This is a plastic water bottle, and when I
place it on my cart and bring a plastic pipe
next to it, nothing happens. But I have another
water bottle that is made out of aluminum,
and if I place this one on the cart, and then
bring my pipe next to it, it rolls.
You can use either a PC pipe or a balloon for this
demonstration, and the reason that it works
is because balloons and plastic are both materials
that do not conduct electricity. And that
means that they can build up a static electric
charge. All of the material around us that
we can touch and see is made up of atoms,
and atoms have small particles called electrons.
Those electrons can come and go from the atom
in the way that the other parts of the atom
cannot. So if you take the pipe, or the balloon,
and you rub it on a fuzzy cloth, or on someone's
head, that friction between those two materials
will actually gather electrons to the pipe
or to the balloon, and then it becomes charged.
And when it's charged, anything that conducts electricity,
such as this metal can, will be
 attracted to that charge. It's a very fun
demonstration to make a can roll across a
table, but this is not a science experiment
because there is nothing that we are changing,
there is nothing that we are measuring.
But you can make it an experiment by testing cans
of different weights. If we compare a soda can,
an empty peaches can, and a can that
is full of soup, then you'll see that they
behave very differently when we bring the
same pipe next to each of them.
On our website, we have a science fair guide where you can see several ways that you can turn this simple
demonstration into a full science project.
Gather data, find out exactly how much weight
static electricity is able to move across
a table, fun things like that.
Don't forget to come back next week for another science
activity, and a special thank you to this month's
Navigator Patron Noelani Nomiyama. If you'd
like to join us and help us bring science
to the world, check us out at www.patreon.com/ScienceMom.
