Last year, BBC cameramen H. Miller and D. Anderson filmed the formation of an underwater icicle:
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Credits: cameramen Hugh Miller and Doug Anderson for the BBC One series Frozen Planet
Because it is formed by
freezing brine sinking into sea water, this phenomenon has been named "brinicle".It was first
described in the sixties but, because it is very difficult to know when and
where it will occur, it's the first time someone has actually managed to film
it. The cameramen also have to work under extreme conditions: freezing
water under a thick layer of ice. "I do remember it
being a struggle... All the kit is very heavy because it has to sit on the sea
bed and not move for long periods of time" says Mr. Miller
How does the brinicle form? When cold water freezes, it excretes impurities (such as salt) in the crystallization process. This leads to the formation of little pockets filled with very dense salty water which does not freeze at 0°C (the salt lowers the freezing point). The brine then travels through a tiny network of channels until it reaches the sea surface. Being denser and colder than sea water, it sinks and, as it freezes the relatively warm sea water it comes in contact with, forms a thin and fragile tunnel of ice which grows into a brinicle. Brinicles don't last very long; it has to be relatively calm for them to grow. Eventually, sea currents will destroy them, often before they reach the ground.
Learn more on the BBC website
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Affichage des articles dont le libellé est Physics. Afficher tous les articles
Affichage des articles dont le libellé est Physics. Afficher tous les articles
jeudi 28 juin 2012
mercredi 27 juin 2012
Up there
Talented
graphic artists, an old electro-magnet found on Ebay, plastic colour balls and a lot of
work: that's what it took the Physalia Studio team to create this esthetical
dynamic experience. The video shows how they first had to incorporate a tiny
electro-magnet into each plastic ball. A microchip enables to control individually
the intensity of their electromagnetic field. After
the huge bargained electromagnet is turned on, the balls levitate harmoniously.
(Click on the picture to play the video or watch it directly on the Physalia Studio website. ):
Actually,
this video may be a fake; it would still be a pretty sweet graphic performance.


