Our Listener Question Show

Hi, I'm Jamie Poisson, and every weekday I host a news podcast called FrontBurner. We do one story a day, and we try to give you a deep but not overwhelming amount of information and context. Lately, there has been a ton of political news to keep on top of. Canada is facing a pivotal election, there's a power struggle at the heart of the Liberal Party, and the uncertainty of Trump's second term looms over all of this. So if you want to keep up with what's happening, follow FrontBurner.

This is a CBC Podcast. Hi, am I Bob McDonald? Can I welcome you to the Quirks and Quarks question show? Should I tell you what's on today's program? Bob, what are you doing? Well, can't you hear I'm introducing the question show? I mean, don't you know we have fascinating questions we'll be answering today? And why are you doing it like that?

Come on, Jim, isn't it obvious? Isn't it called the question show? Shouldn't everything be a question? It's the listener question show. They ask the questions. We find the experts with the answers. So I don't need to say everything like it's a question? Yeah, just do your normal voice, please. Okay, good. That's a relief. Well, welcome to another edition of our famous, fabulous, and fun Quirks and Quarks listener question show.

So let's get to your questions. Hello, my name is Genevieve Willis from London, Ontario. And my question is, is there any evidence to suggest that getting cold by, say, dressing inadequately in cold weather or sitting in a cold draft actually increases our susceptibility to illness? Dr. Michael Kennedy from the University of Alberta has the answer for this cool query. He's an associate professor of exercise physiology. Hello and welcome to our listener question show.

Well, thanks for having me, Bob. So can being cold give you a cold? Yeah, so if we look at respiratory viruses primarily, where they're transmitted, obviously, via the air, there is some evidence to say that if you're in a colder environment and you're breathing cold air, that your immune defenses, as well as the ability for the virus to replicate, are increased. So it's not the cold air itself that's making you sick.

That's true. It's not the cold air itself. It's the influence that the cold air is having on your body. And primarily that is focused on the respiratory or the lungs and the nasal passages, not necessarily your whole body or your whole body temperature. So that sort of feeling of cold, wet discomfort or the feelings of shivering that you might have.

I see. But if you're going to get a cold, you still have to have some kind of infecting bug. It's not just the air itself. That's correct. And cold air does actually allow viruses to be transmitted more easily. So they stay airborne and suspended more effectively in cold air. And that then also increases your risk of getting a cold virus or a flu virus. Well, what is it about cold temperatures that can lead to this increased susceptibility?

Yeah, so on the sort of respiratory tract, so if we think about our nasal passages and our upper airways, our throat, our mouth, if you breathe cold air, there are some things that happen to the lining of your airways in your nose as well as in your throat. And that allows viruses to take hold more easily than if you were breathing warm air.

One of the really interesting things is in the nasal passage, you have these tiny little hairs that help you clear out debris and viruses and things that are accumulated in the mucus of your nose. And those don't function as well in cold air. So that's be one sort of specific example of how breathing cold air reduces your ability to sort of get rid of some of those viruses that might be taking hold in your nasal passages. Now, how can the cold affect our immune system?

With the immune system, there is some evidence to show that you have reduced interferon responses, which is one of the sort of very important antiviral defenses. And so if you're breathing or in cooler temperatures, your body's ability to sort of mount those defenses is lessened than if you were in summertime temperatures or warmer indoor temperatures. What about the fact that during cold weather, we tend to spend more time indoors? Is that going to have an effect?

Yeah, that's a great question. Absolutely. And I was as I was thinking about talking to you today, I thought about last Christmas going alpine skiing in the Rocky Mountains and having a fantastic morning skiing and then going into a very sweaty, warm, crowded lodge and sort of wanting to turn around and just walk straight back out onto the snow. So we would call that an indirect factor. And that just that compression then of people, especially.

people that higher breathing rates that have come from outdoors to indoors does also increase your risk of transmitting those between individuals. Dr. Kennedy, thank you for your time and stay warm. All right. Thanks very much, Bob. Dr. Michael Kennedy is an associate professor of exercise physiology from the University of Alberta.

Now, I don't know about you, but the holidays just went by in a bit of a blur for me. This question is about why time seems to pass by so quickly, especially as we age. Jim Razzo from St. Albert, Alberta wrote to us, My question has to do with our sense of time passing. As I've gotten older, I'm 73 now, I notice that time seemed to pass more quickly.

Why does this happen? To find out, I'm here with Dr. Holly K. Anderson, a professor of philosophy at Simon Fraser University in Burnaby, British Columbia. Hello and welcome to our show. Hello, thank you very much for having me. So, does time pass more quickly as we get older?

Well, our experience of time definitely changes as we get older. Sometimes people think that because time seems to take up a smaller percentage of our overall life that we notice a year less and less. But actually, it's a series of other things that really make us experience time going faster as we get older.

