referring to the three laws of motion and interaction formulated by Sir Isaac Newton (1642 - 1727), English scientist and mathematician. These laws are intended to describe how all moving bodies on the Earth react: (1) a body at rest remains at rest and a body in motion remains in motion unless acted on by an external force; (2) the motion of a body changes in proportion to the size of the force applied to it; (3) every action produces an equal but opposite reaction. —5th ACC Vol 2 Glossary (Final Approval 7/12/89), 5th ACC Glossary Part 1. Final approval 2.12.89