Physics Animations Simple PendulumAnimates the motion of a pendulum with sliders to set the initial angle and angular velocity. Pendulum + Angle GraphShows the plot of $\theta(t)$ next to an oscillating pendulum. Pendulum + Phase SpaceShows the flow in phase space next to an oscillating pendulum. Pendulum + Energy GraphShows how the motion of a pendulum can be understood by sketching the potential energy curve. Hanging RopeDraws the catenary shape of a rope hung between two endpoints. Electric Field LinesDraws the electric field lines between two opposite charges. Orbits and the Effective PotentialShows how the shape of the orbit of a planet can be understood by sketching the effective potential. Orbits by EccentricityShows the orbit of a planet or comet with a tunable eccentricity. Mass on a SpringShows the motion of an oscillating block attached to a spring. Spring + Displacement GraphShows the $x$ vs $t$ curve for a block attached to a spring. Spring + Energy GraphShows the motion of a block attached to a spring next to its potential energy curve. Double PendulumAnimates the motion of a double pendulum. Things get chaotic! Expanding Around EquilibriumAlmost any potential looks like a harmonic oscillator near its stable equilibrium points. Spring PendulumAnimates the motion of a pendulum with a spring in place of a rigid rod. BrachistochroneDraws the shortest route for a bead sliding along a wire between two points. Keep In Touch! Sign up below to get my newsletter about cool science stuff.