Good Physics Applets

Evaluated by Donald F. Collins, Warren Wilson College

Adding colors

http://www.osc.on.ca/JustFun/InteractiveZone/AddCol/addcol.htm
http://webphysics.ph.msstate.edu/jc/library/30-7/index.html

Both of the above are good applets.  The first one requires that you install Shock Wave.  They both contain links to variations.  Highly recommended.

Sound and waves

http://www.phy.ntnu.edu.tw/java/sound/sound.html– tricky, but good.
This applet was created by Fu-Kwun Hwang Dept. of Physics National Taiwan Normal Univ.  It contains controls to synthesize complex sound waves as well as plays the sound into a systems speaker.
Same applet available at: http://webphysics.ph.msstate.edu/jc/library/15-4b/index.html

http://phys.kookmin.ac.kr/~key/physengl/stlwaves.htm -- good
This demonstrates standing longitudinal waves.  The animation provides a visual quality which is usually omitted in textbooks of longitudinal standing waves.

http://bumper.kettering.edu/~drussell/demos.html -- good.  These are a number of animations produced by Dr. Dan Russell of Kettering, University.  They show modes of vibration, standing waves, vibrations of membranes, etc.
 

Optical ray tracing

http://wigner.byu.edu/LightRefract/LightRefract.html - Fair.

http://www.phy.ntnu.edu.tw/java/propagation/propagation.html
This shows the refraction of light by re-radiation from the molecules at the surface.  Good, but the server at ntnu.edu is often slow.
http://home.a-city.de/walter.fendt/physengl/huygensengl.htm– good!
This demonstrates the same phenomenon as the first ray-tracing applet above.  Notice some weak points.

http://webphysics.ph.msstate.edu/jc/library/22-6/index.html - Excellent!  User can manipulate object size and position, lens size and thickness, and examine the image created.  This applet is referred in a separate compilation rather than the original source.

http://www.cbu.edu/~jvarrian/applets/rainbow1/rainbo_z.htm - Good!  Ray-tracing through a raindrop to show the dispersion and minimum angle of deflection.

http://webphysics.ph.msstate.edu/jc/library/24-8b/index.html - Good!  Good, complete ray-tracing for all colors through raindrop.  Shows all exit rays, shows secondary rainbow.  Tends to hang-up.

Interference of light

http://www.phy.ntnu.edu.tw/~hwang/waveInterference/waveInterference.html
http://webphysics.ph.msstate.edu/jc/library/24-3a/index.html
These demonstrates animated 2-source interference, both authored by F. K. Hwang.  The second source is more quickly available.
 
 

Interaction of light with matter

http://www.colorado.edu/physics/2000/applets/h2ob.html  - Excellent!  The physics 2000 at the University of Colorado is extremely well done - and addictive....   This shows the response of a water molecule to the electric field from an isolated negative charge which the user can manipulate.
 

Atomic physics

http://www.colorado.edu/physics/2000/applets/orbits.html - Excellent!  The user can place an electron anywhere in the field of a positive particle and watch the particle become "sucked-up" into the massive central particle.  Try giving the electron a lateral push.  This is a classical physics simulation and can represent gravitational orbits as well.

Quantum physics

http://www.colorado.edu/physics/2000/schroedinger/two-slit3.html - fair.  This simulates the interference pattern as random events of electrons being shot through two slits.

http://www.colorado.edu/physics/2000/waves_particles/wavpart2.html - Same as orbits above

http://www.colorado.edu/physics/2000/quantumzone/schroedinger.html - Good.  Shows electron orbiting in a Bohr-like orbitals, the energy diagram is shown.  A third panel shows the wave function for the Schrodinger wave function which is seldom pictured in the textbooks.

http://www.colorado.edu/physics/2000/quantumzone/debroglie.html - Good.  Fits circular wavelengths into circular orbits.  Simple model to explain quantum levels as a result of waves.

http://www3.adnc.com/~topquark/quantum/quantumapplets.html - Excellent.  Views wave functions for simple quantum-mechanics problems (square well, harmonic oscillator, H-atom).  By Mark Sutherland.

http://www.kfunigraz.ac.at/imawww/vqm/pages/samples.html - Excellent.  These are animations viewed in Quick-time showing samples from Visual Quantum Mechanics by Bernd Thaller.

Laser

http://www.lightlink.com/sergey/java/java/laser/index.html - Fair.  Shows the population inversion and metastable state and cartoon animations of photons.  Eventually all the atoms in the metastable state decay to the ground state emitting photons in phase.  Does not show the stimulated emission very well.

http://www.colorado.edu/physics/PhysicsInitiative/Physics2000/lasers/lasers2.html - Excellent.  Shows stimulated emission by excited atoms.  Photons are "bullets".

Electromagnetic waves

http://www.colorado.edu/physics/2000/waves_particles/wavpart4.html - Good.  Shows the propagation of electric waves from a vibrating charge.  This is difficult to explain with talk and chalk.  Somewhat fun!
 

X-rays

http://www.colorado.edu/physics/2000/xray/making_xrays.html
 

Radioactivity

http://home.augsburg.baynet.de/walter.fendt/physengl/lawdecay.htm - Good.  Radioactivity is simulated by means of random numbers.  The display shows a collection of live and dead nuclei, how the counting rate decreases as time progresses.

Semiconductors.

http://jas.eng.buffalo.edu/applets/index.html  This is an index of animated semiconductor applets.
http://jas.eng.buffalo.edu/applets/education/fab/pn/diodeframe.html This animates the manufacture of integrated circuits.
 

Astronomy

http://home.augsburg.baynet.de/walter.fendt/astro/himmpole.htm – in German.  Simple, yet good.  Tries to enhance the difficult concept for students to learn about the relationship of horizon, celestial pole, and earth position.
 http://physics.syr.edu/courses/java/mc_html/kepler.html  Kepler's Second Law.  Good.  Takes some time to visit and experiment with.  By David McNamara and Gianfranco Vidali

Mathematics

http://home.augsburg.baynet.de/walter.fendt/math/sektang.htm  - in German.  Fair.  Rather sluggish response from mouse.  This shows how the average slope between two points on a parabola approach the slope of the tangent as the user moves the two points closer together.

http://suhep.phy.syr.edu/courses/java-suite/crosspro.html - Good!  User manipulates a vector in the A x B  regime and the result is displayed.  Can also view from below the plane.

http://www.warren-wilson.edu/~fsolomon/poly.html - Rotations of polyhedra.  Produced by Fred Solomon at WWC with an ACA grant for faculty-student research.

Compilations

http://webphysics.ph.msstate.edu/jc/library/ - This compilation is an easy to find catalog of applets for physics.  Many of the applets shown in this presentation were found here.  Many applets on slow servers are much more available on this server.  Credit is given to the authors.