Speaker
Description
In my previous talk I outlined the role of quantization considerations in the emission spectra of ionized elements and in the colors emitted by Light Emitting Diodes. I have created an inexpensive set of demonstrations that can be given to students and outreach audiences of almost all ages so that they can directly experience these surprising phenomena. I cut small squares of linear diffraction gratings, typically 500 to 1,000 lines/mm and tape them over holes punched in business cards. For the diodes I include a colored lens, several ‘clear water’ of varying wavelengths, a UV spectrum, and RGB flashing LEDs along with a 3V lithium battery. Students can clearly see the circuit components through the magnifying clear plastic lenses. They quickly note that when several LEDs are connected to the battery several short-wavelength LEDs dim or go out while the red/yellow ones remain lit—a great introduction to band gaps in the semiconductors. I will have several kits to hand out to interested attendees. This talk is given in memory of Drs. Rae Carpenter and Richard Minnix for their decades of service to the state of Virginia and Physics teachers worldwide.
