This school year marks my fifth year of teaching in Southfield, but my forth year at Southfield-Lathrup High School. Before entering the teaching profession, I worked for 20 years in corporate research and development in the vitamin and flavor industries, obtaining several patents along the way. Before that I received a Ph. D. in chemistry developing test-tube methods to synthesize DNA chemically. Those methods have since been adapted to automated machines in which a sequence of DNA can be dialed in and produced in simple, short order. For more about me visit http://expedioscientiam.net/bkgrd/.

What’s up with the picture above?

The students are wearing diffraction grating glasses while looking at gas discharge tubes. The tubes are filled with specific gases such as hydrogen, helium, neon, etc. When subjected to high voltage, 5000 V in this case, the excited electrons in the gases emit photos of specific energies. The energies correspond to specific wavelengths. The students are observing the bright line spectra for this gases.

Here is a photo of what they are actually looking at if they look at the filament of a clear incandescent bulb

The see multiple continuous (rainbow) spectra.

Here is what they see if they are looking at a pure gas:

They see “bright” lines due to the relaxation of individual excited electrons to some lower energy state. The energy of the photons released correspond to specific wavelengths of light.