Describes a laboratory activity in which students speculate about the extent to which Galileo actually performed an experiment to determine that all pendulums of a given length have the same period, independent of amplitude. (WRM)

Describes an experiment that extends Newton's instantaneous-impulse method of orbital analysis to a graphical method of orbit determination. Discusses the experiment's usefulness for teaching both horizontal projectile motion and instantaneous impulse. (WRM)

Describes a laboratory activity in a liberal-arts physics course entitled "Galileo to Newton and Beyond" in which students examine the orbits of Earth and Mars from heliocentric and geocentric viewpoints. (WRM)