Quirks and Quarks

00:00 If you're listening to this, I already know you have great taste in podcasts. But maybe, if you're like me, you still wonder if you're missing out on the best stuff. That's where the Sounds Good newsletter can help you out. Every other Thursday, the audiophiles at CBC Podcasts highlight one must-hear show and lots of other new and noteworthy titles. They do conversation starters, they do hidden gems, and they also tell you about the stuff they love that they didn't make. Go to cbc.ca slash soundsgood to subscribe. 00:31 This is a CBC Podcast. 00:35 Welcome to the Best of Quirks and Quarks. This program was originally broadcast on January 3rd. 00:45 Hi, I'm Bob McDonald. Welcome to Quirks and Quarks. To start the new year off right, we have our ever-popular and always satisfying listener question show, where you tell us your burning science questions and we find the answers for you. Because the important thing is to never stop questioning. As Albert Einstein once said and added, it is enough if one tries merely to comprehend a little of this mystery each day. Well, we're going to take that up a notch and get to the bottom of the many science mysteries you've been wondering about. 01:18 Like, why do some athletes stick out their tongues when they play? How is the dust inside our homes changing? And why did a Canadian astronaut's eyesight change when she was in space? All this and more on today's Listener Question Show. 01:39 Our first question is out of this world. Well, off of our world, at least, in low Earth orbit. 01:46 My name is Michael Kaczmarek. I'm here in Toronto, Ontario. Some years ago, many years ago, in fact, I'd heard that when Roberta Bondar came back from space, her nearsightedness had actually improved. 01:59 Now, if that's correct, I would love to know what that was about. Thank you very much. 02:05 Well, do we ever have a treat for you? Here to answer that question is none other than Dr. Roberta Bondar herself, who in 1992 became the first neurologist to ever fly in space. She also spent a decade as the head of an international space medicine research team at NASA to better understand the neurological effects of being in space. 02:27 Hi, welcome back to Quirks and Quarks for our annual holiday question show. Great to be here. 02:33 So what did you notice had changed about your eyesight when you were in space? 02:37 It was fantastic, actually. 02:39 I could see without my glasses on. I remember looking out the flight deck window and out the little window in the space lab and being able to read emblems and things without my glasses on. In fact, I even squinted to see if I could make my vision better, but I couldn't. So I didn't wear my glasses the whole flight. 02:58 Why did you need glasses in the first place? 03:01 Well, I was nearsighted. That meant that I needed to have glasses. I had astigmatism, which meant that I need to have a bit of what's called a cylinder in my glasses so that when I looked at things, they were perfectly clear. So on Earth, as a pilot, I was able to fly because my visual correction was such that I passed all the tests. So I had glasses as a lot of people do when they go to fly in space. But being nearsighted, it was also actually quite a nice deal because when I got into space, I became more farsighted. 03:37 And so that actually nullified or canceled out my nearsightedness and it became normal sighted. 03:44 Wow. 03:44 No glasses required. It was a gradual change, I think. Well, for me, it seemed to be gradual. because I was flailing around and being sick a bit for the first day or so. So I didn't really want to wear my glasses because they did make me feel a little bit more queasy, I would say. So I probably was going through those changes at the time. So certainly by about the first 24 hours, I didn't really wear them very much. And it was probably about, I guess on about day two that I really noticed I didn't want to wear my glasses at all. 04:18 And I had them, I had some duct tape as we always had in space and I duct taped them onto a counter and I didn't even notice they were gone. And about day three or day four, the commander came up and he said, hey, Bonder, are these yours? And they were my glasses and they had actually come off. The duct tape had released itself from the side of the cupboard and it floated with the air currents into the flight deck and they had smacked the commander in the face. So he kind of said, oh, these must be Bonders and dragged them back, but I didn't need them at all. 04:50 But they certainly had their way with the air currents. 04:54 Well, I'm thinking about the eyeball like when you see astronauts playing with water and it forms a perfect sphere when it floats in space. So the eyeball, how did the shape of your eyeball change that gave you the perfect vision? 05:08 Well, we don't really know exactly how it changes because the eyeball itself is comprised of many things. It does have a gel inside it, and it does have part of it that is aqueous, that has water. And it also has a tear film on the front that you can imagine does have some type of viscous change or some type of physical mechanical changes. And the lens itself, and certainly a lot of people who fly in space are older, so the lens may not be as pliable as it is with younger people. And there's also the things that are in the orbit itself, in the back of the eye that keep the eye constrained. 05:43 There are the muscles and the ligaments. and the fatty tissues. So there's lots of stuff in there that really can change differently according to their viscosity and the tensile strength of the eye. So we're really at early stages now. They're using a special type of visualization of the eye to look at the thickness of the retina, and the thickness of the retina is actually changing as well. So there's a lot going on there, and we're just taking baby steps right now to understand what part of the eye is actually changing its shape that really changes the way that vision is coming through the optic nerve to be part of what the brain sees. 06:29 So it's more than just the overall shape of the eyeball going from round to, say, football shape, so it's too long or too short to focus properly. 06:37 Yeah, that's right. But the shape of the eye has a lot to do with the path that the light takes through the eye to get to the retina for sure, whether it's going to be a farsighted eye or a nearsighted eye or one that has astigmatism, the shape of the eye and the cornea itself. 06:55 Right. So which was it in your case? 06:58 Well, when I started and I had this short-sighted eye and then it elongated and it became a far-sighted eye, it canceled out my little short-sighted eye and I became more of a normal eye that was 20-20 without any correction. So when I came back from space, of course, I wanted to get my eye lasered so that I had perfect vision because I kind of liked not wearing the glasses. 07:21 I'm just thinking back to my high school physics where you have a magnifying glass that has a focal point. You've got to be just the right distance to get that focal point there. So if the eye isn't the right shape, that focal point will either be in front of or behind the retina. Is that also part of it? 07:36 That's correct. That's right. That's what makes a nearsighted eye or a farsighted eye, whether it's in front of the retina or behind the retina. Absolutely. 07:45 How long did your improved vision last when you came back to Earth? 07:49 I could say not long enough, but it probably was a few days. I can't tell you exactly when because I was doing so much other testing. 08:01 I was so, so tired. I mean, gravity really had its way with me. It was just really, really hard. I could feel a business card on the back of my hand dropping my hand. It was It was very difficult to walk. I was trying to do all kinds of things, but I was doing post-flight experiments that were dependent on me, not fooling around too much. 08:25 especially balance studies that I was doing, vestibular studies. So people were very interested in me being pristine. 08:32 So it was not a time when I was gonna try to exercise necessarily some of the actual things I wanted to do about my vision. But I could probably say that within two days, I needed my glasses again to do many things like trying to drive a car. 08:51 That must've been a sad moment. 08:53 It was a sad, sad moment. 08:56 Dr. Bondar, always a pleasure to have you on our show. Thanks for being part of our question show. 09:01 And thank you very much for inviting me. And thanks for the question. That's a good one. 09:05 Dr. Roberta Bondar is a neurologist and was Canada's first female astronaut in space. 09:11 For our next question, you may be able to see the frozen crystallized inspiration for it right outside your window. 09:19 Bruce Wilkinson here from North Cowichan on Vancouver Island. My question is, it's been said that there are no two snowflakes alike. How do we know that? And compared to a drop of water from a tap, how much water would the average snowflake be composed of? 09:36 Here with the answer is Dr. Stephen Morris, a physicist and emeritus professor at the University of Toronto. Dr. Morris, welcome back to Quirks and Quarks for our question show. Glad to be here. First of all, is it really true that no two snowflakes are alike? 09:51 It's true. And we do know this. 09:54 The first person to suggest this idea that no two snowflakes were like was a kind of crazy Vermont farmer named Wilson Bentley. 10:04 And he's always known as Snowflake Bentley because he invented a camera for taking pictures of snowflakes back in the 19th century. And he spent his life taking thousands and thousands of pictures of snowflakes. And he eventually published a book of thousands of pictures and no two snowflakes are alike. So he's responsible for that idea. And it's true. 10:23 Well, I mean, for sure, that's for thousands of thousands, but there are trillions even just in a snowbank. Is it even possible to know that no two are alike? 10:32 No, but we have good reasons for believing that it's true. 10:36 And the reason we believe it is that you can make snowflakes in the laboratory. And back in the 1930s, a guy named Yukichiro Nakaya created a device in the laboratory in Japan to make artificial snowflakes in the lab. And he studied how their form and how their shape depended on the temperature and humidity. And he discovered that if you change the temperature and humidity over a wide range, there's a very sensitive dependence of the shape on those parameters. And so if you hold the temperature and humidity very tightly controlled, you can make two snowflakes, which are very, very similar, almost identical to each other. 11:14 But that's not what happens in natural snowflakes. Natural snowflakes blow around in the cloud and they encounter many different temperatures and humidities. And they grow a little bit different this way, a little bit different that way. And so by the time they get to the ground, each snowflake records a kind of history of its growth in the cloud. And so that's a good reason for believing that they're all different from each other. Their motion is quite random in the cloud. So their forms are quite complex and result of history. 11:40 Okay. So other than the temperature conditions and the clouds, just generally what determines the shape of a snowflake? 11:47 It's a combination of the temperature and the humidity, how much water there is in the air. Snowflakes are crystals which grow directly from vapor. And it turns out that if you change the temperature just a tiny bit, the whole shape of them changes. In one narrow range near minus 15 degrees Celsius is kind of a sweet spot. They grow these dendrites, these branches that look like little trees. And each branch grows little side branches at 60 degrees. And that's the region where you get the most complex snowflakes. But just very near there, there's a region where they look like little hexagonal plates or little rods. 12:22 So if the snowflake moves around between those regions, it grows first with branches and then with plates and then with rods. And so you get a complicated shape at the end. 12:32 But they always seem to have kind of, as you say, a hexagonal shape or six sides to them. 12:37 Right. Yes. All snowflakes have six points or six sides. They're basically hexagonal. And that's because they inherit the shape of the most simple unit of ice, which is a little hexagon made out of water molecules. Water molecules are actually bent H2O. The two hydrogens are a little bit bent away from the straight line. And the smallest part of an ice crystal is a hexagon of water molecules with the oxygens at the corners. And it turns out that that's just repeated throughout the crystal and all the way to the full size of the crystal. 