![]() ![]() Light pipes and prisms can also be cut from gelatin to show Total Internal Reflection (TIR). The measurement and concept of index of refraction can then be related to the concept of eye-glasses, microscopes, telescopes and camera lenses, although fewer students are familiar with cameras not enclosed in their cell phone. Figure 3 shows the set up for this demonstration. Two or more batches of gelatin can be prepared with and without sugar to adjust the refractive index so different measurements can be made. ![]() The index can be read off the scale on the right side. ![]() The lens is cut from a block of gelatin with a sharp knife for the plano side and a piece of sharpened aluminum roof flashing bent to match the radius of the convex side. Refractive angles for a given input angle, optical shape and index values are pre-calculated and printed onto a template. The refractive index can be measured with a laser line and a template. It is also useful to point out that the Gelatin does not contain any sugar, so it won’t taste very good. Gelatin is fun to handle by the audience so making extra is recommended as the optical components do not last long under probing, poking and bending, even at double strength. We use a double concentration of Knox which holds up well at room temperature. The Gelatin also scatters light so a laser beam is visible as it passes though the material allowing students to see the path that theoretical (or in this case very real) rays would take through an optic. Lenses, lightpipes, and prisms can be easily cut from a sheet of Gelatin. Optical components are useful to illustrate basic optical concepts, and with ‘Jello Optics’ we generate a method to demonstrate basic concepts of refraction with a medium that is very engaging to young students. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |