Video clips, animations, and computer simulations that bring to life the equations of physics



Robert Dalling


See http://faculty.lsmsa.edu/RDalling/physlink.htm for a collection of 2,000 links to websites that explain most every topic in the introductory physics course. Thousands of teachers have been conducting the same internet searches for the same topics. This collection might shorten the new teacher’s search to a few minutes per chapter. The links provide teaching and learning tools and are organized by textbook chapter. In addition, there are links to online textbooks and to topics involving science in history, society, and art, see http://www.bugman123.com/Physics/Physics.html. There are links to examples of everyday physics–for example, the flow of energy in living creatures, human beings, the planet, homes, and factories and such.
   

By spending a few minutes with a computer simulation, a student may build as much physical intuition as results from solving several numerical problems. The static photographs shown in textbooks can not compare to these simulations. For example, two-d collisions come to life in Drew Dolgert’s applet, see http://galileoandeinstein.physics.virginia.edu/more_stuff/Applets/Collision/jarapplet.html. In this simulation of Newton’s Cradle, see http://www.sd83.k12.id.us/newtons_cradle.swf, push the second sphere rightward to give four of five spheres a sideways toss and then watch the evolution of the momentum exchanges. Follow this example of velocity exchange with David N. Blauch’s visual development of Maxwell’s velocity distribution, see  http://www.chm.davidson.edu/ChemistryApplets/KineticMolecularTheory/Maxwell.html, and with Noriyoshi Kato’s Motion of Ideal Gas Molecules in a Cylinder, see http://www2.biglobe.ne.jp/~norimari/science/JavaApp/e-gas.html. Selman Hershfield brings the lens equation to life at http://www.phys.ufl.edu/~phy3054/light/lens/applets/convlens/Welcome.html. Paul Falstad animates 3D wave interference, see http://www.falstad.com/ripple (press the down arrow twice and then click 3D-View).
   

A teacher’s verbal description of a phenomenon may have less educational value than does a student’s interaction with a simulation or viewing of an animation. Some examples include Rutgers University’s demonstration of centripetal force, see http://paer.rutgers.edu/PT3/experiment.php?topicid=5&exptid=56, E. Manousakis’ animation of Kepler’s Equal Area Law, see http://www.physics.fsu.edu/courses/fall98/ast1002/section4/kepler/10_13_27.mov, and David Kirkby’s Simulation of Sound Traveling Through Air, see http://positron.ps.uci.edu/~dkirkby/music/html/demos/PlaneWave/SoundWave.html. Alex Krizhevsky shows the dynamic superposition of two sine waves, see http://thespoon7.tripod.com/wave.htm.
   

Some links involve video of real life physics. For example, inertia is demonstrated in the space shuttle, see http://www.nas.nasa.gov/About/Education/SpaceSettlement/Video/thrust.mpg, or the student might analyze the trajectory of a leaping dolphin, see http://www.arkive.org/species/GES/mammals/Lagenorhynchus_obscurus/Lagenorhynchus_ob_06b.html?movietype=rpMed. The Phet simulation compares trajectories with and without air resistance, see http://phet.colorado.edu/sims/projectile-motion/projectile-motion.swf. 
   

Not every school can afford the equipment needed for classroom demonstrations, so the collection includes links to video clips of demonstrations conducted at various universities. Wake Forest University has a video of a Van DeGraaff generator at  http://www.wfu.edu/physics/demolabs/demos/avimov/e_and_m/vdg/VandeGraff.MPG and a Telsa Coil at http://www.wfu.edu/physics/demolabs/demos/5/5n/5n2050.ram. If we had time, each of us teachers would build and demonstrate a bed of nails. We can instead show Mahanakorn's video, see http://www.mut.ac.th/~physics/PhysicsMagic/nails.htm.
   

The listed simulations also encourage the student to pursue further study. A simulation of an advanced topic illustrates that the professional scientist or engineer uses nothing besides the equations contained in the introductory textbook. The only difference is that a computer is used to do more calculations than a person can do, see http://ircamera.as.arizona.edu/NatSci102/movies/twogalaxymerger%5b1%5d.mpg and http://vis.lbl.gov/Vignettes. 
   

The links have been incorporated into some online lectures, see http://faculty.lsmsa.edu/RDalling/toc.htm, in which the links serve to illustrate the point of many individual sentences.



Robert Dalling, rdalling@lsmsa.edu