13:10 So it reflects this hexagonal shape of the immune cell, the smallest part of the ice. 13:15 Okay, let me see if I've got this right. You have six H2O water molecules that freeze into a six-pointed hexagonal shape with the oxygens in each corner. Okay. Okay. 13:28 Well, it's still astounding to me that if they're all going to have six points, that the snowflakes can still be all different from each other. How does that work? 13:36 Yeah. Well, the six points are sometimes just the corners of a hexagon. But it turns out in some conditions, the corners grow much faster than the sides. So it grows these long branches out the corners. And that gives you the six-sided, six-pointed snowflake. And then the side branches can grow branches to make a kind of tree structure. But all those pieces of the snowflake meet each other at 60 degrees at one-sixth of a circle. So basically, it's a flat hexagon. And that reflects the flat hexagon of the unit cell of the ice surface. 14:05 Now, are there any other factors that would affect its shape as it's falling from the sky? 14:10 Often they clump together, so it's rather tricky to get a single snowflake. Usually what we see is clumps of snowflakes. Individual snowflakes are quite a lot smaller than the clumps. 14:20 I would also think that maybe they might bump into each other and break some of those points off. 14:26 Probably, but they also stick together when they bump into each other. 14:29 Well, turning to the final part of Bruce's question, how much water is there in the average snowflake? 14:35 Well, the raindrops that we experience on the ground are actually often melted ice or snow. So roughly a little clump of snowflakes is equal in mass to a water droplet or a raindrop. 14:47 But most snowflakes are probably much lighter than raindrops. 14:50 So not much. Not much. 14:53 Dr. Morris, thank you so much for your time. Thank you. 14:56 Dr. Stephen Morris is a physicist and an emeritus professor at the University of Toronto. 15:02 Our next juicy question comes from Mark Ferguson in St. John's, Newfoundland. Why is most fruit round? And fruit that isn't, like bananas and pineapples, why aren't they round? For the answer, we're going to Montreal, where Dr. Anya Geitman is a professor in plant science and Canada Research Chair in Biomechanics of Plant Development at McGill University. Hello, and welcome to our holiday question show. Hello. Hello. So why is most fruit round? 15:32 So the shape of fruit is actually related to the shape of flowers, and that means that diversity of flowers is reflected in the diversity of the shapes of fruit. Fruits are formed from the female part of the flower, the so-called genetium or pistil, and it's formed after fertilization. And so when we come to a very typical round fruit, such as the peach, We can deduce that there is a single pit in the peach, right, which is the seed, and the optimal packing of a single thing in an envelope, which would be the ovary or the genetium, would be round. 16:11 So what makes the round shape optimal for most fruit? 16:15 In a round fruit or any round object, the volume to surface ratio is as high as it gets, meaning there is very little surface to a lot of volume. And surface exposes a fruit to evaporation or water loss or to the attack of pathogens. And so you want to minimize that surface. So a round shape would be advantageous for that. 16:37 Oh, okay. That's the best packaging available then. 16:41 Exactly. It's the optimal packaging. It doesn't mean that all the fruit actually do that kind of optimal packaging. We know that bananas are differently shaped. 16:49 But what's going on in the banana? What gives it its shape and the pineapple? 16:53 Right. So in the banana, we have a whole lot of seeds that need to be arranged. You could do that still in a round shape, like in an apple, for example. It's still a round fruit, despite the fact that we have many seeds in there. But they're all collected sort of in the center and still that optimal packing. 17:10 There are different ways of packing things. And so the banana has packed its seeds in a longitudinal arrangement, right? So all in a row. 17:20 And that kind of packing then results in a cylindrical fruit. The pineapple, on the other hand, is a completely different beast. It's not even a single fruit. It's actually a series of fruit because it arises from a series of flowers that fuse together. And so each sort of little compartment that you see at the surface of the pineapple is actually a fruit. And so one pineapple that we buy in the grocery store is up to hundreds of fruits. 17:52 Wow. Together, yeah. 17:54 I didn't know that. When I look at a pineapple, I'm looking at a collection of fruits rather than just one. 18:00 Exactly. So you get a superb deal in the supermarket when you buy one, but you actually get hundreds. 18:05 Yeah. 18:06 So I guess it all comes down to how the flowers are arranged. Exactly. Whether they're all together or in a line, that will determine the shape of the fruit. 18:14 Yeah, that's exactly it. And so I give you another example. The blueberry or the cranberry is a very typical single fruit, actually, where there is one or very few seeds in that fruit and it's round. Yeah. But something like a mulberry, for example, is again from multiple flowers, just like the pineapple. So multiple fruit in one single thing that we buy is a single fruit. The strawberry on the other end is a completely different beast again. 18:43 The part that we eat, the part that we appreciate that is sweet is not even the fruit part. The fruits on the strawberry are the little things that we call seeds, but they're really the fruits. And the part that we eat and love to eat is or accessory parts of the flower. 19:01 Now, we know that the object of a plant in producing fruit is to spread those seeds around. So how does the shape affect how well the seeds are going to be spread? 19:12 So one way of spreading fruit is, of course, by being transported by animals or humans. And in order to do so, you have to be attractive to animals, either to be consumed or to attach to animals. 19:24 Or if you're round by rolling, because you can get a roll down the hill, right? 19:29 Or if you're round by rolling, yeah, for sure. 19:32 Boy, those seeds certainly are clever, aren't they? 19:35 They are. Evolution makes it such. 19:38 Dr. Geitman, thank you so much. 19:40 It's my pleasure. Thank you. 19:42 Dr. Anya Geitman is a professor of plant science and Canada research chair on biomechanics of plant development at McGill University. 