Geometric Optics
The following resource is a no-cost Java simulation that allows the user to produce ray diagrams of light sources passing through a converging lens. Users are able to manipulate properties of the converging lens in multiple ways to better understand how images are formed. Tools for manipulating the simulations include toggle boxes and slide controls. Quantitative data is displayed as well as visualized in multiple ways. The simulation may be run online by computers with Internet access or downloaded to be run offline as an applet.
The construction of ray diagrams by hand is a valuable pursuit but one that is time consuming and prone to error. Students are often so concerned with drawing lines properly that they fail to develop an intuitive feel for the kinds of images that converging lenses create. The advantage in using this simulation is that students are freed from laborious geometric construction and permitted to adjust several variables. In addition to the object distance and number of light sources (one or two), the user can adjust properties of the converging lens which alter the focal length (curvature radius and refractive index). Adjustment of refractive index reinforces the idea that the behavior of lenses is a direct consequence of refraction. Teachers can use the simulation to emphasize that images are formed from multiple points of an extended source by choosing to display a movable second point on the object. The distinction between real and virtual images is another option, as the user may choose whether to display virtual images and also has the choice to see an image or to use a screen to display the image.
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eduToolbox® is a resource-sharing portal developed by the Ayers Institute for Learning & Innovation with collaborative support and funding from the Tennessee Department of Education and the U.S. Department of Education's Math & Science Partnership program.