Yeah, well, as someone who is older and noticing that, there are more years behind me, so they seem to compress together in the past, right? This is true, but that doesn't actually change how much this year seems to go. Once you've hit a sort of...

sort of stable adult brain. So when we're a kid, our brain is actually still developing. And a lot of that affects how we perceive the passage of time. Another really big contrast between when we're younger and when we're older that affects how we experience the passage of time is the kind of expectations that we have and how familiar or unfamiliar things are. So if you think about driving somewhere new in a car, for example, the very first time you drive there on roads that you've never seen before, it's sometimes

feels like it takes a really long time to get to wherever you're going. But then once you get used to it, then the time just seems to fly by. And then once we are driving to familiar places all the time, it feels like hardly any time passes. Is that why time seems to pass more slowly for kids because everything is new to them?

I think so. So for kids, a lot of stuff is new. And also sometimes they just don't know, like we don't always tell them as adults where we're going or what's about to happen. We don't give them a sort of play by play of what to expect. And so a lot of it is just really fresh and immediate. They don't have sort of those grooves of automatic habit that they have carved into their brains yet. And so that's part of why the present moment can feel different to them versus to adults.

And I guess in some cases, adults have fewer new experiences as we get older. Yes, but you might notice that if you do try something new or you're not sure what to expect, it can suddenly really change and you're like, wow, I am paying a lot more attention to each moment. Now, what about moments when it feels like time slows down in an emergency? So that's one of the ways in which your brain is sort of helping you take in more information suddenly.

What you're doing when you're taking in a lot of new information in an emergency is actually, I think, somewhat similar to what's going on when you've got a lot of new information that you're taking in under other sorts of unfamiliar circumstances. So when you're suddenly keeping track, when your brain is holding on to all of this information instead of just kind of culling it out for you, then it really feels like time slows down or that the present moment is just more full of experience than it usually is.

So then the speed with which time passes really depends on how much attention you're paying to what's going on around you. A lot of it...

Depends on that. There's another feature of it that has to do with how we experience longer passages of time. So, so far we've been talking about like moment to moment, how does it seem like, you know, time is going, but sometimes it can feel like, oh, this day took forever. And then the next one, there was just so much in it. And then somehow the month went by like, you know, incredibly quickly. And so there's a way in which our experience of longer chunks of time is also related to how much new and different material.

there is. And so it can feel like a year goes by really fast if you're really occupied moment by moment or day by day doing a lot of new or different kinds of things. And there's one more for me when time really slows down, and that's when I'm at a red light. It never turns green. It never turns green. This is true. Dr. Anderson, thank you so much for your time. Okay, thank you. Dr. Holly K. Anderson is a professor of philosophy at Simon Fraser University.

Well, now that the dust has settled, let's get to our next question. Hi, I'm Dan from Chateau Richet, Quebec. My question is, since there is no air or water on the moon to cause erosion, where does moon dust come from? For the answer, I'm joined by planetary geologist Dr. Gordon Ozynski, a professor of earth sciences at Western University. Hello and welcome back to our program. Thanks for having me back on the show, Bob.

Now, I know that you've actually analyzed moon samples sent back from the Apollo missions. What's that stuff like? So the surface of the moon is covered in this thick, you know, up to several meters thick layer of really dust. We call it the regolith or even the lunar soil, but the soil is a bit of a misnomer. How so?

So on Earth, soil is formed through erosion, by wind and water, and also by the decay of organic material, but none of these processes are possible on the Moon. Instead, the dusty lunar regolith is formed through what we call micrometeorite bombardment.

So on the Moon, just like on Earth, many kilograms of space material hit the surface every day. On Earth, though, we have an atmosphere, and that essentially filters out all the material kind of smaller than a few meters across, and it burns up in the atmosphere to create shooting stars. The Moon, in contrast, doesn't have an atmosphere, and so all the material hits it.

So if you can imagine thousands of micrometeorites, the size of a grain of sand or a basketball, hitting the surface of the Moon every day, it's this pummeling over millions of years that has created the dusty lunar regolith and that dusty surface of the Moon we see today. Well, does the Moon dust, when you look at it or hold it, does it feel and look like sand here on Earth?

So that's a really great question, too. And, you know, it looks almost a lot like talcum powder or something that you might apply to your body. But I absolutely wouldn't because we know when we look at it under the microscope that this dust is actually incredibly sharp. And the closest thing we kind of generate here on Earth would be volcanic ash.

So when you get a volcanic eruption, you get tiny droplets of liquid magma that quench to form glass. They break apart. And so essentially the regolith is like little shards of microscopic glass, which is really sharp. And this actually creates a lot of issues. We know from Apollo missions, for spacesuits, you know, for any moving part on the surface of the moon, this lunar regolith is going to be a big challenge.

So what, because it sticks to everything? What's it do when it gets into equipment? So if you ever follow the news during a volcanic eruption, one of the first things they do is actually to divert aircraft.

because one of the worst things you can do is fly a jet engine in particular through volcanic ash, because it will literally, even though these specks are microscopic, it will destroy the jet turbine engine. And so the same kind of principle applies for the moon. If you can imagine a bearing or a joint on a spacesuit or the bearings on a wheel, you'll get little microscopic, very sharp particles in there, and it will just grind them to bits.

So if we didn't have an atmosphere on Earth, does that mean that we would also be covered in this kind of dust? Absolutely, yeah. And so, you know, if you look at other objects in the solar system, asteroids are another good example, or any object which doesn't have an atmosphere, you're going to get the same process happening of just, yeah, bombardment day after day after day of tiny microscopic bits of material from space and just kind of grinding down the surface of that object.

Dr. Osinski, thank you so much. You're welcome. Dr. Gordon Osinski is a professor of earth sciences at Western University in London, Ontario. Our next listener question is a real stinker. Hello, corks and corks. My name is Scott Beach. I'm from East York, Ontario. I have a question. We have a couple of small dogs, little terrier-type things, and I've seen one lick the other's anus. They're disgusting little creatures, I realize.

but is there a scientific reason why they would do this? Why do dogs sniff and lick each other's butts like this? Thanks so much. Bye. To get the answer, I'm here with Dr. Simo Gadboa. He's the principal investigator at the Canine Olfaction Lab at Dalhousie University in Halifax. Hello and welcome to our program. Hello. Nice to be here. First of all, what information can dogs get from each other's butts?

Well, in dogs, actually, they can get quite a bit because, as you know, when there's a problem with them, they have inner glands. So those inner glands are one of about four or five sets of very well-known glands that produce what we call pheromones. And pheromones are basically social odors. So they contain all kinds of information about the status of that dog.

their reproductive status, for instance, what they ate if they're sick, and including, actually, we think, at least from research with rodents, information about, you know, if they're closely genetically related, for example. But why the butt? Why not have glands around the mouth or the ears or anywhere else in the body?

Well, they do, actually. We just probably don't notice it as much, but they do investigate each other elsewhere. But, you know, there's quite a bit of high concentration of odors around there and, yeah, can give a lot of information. In fact, we think that in wolves and coyotes, for instance, it's a way of figuring out if your companion or your friend has parasites, which may actually drive sometimes their decisions in terms of who they will mate with.

and all that kind of nice stuff. Well, how important is this information to the dogs?

Well, it's a little bit like they're checking their pee mail, if you want, or they, you know, reading Facebook posts. Like when you walk your dog and they keep every 10, 15 meters stopped to pee. That's what they do. They leave messages. They investigate the messages from others. So it's a way of exchanging information the same way that, in a sense, we do with social media, except that they do it with scent. And it's not just mammals. It's also reptiles. The fish do this to some.

extent as well. Now, our listener asked specifically about licking. Why would dogs lick in order to get at this information? There's actually, in most mammals, two olfactory systems. There's the primary olfactory system. That's the one that we know very well in humans because that's our main one. And then there's the secondary or accessory olfactory system.

that includes an anatomical part that we call the VNO, or vomeronasal organ. And that organ is very specialized in decoding those pheromones I was mentioning earlier, those social odors. So interestingly, there is a little...

bump right in front of the mouth of the dog on the palate, on the top of the mouth that you can actually feel if you put your finger in there. And it's called the nasal palatine duct. And that is a direct entry into that VNO or vomeronasal organ. So basically when dogs lick, what they do basically is they go and get the molecules with their tongue and they bring those back in.

the mouth at the top of the palate so they can enter directly into the VNO. So that's why licking is a huge part of olfaction, at least for pheromones in dogs and a lot of mammals, actually.

So the dog's getting information both through its nose by sniffing and through licking through this other organ. So it's getting even more information. Absolutely. And in some mammals, we actually know that the information is actually different between the two systems. The primary olfactory system is sometimes involved in decoding for amounts as well, but sometimes it's just regular neutral odors. But yes, they certainly have two very special aspects.

systems, at least in dogs and wolves. So for dogs, it's not a disgusting habit. It's an interesting habit. As interesting for us as it is to check Facebook and, you know, read our social media posts, I guess. Yes. Dr. Gadbois, thank you so much for your time. My pleasure. That was fun. Simo Gadbois is the principal investigator at the Canine Olfaction Lab at Dalhousie University.

Our next question sounds like it might be a bit of a pain to answer. Hi, I'm Rob Smith from Victoria. My wife and stepdaughter are both redheads, and anecdotally they seem to be extra sensitive to pain. When getting dental work, for example, my wife always requires more painkillers than expected. Is there evidence to suggest redheads are particularly sensitive to pain?

To get the answer, we're speaking with Dr. Jeffrey Mogul. He's the E.P. Taylor Professor of Pain Studies at the Allen Edwards Center for Research on Pain at McGill University. Hello, and welcome back to Quirks and Quarks. Hi there, Bob. Nice to be back. Now, you actually researched redheads in pain. What did you find?

