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ATOMS
"'Atom.' The word comes from the Greek a-tamos, meaning 'indivisible.'
At the time these particles were named, scientists thought that atoms
were the smallest bits of stuff existing in nature. We no. . . " |
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BRIDGES
"Picture yourself on one side of a raging, crocodile-infested river. You
desperately want to get across. However, swimming with crocodiles is out
of the question, and walking around the river could ta. . . " |
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ELECTRICITY
"Flip on a light switch. Now flip it off. That simple action -- On/Off
-- helps show electricity's power. Turn on a computer or a TV or a hair
dryer. They show electricity's power, too. Most of the ti. . . " |
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ENERGY
"Brrrrrraaaaa! The alarm clock sounds. Do you leap out of bed already in
high gear? Or do you bury your head under the pillow and go back to
sleep? No matter what you do, you're using energy. Scientis. . . " |
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INVENTIONS
"Today, electricity lights our homes with the flick of a switch. A car
or bus speeds us to the movies, and a telephone lets us chat with
friends all over the world. Radio and television give us instan. . . " |
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LIGHT
"Take a look at your thumbnail. Now picture a spot the same size on the
sun. This tiny spot would be as bright as one million candles shining
all at once! The sun is our brightest and most important s. . . " |
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MOON
"The Moon has always been a source of mystery. In ancient times, people
thought it had the powers of a god. Astronomers eventually proved that
the brightest object in our nighttime sky was really just. . . " |
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PLANETS
"Our solar system consists of a star (the Sun) and the group of planets
orbiting it. The planets closest to Earth can be seen in the nighttime
sky without a telescope. No two planets are alike, altho. . . " |
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SIMPLE MACHINES
"Which is easier: lifting a piano ten feet up in the air or pushing it
up a ramp until it is ten feet from the ground. Most people would prefer
to push the piano up the ramp. Ramps, also called inc. . . " |
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SOLAR SYSTEM
"In the solar system, nothing stands still-- not even you. You and
everything else on Earth are traveling up to one thousand miles per hour
right now! That's how fast the planet's surface is spinning . . . " |
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SPACE
"Human beings are explorers. Throughout history, the impulse to venture
into the unknown has been strong. What will I find over the hill? What's
on the other side of the immense sea? Will I find somet. . . " |
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SPACE EXPLORATION
"Space is so close and yet so far away. It begins where the atmosphere
ends - about one hundred miles above Earth's surface. A drive from
Philadelphia, Pennsylvania, to New York City is a longer trip.. . . " |
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SUN
"In the grand scheme of things, the Sun is no big deal. It's just
another medium-size star in a remote corner of the Milky Way galaxy.
There are billions of others in the universe just like it. But to. . . " |
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TELESCOPES
"On a clear night, thousands of stars can be seen twinkling above Earth.
Years ago, people assumed that they knew all there was to know about the
sky. Then, in 1608, a Dutch lens maker put two glass l. . . " |
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WATER
“All animals and plants need water to survive. The human body is more
than three-fourths water. Life-forms use water to transport nutrients
around the body and to carry off waste. Water also helps . . . " |
