Halloween Laser & Fog Fun

For this experiment, you will need:

1. Any kind of laser beam or laser show machine
2. A large container
3. Dry ice

Make sure to follow all dry ice safe handling precautions.

Low powered VLDs and HeNe lasers do not produce visible beams in clear air. However, if you look directly into them, you can see a sparkling effect produced by the beam scattering off dust particles. Try mounting a laser on a tripod and aim it across a large field at night. Hike to the other end of the field and look back at the laser. In order to see the beam from larger angles requires the beam to be scattered by more than just dust. Drop chunks of dry ice into hot water for a dense, ground-hugging fog and see what happens to the beam. Do not allow anyone (including pets) to lie in this fog because too much CO₂ can be toxic.

Fog Cutter - If you have dry ice fog filling a room for a Halloween party, try this:

Take a small polished cylindrical object, such as a drill bit, and aim the laser beam at the cylinder. The beam will spread out into a fan. Aiming the beam through a glass or clear plastic stirring rod will have the same effect. Now orient the cylinder or rod vertically so the laser fan sweeps out in a horizontal sheet. The laser beam should create spectacular cross section cuts in the fog.

Dry Ice Safety Tips