Well, we did, and it was a long time ago. There were a number of studies. It's interesting that if the wife requires more painkillers, there are actually two possibilities. And one is that she's more sensitive to pain, but the other is that she's less sensitive to painkillers, also known as analgesics. And both of these have been studied in relation to having red hair. I think, though, overall, the existing evidence would be

go in the direction opposite to the anecdote. So first of all, we found starting back in 2003 that redheads were more sensitive to analgesics, although this was for opioid analgesics, the more powerful type. I don't think anyone has looked at the over-the-counter drugs like aspirin or acetaminophen.

For pain sensitivity, the situation is a little bit more complicated. There are actually two studies performed in 2005. One was by our group, and we found that redheads were less sensitive to pain from electric shock. And we also tested redheaded mice and found them to be less sensitive to pain across a wide variety of pain types. But there was another study published by an American group the same year.

And they actually found that redheads were more sensitive to pain from heat and cold stimuli. So who is right?

Well, you know, no one's done it since, so we don't really know. Okay. This is one of these scientific questions where more research is needed, right? Indeed. Although I do want to point out that there was a study published in 2020 that's probably more important than anything that was done before. And they looked at data in the UK Biobank, which is a collection of data from 500,000 Brits. And this analysis found that redheads were less likely.

report having chronic pain, which is probably more important than what happens when you go to the dentist. Well, where did this whole idea of unique pain sensitivity in redheads come from?

Right. It wasn't like we woke up one day and decided we're going to study redheads. We were looking for a gene in mice, and that gene turned out to be MC1R, the melanocortin-1 receptor gene. And once we found that that was the gene we were looking for for analgesia, we realized, of course, that that's also the gene for red hair. And so an easy way to test it in people would be to get some redheads.

Okay. So we got the two conditions here. There's the sensitivity to pain, but then there's the sensitivity to the drugs that try to kill pain. Exactly. And you're saying that you can get conflicting results on both.

That's right. Genes that predispose to how sensitive you are to pain are not necessarily the genes that predispose to how sensitive you are to analgesics, although they could be. And there's one more thing that makes it even more complicated, which is that there's also a published involvement of this same gene in anesthesia. And so it turns out that anesthesiologists have been whispering amongst themselves for many decades that redheads were harder to put down.

with gas anesthetics. And a group in 2004, I think, decided to look and to see if this was true. And it turned out to be true. Redheads respond less well to anesthesia. So what's your message to redheads? I think the preponderance of the evidence would suggest, in fact, that redheads are less sensitive to pain. But there are many, many, many, many other genes involved.

maybe thousands, and we only know a few of them right now. Dr. Mogul, thank you so much. My pleasure. Dr. Jeffrey Mogul is the E.P. Taylor Professor of Pain Studies at the Allen Edwards Center for Research on Pain at McGill University. From the Los Angeles Times, this is Boiling Point. I'm Sammy Roth. I've been reporting on energy and climate change in California and across the American West for a decade.

I'll be asking scientists, politicians, activists, and journalists the same questions. What are the challenges we face to building a better world? And what are the solutions we need to embrace, even when it's hard? Boiling Point will be available everywhere you listen to podcasts, starting January 16. I'm Bob McDonald, and you're listening to the Quirks and Quarks Listener Question Show 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 next, more of your questions on what birds see in themselves, animal sleep schedules, artificial elements, and the expanding universe. Hello, my name is Stephen Quinn from St. John's, Newfoundland. My question is, how can the universe be expanding at the same time as galaxies are colliding?

Well, standing by with the answer is Dr. Sarah Ellison. She's a professor of physics and astronomy at the University of Victoria. Hi, Dr. Ellison. Welcome to our show. Thank you, Bob. I'm excited to be here. First of all, tell me about the expansion of our universe. What does that actually look like? So the classic analogy we give to our students is to imagine...

a ball of dough in which we have embedded raisins. And before we put it in the oven, we've made sure that the raisins are more or less equally spaced from one another. And then when we put the dough in the oven and it's expanding in all of its three dimensions, all of those raisins are moving away from each other because they're being carried along by the expansion of the dough. And so in this analogy, the dough is space and the raisins are the galaxies. And so they're all moving away from one another.

And one of the important parts of this analogy is that even though we observe almost all galaxies to be moving away from us, it doesn't mean that we live at the center of the universe. We could live in any galaxy and we would be making the same observation, just as if we placed ourselves on any of these raisins in this loaf, it would seem as if all of the raisins were moving apart from one another. Okay, so...