19:51 Our next question is about an unusual habit we sometimes see in professional athletes. Brian McCarthy in Calgary, Alberta wants to know, I've noticed that many professional athletes will stick out their tongue to one side when competing, like Michael Jordan. Why is this? 20:09 Well, believe it or not, Brian, a Canadian scientist has actually studied this in mice. Dr. Ian Wishaw is a professor of neuroscience at the University of Lethbridge in Alberta. Hello and welcome to our question show. Thank you, Bob. 20:24 Now, before we get to the question about athletes, tell me about your work studying this behavior with mice. What did you see there? 20:31 Yeah, this is a fun story, and it began with mice. And I study hand use in animals, the evolution of hand use. And I was training mice to reach for food, just the way we'd reach for an object on a table. And I noticed that they stuck out their tongue. And that wasn't the important part. The important part was when they stuck out their tongue. So when we reach for something, we lift our hand up into what you could call an aiming position, and then we advance it to the target. And mice did the same thing. 21:02 And it was when they had their hand in the aiming position that they stuck their tongue out. 21:07 And it almost seemed as if they were pointing to the target to help the hand get there. And this implied... 21:17 that probably there are important neural connections between the tongue areas of the brain and the hand areas of the brain that allow them to cooperate for reaching. 21:28 Oh, so were they sticking out their tongue in the direction of the food? 21:32 Yes, they were. They were pointing their nose at the food and they'd stick out their tongue quickly and briefly, and then they would reach. 21:40 So what's the connection then between our mouths and our hands? 21:44 Well, I'm a basketball fan and I knew about Michael Jordan and his tongue. So I got videos of Michael Jordan dunking a ball. And that's when he's famously known to stick out his tongue. 21:56 And he, just like the mice, stuck out his tongue when his hand was in the aiming position just before the dunk. 22:04 It wasn't during the dunk and it wasn't during lifting the hand. It was when the hand was positioned to make the dunk in the aiming position. 22:11 But athletes are not reaching for food, so what's the connection here between a hand action, like dunking a basketball, and sticking out the tongue? 22:20 The relation between the tongue and the hand is a common phenomena, and if you watch children, for example, They're manipulating an object with their hand. If you watch their face, they're manipulating the tongue in the same way. 22:35 And many people who speak, when they search for words, will stick out their tongue as if they're using their tongue to find the word. And the implication is they're powered by pretty similar neural circuitry. 22:47 So is it a sign of concentration? 22:49 No, it's actually aiming, I think. And the proof of that comes from a really interesting story told by Andrew Agassi, the world champion tennis player. And he played numerous games against Boris Becker. And Boris Becker had an absolutely fantastic serve that no one could handle, but Andrew Agassi could handle his serve. And after they both retired, Andrew Agassi told the story that he noticed that that when Boris was making his little aiming movements, preparing to hit the tennis ball, he stuck out his tongue in the direction he was going to hit the ball. 23:29 So all he had to do was, and he'd watch videos to determine this, so all he had to do was to watch Boris Becker. When he stuck out his tongue, he knew where the ball was going to go and he could volley back the serve. So I think that really brings in the point that the tongue is aiming at the target. 23:49 So athletes could be giving out information they don't even realize it to their competitors and give the competitors an edge. 23:56 That's right. I was giving a talk on this just before the Super Bowl and when Patrick Mahone was playing and he stuck out his tongue. 24:04 So I refused to answer that question at the time because I didn't want to get bold in the Super Bowl. 24:10 It's just amazing how the tongue is much more expressive and has more than one function instead of just handling speech and food. 24:18 Yeah, well, it makes sense in a way because when we speak, we wave our hands around and make gestures. And when we make gestures, we move our tongue around as well. 24:27 Dr. Wushaw, thank you so much for your time. Oh, you're welcome, Bob. Dr. Ian Wushaw is a professor of neuroscience at the University of Lethbridge in Alberta. 24:38 I'm Bob McDonald, and you're listening to Quirks 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. 24:50 Coming up later in the program, what would have happened if the dinosaur... All your favorite CBC podcasts are now available on YouTube. 24:58 The best in award-winning true crime investigations, hilarious comedies, vibrant pop culture conversations, and even more audio series are all available on CBC Podcast's YouTube channel. You'll also find exclusive video first episodes, YouTube shorts, and behind-the-scenes content from our hosts and producers that you can't find anywhere else. So if YouTube is your go-to source for podcasts, just search CBC Podcasts and hit subscribe, and you'll never miss the latest update. 25:23 Killing asteroid didn't slam into the Earth 66 million years ago. 25:29 It may have really hampered the evolution of our lineage leading to humans. So yeah, we might not be having this conversation if that didn't happen. 25:44 All right, let's dust ourselves off for our next question. 25:48 Hi, Quirks and Quarks. My name is Elizabeth Circum, and I live near a small town called Hansport in rural Nova Scotia. My question is, since dust is everywhere in our environment and is made up of everything in our environment, are there scientists who study dust? I would also like to know if the composition of dust is changing over time to have more synthetic stuff like plastics in it. Thank you. 26:16 Well, Elizabeth, we'll take the first part of your question. Yes, there are scientists who study dust, like Dr. Miriam Diamond, who's been studying dust for the past 20 years. She's a professor in the Department of Earth Sciences and School of the Environment at the University of Toronto. Hello and welcome to our holiday question show. 26:36 Thank you so much. I'm so pleased to be with you. 26:40 Okay, so what is dust made of that we find around our house? 