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What is plate tectonics? Earthquakes and volcanoes

By | 2017-09-21T15:19:05+00:00 September 21st, 2017|Geology|

The world as seen from space (flattened out) When you look at a map of the world, it seems as though it was always like that - North America on top of South America, Europe north of Africa, Australia off at the bottom right. But really all of the dry land on Earth moves around like floating shapes about 60 miles [...]

What is flint good for? Stone tools

By | 2017-09-05T12:53:38+00:00 September 5th, 2017|Africa, Prehistory, Science|

Flint is a sedimentary rock. Flint is a kind of sedimentary rock. It's pretty common; you can find flint all over  China, West Asia, North Africa, and Europe. Flint is easier to knapp (to shape) than a lot of other kinds of stone, and it will hold a sharp edge longer, so in the Stone Age people made most [...]

Ibn Sina (Avicenna) – Medieval Islamic medicine – Islamic Empire

By | 2018-01-10T13:05:25+00:00 July 27th, 2017|Islam, Science|

Where Ibn Sina came from: Uzbekistan Ibn Sina and the Samanids in Uzbekistan Ibn Sina (known to Europeans as Avicenna) was a scientist. He was born about 980 AD in the north-eastern part of the Abbasid Empire. That was in the kingdom of the Samanids. (It's modern Uzbekistan.) The Samanids supported science and art, so many scientists and artists [...]

What are sedimentary rocks? Shale and limestone

By | 2017-06-26T02:19:25+00:00 June 26th, 2017|Geology, History|

Limestone cliffs in Saudi Arabia When the Earth was first forming, about six billion years ago, there weren't any sedimentary or metamorphic rocks. The only rocks were igneous rocks like quartz. These formed when melted silica, carbon, and other molecules cooled off and stuck together. But gradually some of these igneous rocks started to [...]

What is jade? Metamorphic rock

By | 2017-06-26T01:03:32+00:00 June 26th, 2017|History|

Jade rock from Alaska Jade is really two kinds of metamorphic rock, jadeite and nephrite, that look pretty much exactly the same. Scientists can tell them apart using chemical tests and x-rays. Like quartz, both jadeite and nephrite are chains of silicon and oxygen atoms. Jadeite is a simpler chain and nephrite is [...]

What are metamorphic rocks? Marble, slate, diamonds

By | 2017-06-26T00:52:44+00:00 June 26th, 2017|Geology|

Slate rocks in Cascadilla Gorge, Ithaca, New York About 450 million years ago, some of the sedimentary rocks began to transform into metamorphic rocks. When sedimentary rocks like limestone or shale were under water, the weight of the water pressed them down. Sometimes the weight of the water pressed them so hard that [...]