To get to our question, if the universe is expanding, why are galaxies like our own Milky Way and our nearby Andromeda galaxy rushing towards each other and will eventually collide? Right. So if we go back to my analogy about the raisin loaf, and I said if we put the raisins in an equally spaced distribution in the loaf, but galaxies actually are not evenly spaced in that real universe. And this is the crux of why we sometimes get galaxy collisions. So if you could make a map.

of the distribution of galaxies in space you would see that they like to be quite social they're clustered together in groups of a few tens or in massive clusters where the galaxy numbers are up to a thousand or so and then in between these big groups and clusters there are these large voids and so if you were to make a two-dimensional map

of the galaxy distribution, it would actually look a lot like a satellite image of say North America at night where you see people clustered together in big cities and then there are big voids in between. And so when galaxies live in these over dense regions of groups and clusters, the force that they feel most strongly is the gravity of their near neighbors. So even though space on a large scale is expanding, what they are feeling more keenly is the attraction of their neighbors in this small.

And so they can be whizzing around one another in an orbital configuration that is somewhat distinct from this greater expansion. Oh, I see. So it's a local effect among local groups of galaxies. I'm thinking of a crowd of people coming out of a concert and everybody's spreading out in different directions, but then there are families that stick together. That's an excellent analogy. So what happens when galaxies do collide?

Big fireworks. So galaxies are mostly composed of gas and stars with some dark matter. And then they also have a central supermassive black hole in their centers. And the interaction of these various components. can completely disrupt the normal goings-on in a galaxy. So for example, when two galaxies have a close passage, the gravitational interaction leads to the gas that is normally settled in a nice regular disk to flow towards the centre. And in the centre then we have this big pile-up.

of gas and that can trigger something that we call a starburst so suddenly many new generations of stars are produced but perhaps

the most exciting, the most dramatic event is when that gas can make it all the way down onto that supermassive black hole that's in the middle of the galaxy. And that can trigger very, very energetic events, things like a quasar. So this is where the material in the center of the galaxy, this gas is kind of going down the plug hole. It's being funneled all the way down onto this black hole whose mass can be millions or even billions of times the mass.

of the sun and it can produce very, very energetic reactions. Wow. So how long have we got to wait before the fireworks begin when our galaxy collides with Andromeda? Well, the good news is that you don't have to cancel your weekend plans. It's still going to be another four billion years or so until that happens. Dr. Ellison, thank you so much for your time. You're very welcome. Dr. Sarah Ellison is a professor of physics and astronomy at the University of Victoria.

Our next question is elementary. Hello, it's Susan Boyd from Ottawa. And my question is, since some of the elements in the periodic table do not occur naturally, is there a limit to the number of elements that could be created artificially? If so, what is the limiting factor? Thank you, Quirks and Quarks. For the answer, we're going to Dr. Uris Maya, who is a research officer with the National Research Council of Canada.

Hello and welcome to our question show. Hi, Bob. As I look at the periodic table of the elements here, I notice that there are 118 of them. So how many of those are naturally occurring versus artificially made? Well, we have about 118, as you said, in the table today. And pretty much everything up to uranium, which is 90 elements, are occurring on...

in nature, and everything beyond that, so about 30 more, would be all synthetic. Well, how do scientists create a new element? I can give you an example of how the last one was made. It's really just a glorified smashing two smaller elements together in hopes that they actually fuse and make one larger atom. And what was that one? So the last one was made in...

2010 that's the element tennessee this was a collaboration between usa and russia back when when these kind of collaborations were still possible and so what happened there was the calcium was the number 20 element was the bullet if you wish and so to make 117 you would then need

element 117, you would need 117 minus 20, which is 97. So that's the target element at which you then would shoot the calcium atoms. And so the target was made in Tennessee, hence the name Tennessean for the 117 element. And it was sent by a commercial flight from New York to Moscow. And that's where it was bombarded with calcium for six months or a year.

And they made a few atoms of this new element. So it sounds like making a snowball here. You take a handful of snow, another handful, you smash them together, you get a bigger snowball. Exactly. Expensive snowballs. Yes, instead of your hands, you need a particle accelerator to do that. Now, when you mention numbers like 2097-117, what does that represent? So that's the number of protons in the nucleus. That's literally the defining.

hallmark of an element. It seems then that as we build these artificial elements, they're getting bigger and bigger and bigger. What's the limiting factor there to how large we can go? The basic classical model of the atom just thinks of the nucleus as a small droplet. And the nucleus themselves is like a ball of two types of particles. You have the neutrons and you have the protons. And the glue that keeps them together is the so-called strong force.

That's what keeps all these elementary particles together. But here's the catch. Because the protons are positively charged, right? They don't want to stick together. And so the stability of these atoms is ultimately by this delicate balance of these two opposing forces. So strong forces that keep neutrons, protons together and electric forces that pull them apart. And so, of course, the heavier the nucleus, the harder it is to keep them all together.

