In this activity related to light and perception, learners use a pinhole in an index card as a magnifying glass to help their eye focus on a nearby object. Learners will also discover that because this magnifier limits the amount of light that reaches their eye from the object, the pinhole makes the object appear dimmer. Learners are encouraged to explore using pins and needles with different diameters to make different-sized holes in index cards to see how this affects the image. They can also try forming a pinhole by curling their index finger.

In this activity, learners work in groups to determine the mass and volume of four samples: glass marbles, steel washers or nuts, pieces of pine wood, and pieces of PVC pipe. Learners then plot the data points on a large class graph of mass vs. volume to discover that data points for a particular material form a straight line, the slope of which gives the density of the material.

In this activity, learners explore how polarizing sunglasses can help diminish road glare. By rotating a pair of polarizing sunglass lenses or other polarizing materials, learners will discover that some angles are better at reducing glare than others. Learners observe light from the sky, reflected from a mirror, or reflected from the surface of a pond. Use this activity to introduce learners to principles of light and polarization.

In this activity, learners explore their eye pupils and how they change. Learners use a magnifying glass, mirror, and flashlight to observe how their pupil changes size in response to changes in lighting. Learners also experiment to determine how light shining in one eye affects the size of the pupil in their other eye. This resource guide includes background information about pupils and why they change as well as information related to emotional stimuli, involuntary reflexes, and photography.

In this group activity, learners use some common objects and work together to simulate the Coriolis effect. During the challenge, learners make predictions and test different scenarios. This resource includes background information about the Coriolis effect and helpful hints.

In this activity, learners explore how different deodorants work. Learners treat agar plates with different types of deodorants and compare the bacteria growth on the plates to the control sample.

In this activity you'll see how the sun's tilt on its axis changes the length of shadows. For example, why is your shadow longer in winter than in summer? It's easy to see the answer if you have a "sun" and an orbiting "earth" to demonstrate. Like many other ancient people, the ancient Chacoans used the annual changes in shadows to measure the passage of time and the change in seasons. You can too!

In this quick optics activity, learners use a dim point of light (a disassembled Mini MagLite and dowel set-up) to cast a shadow of the blood supply in their retina onto the retina itself. This allows learners to see the blood supply of their retina and even their blind spot. Learners are encouraged to wear eye protection.

In this activity about electricity, learners explore what happens when you blow a fuse. Learners short-circuit a battery using copper wire (a good conductor with very low resistance) and thin iron wire. Learners will discover that when they connect the clip to the iron wire, the voltage of the battery pushes electrons through the circuit against the resistance of the iron wire, causing the iron wire to heat up. Note: the wire gets very hot! Use this activity to introduce learners to basics of electricity including conductivity, resistance, and currents as well as electronics safety and circuit breakers.

In this activity, learners build a simple mechanism that regulates the "escape" of energy released by a falling weight by portioning it into discrete amounts. Escapements are found in mechanical clocks, such as those driven by a pendulum or a spring. Learners will build the wrapping form of escapement said to be used in a fifteenth-century German clock.

In this activity, learners create a tiny electric, motorized dancer. Learners use the interactions of magnetism and electric current to make a wire spin, while displaying the Lorentz Force in action. This lesson guide provides one of many ways to build the spinner and links to other methods.

This site from the Exploratorium looks at the physics of skateboard tricks (ollieing, mid-air maneuvers, and pumping for speed) and the physics of the skateboards themselves (wheels, bearings, trucks).

Learners explore three-dimensional geometric frames including cubes and tetrahedrons, as they create bubble wands with pipe cleaners and drinking straws. Then they investigate how soap film flows into a state of minimum energy when they lift the wand up from the bubble solution. Learners also see how light reflection and interference create shimmering colors in the bubbles.

looks at how the sun creates a changing set of conditions in space. Learn about coronal holes, solar flares, coronal mass ejections, solar wind, magnetosphere, and auroras. See photos, graphs, and live data. Make your own space weather predictions.

In this art meets science activity, learners pack silver, ball-shaped ornaments in a single layer in a box to create an array of spherical reflectors. Learners can use this as a tool to study the properties of spherical mirrors while creating colorful mosaic reflections. This is a great optics activity to use during the holiday season or any time of year.

In this activity, learners use a chemical reaction to visualize where moisture forms on the body. Learners use the Minor's iodine-starch test, a diagnostic test that doctors use to detect hyperhidrosis (excessive sweating), to identify where moisture is forming. Learners also use this method to test the effectiveness of different antiperspirants.

Closing one eye eliminates one of the clues that your brain uses to judge depth. Trying to perform a simple task with one eye closed demonstrates how much you rely on your depth perception. In this activity, learners compare their ability to perform simple tasks with one eye versus with two eyes.

In this activity, learners overlap the three primary colors to see how all other colors are made. This activity also explains how color can be explained by the subtraction of colors of light, related to the principles of absorption and reflection of light.

In this activity, a lightbulb is placed in front of a concave mirror. The actual lightbulb is not visible to the viewer, but the viewer can see the mirror image of the lightbulb formed in space. When the viewer tries to touch the lightbulb, they are attempting to touch an image. Their hand moves right through what seems to be a solid object! Learners will enjoy this illusion, while investigating principles of light and mirrors. In this version of a popular Exploratorium exhibit, a lightbulb is substituted for a spring.

In this activity, learners create a tornado in a bottle to observe a spiraling, funnel-shaped vortex. A simple connector device allows water to drain from a 2-liter bottle into a second bottle. Learners can observe the whirling water and then repeat the process by inverting the bottle. Use this activity to talk about surface tension, pressure, gravity, friction, angular momentum, and centripetal force.