26:45 It's made of life. It's really a reflection of who we are. So dust is comprised of skin cells, bits of bugs, bits of your clothing, bacteria, fungal spores, dust mites, soil, pollen, soot. Oh, I forgot to mention hair, dog hair, cat hair. 27:06 Wow, it sounds really gross. It's got all this life in it. Well, how has dust inside our homes changed over the years? 27:13 It has changed because dust is a reflection of who we are, what our products are indoors, and in fact, even the indoor environment. So you can imagine dust from, let's say, 100 years ago. That would be comprised of, well, it would still have the bug bits and the dander and so on. But it would have more natural materials because 100 years ago, homes were made of more wood, plaster, and so on. And couches were made of horsehair, so that would be a component. 27:45 Today, our houses are very different. Houses are made of more synthetic materials, and also what we have in our homes have more synthetic materials. So the couch is no longer made of horsehair. It's made of polyurethane foam covered probably with a polyester textile. So you're going to find bits of the polyurethane foam and bits of that polyester textile, not to mention bits of other plastics that have abraded. 28:14 Wow. Well, what's it doing to us to be surrounded by all these micro particles and all this stuff that's just floating around our home? 28:23 Yes, we are. We're exposed to dust, and that's why it's both good and a concern. So why is it good? Well, it's good to be exposed to different types of allergens. It builds our immune system. So we don't want to live in super clean houses. We do want to be exposed to hair and pet dander. We don't want to be exposed to, for example, the dander of vermin. But the problem is we've got so many synthetics and chemicals of concern indoors. 28:57 So even if you start with, say, clean dust, okay, like my skin cells, for example, are relatively clean, I hope. 29:06 But then the chemicals that are coming out of products get into that sort of clean dust and the products themselves abrade. So we could be exposed to the chemicals, chemicals of concern, through dust. 29:21 How do you use dust in your work? 29:23 We use dust to look at exposure to chemicals of concern because it gives us insight into exposure. It's much harder to take samples of blood and samples of urine. So we can use dust as a proxy for the chemicals to which we're exposed. We've looked at, for example... Flame retardants that are of toxicological concern and how we're exposed to them through dust. So, for example, an adult, we're exposed to anywhere from like about 3 to 60 milligrams per day of dust. 30:00 And to put that in perspective, just think of how many milligrams per day of salt that you're exposed to. But if you're a kid, especially a toddler, you're exposed to considerably more dust. So that would be 30 to about 140 milligrams of dust per day. The reason why toddlers are more exposed is because toddlers are close to the floor. If they're crawling, they resuspend the dust, breathe it in, take it in through their mouths, and also dust that adheres to toys. 30:32 So you were mentioning that we do need to be exposed to some dust. So how much is enough dust in your home? How clean should you try to keep it? 30:41 That's a really hard one as well. And I'm not actually aware of any studies that can answer that question. But we do know that little kids who are exposed to dust at a young age will have a lower incidence of developing asthma. But then we also know that kids who are exposed to dust that have certain plasticizers in them could actually have a greater chance of developing asthma. So here are some solutions that I would suggest. 31:12 You want to keep the amount of clutter in your home to a minimum, especially those products that are high in chemicals of concern, such as the forever chemicals, the stain and water repellents. You want to keep your house clean. as free from plastics as much as possible. So the plastics, we're concerned about some of the polymers themselves, like polystyrene, but we're also concerned with plastic additives. 31:43 And the additives are there anywhere from dyes and UV blockers. I'm not saying get rid of all the contents of your house. You just want to keep your house sort of with low clutter. 31:55 Dr. Diamond, thank you so much for that. 31:58 Thank you for having me. 32:00 Dr. Miriam Diamond is a professor in the Department of Earth Sciences and School of the Environment at the University of Toronto. 32:08 Our next question is a prehistoric what-if scenario. 32:12 Hello, everyone at Quarks and Quarks. This is Eric Hiber from Edmonton, Alberta. My question is, if the big Chicxulub meteor strike of 66 million years ago had not happened, is it possible the non-avian dinosaurs would still be around today? Thanks for your time. 32:29 For the answer, we're going to the dinosaur capital of the world in the Canadian Badlands. Dr. Caleb Brown is the curator of dinosaur systematics and evolution at the Royal Tyrrell Museum in Drumheller, Alberta. Hello and welcome back for our question show. 32:45 Hello. 32:45 First of all, just paint me a picture of what did happen when the asteroid hit 66 million years ago. 32:51 Yes, we know there was an impact in Mexico and kind of the Yucatan Peninsula. And it would have had global effects. First off, it would have had shockwaves locally. It would have thrown up a lot of matter into the atmosphere. 33:05 There would have been tsunamis and earthquakes. And then all that dust and debris would have really blocked out some of the sun and reduced photosynthesis. So there would have been kind of a global impact. 33:16 ecosystem collapse in many areas. And that's what ultimately did in the dinosaurs and many other groups of organisms during that end Cretaceous extinction. 33:23 Well, how much of a factor was the asteroid impact in the extinction of the dinosaurs compared to what else was going on at the time? 33:30 Yeah, so there is a debate about how impactful that impact actually was, if it was the single cause or if there was other factors. And I think most paleontologists agree that that impact was the big thing that did it. There is a bit of a debate that dinosaur diversity was declining in the last 10 million years or so of the Cretaceous. But a lot of that is probably due to some sampling. 33:51 Well, what else was happening that could have led to their decline? 