Question

A calcite crystal is placed over a dot on a paper sheet and the crystal is rotated. On viewing through the calcite one sees

• A. A single stationary dot
• B. Two stationary dots
• C. Two dots rotating about one another
• D. One dot rotating about the other stationary dot-sometimes coinciding with it

Answer 1

Answer: (D)

One dot rotating about the other stationary dot-sometimes coinciding with it

This effect can also be observed by inking a dot on a piece of paper and placing a calcite crystal over it. One will observe two dots from above. If the crystal is rotated while kept flat on the paper, the dot produced by the e-ray will rotate around the stationary dot