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2009 Winners
Category 1: Science in Action |
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Photographer: Mr Kim van Zyl
Title: Lightning over Cape Town
Description: This was taken during a rare thunderstorm over Cape Town just before sunrise on 21st May 2009. It shows the intricate pattern of the lightning strike as it releases huge amounts of energy. The average peak power output of a single lightning stroke is about a terawatt (1012W) and the stroke lasts for about 30 microseconds. Lightning rapidly heats the air in its immediate vicinity to around 20,000 degrees C - about three times the temperature of the surface of the sun. This compresses the surrounding clear air and creates a supersonic shock wave which decays to an acoustic wave that is heard as thunder. |
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| Runner Up |
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Photographer: Mr Kim van Zyl
Title: Water column
Description: This shows what happens after a drop of water has fallen into a bowl of water. The resulting rising column of water is caused by the rushing back to fill the void created by the displacement of the falling drop. This upper portion of this column sometimes creates a secondary drop that repeats the process, but to a lesser extent. |
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| Runner Up
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Photographer: Mr Stephen Libera
Title: Drawing beneath the stars
Description: The use of a longer shutter speed allows time for the camera to catch the light dispersed from a LED torch used to trace the people, while a lower aperture gives clarity to the LED light; above in the sky the Southern Cross can be clearly seen. |
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