Turn the lights off and tilt the jar so the water flows out the largest hole into a large container. Lasers are used all around us. Find as many of their uses as you can. Ask your doctor about laser surgery. Try to attend a laser light show to see energy waves become art.
Laser light is contained in an optical fiber because of internal reflection.
A periscope uses the same principle but with mirrors instead of optic fibers. Investigate ways light is used in communication. Learn more about Morse code and see if you and your friends can send messages to each other in the dark with a flashlight. Energy moves from one place to another in waves. Tie a long piece of rope to a tree or a pole.