Description: This demo shows the linear nature of a laser beam by clapping a blackboard eraser near it.
This can also be done with a can of compressed air (fog in a can will work too).
- Laser on stand
- Compressed air or black board eraser
- Turn on the laser.
- Turn of the lights.
- Spray some compressed air in front of the laser, or clap a black board eraser in front of it.
- Note that you can now see the laser beam because the laser light is scattered off the particles and enters your eyes.
- When finished, turn off the laser.
Do not stare at the laser beam. Do not point the laser at students.
Note: This picture is time elapsed. In person, the beam will not be as bright.