Isaac Newton, in his Mathematical Principles of Natural Philosophy of 1687, used the heading “Axioms (or laws)” for what we know as the three laws of motion. The term “axiom” puzzles me, because an axiom should be a given, requiring no further proof, and used as a premise when reaching a conclusion. But in this case the axiom (or law) seems to be something that Isaac Newton is setting out to prove applies universally, to celestial bodies as well as objects on Earth.

# newton

# MIT: STEM Concept Videos

A series of 46 videos covering essential (not basic) concepts in Science, Technology, Engineering and Mathematics subjects, produced by MIT and available for viewing and download on the MIT OpenCourseWare site. The videos are designed for first and second year engineering students.

# Space and Time: Inertial Frames

Stanford Encyclopedia of Philosophy

Space and Time: Inertial Frames

First published Sat Mar 30, 2002; substantive revision Wed Nov 4, 2009

This is a fascinating review of the concept and history of inertial frames, from Galileo to Einstein. More about inertial frames of reference