Jan 2: Listener question show — we answer your science questions
Where are the missing dinosaurs, why does cold make you pee, do insects feel pain and much more
To start the new year, we present another edition of our ever-popular Listener Question Show, where we find the experts to answer your questions.
Joel Casselman from Ottawa asks: "How likely is it that there may have been species of dinosaurs whose existence may never be known?"
Victoria Arbour, Curator of Paleontology at the Royal BC Museum in Victoria says there are certainly many dinosaur species that we'll never know about. These include species that lived in rainforest or alpine environments, where fossilization is unlikely, and species that lived in environments where geological activity has erased the fossil record of the time. A back-of-the envelope calculation suggests that the roughly 1000 species we know of is perhaps one per cent of all the species that might have existed.
Lydia de Groot from Bridge Lake, British Columbia asks: "How come when I get cold I have to pee so much?"
Michael Leveridge, Associate Professor in the departments of Urology at Queens University explains that typically this happens because of a process called Cold Diuresis. When we get cold outside, our blood is drawn away from the skin and closer to our organs to dissipate body heat, and this tricks your kidneys into thinking you have more water in your body, and higher blood pressure, than you actually do. And one of the ways your kidneys modify blood pressure is by kicking out excess water. It could also be because our bodies go more rigid when we get cold, which puts pressure on the bladder.
Valerie Coles from North Vancouver, British Columbia asks: "We know planets orbit a star but do stars themselves orbit? If they do, what do they orbit?"
Heidi White, an astronomer with the Dunlap institute for astronomy and astrophysics at the University of Toronto, explains that yes, stars do have an orbit. Moons orbit planets, planets orbit stars, stars orbit around through the galaxy, and the Milky way itself is moving through the universe. There are even some smaller galaxies that are orbiting our galaxy itself. Orbits are determined by gravity, so smaller bodies get pulled in towards a bigger entity. But that bigger entity is also getting pulled constantly, too. Like, our sun. Because the orbit of our solar system is determined by the distribution of weight, as the planets move, the sun gets pulled around, so it has a tiny wobble of an orbit as well.
Doug Page of Victoria asks: "How much of global warming could be attributed to direct human caused heating from burning fossil fuels versus "indirect" heating from the greenhouse effect from the resulting CO2 and sunlight?
Greg Flato, Senior Research Scientist with Environment and Climate Change Canada in Victoria explains that the contribution of the heat from burning fossil fuel is ultimately a tiny fraction of the amount of heat trapped by CO2 that is released by that fuel. It takes roughly two months for the heat trapped by the CO2 to equal the heat produced by burning the fuel it came from. However CO2 remains in the atmosphere for many centuries, and ultimately can trap 100,000 times more heat than was produced by the fire that released it.
Janet McLeod from Hammonds Plains, Nova Scotia asks: "Do insects feel pain?"
Shelley Adamo, a professor of invertebrate behavioural physiology at Dalhousie University, says that while we can never truly know if insects experience pain, we don't think they do. Yes, they have aversions to painful stimuli the same way humans do, which makes sense, as any living thing wouldn't last very long if it didn't avoid things that hurt it. But they also don't seem to have any of the mental reactions to pain like anxiety or distress, as evidenced by the fact that they do things like eat their own insides, or not react if they lose a limb.
Ryan Holmes from Edmonton, Alberta asks: "How long was the CN Tower built to last, and what will happen when it reaches the end of its lifespan?"
Douglas Hooton, a professor in the Dept. of Civil & Mineral Engineering at the University of Toronto, explains that the CN Tower was actually built to stand for 300 years, but could likely stay standing much longer than that. In fact, a recent study showed that the wires inside the CN Tower that are holding it up could stay strong for over 1100 years. As to what happens at the end of its lifespan, Hooton says that if it were happening with today's technology, they would likely remove the antenna and restaurant pod with a helicopter, and then slowly nibble away at the concrete base, pushing it into the tower's hollow centre. Implosion isn't an option because of all the tall buildings that surround the tower.
Kevin Walker from Stittsville, Ontario asks: 'Since the Earth spins around once a day, why are there two high tides a day instead of just one when we happen to be on the side of the Earth closest to the moon?"
Prof. Laura Fissel, an assistant professor of astronomy at Queens University, says the reason we have two tides a day comes down to how gravitational pull from the Moon deforms the water on Earth. That pull will be the greatest on the side of the Earth closest to the Moon and will still be pulling, although not as strongly, on the far side of the Earth to the Moon. That results in the water on Earth becoming flattened, into an oval shape, and it also nudges our planet a bit closer to the moon, so you have a spherical Earth inside an oval shaped water that bulges on the nearest and farthest sides to the Moon. Then as the planet rotates, that bulge rotates so that a person standing on the nearest side to the Moon will experience another bulge, albeit a bit less of one, about a half a day later.
Mara Stenabaugh, a curious eight-year-old from Edmonton asks: "How do brains make dreams?"
Lia Turner from the Science of Imagination Laboratory at Carleton University in Ottawa says that dreaming is most likely related to complex neuro-chemical mixtures in the brain. Some including serotonin and histamine are absent during sleep, while chemicals including dopamin are elevated during the waking hours. This shift may be responsible for our dreams. Also, new research suggests that dreams during sleep are equivalent to thoughts during wakefulness. Dreams are also known to be a way in which we build memories, process emotions or simply clear away partial or unnecessary information that we are holding on to.
Dorian Ayala from Springfield, Massachusetts asks: "If one star goes Supernova in a binary system, what happens to the other one?
Nayyer Raza, a Masters student in Astronomy at the University of British Columbia explains that a Supernova usually occurs in a binary system in which the two stars are very close together. One star, the larger Red Giant, becomes hyperinflated and starts to lose its outer layers. The companion star, the much smaller White Dwarf, starts collecting that material until it experiences a thermonuclear explosion, which is a Supernova. The White Dwarf is destroyed, the Red Giant usually escapes relatively unscathed.
Peggy West from Ottawa asks: "A few years ago I took a photograph of the most beautiful frost on a winter window. My question is why does the frost form in detailed leaf patterns with an obvious stem running through each leaf and veins going off the stem almost like needles?"
Prof. Stephen Morris, a professor of physics at the University of Toronto, says we can thank the shape of a water molecule for the beautiful "frost ferns," as they're called, which he says is essentially the same thing that forms snowflakes, except the design grows on a surface instead of in the air. He says the H2O molecule, with oxygen in the middle is shaped like a "V." Six water molecules come together to make hexagonal shapes. If the humidity, temperature and dirt pattern on your window is just right, water will come out of the air and attach itself onto glass and will generally grow more quickly at the tips because it's more energetically favourable to do, and instabilities make the water molecules branch.