Other
The Ptolemaic Model of the Planetary System
An easy-to-read description and history of Ptolemy's geocentric model of the universe. Geocentric means that Ptolemy believed the Earth was the center of the universe.
Other
The Astrolabe: Home Page
This site provides a very general overview of astrolabe principles with links to other pages for more detailed information.
Other
Nine planets.org: Ptolemy
This site from the University of Arizona provides a background of Ptolemy's profound influence in the areas of astronomy, geography, and cartography. Includes good pictures and related links.
Treehut
Suzy's World: Black Holes
Use this site to find out what is a black hole in space and try an experiment.
![Pbs Teachers: The Dark Side of the Universe: Doppler Shift [Pdf] Lesson Plan](https://content.lessonplanet.com/knovation/original/120528-27b1e0832d6ded7211396a70c5d6c972.jpg?1661407624 "Pbs Teachers: The Dark Side of the Universe: Doppler Shift [Pdf] Lesson Plan")
PBS
Pbs Teachers: The Dark Side of the Universe: Doppler Shift [Pdf]
Investigate how astronomers detect movements of stars by studying the Doppler effect on the star's light spectrum. Construct a model that illustrates this concept underlying red shift.
NASA
Nasa: Imagine the Universe: "Twinkle, Twinkle (Really Fast!), Little Star"
"The Rossi X-ray Timing Explorer has discovered neutron stars that emit streams of X-rays pulsing over 1,000 times a second." Visit this site to read the rest of this article. Site offers additional resources as well as a Teacher's Corner.
Space Telescope Science Institute
Hubble Site: Supernova Shock Wave
This site from the Hubblesite highlights an article written about a supernova shock wave. Provides images as well as video footage. Site offers links to fast facts, a question and answer section as well as related links.
Space Telescope Science Institute
Hubble Site: Secret Lives of Galaxies
This site is provided by HubbleSite from NASA. "Telescopes around the world are beginning to harvest new clues to the origin and evolution of the universe's largest building blocks, the galaxies." Site offers links to images, video,...
NASA
Nasa Star Child: What Is a Light Year and How Is It Used?
This is a definition and example of how distance is measured in astronomy, such as the distance between our earth and the stars.
Science4Fun
Science4 Fun: Al Khwarizmi
Brief biographical sketch of Muhammad Ibn Musa Al-Khwarizmi, famous mathematician who developed Algebra.
Robin Chew
Lucid Cafe: Sir Isaac Newton
The notable English scientist and mathematician Sir Isaac Newton lived from 1642-1727. This site is a brief biography.
National Institutes of Health
National Library of Medicine: Paracelsus, Medical Revolution of the Renaissance
This site explores the work of Paracelsus, a leading physician during the Renaissance. It provides biographical information on the great physician, gives an overview of Renaissance humanism, and explains how different theories of medical...