Tag Archives: Uppsala University

today’s birthday: Charles Darwin (1809)


Charles Darwin (1809)

Darwin was an English naturalist who developed the modern theory of evolution. Along with naturalist Alfred Russel Wallace, he proposed the principle of natural selection: the mechanism by which advantageous variations are passed on to later generations and less advantageous traits slowly disappear. Darwin’s intensely controversial theory of evolution aroused widespread argument and debate among scientists and religious leaders. How did Darwin view religion and God? More… Discuss

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Sandstone


Sandstone

Sandstone is a sedimentary rock formed when

English: A classification chart of sedimentary...

English: A classification chart of sedimentary rocks. (Photo credit: Wikipedia)

grains of sand have been cemented together by a material such as silica, iron oxide, or calcium carbonate. It usually consists mainly of quartz and can vary in color from yellow or red to gray or brown. Sandstone’s porous nature makes it ideal for aquifers, and it is also widely used in construction and industry. Why is sandstone commonly used for decorative features in buildings? More… Discuss