I see. What about the role of the electrons around the outside? Yes, that's just another way of we can see how far, how big we can get. And this was an idea that was popularized by Nobel laureate Richard Feynman. And the idea is that because the atoms are very much like the solar system, right? And you have the electrons that are spinning around circular orbits around the nucleus because they have opposite charges, right? But as the nucleus becomes larger and larger,

these electrons now have to move even faster and faster in order to stay in their orbits. And, of course, at some point, they would have to move faster than speed of light, which, of course, is not possible. And that occurs around element 137. Ah, okay. So 137, largest one we could get. What do you think that would be called? Well, there is no name for these officially, but because, of course, Feynman was the one who popularized this simple...

Mark, it's almost everywhere you would find this element goes by Feynmanium in honor of Richard Feynman. What kind of applications can these artificially made elements be used for? I guess a good answer would start with the very first artificial element, technetium. And this was made in the 1930s. And it remained a...

just pure scientific curiosity for decades until scientists realized its potential in medical imaging. And so today, almost 100 years later, technetium is one of the most common medical isotopes in the world. So it enables us literally to see how various parts of our body are functioning. I mean, we have other very good examples, like, you know, you have smoke detectors at home. They are made possible by artificial elements.

You have Mars rovers roaming around the Mars. Well, they get their electricity from artificial elements and so on. So we have a wider variety of almost everyday examples of these artificial elements today. Well, what is it about these artificial elements that make them so useful? Well, it's largely the fact that they are radioactive. And so we utilize...

those energies that they give off in different ways. So whether it's to make an image of our bodies or to generate electricity or to catch smoke particles. Dr. Maya, thank you so much for your time. All right. Thank you. Dr. Yuris Maya is a research officer with the National Research Council of Canada. He also just so happens to be one of the official guardians on the International Selection Committee that curates new entries into the periodic table.

Hi, Quarks and Quartz. I'm Robert Laroche from Halifax. And my question is, why is the color of wet clothes always more vivid than when they are dry? For the answer, I'm here with Dr. Sarah Purdy. She's a physicist at the University of Saskatchewan who uses light to investigate materials. Hello and welcome to our program. I'm so happy to be here. Now, I've definitely noticed that when I get sweaty or spill something and you get these dark marks on your shirt, so why is that?

This has everything to do with the texture of the material that is wet. So when a material is dry, the surface might be rough. This is a lot of opportunities for light to be scattered in all kinds of different directions. And so because that light gets spread out and maybe reflected at different wavelengths, then it looks dull to our eyes. Okay, so what does the water do? When the water...

touches the surface, it kind of fills in some of those gaps. And you can have a couple of things that happen. When light hits a surface, it can be reflected, it can be absorbed by the material, or it can penetrate into the material and sometimes pass through. And this is what happens with water. So some of the light is reflected, and that we can see is kind of a bright spot.

But the rest of the light passes through into the water and then bounces around in the crevices of the texture of the material. And that gives more and more opportunities for the light to be absorbed by the material. And the color that we see reflected back out is what survives all of those absorption events. Now, is this the same effect that happens when you see a nice colorful rock in a river or a lake and you pick it up? It looks great until it dries out, then it's really dull.

Yeah, this is exactly what's happening with rocks that are wet. That rough surface, the gaps get filled in by the water and the light gets reflected back down into those crevices and comes back out as the color that the rock is reflected. So any rough surface really is going to do this. And you'll notice that if you put a polished rock into water, you won't see the color come out more vividly.

Because you're comparing that contrast, your brain is comparing the rough surface rock with something that's a little bit more smooth. Dr. Purdy, thank you so much. My pleasure. Dr. Sarah Purdy is a physicist at the University of Saskatchewan. This next listener is curious about whether animals are getting enough beauty sleep. Hello, my name is Paul and I'm calling from Newmarket, Ontario. My question is this.

If animals wake up at sunrise and go to sleep at sunset, how do they cope with the varying hours of sunlight? How do they do compared to humans who are supposed to get eight to nine hours of sleep regardless of the length of sunlight? Thank you. For the answer, we turn to Ming-Fei Li, a PhD candidate at the University of Toronto in anthropology. Hello and welcome to our question show. Hi, Bob.

So is the sleep of animals affected by changing daylight hours throughout the year? Yes, but before I tackle that part of the question, I just want to clarify that. So not all animals wake up at sunrise and go to sleep at sunset. These are true for some diurnal species, but animals can also be active during the night if they're nocturnal. They can be active during dawn and dusk if they're crepuscular. So not all animals are waking up as the sun rises.

Okay. What about the length of time that animals sleep? Does that vary as well? Yes. There's a huge variation in sleep duration for animals. I think one of the shortest sleepers that we know is the elephant. They sleep for around two hours a day. And on the other extreme end would be brown bats, who are super long sleepers. They'll sleep for 19 to 20 hours a day. And the length...

of time that an animal needs to sleep for is dependent on several intrinsic factors such as body mass, brain mass, metabolism, their feeding requirements, and of course predation pressure. So the daylight cycle is just one of many factors that affect how long an animal sleeps for. But are there animals that do rise at sunrise and sleep at sunset the way we're supposed to do ourselves? Yes, there definitely are.

