The 3D Refraction Interactive is an adjustable-size file that displays nicely on smart phones, on tablets such as the iPad, on Chromebooks, and on laptops and desktops. The size of the Interactive can be scaled to fit the device that it is displayed on. The compatibility with smart phones, iPads, other tablets, and Chromebooks make it a perfect tool for use in a 1:1 classroom.

 

This simulation displays a narrow light beam incident upon a hemi-cylindrical block of material. The beam is incident towards the center of the flat side of the block. As such, the incident and refracted ray at the curved side does not undergo refraction. The set up allows a student to investigate the refraction and reflection of light at the flat side of the block. The angle of approach of the light can be modified by clicking anywhere within the simulation. The reflection and the refraction of the light ray are shown at the flat side. The angle of incidence (∠i), refraction (∠r), and reflection (∠r) are shown in black, blue, and green respectively. The brightness of the three rays is conveyed by the thickness of the ray; a brighter ray is a thicker ray. Thus, the effect of the angle of incidence upon the proportion of light energy that reflects and refracts can be observed. 

The light can be dragged to either side of the block so that it is incident on the flat side from the block to the surroundings or from the surroundings to the block. The indices of refraction of the block and the surroundings can also be adjusted. This allows a student to investigate the conditions that leads to total internal reflection at the boundary.

The simulation has a 3D features. Right-clicking and dragging allows you to adjust the view of the block. There are no limits on how you can view the block and incoming light.  The simulation also includes a Calculation mode. Tapping on the Show Calculations button pops up a display in which the critical angle (where applicable), the angle of refraction, and the angle of reflection are calculated and displayed. There is also a question mode available (radio button on right side of sim). The question mode hides the angle values and calculations. Students can set the angle of incidence and indices of refraction to any value and calculate the angle of refraction. Then the student can tap the answer button and self-check their answers. Finally, there is an auto-rotate mode that allows automatically rotates the incident beam through a full 360° rotation and displays all rays and values in the process. The auto-rotate feature can be paused at any moment and then later continued from the paused angle.

This Interactive can be effectively used at any stage of a learning cycle on refraction.  The Interactive lends itself to both quantitative and qualitative studies. The Interactive allows students to explore concepts like the direction of bending, the effect of angle on the amount of deviation from the original light path, the effect of the indices of refraction upon the amount of refraction, the effect of incident angle upon the proportion of reflection and refraction (indicated by the thickness of the rays), the conditions under which total internal reflection occurs, etc. The Interactive also allows one to investigate quantitative relationships such as Snell's Law, the effect of indices of refraction upon the critical angle, etc.

 

There are numerous resources at The Physics Classroom website that serve as very complementary supports for the 3D Refraction Interactive. These include:

 

Additional resources and ideas for incorporating the 3D Refraction Interactive into an instructional unit on Refraction and Reflection can be found at the Teacher Toolkits section of The Physics Classroom website.  Visit Teacher Toolkits.

 

 

 

We owe a special thanks to Physics teacher Martin Kirby for donating the 3D Refraction Simulator to our Interactives collection. If you like this sim, you can tap on the Donate button and buy him a cup of coffee (or a pot of coffee); he'd appreciate it. Martin has contributed many other simulations to our Interactives collection. You can view them all by visiting our page listing all Martin Kirby Simulations. Or visit Martin's website (https://sites.google.com/a/kirbyx.com/) to learn more.