Optics are intriguing and provide lots of practical and creative opportunities for students and adults, most of which require just a few simple pieces of equipment. With the help of this article, you will learn the physics of waves so you can impress your friends with your new abilities to manipulate light and color. Let’s get started!
Your own ice lens
Almost all optical instruments, from simple binoculars to complicated cameras and eyeglasses, contains lenses that were crafted by opticians. But, with this small experiment, you too will learn how to create a simple one from ice.
First, cut a tennis ball in half, and fill one of the halves with clean water until you touch the rim of the ball, and make sure you can get as close to a hemisphere as possible. Put it in a glass bowl, and the resulted assembly in the freezer.
After you made sure the water has frozen, pop it out with care so that you won’t break it. Smooth it out and then hold the lens over a glossy newspaper, with the curved side facing your eyes. You will see that the text looks bigger than without it. Afterward, you could move the ice lens up and down to see what scientists refer to as the focusing effect.
Diffraction and wax blocks
Diffraction might sound like a hard thing to grasp, but it is just the bending of a light wave around any given obstacle. Try this short activity out to see what happens when you add wax blocks to a small ripple tank.
The first thing the scientist in you has to do is cut a wedge shape of two medium-sized wax blocks. Place them in a ripple tank, then make some sort of a barrier with the wedged ends of the wax forming a tiny opening of around one-quarter inch. After that, you should generate straight-line waves with the help of the ripple tank.
Watch its screen to see what happens to the generated waves as they go through the small opening. They should emerge in a semicircular shape, and as you change the opening by moving the blocks, the form of the wave should change too.
For this activity, you will use Jell-O to explore lenses and the different angles of light entry. To do it properly, you need to buy or prepare some yourself. Cut the Jell-O with the knife into concave and convex lens shapes. Moreover, you should also cut a long and thin rectangle of Jell-O before moving forward.
For the next step, get a flashlight and place thick strips of black electrical tape across the lens to create a narrow opening for the light. Turn the flashlight on and darken the room where you’re experimenting.
Shine the narrow light beam through the different sized Jell-O lenses and observe how light exits each piece. Then repeat the same thing with the rectangle, from its end to the middle, and see how different the light looks. To compare, you could remove the tape and experiment again.