Do you know that a \"movie" doesn't really move? Your eyes make it look as if it's moving! A movie is made with a camera that takes pictures very fast---twenty-four pictures in a second. Each...
Putting atoms to work
What makes the electricity for your home? It comes from buildings called power plants. In most places, power plants use energy from coal, oil, or gas to make electricity. But some power plants use a...
An airplane pushed by gas
Have you ever wondered why certain kinds of airplanes are called jet planes? The word jet means a stream of something that's shot out of an opening. And that's how a jet plane flies---by squirting...
Put-together things
Are your shoes made of leather? Is your sweater made of wool? Are your glasses really glass? Maybe---and maybe not. Any of these things could be plastics. But what are plastics? They don't grow as...
A machine that helps you think
> This child is using a science program on her home computer to study > fish. She can use many other programs to study different subjects. If you're an astronaut in a speeding spaceship, you have a...
More Things That Work
More Things That Work More Things That Work
Putting sound to work
What makes sounds like a violin, a singer, and a big brass band? A phonograph, of course. It makes the sounds you hear from the records you play. This machine is cutting the sound grooves in a blank...
Hunter in the Darkness
In a cave in Texas, a furry, gray bat hung head downward, his eyes closed. The curved, sharp claws on his toes clung to the rough rock of the cave's ceiling. Even though he slept, the bat could not...
“Seeing” with your ears
When a friend calls your name across the playground, do you know which way to look? Usually you do---your ears tell you. The outer part of your ear traps sound waves and funnels them into your ear....
Rattle and roar
Rattling trucks, roaring jets, squeaking chalk, and creaking doors don't make music. They make sounds we don't want to hear. These unwanted sounds are called noise. Noise is hard to stop. Like other...