Utah State Office of Education
Utah Science: Matter
Discover atoms and molecules which make up matter, motion of atoms and how to measure the mass, volume and density of matter.
Other
Perpetual Motion Page: Machines
This personal site provides a good selection of proposed perpetual motion machines complete with drawings and detailed explanations of the machines.
Space Telescope Science Institute
Nasa: Hubble Space Telescope: Galaxies
At this site from HubbleSite you can learn all about galaxies and black holes. Click on the movie link and discover how old the universe is or study about what happens when two galaxies collide!
Other
Eric's History of Perpetual Motion and Free Energy
This personal site, "Eric's History of Perpetual Motion and Free Energy Machines," provides a timeline of the machines and their makers.