About paper

Authors

Volume

Paper topic

Keywords

Type of use

  • Elementary school
  • High school / University

Equipment

  • Simple equpiment
Czech original

Physics In A Box

Kaštilová D.

Equipment: Black sheet metal, two white-painted wooden pads about a quarter the length of the sheet, several discarded CDs, a semiconductor laser (5 × 1 Watt), optical componets (two convex lenses with short focal length, four small mirrors, a semi-translucent mirror, a glass semi-cylinder), small magnets, glue, black plastic covers, metal strip to cover the laser outlet.

Preparation: glue the selected optical components to one side of the CD and magnets to the other, so the CD can be affixed to the sheet metal. Position the sheet metal vertically and place the CD with the optical components attached in the middle of the sheet. Cover the CD with a plastic cover (also equipped with magnets), so that the optical components can’t be seen. Glue the wooden pads on both sides of the thus created black box so that there is still place for the laser on the sheet metal.

Realization: Cover three of the five laser outlets with metal strips and magnets and point only two parallel laser beams through the black box. After they pass through, they will change their positions.

Box number 1:         The outgoing laser beams are parallel and swap positions.

Box number 2:         The outgoing laser beams are parallel, move to one side and swap positions.

Box number 3:         One pair of beams is horizontal and the second pair is parallel to each other, but under a different angle than the original beams.

Remove the metal strip and point all five parallel beams into the box.

Box number 4:         Three convergent lasers go out of the box.

Explanation:

1. The box contains two convex lenses

2. The box contains 4 mirrors

3. The box contains a semi-translucent mirror Zx

4. The box contains a glass semi-cylinder, which works as a convex lens for the middle three beams, but reflects the outer beams completely.

Note: All these and six more black-box experiments are filmed and available on CD under the name Magic beams. This CD enables the showing of the experiments on a computer monitor in any order (min. Pentium with 800×600 resolution).