can see how muons have certain advantages compared to either electrons or protons. So what's the catch? Yeah, if it was easy, they'd have built a muon collider already, right? So the main issue is that muons are not stable.

We've said a muon is like a cousin of the electron, but if you have an electron in front of you, it might very well stay there until the end of time, but a muon will decay in about two millionths of a second. So, of course, physicists are working on the technology needed to keep them around long enough to use them in collider experiments, but it's a challenge. Well, we've been talking about alternatives

to just building a bigger version of the large Hadron Collider, and a muon collider is one possibility. what else are physicists looking at? Well, as you know, the LHC is big and round, what if it could be smaller and straight? What do you mean? Not shaped like a giant donut? Right.

Think of a chocolate finger rather than a donut. So this idea isn't new. It goes by the name Linear Collider, and in fact we built a powerful one a while back in California that was the Stanford Linear Accelerator or Slack. Right, but as I understand, it isn't the main advantage of a circular collider is that you can sort of give the particles a little push

again and again as it goes around speeding it up. You wouldn't be able to do that with a linear accelerator. That's right. With a circular collider, it's like pushing your kid on a merry-go-round where you can push again and again to build up speed. With a linear collider, it's more like pushing your kit across the ice on a skating rink. If you want them to go fast, you have to give a big initial push. But actually, a better analogy comes not from ice skating, but from another sport.

Here's a clue. Catch a wave and you're sitting on top of the world. What? It sounds like we want our little particles to go surfing? Yes. We want them to catch a wave, in particular an electromagnetic wave in an electric field. I'll let Dr. Spencer Gessner explain how it works.

He's a physicist at the Stanford Linear Accelerator in California. And just a note, when he says RF, that's referring to radio frequency radiation, the same stuff that the CBC pumps out over the airwaves. Here's Dr. Gessner. The linear collider is a long machine, and it is filled completely with devices called RF cavities. So these are metal tubes. They're kind of bulbous. They have a very funny-looking shape to them.

And what they're designed to do is to sort of capture and control RF energy that is fed into them externally. And that creates a electromagnetic wave that propagates through these cavities that an electron beam can ride and gain energy from. So that technology is also present in the circular machine. In the circular machine, you get a little kick from these RF cavities every time you go around. In the linear machine, the whole machine is the RF cavity. So you get one long kick going through the machine to get up to high energy. Okay, Dan, we've talked about muon colliders and linear colliders, what other ideas are on the table? Well, one of the most exciting ideas that I've heard is a variation on the linear

collider called the plasma Wakefield Collider. Now, that's a lot of fancy words. Let's start with plasma. Everyone knows solid, liquid, and gas. Well, if you heat up a gas, you eventually strip the electrons off the nuclei of the atoms. That's called a plasma. And Wake, well, Bob, I know you're an enthusiastic boater, so you know it a is. Right. That's that V-shaped line of waves that follows the boat as it goes through the water

and the turbulence behind it. That's the wake, yeah. Yeah, exactly. And while water waves are fun for surfers, plasma waves get physicists excited. Dr. Gessner has been a keen proponent of the plasma wakefield idea, so I'll let him explain. So you can have waves that propagate in plasmas. and when those waves are, let's say, trailing, something that's sort of pushing the wave, we call it a wake field. So much the way that a boat creates a wake in its wake, we can have particle beams or laser beams creating these waves that trail the particle beams or laser beams as they pass through the plasma. And these waves have a very important feature, which is that they have a very large electric field associated with them. And these electric fields are what we use to accelerate particles.