I think a good example, like a good model species would be dogs, domestic dogs, who have an incredibly flexible activity pattern, meaning they kind of mirror our activity pattern. They can also be nocturnal. Think of livestock guardian dogs, right, where they have to work during the night. Well, in the wild, do the activity patterns of animals change as the length of day and night changes throughout the year?

Some animals, yes, definitely. So I would say with the increase in daylight length or photo period or the decrease in photo period, that's kind of a signal of changing seasons. So many animals will pick up on those cues and they'll start going into torpor or hibernation or migration. But a lot of it also depends on kind of how many hours they need to sleep to maintain healthy functioning. So even in if you think of up north where you have these.

incredibly long polar nights and midnight suns, right? Where it's almost 24 hours of total darkness or total daylight. That doesn't mean that animal is awake for 24 hours or that they're asleep for 24 hours. They still have to meet their physiological needs, but you do see shifts, right? So maybe they tend to forage more.

when there's longer daylight, to prepare them for those long polar nights where they sleep a little bit more and can survive off of their fat reserves. Well, let's take an example here, say a coyote, which lives in the wild, but is also encountering humans in urban areas more. What about that? Yeah, that's a great example. So coyotes are considered crepuscular. They're most active during dawn and dusk.

But they're one of those species that have very flexible activity patterns. So it's been found that coyotes living near a school, like an elementary school, somewhere in the GTA, I believe, they had the lowest activity levels around 9 a.m. and 3 to 4 p.m., which coincides with school drop-off and pickup hours. So they're kind of...

trying to avoid encountering humans, right, to mitigate potential conflict by staggering their activity bouts so that they're not active when humans are the most active. So in other words, animals are less concerned with sleep according to day and night and more about food and predators. Yes, correct. Ms. Li, thank you so much for your time. Thank you, Bob. Ming-Fei Li is a PhD candidate in anthropology at the University of Toronto.

Bonjour, this is Marie Beaudoin from Salt Spring Island, and I have a question for you. How do birds, where the male and females look the same, tell each other apart when it comes to meeting? Thank you very much. For the answer, we go to Dr. Matt Rudink, a professor of biology at Thompson Rivers University in Kamloops, British Columbia. Hello and welcome to our question show. Hi, it's great to be here. Thank you.

What are some of the ways birds of the opposite sex can recognize each other when the males and females look alike? Yeah. So one of the ways to think about this is that we are coming at this question from very much a human standpoint. And we need to try to look at it from an avian standpoint, from what the birds are seeing. And so while to us, to our eyes, these birds might look quite a bit, quite similar, to the birds themselves, they can look extremely different.

Our eyes have very good sensitivity from about 400 to 700 nanometers. That's our human visual spectrum. But with birds, they actually have an extra cone in their eyes allowing them to see from about 300 to 700 nanometers. So there's this whole world of UV visible light that they're able to see. And many species, what we found is while they might look similar to our eyes, within that UV part of the spectrum, they're actually very different. So visibly, they can be...

you know, quite different from each other. But what gets, I think telling a male and female apart is probably just the tip of the iceberg. Realistically, many of these species can tell individuals apart from each other. So it's not probably a very hard trick to be able to tell a male from a female.

Well, they can actually recognize all the neighbors and the other individuals that they are surrounded with and the ones that they're interacting with on a daily basis. They know that that's Bob and this is Matt. And it's pretty easy for them to tell each other apart. Well, what about using songs to help tell each other apart? Yes, absolutely. And so this is something that, you know, especially within songbirds, they recognize the songs of all their neighbors.

And they can tell, you know, who's a threat, who's not. And when you introduce a song of a non-neighbor, a stranger, and you kind of do a playback in the territory of that male, he'll act extremely aggressively because this is someone new that is posing kind of a great threat to that individual being in his territory, a threat in the sense of probably trying to copulate with his female, which is not something that he wants him.

that other male to do. So yeah, absolutely. They can definitely differentiate these different vocalizations from different males and females. And is it usually the male that's doing the singing?

Yes, absolutely. When we're talking about the temperate regions, when you get into the tropics, things get a lot different. And this kind of gets at our bias in a lot of science, where a lot of this work comes from Canada and the United States and Europe, where when you get into the tropics and you get many cases where both males and females are singing and you even get duetting species where they sing back and forth. And so we really have to recognize that we're...

Looking at this male singing kind of from this biased temperate standpoint. Why is it that males and females sing together in the tropics, but they don't do that up here in Canada? There are two parts of this. One is that you have much more prolonged breeding seasons. Here in the temperate regions, our breeding season tends to be relatively short. And so the pair bonds that you get, the associations you get, tend to...

to last a relatively short period of time just during that breeding season. That's pretty much it. When you get into the tropics, you get these year round associations where the males and females will be bonded for the whole season. And the quality of that duet and their ability to duet together not only allows them to strengthen their pair bond together, but also be perceived by others as having the strong bond that's defending this territory.

from others for them to not be able to intrude on it. So it's not just the strength of the individual, it's the strength of the pair that becomes important. Dr. Rudink, thank you for your time. My pleasure. Thank you so much. Dr. Matt Rudink is a professor of biology at Thompson Rivers University in Kamloops, British Columbia. My name is Warren Saylor, and I'm from London, Ontario. My question is this.

