Contrasting Techniques

Concept demonstrated

Demonstrates the impact of materials with two different refractive indices.

Materials

• calcite block
• piece of paper with black dot on it

Practical Setup

• if you have several calcite blocks, give each (group of) student one.
• if you have only one calcite block, take an overhead projector to present
• draw a black dot on a piece of paper and put the calcite block on top of it, then rotate it above the dot. What happens? Why?

Idea/Implementation

Peter Evennett

Concept demonstrated

Demonstrates how polarizers block out light and what happens when birefrigent objects get inbetween.

Materials

Practical Setup

• each student can hold his/her polarizer(s) in front of the light source and rotate the polarizer(s). What happens?
• then let them take a biregringent object and put it inbetween the polarizers ... observe what happens. Why?

Idea/Implementation

Peter Evennett, Humberto Ibarra Avila, Britta Schroth-Diez

Concept demonstrated

Demonstrates the concept of fluorescence absorption and emission. 

Materials

Practical Setup

Idea/Implementation

Ruth Hans