33:55 There was global climate changes happening constantly, not at the rate at which we're seeing today, but there would have been a sea level drop before that impact. And a lot of the areas that would have had isolated habitats now were opened up and they were kind of contiguous. So probably a lot of more homogeneous environments and different radiations because of that. 34:18 Okay. Well, let's get to our question. Suppose the asteroid had missed the Earth. What would have happened to the dinosaurs? Yeah. 34:24 Yeah, it's hard to say who would have done well, who wouldn't have done well. There's been huge changes in the Earth since the end Cretaceous, changing climates, ice ages, stuff like that. It's difficult to know what dinosaurs would have done, how they would have evolved. Obviously, when there's ice ages, there's still areas around the equator that are still habitable. And it's important to point out that even in the late Cretaceous, dinosaurs were living at the North Pole. It was a very different environment. It wasn't nearly as cold. but it still would have had this extreme seasonality. So dinosaurs were very adaptable. I'm sure they would have done just fine and adapted to new niches as the environments changed if they weren't kind of prematurely wiped out. 35:02 So would we still have birds today the same way we do if the asteroid had not hit us? 35:08 Yeah, that's a hard one to answer. I mean, birds were doing quite well and they thrived after the end of the Cretaceous. They probably had this kind of adaptive radiation. 35:17 Whether they would have adapted into all these different niches you see today or whether some of those would have been occupied by dinosaurs, it's hard to know. But I think birds would have done just fine. The other side of the coin is, what about the mammals? 35:28 they're kind of most obviously one of the benefactors from the dinosaur extinction. There's been a lot of research pointing out that after the dinosaurs went extinct, there was kind of a radiation of mammals, both in terms of body size. They got bigger, but they also radiate into different ecological niches. And this is basically what we call this ecological release. There was some constraint keeping them down. And when that constraint was released, they went off and diversified. And that constraint is probably the dinosaurs. 35:58 So you can play the question of if that constraint wasn't released, would mammals have done that diversification? They probably wouldn't have been nearly as diverse as today. You probably would have seen mammals being much smaller, maybe more restricted to arboreal and nocturnal habitats, not these big dominant herbivores that we see in the landscapes today. 36:19 Or us. 36:20 Yeah, exactly. Specifically, it may have really hampered the evolution of our lineage leading to humans. So, yeah, we might not be having this conversation if that didn't happen. 36:31 Dr. Brown, thank you so much for your time. Thank you very much. Dr. Caleb Brown is a curator of dinosaur systematics and evolution at the Royal Tyrell Museum in Drumheller, Alberta. 36:43 Our next question is about the table manners of one of our planet's most important pollinators. It comes from Tom Riddle in Orangeville, Ontario. 36:52 Hello. Recently, I visited a friend who keeps honeybees as a hobby, and we're watching the bees fly in and out of the hive, and I asked him, why don't the bees get stuck in the honey? Honey sticks to everything else. And his eyes opened a little wider, and he looked at me kind of astonished and said, I don't know. 37:11 And so my question for Quirks and Quarks is, why don't bees get stuck in their own honey when they fly inside the hive? 37:17 For the answer, we went to someone who spent hours observing honeybee behavior at close range, expert beekeeper and scientist Dr. Nuria Morfin. She's a professor in honeybee biology at the University of Manitoba and the head of the university's honeybee lab. Hello, and welcome to our holiday question show. 37:37 Hello, Bob, and thank you for the invitation. 37:40 Now, before we get to Tom's question, just briefly take me through the process of how bees actually produce honey. What do they do? 37:47 What do they do? So honeybees, they would forage for nectar. They would go to the flowers, collect nectar, bring it back to the colony, and through a process which involves mixing the nectar with the saliva enzymes... They would break the sugars and reduce the water content to produce honey. 38:09 So honey would be their source of energy. 38:12 So they use saliva to do that? They're doing it with their mouths? 38:17 They do that with their mouths. They would transfer the honey from mouth to mouth, and they would reduce the water content and, through a chemical process, break the sugars to produce honey. 38:31 Okay. Well, if the honey's in their mouths, if they're using their mouths to make it, how close do they get to the sticky honey once it's produced? 38:40 The answer would be they are masters in handling liquids and handling honey. So they would manipulate the nectar and the honey with their mouth parts. So they are actually very clean and very neat when they go through that process. 38:55 And then they have to stuff it into the, or store it into the comb, the honey combs, correct? Yes. 39:00 Exactly. They would use their finely specialized mouth parts to put the nectar inside the cells where it will become honey. So once the honey is mature and they feel it's ready, the honeybees will cap the cell with a layer of wax. 39:21 And if they need to access the honey to get food, then they would use their mandibles to chew the cappings, and access the honey with their mouthparts. 39:32 So how are they able to handle all that honey without getting themselves stuck all the time? 39:37 They are remarkable, clean, highly organized, very efficient insects. And they just know how to handle liquids. Imagine that their mouth part is a straw. So it's like a tube. And they are able to suck the nectar in a process that we call trophallaxis. It's basically passing the nectar from mouth to mouth. And that way, the nectar gets lower water content. And that's how our delicious honey is made. 40:06 Do they ever get stuck in honey? 40:09 Well, I would say by accident. So when beekeepers, when we use this tool that is called a hive tool, so when we handle the honeycomb, take it out, by accident we can break the cells and that's where we can have honey or nectar leaked into the hive. And that by accident is how honeybees could be exposed to the honey and get sticky. 