What does A.D. mean?
What does A.D. mean? Timeline showing BC and AD dates The meaning of A.D. and B.C. A.D. stands for Anno Domini, which is Latin for "year of our Lord," and it means [...]
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10, 2017
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09, 2017
Coca leaves – South American medicine
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 [...]
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09, 2017
What is steel? Ancient and medieval steel
Damascus steel sword from the 1200s AD Soon after 300 BC, with the rise of the Silk Road, people were all looking for new ideas for things they could sell. Thanks to Buddhist [...]
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09, 2017
What is rubber? History of rubber
A big rubber tree in Mexico Olmec people, living in southern Mexico, invented rubber about 1600 BC. It was just as they were beginning to build their empire. Rubber starts out as [...]
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09, 2017
What is a pontoon bridge? History of science
A pontoon bridge from the Column of Marcus Aurelius, in Rome A pontoon bridge is a temporary bridge that you make by lining up a lot of boats crossways across the river, [...]
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09, 2017
Scientific observation – history of science
Black-eyed Susan (the black in the middle is the seeds) Before people had any idea why anything happened, or how, they could at least find out what happened. People watched plants grow. [...]
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09, 2017
Steel history – medieval to modern steel
Steel history: a Safavid steel helmet (Iran, 1500s AD) Medieval steel from India and Iran The wars after the collapse of the Mongol Empire in the 1300s stopped steel production in Uzbekistan and Turkmenistan. [...]
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09, 2017
What is yellow fever? – History of medicine
Kids with yellow fever in Mississippi about 1870. See how all the people are white? The hospital wasn't letting black kids in, or hiring black women as nurses. Where did [...]
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09, 2017
What is typhus? History of diseases
A woman with typhus Nobody seems to have caught typhus before about 1450 AD, so the disease probably didn't exist until then. Typhus is an infection caused by tiny germs (bacteria) [...]
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09, 2017
What is typhoid fever? History of diseases
Typhoid fever: A person with typhoid rash (Iran) Is it typhoid or typhus? Typhoid fever isn't the same thing as typhus at all. You catch typhus from being bit by lice that [...]
