Have you ever seen yourself in a fun house mirror? Do you remember what you looked like in that funny mirror? It was curved, right? What you saw was your reflection in the mirror, which is the reflection of light. Light is bouncing off of you into the mirror, then into your eye in order for you to see yourself. Curved mirrors have lots of uses. The Genesis spacecraft uses a curved mirror to focus solar wind onto a target.

Next stop: ! Blast's favorite hole looks just like this! Can you shoot the ball into the cup? Practice so that you can get your ball into the cup every time.

What You Need:

• Plastic cup
• Five rubber balls
• One meter (the distance from the bottom of a door knob to the floor) curved surface (3/4 inch copper tubing works well)

What You Do:

1. Set up the materials so that it looks like the diagram above.
2. Try to roll the rubber balls so that they bounce off the curve and go into the cup. Each person gets a turn rolling the balls so that everyone gets practice. Everyone can take lots of turns!
3. You may want to fix the curve and experiment so that you can get the balls into the cup every time.
4. Each person gets five tries. Keep track of how many times you can roll the ball into the cup!
5. Draw a picture that shows the motion of the rubber balls at each step.

Did You Know:

The Genesis spacecraft has a special thing called the concentrator. It's designed to collect specific types of solar wind. It is a curved mirror that reflects light and allows the collection of only ions (basically, they're charged particles) . In this activity, the rubber balls represent the solar wind particles as they enter the Genesis solar wind concentrator. The Genesis concentrator is not collecting hydrogen and helium, because most of the sun is made up of these elements.

Going Further:

• You can make another type of curved mirror (ok, it's aluminum foil) to cook hot dogs, just by the heat of the sun! It's called a solar cooker. Have interested students build one to cook some hot dogs. Here are the directions for the hot dog cooker assembly in PDF format.
• Older students might be interested in learning more about the Genesis concentrator.