40:36 So what happens if they do get covered in it? I mean, I'm thinking about, you know, those sticky fly traps that used to hang in restaurants and things where the flies stuck on it, they get their legs on it and they can't get out. Can that happen? 40:49 Well, bees are amazing. So they have a solution almost for everything. So bees, what they would do is groom themselves. So they will use their mandibles, their mouthparts, their legs to groom themselves. Or they would ask for help to one of their nest mates. And they would lick each other, groom each other, and make sure everybody's clean. And they would do that to get rid of nectar, honey in these accidental cases. And they would do the same when they get covered by pollen, for example, or even by parasites. 41:25 So that is a way that they keep themselves clean. 41:28 That's astounding. Absolutely. 41:30 Absolutely. 41:32 What does it say to you about the nature of honeybees, that they look after each other like that so that we don't find bee parts in our honey? 41:40 Yeah, absolutely. So bees are called eusocial or truly social insects. They are highly organized. So they have bees specialized for reproduction, which are the queen and the thrones. The worker bees would do the rest of the tasks, and they are amazing. Depending on their age and what the colony needs, they will decide what their job would be. So that would be from nursing, from keeping an eye on the queen, foraging, building wags, and handling honey. 42:15 So to answer Tom's question, the bees don't get stuck in the honey because they handle it with their tongues. 42:21 Exactly. 42:22 Dr. Morthan, thank you so much for your time. 42:24 No problem. Anytime, and thank you so much for reaching out. 42:28 Dr. Nuria Morfin is a professor in honeybee biology at the University of Manitoba. 42:35 Our next question takes us to the shores of Lake Superior. Hi, Bob and company. It's John Brennan from Maple Ridge, B.C. My question is, Lake Superior is the largest body of freshwater in the world, so why doesn't it have tides? For the answer, we go to Thunder Bay, Ontario. Dr. Mike Rennie is an associate professor and the chair of the Department of Biology at Lakehead University and a research fellow with the International Institute for Sustainable Development Experimental Lakes Area. 43:07 Hello and welcome to our question show. 43:08 Thanks, Bob. 43:10 So, does Lake Superior get tides? 43:14 So the short answer is yes, but the more complicated answer is that they're so small that you just can't see them. So you would get a tide. And if Lake Superior was perfectly still for a 24-hour period, which it almost never is, you would be able to measure differences in water level of a couple of centimeters, but that's about as much of the influence that the moon has on even a water body that's the size of Lake Superior. Very, very small. 43:44 Okay, a couple of centimeters. That's not a lot to worry about. Are there other factors that might cause water levels in Lake Superior to fluctuate? 43:52 Oh, sure. So, yeah, even so even though that, you know, the waves and stuff on Lake Spurrier won't let you see variation in that amount of water level, what you do get are so seasonal changes. So as we move through seasons and have sort of rainier periods versus drier periods in a year. We'll see smaller fluctuations in water levels with Lake Superior on that basis of about, you know, 10 to 20 centimeters. The other thing that we'll often see, though, and this is more common, is that when we get a storm surge. 44:25 So if we get a lot of water sort of or a lot of wind, I guess, blowing on the water and pushing that water to one side of the shore. 44:33 What can happen is that water will pile up where the wind is blowing it on shore. And then when the wind stops, it'll slosh backwards. Imagine Lake Superior is a giant bathtub. Once the wind stops, the water sloshes backwards and will oscillate back and forth like that. And we call that a surface seiche. 44:55 And so a good example of that was with Hurricane Hazel on Lake Ontario. So when Toronto flooded because of that storm surge, when the wind stopped, it all sloshed back and went back to the south shore and caused quite a bit of flooding on the south side as well. 45:11 So how much can this sage cause the water to go up and down? 45:16 Pretty considerable. If you look up the Wikipedia entry on Seiche, they have a really good example on Lake Erie from like 2003 where wind was blowing in the direction of Buffalo, I think. And so the water level there was about four and a half feet higher than normal. And it was about four and a half feet lower in Toledo. So it can be pretty substantial. 45:41 Now, do these Seiches have any effect on the animals that live in the water? 45:46 Yeah, they can. 45:47 And the interesting way that it sort of affects animals is not from those sort of surface oscillations, but it actually drives changes in the water as well. So if you've ever gone swimming in a lake in the summertime, you might notice that if you swim down deep enough, the water gets pretty cold. And that's because we get what's called a thermocline in the lake. So the warm water floats on top in the lake and the cold water falls below. Yeah. So when you get that wind pushing all the water to one side of the lake, what it's actually doing is it's pushing all that warm water to one side. 46:23 So you get a buildup of warm water on one side of the lake, and all the cold water gets pushed to the downwind side. And when the wind stops blowing, you get an internal seiche, which means the thermocline, sort of that line between the warm and the cold water in the lake, will slosh back and forth. 46:41 inside the lake. And so you can't really see it, but you can measure it if you're looking at temperature strings, say, in the water column. So if you're something like a mussel that's living on the bed of the lake, that can cause really dramatic changes in water temperature. You'd be going from, you know, something like 23 degrees in the warm water, and then when that cold water rushes in, you're down to like, you know, four degrees kind of thing. So it can be really, really, really dramatic changes in those transition periods. And the amplitude, the oscillation of those internal stations can last for days. 47:14 Wow. So how large would a body of water have to be before you start seeing tides that are significant? 