PHYSICS RELATED

• American Institute of Physics
• American Physical Society
• American Association of Physics Teachers
• Yahoo Physics List
• Exploratorium
• Institute of Physics
• Berkeley Physics Demonstrations
• Wonders of Physics, Professor Sprott's annual public lectures at UW-Madison
• National Science Foundation
• Los Alamos National Lab
• Fermilab
• CERN - European Center for Particle Physics
• National Institute of Standards
• Sandia National Laboratory
• Stanford Linear Accelerator Center
• Department of Energy
• Argonne National Laboratory
• Lawrence Berkely Laboratory
• Lawrence Livermore National Laboratory
• Oak Ridge National Laboratory

ASTRONOMY RELATED

• Astronomy Picture of the Day
• Astronomy Cafe with Many features including ask the Astronomer
• American Astronomical Society
• SEDS - Students for the Exploration and Development of Space
• Astronomical Society of the Pacific
• Sky Online - A great source for News and Information
• List of Observatories on the Web
• Archive of Space Images
• WebStars