Picture of Ptolemy
The Bettmann Archive

Ptolemy

Ptolemy was a Greek astronomer who lived between 85-165 A.D. He put together his own ideas with those of Aristotle and Hipparchus and formed the geocentric theory. This theory states that the Earth was at the center of the universe and all other heavenly bodies circled it, a model which held for 1400 years until the time of Copernicus.

Ptolemy is also famous for his work in geography. He was the first person to use longitude and latitude lines to identify places on the face of the Earth.


You might also be interested in:

Ready, Set, SCIENCE!: Putting Research to Work in K-8 Science Classrooms

What types of instructional experiences help K-8 students learn science with understanding? What do science educators teachers, teacher leaders, science specialists, professional development staff, curriculum designers, school administrators need to know to create and support such experiences?...more

Aristotle

Aristotle was a Greek philosopher who lived between 384-322 B.C. He was one of the greatest thinkers of the world and his written works encompassed all major areas of thought. Aristotle mistakenly believed...more

Nicholas Copernicus

Nicholas Copernicus was a Polish astronomer who lived between 1473-1543. Before his time, people believed in the Ptolemaic model of the solar system, which maintained that the Earth was the center of...more

Tycho Brahe

Tycho Brahe was a Danish astronomer who lived between 1546-1601. For over twenty years, he made very accurate observations of the night sky, all without the aid of a telescope, which had not yet been...more

Archimedes

Archimedes was a Greek mathematician and engineer who lived between 287-212 B.C. His greatest contributions are in the field of geometry and in the development of war machines. Legend has it that Archimedes...more

Democritus

Democritus was a Greek philosopher who lived between 470-380 B.C. He developed the concept of the 'atom', Greek for 'indivisible'. Democritus believed that everything in the universe was made up of atoms,...more

Eratosthenes

Eratosthenes was a Greek scientist who lived from 276 to 194 B.C. He studied astronomy, geography, and math. Eratosthenes is famous for making the first good measurement of the size of the Earth. He spent...more

Plato

Plato was a Greek philosopher who lived between 427-327 B.C. He founded the Academy in Athens, a school which made many important scientific discoveries during ancient times. Although Plato made no important...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA