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Past Shows
March 21, 2009
 Download an MP3 of the entire program (22MB).
Bats Land Head-Under-Heel
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One of Dr. Riskin's bats, just hanging around, courtesy Dr. Riskin
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Bats have their work cut out for them. Not only do they have to fly through the dark and find food by echo-location, but once they've finished their flight, they have to manage to land - upside down. Just how they do this has been a bit of a mystery, since they're so quick. But Dr. Daniel Riskin, a Canadian biologist at Brown University in Rhode Island, has developed some specialized equipment to do the job. Dr. Riskin has been studying several bat species and has used high-speed photography to paint a detailed picture of how they do their upside down bat-crobatics. It turns out that bats have different landing procedures, depending on their habitat.
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Left-Handed Acid from Space
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Chiral molecules - NASA/Mary Pat Hrybyk-Keith
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If you think of life here on Earth as a vast metropolis, then amino acids are the bricks that built that city -- the building blocks that make up proteins. The funny thing about those bricks is that they're all left-handed. That may sounds strange but, in nature, all amino acids exist as one of two possible mirror-image forms, kind of like our hands. However, the amino-acids that life uses are all exclusively left-handed, which has puzzled scientists. After all, life could have used right-handed amino acids but, for some reason, didn't. Dr. Daniel Glavin, an astrobiologist with the Goddard Space Flight Center in Maryland, has been studying meteorites that pre-date the Earth, to try to find an answer to this sinister question. Dr. Glavin found an abundance of left-handed amino acids on the rocks he studied, suggesting that the early Earth was bombarded with more left than right-handed amino acids which, in turn, may have tipped the balance towards life choosing to lean left rather than right.
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Matriarchal Mystery
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Hyena jaws from juvenile to mature - courtesy the Royal Society
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Very few animals live in true matriarchal societies, in which the females socially dominate the males. Spotted hyenas are one example, and Dr. Heather Watts, currently a post-doctoral fellow in the department of Neurobiology, Physiology & Behavior at the University of California, Davis, has been trying to understand why. She thinks it's due to the fact that it takes hyenas' bone-crushing jaws so long to develop and mature. Because of this, juvenile hyenas can't compete effectively for food during the pack's frenzied feeding. This means mothers must intervene physically to ensure that their cubs get a chance to eat, which has led to their physical and social evolution to dominance.
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GOCE - Feeling Gravity's Pull
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GOCE in orbit - artist's conception courtesy ESA
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Europeans do everything with style, of course, which might be why their latest space mission is all about finding out how attractive the Earth really is. The European Space Agency successfully launched the Gravity field and steady-state Ocean Circulation Explorer, or GOCE, this week after some delays, much to the gratification of people like Dr. Mark Drinkwater, Mission Scientist on GOCE. The streamlined GOCE spacecraft will fly in a low orbit around our planet for two years, using sensitive instruments to build up a picture of the minute variations in the Earth's gravity. These variations can reveal everything from geological features, hundreds of kilometers beneath the Earth's surface, to the watery bulges produced by great ocean currents that have so much influence on our climate.
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Wait a Second - What's an Attosecond?
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Dr. Corkum shows his Herzberg Medal to Prime Minister Harper
(The Canadian Press)
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Back in the first half of the 20th Century, engineers paired together strobe-lights and high-speed cameras and developed the modern art -- and science -- of high speed photography. You've likely seen the now-famous photos of a bullet piercing an apple or the crown that a drop of milk makes when it lands on a surface. This technique became an invaluable tool for studying the physics of everyday life and an art form in its own right. Well, Dr. Paul Corkum, an experimental physicist with the National Research Council and the University of Ottawa, has developed an analogous tool that allows researchers to capture images of the very small and extraordinarily fast-paced world of molecules and atoms. Now, while a speeding bullet is quick, it's nothing compared to how quickly subatomic particles move, measured in increments called attoseconds (one attosecond is to a second what a second is to the age of the universe). Remarkably, Dr. Corkum has developed a way of imaging molecular interactions with a pulse of light that lasts only 80 attoseconds. Now that's quick! Dr. Corkum's innovation has opened up a whole new way of visualizing and studying molecular processes and, for this remarkable achievement, he was awarded this year's Herzberg Gold Medal for Science and Engineering - Canada's most prestigious science award.
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Fact or Fiction: Alcohol and Altitude
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And now, another episode of our occasional feature, Science Fact or Science Fiction. From time to time, we'll present a commonly held idea or popular saying - and ask a Canadian scientist to set us straight on whether we should believe it or not. And today's example is one that we often hear: Alcohol packs more of a punch when you're flying at high altitude.
For the scientific lowdown, we spoke to Dr. Jose Lanca, an assistant Professor in the Department of Pharmacology and Toxicology at the University of Toronto.
Theme music bed copyright Raphaël Gluckstein.
Creative Commons License by-nc-nd-2.0
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