Model of a Carousel - Sep 1, 2008

You can investigate circular motion with Walter Fendt's simulation Model of a Carousel by changing the variables and observing the resulting motion.  Be sure to choose the option "Carousel with forces"--the red arrow gives the direction of the net force, which is the same as the direction of the acceleration.

Seafloor Spreading Interactive Animations - Aug 16, 2008

Try UCAR's Seafloor Spreading Interactive Animations for a simulation of the magnetic stripes on the ocean bottom--you can spot them by moving a compass around on a map of the mid-Atlantic Ridge.  For related geophysics simulations from Cornell, see the Plate Tectonics section of Discover Our Earth.

Wave on a String - Aug 1, 2008

In the PhET applet, Wave on a String, you can drag the end of the string up and down to simulate wave motion. To learn more, visit Physic 2000's Standing Waves and Resonance.

Dark Matter - Sep 1, 2008

Imagine a universe where physicists understand only a small percentage of the matter in it--that's the situation today with the Missing Mass, one of the great unsolved questions in physics.  For a discussion of the observations that led to this challenging situation, visit the Wikipedia entry Dark Matter.

Magnetic Reversals and Moving Continents - Aug 16, 2008

Magnetic stripes on the ocean floor provide the key evidence for the plate tectonic theory and seafloor spreading. To learn more, visit Magnetic Reversals and Moving Continents and Magnetic Stripes and Isotopic Clocks.

Standing Waves: Harmonics and Patterns - Aug 1, 2008

To find out how two running waves in a tube add up to a standing wave, visit the Physlet applet Standing Waves: A Tube Closed at Both Ends. For a related video, see Standing Wave Movie. For a tutorial on standing waves, with animations, visit Standing Waves:  Harmonics and Patterns.