If you have staff to do simple demonstrations here are a few activities that can be done using inexpensive items. Choose one of the 3 activities linked directly below to jump down to the information, see the materials required, or watch a sample video.
ACTIVITY #1: FLATTENING THE SUN
Core Concept: Objects look different when viewed through a medium that bends the direction of light rays passing through. The atmosphere can alter the Sun's appearance at sunset. This activity encourages visitors to explore this process themselves using a ball and a square vase.
Exhibit connection: Lensing
Materials: A square glass vase, yellow ball, image of sunset
Background: The Sun is a sphere, not the misshapen oval that appears in this sunset picture. The distortion happens because the Earth's atmosphere is acting as a lens. Light from the bottom of the Sun is being bent more than from the top because the light must pass through more of the atmosphere the closer we look to the horizon. The effect is that the apparent location of the bottom of the Sun is raised more than the top, making the whole Sun look oval-shaped.
Suggestions for introducing the activity: Ask visitors if they have ever watched a sunrise or sunset very closely. Have they ever noticed the flattened appearance of the Sun as depicted in the exhibit photograph? Do they have any theories for why this might happen? What's different when you see the Sun on the horizon vs. when you see it overhead? (You're seeing it through a lot more of Earth's atmosphere).
Demonstration Video: SUNSET SIMULATION.
ACTIVITY #2: SHIFTY SHADOW SHAPES!
Core concept: The shape of a shadow can change given the orientation of the light or the object blocking the light. This activity explores shadows cast by various shaped objects and those cast by light sources at different angles.
Exhibit connections: Shadows
Materials: Adjustable light, block stands, solid screen, translucent screen, wooden shapes, image of shadows of people on a beach, images of Jupiter moon and shadow, and image of shadow of Curiosity Rover on Mars
Background: Shadows are our ever-constant companion. They are created when an object obstructs (absorbs or reflects) light from a light source, creating a region behind the object where light cannot reach. The size and shape of a shadow changes when the orientation of the object or the light source is changed. When the light source is directly above the object (like the sun overhead in the sky) a shadow cast will be short. However when the light source is at an angle to the object, the shadow will be long.
Misconception alert: Young children especially have difficulty understanding that light travels in straight lines from a source, and that shadows are the result of an object blocking light from passing straight through. They may think that they can only have one shadow, and when asked to draw a picture showing how shadows form, they rarely include a light source. Adults are often surprised by the idea that shadows can be cast in space. You can use theseactivities to help visitors identify the relationships between a light source, the path light travels, and objects that may block or reflect light from the source, whether they are on Earth or in space.
Suggestions for introducing the activity: Ask visitors to look for their shadows. What in the room is causing the shadow? Are the edges of your shadow crisp or blurry? What would happen if there was just one light in the room, or if you were standing outside? This introduces the concept that shadows occur when an object blocks light, and the number of shadows depends on the number of light sources being blocked!
Procedure: Set up the adjustable lamp so the light shines directly on the center of the solid screen (approximately half-way up the shaft). Ask one visitor to choose a wooden shape and use it to make a shadow on the solid screen. Explore the shapes the shadow makes as the orientation of the shape is changed. For example, what happens to the ring if it is held edge on toward the screen? Observe the shadow of the rectangle. Now move the light to the bottom of the shaft. What happens to the shadow? Now slide the light to the top of the shaft. What happens to the shadow?
Discussion/Questions for visitors to consider: What happens to other shapes when the light is shone at different angles? Ask visitors to look at the image of the shadows of people on a beach. Where do they think the sun was positioned in the sky when the picture was taken? That is, what time of day was it when this image was created? Now have visitors look at the images of Jupiter's moon and of Curiosity's shadow on the Mars landscape. What is the light source? Where is the light source? Next, change the solid screen to the translucent screen. Ask a visitor to choose another wooden shape, and place it on the lighted side of the translucent screen. Encourage other visitors to stand behind the screen so they cannot see the actual object and to guess the shape of that object just by observing the shadows. Are there any shapes that always look the same no matter how they are oriented?
Demonstration Video: BLOCKS.
ACTIVITY #3: THAR SHE BLOWS!
Core concept: wind has a direction and a speed
Exhibit connections: Wind
Materials: AirZooka Air Cannon, Model Comet, image of comet
Background: The AirZooka air cannon produces a ball of air that can travel up to 20 feet away. This will serve as a source of wind, or movement of air. The air will interact with different items, including visitors and the tail of the model comet.
Misconception Alert: People may think there can be no wind in space because there is no air, but there IS material in space that can be blown from one place to another, even if it's not very dense: interstellar clouds of dust, atoms and molecules of gas, or sub-atomic particles such as electrons and protons. These are the particles that can form winds in space if they are forced into motion.
Suggestions for introducing the activity: Ask a visitor to stand with their eyes closed. When they have closed their eyes, move to a new position to their left or right. Then, fire the AirZooka air cannon at their hands from your new position. Ask them to guess from which direction the air blast came. Can the visitor estimate how fast the air was moving? How does this speed compare with a light breeze?
Procedure: Have one volunteer agree to hold the comet, and another the AirZooka-the source of wind. After practicing with the AirZooka air cannon, have the visitor shoot air at the comet from different directions. Then ask them to try blowing on the comet.
Discussion/Questions for visitors to consider: What can visitors notice about the comet's tail? How does it react when being fired at from different directions? When one blows on the tail, does it react the same way? What are the differences between the wind you can blow and the wind that the air cannon creates? Ask visitors to look at the image of the comet. Can they tell from which direction the solar wind is blowing? You may want to call attention to the two tails in the comet image, and note that it's the blue-ish tail of charged atoms (ions) that is always pointing away from the Sun because of the solar wind (see exhibit label). The heavier tail of dust particles is less affected by the solar wind.