by: Martin Sagendorf
Most everyone knows that an equilateral prism will refract white light into its constituent colors: a spectrum ranging from red to violet. But, if one uses two prisms, there’s much more to be discovered.
Two Prisms: Four Demos
November 26, 2011
8 Comments | 
High School level, Middle School level, Physics | Tagged: light, light spectrum, PBL, phenomenon based learning, phenomenon-based science, prisms, refraction, science, Sir Isaac Newton | 
Permalink
Posted by Tami O'Connor
Making Optics Demos Easier
May 20, 2010by: Martin Sagendorf
We’ve all likely encountered the time-consuming effort required to set up an optics demo; all the necessary components are on hand, but they don’t easily work together. The difficulty is obvious: the various components are either ‘loose’ or mounted at differing heights. Thus: wasted and frustrating time ‘shimming’ with books and pads to match the heights of the components.
The solution is simple: choose a height (above bench top) and mount every optical component at the same (optical centerline) height. But, how does one choose a height? Simple: first, determine the optical component with the highest centerline then second, build supports for all the other components – matching this centerline height.
I began with a 100 Watt clear light bulb mounted upon a wooden base – the center of the filament was 4-3/4” above the bench top. I then ensured that everything else I had, or planned to incorporate in demos, could be centered at this height.
The supports shown in the following illustrations are of ¾” pine – either screwed or glued together. Where required, various combinations of rubber feet and jackscrews provide support and positioning capability. When applicable, stacks of steel washers are incorporated to add stability. Read the rest of this entry »
2 Comments | College level, experiments, High School level, Physics | Tagged: lasers, lenses, light, optics, physics demonstration apparatus, prisms, reflection, refraction | Permalink
Posted by Tami O'Connor