Claudius Ptolemy was a Greco-Egyptian writer of Alexandria, known as a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in the city of Alexandria in the Roman province of Egypt...

Nicolaus Copernicus was a Renaissance- and Reformation-era mathematician and astronomer who formulated a model of the universe that placed the Sun rather than the Earth at the center of the universe, likely independently of Aristarchus of S...

Galileo Galilei was an Italian polymath: astronomer, physicist, engineer, philosopher, and mathematician. He has been called the "father of observational astronomy", the "father of modern physics", the "father of the scientific method", and...

Johannes Kepler was a German mathematician, astronomer, and astrologer. A key figure in the 17th century scientific revolution, he is best known for his laws of planetary motion, based on his works Astronomia nova, Harmonices Mundi, and Epi...

Christiaan Huygens was a prominent Dutch mathematician and scientist. He is known particularly as an astronomer, physicist, probabilist and horologist. Huygens was a leading scientist of his time. His work included early telescopic studi...

Alexander von Humboldt was a German naturalist and explorer, and the younger brother of the Prussian minister, philosopher, and linguist, Wilhelm von Humboldt (1767-1835). Humboldt's quantitative work on botanical geography was foundational...

Albert Einstein was a German-born theoretical physicist. Einstein developed the theory of relativity, one of the two pillars of modern physics (alongside quantum mechanics). Einstein's work is also known for its influence on the philosophy...

Wernher von Braun was a German, later American, aerospace engineer, and space architect. He was the leading figure in the development of rocket technology in Germany and the father of rocket technology and space science in the United States...

As spacecraft commander for Apollo 11, the first piloted lunar landing mission, Armstrong gained the distinction of being the first person to step on the surface of the Moon. On July 16, 1969, Armstrong, Michael Collins, and Edwin E. "Buzz"...

Yuri Alekseyevich Gagarin was a Soviet pilot and cosmonaut. He was the first human being to journey into outer space, when his Vostok spacecraft completed an orbit of the Earth on April 12, 1961. Gagarin became an international celebrity, a...