Definitions

Robert Hooke (1635-1703) was an English scientist, architect, and natural philosopher who became a key figure in the Scientific Revolution. Hooke conducted his scientific experiments outside the auspices of universities, and he was a great...

Isaac Newton (1642-1727) was an English mathematician and physicist widely regarded as the single most important figure in the Scientific Revolution for his three laws of motion and universal law of gravity. Newton's laws became a fundamental...

Marcus Junius Brutus (85-42 BCE) was a Roman politician and a leading figure in the assassination of Julius Caesar in 44 BCE. Although he was granted amnesty after the Ides of March, a new civil war soon broke out. Brutus committed suicide...

Claudius Ptolemy (c. 100 to c. 170 CE) was an Alexandrian mathematician, astronomer, and geographer. His works survived antiquity and the Middle Ages intact, and his theories, particularly on a geocentric model of the universe with planets...

Galileo Galilei (1564-1642) was an Italian mathematician, physicist, astronomer, and natural philosopher. He created a superior telescope with which he made new observations of the night sky, notably that the surface of the Moon has mountains...

The Sun Dance is a ritual ceremony observed by the Plains Indians of the regions of modern Canada and the United States to awaken the earth, renew the community, give thanks for the sun, and petition or give thanks for favors from the Great...

The War of the Sixth Coalition (1813-1814), known in Germany as the Wars of Liberation, was the penultimate conflict of the Napoleonic Wars (1803-1815). The Sixth Coalition, which included Russia, Austria, Prussia, the United Kingdom, Sweden...

The Sioux are a native North American nation who inhabited the Great Plains region of, roughly, modern Colorado, Montana, Nebraska, North Dakota, South Dakota, and Wyoming. They are one of the many nations referred to as Plains Indians who...

The astrolabe is an astronomical instrument used from around the 6th century to measure time and position by determining the altitude of heavenly bodies like the Sun and certain stars. Measurements were taken in reference to the viewer's...

Johannes Kepler (1571-1630) was a German astronomer and mathematician most famous for creating what was up to that point the most accurate model of planetary astronomy with his three laws of planetary motion. Kepler was the first to present...