http://www.compadre.org/informal/ The latest material additions to the Physics To Go. en-US Copyright 2008, ComPADRE.org managingEditor@compadre.org editor@physicstogo.org Thu, 24 Jul 2008 15:28:25 EST http://blogs.law.harvard.edu/tech/rss http://www.compadre.org/portal/services/images/LogoSmallInformal.gif http://www.compadre.org/informal/ 125 35 http://www.compadre.org/informal/items/detail.cfm?ID=3857 This website is an image gallery of some of IBM's published scanning tunneling microscope (STM) images. A short description of STM is provided along with a series of images showing different atomic structures. These images are properly treated as art as well as science. Modern Physics/Condensed Matter http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=3857 Thu, 24 Jul 2008 15:28:25 EST http://www.compadre.org/informal/items/detail.cfm?ID=3857 http://www.compadre.org/informal/items/detail.cfm?ID=4592 This interactive simulation allows users to explore how people view colors. The first part of the simulation explores the use of three monochromatic lights of varied intensity to produce multiple colors. The second part of the simulation allows you to filter white light and monochromatic light and study how the filter determines what colors pass through to the eyes. The color of both the light and the filter can be controlled. This simulation is part of a large and growing collection. It has been designed using principles from physics education research and refined based on student interviews. Optics/Color http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=4592 Fri, 18 Jul 2008 16:00:55 EST http://www.compadre.org/informal/items/detail.cfm?ID=4592 http://www.compadre.org/informal/items/detail.cfm?ID=7684 This site, hosted by MIT, explains the science behind the LIGO interferometer and its detection of gravitational waves. The site gives a description of gravitational waves and a brief history of Einstein's prediction of them. Classical Mechanics/Gravity http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7684 Fri, 18 Jul 2008 15:54:56 EST http://www.compadre.org/informal/items/detail.cfm?ID=7684 http://www.compadre.org/informal/items/detail.cfm?ID=7685 This Hyperphysics site gives an explanation of nuclear fission in uranium-235. Images and diagrams are also offered as well as numerous links to related concepts. Modern Physics/Nuclear Physics http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7685 Fri, 18 Jul 2008 15:53:10 EST http://www.compadre.org/informal/items/detail.cfm?ID=7685 http://www.compadre.org/informal/items/detail.cfm?ID=7686 This site from Hyperphysics offers a detailed description of static friction. Several graphs show the relationship between applied force and frictional force for an object resting on a surface. Classical Mechanics/Applications of Newton's Laws/Friction http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7686 Fri, 18 Jul 2008 15:52:11 EST http://www.compadre.org/informal/items/detail.cfm?ID=7686 http://www.compadre.org/informal/items/detail.cfm?ID=7687 This Hyperphysics site gives an explanation of "Blackbody" or "cavity" radiation, offering examples using both classical and quantum physics. A number of diagrams and example plots are used to aid in the description. Modern Physics/General http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7687 Fri, 18 Jul 2008 15:51:06 EST http://www.compadre.org/informal/items/detail.cfm?ID=7687 http://www.compadre.org/informal/items/detail.cfm?ID=7689 This Hyperphysics site provides an explanation of standing waves in strings and air columns. Diagrams explain phase changes, nodes, anti-nodes, and reflection. Links supply further information. Oscillations & Waves/Wave Motion/Standing Waves http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7689 Fri, 18 Jul 2008 15:48:26 EST http://www.compadre.org/informal/items/detail.cfm?ID=7689 http://www.compadre.org/informal/items/detail.cfm?ID=4544 This interactive simulation allows users to explore magnetic fields and Faraday's Law. Users can control settings such as magnet strength and position, and use a handy field viewer to look at the magnetic field x and y components, total field, and flux. Other options allow users to view the effects of changing fields through coils of wire. Simulated electromagnets are also provided, including explorations of their effects and uses as transformers and generators. In these simulations, position and strength of the magnet can be controled, as well as number and area of coils. Both AC and DC sources can also be examined. This simulation is part of a large and growing collection. It has been designed using principles from physics education research and refined based on student interviews. Electricity & Magnetism/Electromagnetic Induction http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=4544 Wed, 16 Jul 2008 09:27:15 EST http://www.compadre.org/informal/items/detail.cfm?ID=4544 http://www.compadre.org/informal/items/detail.cfm?ID=4514 This simulation provides a highly visual, interactive way to explore gas properties. As you pump gas molecules into a chamber, you control volume, add/remove heat, and change gravity. A pop-up histogram helps you see the relationship between kinetic energy and heat. