2. Every magnet has two
poles, the north and the
south. It’s true for magnets
big and small, short and tall. If
you break a magnet into
smaller pieces, then each
small magnet ends up with a
north and a south. (Magnets
are said to be
polarized, because they have
two poles.) For magnets, if
you have a north, you have a

3. Polyester is everywhere: The plastic fabric can
be used to make
fleeces, shirts, pants, furniture and blankets.
It’s synthetic, which means it’s created from
chemicals in a lab to resemble something
natural. Scientists recently found that
polyester clothes shed plastic fibers while in
the washing machine. During the rinse
cycle, these microscopic threads wash down
the drain, zip through water treatment plants
and end up on the coasts.

4. Back in the Stone Age, humans had to put up
with all sorts of creepy crawlies. Parasites —
organisms that live on or in another organism
— lingered inside our bodies, living off of our
blood. Because internal parasites go mostly
unnoticed, they were able to keep living with
humans. People can survive a long time with
tiny parasitic worms in their intestines.

5. When you hear the word “farm,” chances are
you picture rolling hills in the country covered
with cows and cornstalks. But some
scientists, engineers and city planners say the
farms of the future could rise straight into the
air — in skyscrapers in the world’s most
populated cities

6. When you think about math, you probably
don’t think about breaking the law, solving
mysteries or finding criminals. But a
mathematician in Maryland does, and he has
come up with mathematical tools to help
police find crooks.