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 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 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.

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.

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 explore center of gravity, or balance point, of stacked blocks. Simple wooden blocks can be stacked so that the top block extends completely past the end of the bottom block, seemingly in a dramatic defiance of gravity. A mathematical pattern can be noted in the stacking.

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, 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.

In this activity about light and refraction, learners make a lens and magnifying glass by filling a bowl with water. Learners explore why the lens inverts images and also reverses the motion of images. Use this activity to introduce learners to basic principles of light and lenses. Activity includes light-ray diagram to explain how image is formed.

In this activity, learners make a stroboscope--a spinning disk with slits around the edge that you look through. Brief but frequent glimpses of images seen through the slits lead to a surprising result, which teaches learners about vision and the human nervous system. The activity includes three short online videos: Introduction, Step-by-Step Instructions, and What's Going On. Also available: a concept map and a "Going Further" document that suggests variations on this activity.

Think of some of your favorite tastes: savory Thanksgiving turkey, buttery mashed potatoes, tangy cranberry sauce, and warmly spiced pumpkin pie. We perceive food's complex, layered flavors through the work of five* types of receptors on our tongues—those that detect either sweet, sour, salty, bitter, and umami (savory). These receptors bind to chemicals in our food and transmit the information about the chemicals to our brains, resulting in a healthy appreciation for the nuances of chocolate, coffee, strawberries, and more.