History of coca leaves: Coca farming in the Andes Mountains When did coca plants evolve? Like potatoes, tomatoes, and tobacco, coca plants grow wild in the Andes Mountains of South America. They probably evolved [...]
Greek sculpture: Winged Victory (Nike of Samothrace) - Now in the Louvre, Paris What happened to all the Greek statues? Not very much Greek sculpture has survived for us to [...]
Before the New Stone Age, people had lived in caves, but around 6000 BC people living in Greece began to build houses for themselves instead. At first they built small houses out [...]
A Greek architrave: the stones running along the tops of the columns. This is the Temple of Hera - Agrigento, Sicily (ca. 450 BC) Greek temples on platforms Greek architects [...]
Temple of Herakles, Agrigento, Sicily In early Archaic Greek temples, the columns and the roof were made of wood. To keep the wood from rotting, Greek builders put a flat stone under [...]
Sedimentary rocks: Limestone cliffs in Saudi Arabia Before sedimentary rocks When the Earth was first forming, about six billion years ago, there weren't any sedimentary or metamorphic rocks. The only [...]
Erosion of a cliff in Canada Igneous rocks came first When the Earth first formed, about four and a half billion years ago, it was all liquid rock and liquid [...]
Granite rock There are three different kinds of rocks on Earth, and they form in very different ways. The first kind is igneous rock, which means "fire rocks". Igneous rocks [...]
What is quartz? A chunk of white quartz What is quartz made of? Quartz is an igneous rock made out of molecules of silicon and oxygen atoms held together in [...]
Himalaya Mountains India breaks off of Africa About 55 million years ago, plate tectonics made the land that is now India break off from what is now Africa. At this [...]
