Beam Bounce

Little levels (ages 4 to 6)

1. Wake the flower Tap one mirror to bounce the light up to a sleeping flower.
2. Around the rock Use a mirror to send the light around a rock.
3. Two mirrors Bounce the light twice.
4. Two flowers Two lamps, two flowers, two mirrors.
5. Zig zag Four bounces to reach a far-away flower.
6. Garden party Wake up three flowers at once.

Big levels (ages 7 to 9)

1. Plan, then shine The light starts off: set the mirrors first, then test the plan.
2. Red glass Red glass lets only red light through.
3. Pick the glass Tap a glass to change its color so Green and Blue each get their own light.
4. Glass gobbles Two different glasses in a row block all the light.
5. Mix yellow Red light plus green light makes yellow light.
6. Rainbow maker White light through a prism fans out into a rainbow.
7. Lumi's secret Red, green and blue light together make white light.

The big ideas

• Light travels in straight lines. A beam keeps going straight until something stops it or bounces it. That is why a rock blocks the light and why shadows have sharp edges.

• Mirrors reflect light at the same angle it arrives. A mirror tilted at 45 degrees turns a beam by exactly 90 degrees, which is what makes the puzzles predictable.

• Colored glass is a filter. Red glass lets red light through and absorbs the rest. Put red glass and green glass in a row and almost no light gets through, because each one removes what the other lets pass.

• Colored light adds up. Red light plus green light looks yellow, and red plus green plus blue looks white. Phone and TV screens make every color from tiny red, green and blue lights.

• A prism spreads white light into a rainbow. Glass bends each color by a slightly different amount, so the colors fan out. A prism cannot make a rainbow from light that is only red.

Try it at home

1. Flashlight tag In a dark room, bounce a flashlight beam off a hand mirror onto the ceiling. Tilt the mirror a little and watch how far the spot jumps.
2. Colored glass Look through a piece of red cellophane or a colored candy wrapper. Which things keep their color and which turn dark?
3. Mix light Shine two flashlights covered with red and green cellophane onto the same white wall. Where they overlap, look for yellow.
4. Make a rainbow Hold a glass of water in a sunbeam near a white wall, or spray a hose mist with the sun behind you, and look for the colors.

Ask after playing

• What happens to light when it hits a mirror?
• Why did the green glass gobble the red light?
• What colors of light make white?