So it's basically harnessing this intrinsic power of the plasma to support very large waves in order to accelerate particles to very high energy in a very small distance. Okay, so particles catch a ride on these plasma waves, pushed along by an electric field. So what's the big challenge of building this one? So the main challenge seems to be achieving the level of precision that you need, in order to make it work. Here's Dr. Gessner. So an RF cavity, it's a big macroscopic tube that is fixed in space. And so you can imagine aligning a beam of particles down the center of this tube and having them propagate through. And that's all great. Now, the plasma wave,

it's more ephemeral. We're typically talking about plasma waves that have a transverse extent of about 100 microns, which is the thickness of a human hair. Compare that to the RFSAW. earth cavities, which have an aperture of, you know, several centimeters. So like a Pringles can, let's say. So shooting something through the center of a Pringles can, that's one thing. Shooting something through the center of a human hair, that's a totally different thing. Wow. So a promising technology, but with some significant challenges, I guess the same goes for all of these proposals. So is part of the appeal of that first idea, making a bigger version of the Large Hadron Collider, just that it would use?

existing technology that's already tried and you test it? Yes, I think that's a big factor. Now, it would be huge and expensive, and it would take many, many years to build, but we know how to do it. We know how to make a Higgs factory by smashing electrons, and we know how to smash protons, which would be that later phase of the project pushing up into the energy frontier. Here's Dr. Max Svetlowski again. The future circular collider is doable.

We can do that. You know, beyond that, yes, you know, eventually can we scale up to something bigger than 100 kilometers? That's probably reaching the limit in an engineering sense of what we can do with this technology. And so at that point, I really hope that the technologies like the Mewon Collider or the Plasma Wakefield Acceleration, that, you know, in an ideal world we're developing these in parallel, you know, maybe that they're ready sooner. that'll be great because then we can access these high-energy collisions even sooner than we're thinking. So I sense a desire to avoid putting all of our physics eggs in one basket. So even if the future circular collider does go ahead, it sounds like physicists want to keep

developing these other technologies at the same time. Exactly, because even if the FCC goes forward, well, then what? What would the next project after that look like? Eventually, you just come up against limits in terms of how large you can build stuff. Well, does that mean there are limits to what we can learn about the subatomic world? Well, that's really the question, isn't it? And, you know, the scientists that I spoke with were all generally optimistic, and they obviously love what they do. But, yes, you can't help wondering, is there a limit to what we can know?

Here's Dr. Tova Holmes again. So at a certain time, people thought that an atom was indivisible, and that was fundamental particles, right? And so we've gone through over and over and over and redefined what is a fundamental particle as we've gotten to these smaller distance scales, which is to say higher energy scales. And so we got from elements, we found the nucleus, we found that there were particles inside the nucleus, the protons and neutrons. We found that there were quarks inside of the protons and neutrons. And there's really no reason that we can conclusively say, oh, we found it now we're good. Well, Dan, these projects are all so huge and so expensive.

People might ask, why are we spending so much money on this? What are we getting out of that for the money? Well, that's a good question, Bob. And actually, there are some physicists who believe it's not necessarily the best use of limited funds to go after these huge projects. You know, why not fund a thousand projects at $30 million each rather than one huge one at $30 billion?

On the other hand, it's hard to put a price tag on knowledge, right? How much was it worth to know that the Earth goes around the sun or that our solar system is a speck in a galaxy 100,000 light years across? Those are kind of philosophical questions, and also you never know when there will, in fact, be a payoff. I'll give Dr. Holmes the last word. Particle detection technologies have fully transferred out into medical imaging. Pet scans, mammograms, MRIs are all using technology built in colliders, basically. At some point, the photon was discovered. At some point, electromagnetic waves were discovered in the photon.

And now thinking about the billions of ways, electric magnetic waves affect our daily life is ridiculous, right? So it's very hard to predict when you discover something really fundamental about the universe, how it might come back and be useful in a million other ways. Thanks, Dan. Thanks, Bob. Dan Falk is the science journalist in Toronto. And that's it for Quirks and Quarks this week.

If you'd like to get in touch with us, our email is Quirx at CBC.ca. Our web page is cbc.ca.ca slash quirks, where you can check out our past episodes and find more information on the research we covered in the show. You can also follow our podcast, get us on SiriusXM, or download the CBC Listen app.

It's free from the App Store or Google Play. Quarks and Quarks is produced by Sonia Biting, Rosie Fernandez, Amanda Buchowitz, and Dan Falk. Our senior producer is Hannah Hoag. Special thanks to CBC Radio Archives, Patrick Mooney, Ross Tully, and Zoe Baraklough. I'm Bob McDonald. Thanks for listening. For more CBC podcasts, go to cbc.ca.ca slash podcasts.