| PR: 8
| http://physics.aps.org/ They feature short excerpts and explanations from top research papers obtained from Physical Review Letters. They offer their materials in a language understandable by most physicists. |
| PR: 5
| http://www.geigercounter.org They are a premier site whose core goal is to offer simple explanations of radioactive decay, radiation, and how to protect oneself from nuclear radiation. |