This web site is a basic, non-mathematical introduction to relativity. It covers concepts from Galileo, Newton, and Maxwell through Einstein and special relativity. The site also mentions modern topics such as the...

This page of the Einstein Light site presents the concept of an inertial reference frame, along with explanations of Newton's three laws. The site includes a video depicting the principle and is produced at the...

This site from the Exploratorium presents a demonstration showing that the acceleration of gravity is the same for different objects. The site contains a materials list, assembly instructions for creating the vacuum,...

Authored and curated by David P. Stern, this is a lesson plan for teaching frames of reference. It is linked to text material on reference frames, aberration of light, and a very short introduction to the foundations of...

This web site is the home of Light and Matter Physics, a series of introductory textbooks available online for no cost. There are six main textbooks covering Newtonian Physics, Conservation Laws, Vibrations and Waves,...