This activity from the Exploratorium provides instructions to build an electroscope, a device that detects electrical charge. Common, inexpensive materials including film canisters, 3-M Scotch Magic™ Tape, and a plastic comb are used to show the attractions and repulsions between positively and negatively charged objects. The site also provides an explanation of the results and suggestions for extension activities.

In this fun optics activity, learners explore principles of light, reflection (mirrors), and perception. Learners work in pairs and sit on opposite sides of a "two-way" mirror. Both partners vary the amount light illuminating their faces. As they adjust the light, they begin to see themselves gradually assuming aspects of their partner's features, so that their image becomes a "composite" person. This activate guide includes instructions on how to build a two-way mirror.

In this weather-related activity, learners make a portable cloud in a bottle. Learners discover that clouds form when invisible water vapor in the air is cooled enough to form tiny droplets of liquid water. You an accomplish the same cooling effect by rapidly expanding air in a jar using a wide-mouth jar, rubber glove, matches, and tap water. This activity can be conducted as a demonstration or by learners with adult supervision.

This highly visual model demonstrates the atomic theory of matter which states that a gas is made up of tiny particles of atoms that are in constant motion, smashing into each other. Balls, representing molecules, move within a cage container to simulate this phenomenon. A hair dryer provides the heat to simulate the heating and cooling of gas: the faster the balls are moving, the hotter the gas. Learners observe how the balls move at a slower rate at lower "temperatures."

In this activity about light and refraction, learners discover how a lens creates an image that hangs in midair. A large Fresnel lens creates upside-down images of distant objects and right-side-up images of nearby objects. Learners can locate the upside-down images by using a piece of white paper as a screen. The right-side-up images are harder to find. Activity includes detailed explanations and diagrams to explain how the images are created.

In this activity, learners explore liquid crystals, light and temperature. Using a postcard made of temperature-sensitive liquid crystal material, learners monitor temperature changes. By observing these changes, learners show that dark materials absorb and reemit the energy contained in light more readily than light-colored materials. Learners can also distinguish energy absorbed and reemited by radiation, convection, and conduction by comparing the behavior of black, white, and silver objects. This resource guide includes detailed explanation of the phenomenon and background information about liquid crystals.

In this activity, learners explore why the sky is blue. Learners model the scattering of light by the atmosphere, which creates the blue sky and red sunset, using a flashlight and clear glue sticks. This resource guide includes an explanation of how light scatters and how this scattering can cause the polarization of light.

In this activity, learners discover that it's difficult to distinguish between two different shades of gray when they aren't separated by a boundary. Learners will be surprised when two slightly different shades of the same color look different if there is a sharp boundary between them. But if the boundary is obscured, the two shades appear indistinguishable. Use this activity to help learners explore how the eye-brain system condenses information through a process called lateral inhibition.

In this activity about chemistry and electricity, learners form a battery by placing their hands onto plates of different metals. Learners detect the current by reading a DC microammeter attached to the metal plates. Learners experiment with different metals to find out what combination produces the most current as well as testing what happens when they press harder on the plates or wet their hands. Learners also investigate what happens when they wire the plates to a voltmeter.

In this activity, learners use gelatin as a lens to investigate the properties of laser light. Learners can view total internal reflection of a beam of light and investigate angles of reflection and refraction. Using different colors of gelatin demonstrates its color filtering properties. Use this activity to help learners explore light reflection and refraction, wavelengths, color, and lenses.

The earth’s atmosphere may seem thick when compared to something like your height—but it’s surprisingly thin when compared to the earth’s radius. Here, you can find out exactly how thin, using strips of plastic to model the correctly scaled thickness of the atmosphere on a globe.

Learners use two mirrors to explore how images of images of images can repeat forever. This resource includes a light-ray diagram to help learners understand what they are seeing -- images appear to be grouped in pairs with a front side always facing a front side and a back side always facing a back side. Learners can assist in assembling the Infinity Mirror or use one that has been pre-assembled.

In this activity about light and perception, learners create pictures in thin air. Using a simple set up of a slide projector, slide, moveable screen or poster board, and a "wand", learners investigate how we see projected images such as those from movies and television. Use this activity to help learners understand concepts associated with light and optics including persistence of vision, reflection, and map projection.

In this activity and demonstration about electricity and magnetism, learners observe how the current generated when one copper coil swings through a magnetic field starts a second coil swinging. Learners also explore what happens when they change the polarity of the magnet, reverse the coil, or add a clip lead to short-circuit the coils. Use this activity to illustrate how electricity and magnetism interact. The assembly of the electromagnetic swing device takes about an hour.

In this activity about electricity and magnetism, learners discover how a doorbell works. A coil of wire with current flowing through it forms an electromagnet that acts similar to a bar magnet. The coil will magnetize an iron nail and attract it in a remarkably vigorous way.

In this activity about light and reflection, learners discover that what you see is often affected by what you expect to see. Learners hold on to a device consisting of two mirrors glued back to back to each other with a dowel handle on either side. While looking at one side of the mirror, learners move one hand on the other side of the mirror. They will be surprised as their brain is fooled into thinking that the image it sees in the mirror is actually their other hand. Learners can participate in assembling the mirror device or use a pre-assembled one. This resource also includes a simpler version of this activity in the "etcetera" section at the bottom of the guide.

In this activity about light and perception, learners create and observe moire patterns. These special patterns, which appear when two repetitive patterns overlap, can also be used to help learners understand wave interference. Learners will use various objects including pocket combs, window screens, and transparencies to investigate moire patterns in different ways.

In this activity about electricity and magnetism, learners examine what happens when a magnet exerts a force on a current-carrying wire. Using a simple device, learners discover that when an electrical current flows through a magnetic field, a force is exerted on the current and this force can be used to make an electric motor. Learners will experiment to find out what happens when they reverse the direction of current flow. They will also discover a mathematical tool called the "right-hand rule."

In this activity about light and reflection, learners use a special device called a Mirage Maker䋢 to create an illusion. What they perceive as an object is really an image in space, created by two concave mirrors. Learners will be surprised when they try to grab the object on the mirror and there's nothing there! Activity includes a light-ray diagram to help explain how the image is created.

In this activity, students observe fluid motion and the formation of convection cells as a solution of soap and water is heated. This procedure can be performed as a demonstration by the teacher, or older students can conduct the experiment themselves. A list of materials, instructions, and a description of the convective process are included.