47:22 Basically, you'd need to look to the oceans. Lake Superior is the largest water body by surface area on the planet. And so given that we're only seeing a couple centimeters difference there with the influence of the moon, you need something. The oceans are like half the planet kind of thing, if not more. So you need a much larger body of water for the moon to interact with to really change those water levels on the scale that we see in the tides and the oceans. 47:51 Okay. So Lake Superior doesn't have much of a tide, but it does move. 47:56 It sure does. Boy, does it ever. 47:59 Dr. Rennie, thank you so much for your time. 48:01 Thanks so much, Bob. It's a pleasure talking to you. 48:03 Dr. Mike Rennie is an associate professor and the chair of the biology department at Lakehead University and a research fellow with the IISD Experimental Lakes area. 48:15 Our final question is about a tilted planet in our solar system. 48:19 Francis Como asks, The planet Uranus is tipped on its side. We're usually told this was the result of an impact. But how do you knock a ball of gas on its side? 48:31 And also, why would the moons and the rings follow? 48:35 Here with the answer is Dr. Matthew Dunberry, a professor of geophysics at the University of Alberta in Edmonton. Hello again, and welcome to our holiday question show. 48:45 Hi, Bob. It's a great pleasure to be here. 48:47 Well, before we get to Francis' question, how far over on its side is Uranus tilted? 48:53 So right now, its tilt is... 48:55 over 90 degrees, so I think it's 98 degrees. 49:00 Wow. So it's literally lying on its side compared to all the other planets. 49:04 Pretty much. It's sort of a line closer to the equator. 49:08 So what's the scenario that is believed to have tipped Uranus over like that? 49:14 So the idea of a collision, an impact, is certainly a likely possibility. I mean, the way... all planets formed is from the accretion of material out of that original disk of material. And then you form bigger and bigger planets, and eventually you have sort of large collisions when you only have a few somewhat large planets left. And so one of these collisions in the later stages of planetary formation is probably led to tilts of many of the planets, including the Earth. 49:57 The presence of the Moon on the Earth is thought to originate from one of these large impacts. And so it's likely that a scenario like that could have happened on Uranus as well. 50:08 Well, paint me a picture of how gaseous Uranus is all the way through. 50:12 Yes. So the question is a great question, but it also identifies sort of the fact that we call these planets gas giants is a little bit of a misnomer. 50:25 The terminology comes from the fact that they contain a lot of helium and hydrogen, which, of course, are gases at sea level condition on Earth. But inside these planets, they're so massive that the compression effect increases the density in such a way that it's more like a liquid in the middle of the planet. Once you get to, perhaps, you go down to 80% of the planet's radius, the density becomes higher than the density of water at sea level on Earth. 50:58 Not too different from the density of rocks in the mantle, actually. 51:03 It'd be more like a big splash. 51:05 It'll be a big splash, but ultimately, there's so much material that the impactor will hit the planet and will be stopped. And so it won't pass through. And ultimately, why an impactor can cause a tilt of a planet is that it's essentially the It's a conservation of angular momentum. If an impactor hits a planet close to the pole, then the angular momentum of the impactor is transferred to the planet, and so it can knock the planet on its side. 51:39 But that must have been one heck of a collision because Uranus is much bigger than the Earth to tilt a planet over on its side. 51:46 It's true. It requires a very large impact. And so another possibility is that the tilt may have been essentially a result of interactions with other planets. That is, all planets are not exactly spherical. They're bulgy at the equator because they're rotating. Then this extra mass at the equator can be subject to gravitational pulls by other planets. And so that may lead to changes in the tilt of planets. 52:19 And so it's not impossible that this is something that may have happened for Uranus, that a big part of its current tilt was a result of these gravitational interactions between the planets. 52:36 If it did get instilled from a cosmic collision, when do you think that happened? 52:41 In all likelihood, this happened still in the earlier stages of the solar system, sort of the late stage of planetary formation, but in all likelihood probably at least 4 billion years ago. 52:56 Well, turning to the second part of Francis's question, if Uranus got smacked and tipped over, what about its moons and its ring system? How do they follow the same way? 53:07 Yeah, that's a very good question. And so it turns out it's pretty much the same reason. It's again connected to the equatorial bulge of the planet. So that extra mass at the equator... 53:20 essentially leads to everything that orbits the planet to eventually settle on an orbit which is along the equator of the planet, such that, in other words, the gravitational mass at the equator tries to realign the orbits of the different objects. And so, whether it's the moons, whether it's the rings, And so that's the reason nowadays all the rings of all the gas giants and the ice giants are aligned with the equator, and likewise the major moons of these planets are also orbiting on the equatorial plane. 53:59 Oh, I see. So the bulge of the planet puts a little more mass at the equator, and more mass means more gravity, so they're attracted to the equator. Exactly. Ultimately, that's what it is. 54:10 Dr. Dunberry, thank you so much for your time. Oh, you're very welcome. 54:14 Dr. Matthew Dunberry is an astronomer at the University of Alberta in Edmonton. 54:22 And that's it for our Quirks and Quirks listener question show. If you'd like to get in touch with us, our email is quirks at cbc.ca. You can find 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 Quarks was produced by Rosie Fernandez, Amanda Buckowitz, Livia Diring, and Dan Falk. 54:54 Our acting senior producer is Sonia Biding. I'm Bob McDonald. Thanks for listening. 55:03 For more CBC Podcasts, go to cbc.ca slash podcasts.