From Wikipedia, the free encyclopedia
nationalgeographic.com
Tuesday, June 23, 2009
Lightnings
Lightning is an atmospheric discharge of electricity usually accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms. In the atmospheric electrical discharge, a leader of a bolt of lightning can travel at speeds of 60,000 m/s (220,000 km/h), and can reach temperatures approaching 30,000 °C (54,000 °F), hot enough to fuse silica sand into glass channels known as fulgurites which are normally hollow and can extend some distance into the ground.There are some 16 million lightning storms in the world every year.
From Wikipedia, the free encyclopedia
nationalgeographic.com
From Wikipedia, the free encyclopedia
nationalgeographic.com
Friday, June 5, 2009
Friday, May 15, 2009
Mystirious desert
A desert is a landscape or region that receives very little precipitation. Deserts are defined as areas with an average annual precipitation of less than 250 mm (10 in), or as areas where more water is lost by evapotranspiration than falls as precipitation. In the Köppen climate classification system, deserts are classed as BWh (hot desert) or BWk (temperate desert). In the Thornthwaite climate classification system, deserts would be classified as arid megathermal climates.
wikipedia
flickr
flickr
Moai in the Atacama desert, Chile
The Highlands of Atacama desert
the White Desert
wikipedia
flickr
flickr
Moai in the Atacama desert, Chile
The Highlands of Atacama desert
the White Desert
Thursday, May 7, 2009
Sunday, May 3, 2009
Eyes
Eyes are organs that detect light, and send signals along the optic nerve to the visual and other areas of the brain. Complex optical systems with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in cnidaria, mollusks, chordates, annelids and arthropods.
wikipedia
wikipedia
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