Volume 90, Issue 79

Thursday, February 13, 1997



A first time for everything

By Emily Chung
Gazette Staff

The room was overflowing when I arrived. With some trepidation, I dragged a chair in from the room across the hall and jammed myself into an overcrowded row.

Yesterday, I attended my first colloquium. I'd always wondered about those advertised events with intimidating names like "Resonant Hopf Bifurcation in a Delay Differential Equation." But when I saw one titled "The Chicxclub Impact and the Death of the Dinosaurs," how could I resist?

The guest speaker at this particular colloquium was Alan Hildebrand from the continental geosciences division of the geological survey of Canada. His fascinating lecture/slide show, included an exciting animated video clip showing the fiery impact of the Chicxulub comet with what is now the Yucatan Peninsula of Mexico.

"North and South America would have been burnt to the ground," Hildebrand said dramatically. From the dust that would have been stirred up, "you wouldn't be able to see your hand in front of your face for three months." Enough sulphur dioxide would have been produced to acidify the world's oceans for a year. The ozone layer would have been wiped out for 10 years. The resulting greenhouse effect would have raised the Earth's temperature by 10 degrees Celsius for over a thousand years.

All this was followed by a question and answer period. "How do you know it's a comet and not a meteor?" asked a woman in the second row. A few quick calculations showed how.

"Why didn't the mammals get wiped out too?"

Hildebrand explained that no one really knows, but that it likely has to do with their size. "Think of it this way – if you're a small carnivorous mammal and you find a dead T-Rex, you're set for the bad times!"

This lecture was part of a biweekly series given by the earth sciences department but, due to its wide appeal, was also a joint venture with both the physics and astronomy and philosophy departments. "We try to choose topics that are controversial," explained John Starkey of the earth sciences department.

Anyone interested is free to attend, though such events tend to attract more faculty and graduate students than undergraduates like myself. This is partly because many of the topics are very specialized, Starkey said. If more interest was shown by the students the department may choose topics of more general interest, Starkey explained.

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Copyright The Gazette 1997