This site contains 40+ appplets that can be used in physics, environmental science and astronomy courses. Divided into 4 sections (activities in brackets): Astrophysics (elemenatal spectra, atomic emission, atomic recombination, equivalent width, synthetic galaxy spectra, stellar atmospheres, inverse square law, planck radiation formula, flux within an aperture, CCD detector, planetary detection, kepler's third law, moons of jupiter, planetary cratering simulator, lunar phases , hubble expansion law, stellar parallax, galaxy crash) Energy and Environment (weather, exponential growth, voltage, work, population growth, units, circuit simulator) Mechanics (cannon, inclined planes and friction, impulse and friction, potential energy, momentum, gravity, kepler's third law) Thermodynamics (piston, balloon, first law)