Static
electricity
was
discovered more than 2,500
years ago when the Greek
philosopher Thales noticed
that when amber (a hard,
clear, yellow-tinted material)
is rubbed, light materials like
feathers stick to it. Electricity
is named after the Greek
word for amber, which is
electron.
Project #121
Bending Water
Electricity vs. Gravity:
Electricity is immensely more powerful than gravity (gravity is what causes things
to fall to the ground when you drop them). However electrical attraction is so
completely balanced out that you don’t notice it, while gravity’s effects are always
apparent because they are not balanced out.
Gravity is actually the attraction between
objects due to their weight (or technically,
their mass). This effect is extremely small
and can be ignored unless one of the
objects is as big as a planet (like the earth).
Gravity attraction never goes away and is
seen every time you drop something.
Electrical charge, though usually balanced
out perfectly, can move around and change
quickly.
For example, you have seen how clothes
can cling together in the dryer due to static
electricity. There is also a gravity attraction
between the sweaters, but it is always
extremely small.
Note:
This project works best on a
cold dry day. If the weather is humid,
the water vapor in the air allows the
static electric charge to dissipate,
and this project may not work.
If you have two balloons, rub them to a
sweater and then hang the rubbed sides
next to each other. They repel away. You
could also use the balloons to pick up
tiny pieces of paper.
Electricity
Gravity
Take a piece of newspaper or other thin
paper and rub it vigorously with a
sweater or pencil. It will stick to a wall.
Cut the paper into two long strips, rub
them, then hang them next to each other.
See if they attract or repel each other.
Project #122
Static Tricks
-59-
You need a comb (or plastic ruler) and a water
faucet for this project. Run the comb through
your hair several times then hold it next to a
slow, thin stream of water from a faucet. The
water will bend towards it. You can also use a
plastic ruler. Rub it on your clothes (wool works
best).
Rubbing the comb through your hair builds up a
static electrical charge on it, which attracts the
water.
Note:
This project works best on a cold dry day.
If the weather is humid, the water vapor in the
air allows the static electric charge to dissipate,
and this project may not work.
CM-125_Manual_031514.qxp_CM-125_Manual_031514 4/2/14 12:20 PM Page 60
