Special pictures called holograms make things look real. When light shines through the film, you see the pictured thing from all sides. Your dog was chasing a big red ball when the picture was...
Superlight!
It punches through steel. It carries complicated messages. It performs tiny, delicate operations. Anything that can do many kinds of work should be magic. But this isn't magic---it's a special kind...
Lamp Number 9
Tom Edison sat in his laboratory, watching an assistant light the gas lamps. The sight always bothered him. For years he had been convinced that electricity could be used to make light---a light as...
Eyes for machines
Sometimes only a few people get on and off the elevator. Sometimes lots of people get on and off. But the elevator always seems to know how long to stop. The door doesn't close until the last person...
Seeing things that aren’t there
Can a lake vanish? A few minutes ago you saw cool water shimmering just up the road ahead of the car. But now all you see is miles of hot paved highway. Where is the lake? The disappearing lake is a...
Colors we don’t see
Ouch! When you went swimming, the sun wasn't very bright and the air wasn't very hot. But now you have a stinging sunburn! Where did you get it? Your sunburn came from light---but not from light...
A rainbow of colors
Sunsets and traffic lights, campfires and TV screens---light comes in many different colors. What makes the colors different? Why do we see a rainbow of colors? All the colors of light are given off...
Colors we see
The cheese in your sandwich is orange. The tomato is bright red. The lettuce is green. The light brown bread has a dark brown crust. You would be surprised if your sandwich had red cheese, a brown...
Dark-room pictures
Materials - blanket or cloth (heavy) - coffee can - hammer - nail (small) - rubber band - waxed paper What does the camera \"see" when you take a picture? You can't climb inside it to find...
Smile for the camera
There you are with that stuffed bear you had when you were two. And here you are with that big fish you caught last summer. Both times someone took your picture. The camera made a copy of the way you...