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET). Thermodynamics & Statistical Mechanics/Models/Ideal Gas http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=4514 Wed, 16 Jul 2008 09:17:55 EST http://www.compadre.org/informal/items/detail.cfm?ID=4514 http://www.compadre.org/informal/items/detail.cfm?ID=7653 This Hyperphysics site, from Georgia State University, provides a detailed explanation of simple harmonic motion, including formulas and illustrations. Numerous links provide further information. Oscillations & Waves/Oscillations/Simple Harmonic Motion http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7653 Tue, 15 Jul 2008 15:33:08 EST http://www.compadre.org/informal/items/detail.cfm?ID=7653 http://www.compadre.org/informal/items/detail.cfm?ID=7629 This interactive java application allows you to investigate the properties of converging lenses. You can change the index of refraction and the radius of curvature of the lens. The lens and object can be moved in two dimensions. This is part of a large collection of simulations freely available from the Physics Education Technology group at the University of Colorado. Optics/Geometrical Optics/Thin Lens http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7629 Tue, 15 Jul 2008 11:29:38 EST http://www.compadre.org/informal/items/detail.cfm?ID=7629 http://www.compadre.org/informal/items/detail.cfm?ID=7646 This simulation offers two examples of simple harmonic motion, a mass on a spring and a simple pendulum. The applet allows you to adjust variables and observe the effects these changes have on the movement of the systems. Oscillations & Waves/Oscillations/Simple Harmonic Motion http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7646 Tue, 15 Jul 2008 11:21:11 EST http://www.compadre.org/informal/items/detail.cfm?ID=7646 http://www.compadre.org/informal/items/detail.cfm?ID=7631 This PhET simulation, from the University of Colorado, allows you to explore the properties of water, sound, and light waves. You can measure the wave speed with a stopwatch and ruler, and you can investigate interference and diffraction with movable detectors and customizable slit widths and spacings. You can even change the view to observe from above or from the side. Oscillations & Waves/Wave Motion/Interference and Diffraction http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7631 Mon, 14 Jul 2008 16:11:29 EST http://www.compadre.org/informal/items/detail.cfm?ID=7631 http://www.compadre.org/informal/items/detail.cfm?ID=3542 This simulation provides a realistic virtual mass-and-spring laboratory. Users can explore spring motion by manipulating stiffness of the spring, the hanging mass, the initial pull, damping (friction) and gravity. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET). Oscillations & Waves/Oscillations/Simple Harmonic Motion http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=3542 Mon, 14 Jul 2008 16:06:23 EST http://www.compadre.org/informal/items/detail.cfm?ID=3542 http://www.compadre.org/informal/items/detail.cfm?ID=7588 This news article provides information about the newest version of the “nanoguitar” created at Cornell University. The article describes how a radiofrequency laser beam resonates the guitar strings. The article includes a micrograph of this tiny musical instrument. Modern Physics/Condensed Matter http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7588 Thu, 10 Jul 2008 12:11:05 EST http://www.compadre.org/informal/items/detail.cfm?ID=7588 http://www.compadre.org/informal/items/detail.cfm?ID=7587 This Wikipedia article offers a description of tuned mass dampers, which reduce wind-driven vibrations in structures. The site explains the science behind these devices and their applications in large buildings. Numerous images and diagrams are included in the descriptions as well as a helpful animation demonstrating the operation of these devices. Oscillations & Waves/Oscillations/Simple Harmonic Motion http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7587 Thu, 10 Jul 2008 11:34:59 EST http://www.compadre.org/informal/items/detail.cfm?ID=7587 http://www.compadre.org/informal/items/detail.cfm?ID=7506 This applet, by Zona Land, demonstrates basic wave superposition through an interactive simulation. The user selects two initial waveforms, moves them together, and views the resulting interference. Colorful displays and brief explanations help explain what is happening on the screen. Oscillations & Waves/Wave Motion/Interference and Diffraction http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7506 Tue, 24 Jun 2008 16:39:10 EST http://www.compadre.org/informal/items/detail.cfm?ID=7506 http://www.compadre.org/informal/items/detail.cfm?ID=7505 This website, hosted by the American Museum of Natural History, features several articles on gravitation, from the theories of Newton and Einstein to investigations of gravitational waves at the LIGO observatories. Each essay includes a number of images and diagrams. Classical Mechanics/Gravity http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7505 Tue, 24 Jun 2008 15:11:36 EST http://www.compadre.org/informal/items/detail.cfm?ID=7505 http://www.compadre.org/informal/items/detail.cfm?ID=4966 This paper, by Andrew Davidhazy, describes strip, streak and scanning imaging methods from a visual direction but founded in cartographic and mathematical relationships. Applications include photo-finishes and panoramic views. The material may be considered as a foundation for further mathematical or visual experimentation. Optics/Geometrical Optics http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=4966 Mon, 23 Jun 2008 13:23:48 EST http://www.compadre.org/informal/items/detail.cfm?ID=4966 http://www.compadre.org/informal/items/detail.cfm?ID=7464 This website contains an explanation of gravitational waves and how the LIGO observatories will detect them. The site describes the technologies required for these 21st century instruments. Photos show the 4-km long arms of the interferometer. Optics/Interference/Interferometers http://www.compadre.org/informal/bulletinboard/Thread.cfm?ID=7464 Fri, 20 Jun 2008 14:04:45 EST http://www.compadre.org/informal/items/detail.cfm?ID=7464