Sci News SeptemberBy Linda Pretorius 9 September 2009 | Categories: news
Heres yet more reason to be proudly South African. According to a report in an August issue of the journal Science, humans in southern Africa have ingeniously been using fire during tool making from as early as 72 000 years ago. Evidence from an archeological excavation just off the coast of Mossel Bay shows that controlled fire was used to induce structural changes in a stone, called silcrete, to make better stone tools. In its natural state silcrete does not flake easily and so is a poor raw material for tools. After heating, however, it can be easily chipped to create a thin, sharp tool blade. It was previously thought that humans only made the link between fire and the tool making benefits, that came with heatinduced structural changes, to stone around 25 000 years ago. The researchers think that this engineering skill may have helped humans to conquer the colder Eurasian environment when they moved out of Africa. Seems South African engineers have long had soughtafter skills.
If you think there just isnt enough time in your day, be thankful that youre not on Saturn. According to an article recently published in the journal Nature, a day on Saturn is even shorter than previously thought by a whole five minutes. Because Saturn is a gassy planet as opposed to a solid planet like Earth its difficult to measure the planets rotation around its axis. Scientists previously tracked the movement of ammonia clouds in Saturns atmosphere to estimate the length of a Saturn day at just over 10andahalf hours. However, with new infrared data of gas movement deep inside the planet, they built a 3D map of Saturns winds. This showed large waves and eddies that develop in the planets atmosphere according to its rotation. Although a fiveminute shortening doesnt sound like much, it means that wind speed estimates may be out by more than 270 km/h A gassy planet is a windy place
Im sure James Bond would love to have his car fitted with a traction control system that automatically knows when to deploy. Yet it seems nature is one step ahead of Q. Scientists write in a recent issue of the journal Proceedings of the Royal Society B, that they now know why geckos can run up a wall so surefootedly. The team studied geckos movement behaviour at various inclines. At angles of more than 30 degrees all the animals in the study group used tiny bristlelike hairs beneath their toes to anchor them to the surface. But theres more some animals already activated the system at a 10 degree incline, despite losing quite a bit of speed. It seems that the combination of body orientation and need for speed determine whether the traction control system will deploy. The team hopes to use these insights for commercial applications in space exploration or medical procedures. Take that James Bond
For a cool TED video exploring the movement of geckos visit TED.com.
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