WARNING: Please be careful with the laser. Always close the shutter when not in use.
Equipment:
Theory: When a beam of light strikes an interface at an angle larger than the critical angle, it will undergo total internal reflection. A stream of water will act as a light pipe if a beam of light is directed along the stream.
Description: Fill the 2 litre bottle and cap it to prevent water from flowing out the hole. Set the bottle on one lab jack, with the dish beside it to catch the water. The hole in the bottle should point away from the laser. Place the HeNe laser on the second lab jack, adjusting the height so the laser beam passes through the soda bottle and hits the middle of the hole. Turn down the lights. When the cap is loosened on the bottle (make sure the beam alignment is not disturbed when you do this) a stream of water will emerge from the bottle. The laser beam follows the stream; this can be seen by the red color where the stream hits the dish, or where the stream breaks up into drops.
Setup time: 15 minutes
References: (available in the demo room)