Did Neanderthals speak? If they could not, would that account for the dominance of Homo sapiens? Thank you very much. We reached out to one of our paleoanthropologist friends, Dr. Bensa Viola from the University of Toronto. Hello and welcome back to the show. Thank you. It's great to be back. First of all, do you think that Neanderthals could speak? My personal opinion is yes.

limited differences we see in the morphology between these two species. After all, we are very closely related. Our last common ancestor lived about 600,000 years ago, which in paleontological terms, at least, is practically yesterday. If we look at the kind of behaviors that Neanderthals exhibited, we have a whole suite of them that we usually call symbolic behaviors, which are the kind of behaviors that are hard to imagine to do without being able to talk to each other.

Before we get to that, what about the fossil record? Is there any indication that they had the mechanics to speak? The difficulty with reconstructing speech from fossils is that the most important parts for language are things like the brain that doesn't fossilize and the vocal tract that is also soft and squishy stuff that we don't find in the fossil record. All we find are bones and teeth usually, and the bones are usually...

mostly the thick ones, not the very fragile parts around the base of the cranium, for example, that are important for language. So if we don't have the direct fossil evidence, what are these other reasons that you think that Neanderthals could speak? Various behaviors include things like burying your dead. Another one is the use of various kinds of ornaments and the creation of these ornaments. We have evidence for Neanderthals.

using various kinds of animal teeth, making holes into them so they can be worn as pendants or sawn onto clothes, potentially. We see the use of the claws of raptors, of large eagles and similar things, again, also as ornaments. But I think the complexity of some of the Neanderthal campsites that we also see with clear distribution of tasks in different areas, clear traces of dwellings and so on, are all things that

to me, make little sense without language. It's just very hard to do all these things where you have to think in complex ways and you have to teach your offspring to do them. So you're saying that this level of cultural sophistication among the Neanderthals suggests that they needed language? Yes, I think that is the most likely explanation of how this would be possible.

Now, I understand there's another piece of evidence in a Neanderthal fossil where the person was injured. Can you tell me about that? Yes. I mean, we also see these kind of behaviors with kind of what you could almost call compassion in Neanderthals. We have several Neanderthals who survived with rather severe injuries, and the most extreme is from Shanidar in Iraq.

where we have an individual who probably lost one of his arms, so the lower arm and the hand is missing. And the same individual also has a major impact on the side of the cranium that could have or probably made them blind at least on one eye. And they survived both these injuries for an extended period of time. So if you were injured, you'd have to talk to other Neanderthals to have them take care of you. Exactly. You know, somebody took care of this person for...

an extended period of time, five to ten years at least, but likely significantly more. And it's just hard to imagine these kind of behaviors without being able to exchange ideas to communicate your needs. And we have this newer evidence that Neanderthals and Homo sapiens interbred because we carry Neanderthal genes in this, so there had to be some kind of communication going on there. Exactly. We have a lot of evidence for Neanderthals and modern humans interbreeding.

And to me, it's just hard to imagine that these groups interacted without being able to communicate with each other. So if Neanderthals did have some sort of language, why do you think that Homo sapiens thrived and they didn't? Oh, if I knew that, I'd be very happy. This is one of the big questions. I think there's several things that were going on. Neanderthals disappear at a time when we have major swings in the climate.

A few hundred year long cold periods where the climate became significantly colder probably made it hard for Neanderthals to survive in some areas where they were present. Now, DNA from quite a few Neanderthal individuals, and what we usually see in them is extreme inbreeding. These are individuals who live in very, very small groups. Modern humans that are contemporaneous with them.

don't have the same kind of issues. They have significantly larger genetic diversity, more genetic diversity, and were able to exchange DNA and probably also ideas more frequently with other groups. And that probably helped them a lot with surviving. Dr. Viola, thank you so much for your time. You're welcome. Thanks for having me. Dr. Bensa Viola is an associate professor in the Department of Anthropology at the University of Toronto.

And that's it for this edition of the Quirks and Quarks Listener Question Show. If you'd like to get in touch with us, our email is quirks at cbc.ca or just go to the contact link on our webpage at cbc.ca slash quirks where you can read my latest blog or listen to our audio archives. 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.

Quirks and Corks is produced by Rosie Fernandez, Amanda Buckowitz, and Sonia Bidey. Our senior producer is Jim Lemons. I'm Bob McDonald. Thanks for listening. For more CBC Podcasts, go to cbc.ca slash podcasts.