Answer 1:
Nice question about electricity. It is always
good to question things that we use in everyday
life.
This is a subtle and difficult
question to answer. Let us see if we can ask some
different questions and to understand
it!
-What makes my walkman work? A battery!
And somehow we are told that this contains
electricity.
-What makes my lights shine?
By plugging it into an outlet! Again we are told
that this is electricity, but somehow this form of
electricity seems different from the kind in my
walkman. So, we are stuck. Does my battery or does
my outlet contain electricity? If we assume one
and not the other, then we are confronted with fact
that some appliances can use batteries or an
outlet.
So, let us say that both batteries
and outlets contain electricity, but in different
forms. Since we are concerned with what
electricity is and not what its various forms are,
let us ask how these two forms are the
same.
-What happens when I stick my finger
in an outlet? (Mark's note: DO NOT DO THIS! YOU
WILL ELECTROCUTE YOURSELF.) Besides feeling really
stupid, I feel a strange jolt, almost like
something is moving through me. If I hold the
battery in a similar way I don't feel anything.
But, if I go to my car battery and do the same
thing I feel a similar jolt as the outlet.
So, perhaps a similarity between the two types of
electricity is that both involve the flow of
something. But, what is this thing and how does it
flow?
(Here is where the whole thing gets
technical and you will have to take my word on it.
But, centuries ago people asked themselves these
same questions and centuries later, we have a set
way of speaking about all of these things. So,
bear with me while we go through some
vocabulary.)
Scientist have found that this
flow is the flow of something called
electrons and
electrons have a property know as charge. It is
this charge that transmits the energy to your
walkman and your lights that they need to do what
we expect them to. Another remarkable feature of
charge is that it comes in two forms: "positive"
and "negative" or "plus" and "minus". These two
forms of charge are very particular about who they
hang outwith. Plusses hate plusses and minuses
hate minuses so they stay away from one another or
repel. But, plusses and minuses get along great
and attract. Now these electrons have a negative
charge and so if we want them to move we have to
build up a negative charge close to them so that
they run away. This is not an easy task and so I
won't try to explain to you how it is that people
get batteries and outlets to work. Instead we will
delve into more interesting questions.
-Why
do electrons have charge and nothing else does?
Electrons aren't the only thing that have charge.
In fact many other things do, but electrons are
the most abundant and easy to work with "charge
carriers" that we have around, and so almost all
electrical devices use them. That is why we call
them electrical! In fact electrons are so abundant
that they are in EVERYTHING that you touch and
see. The reason that everything doesn't have a
HUGE charge is that all of these electrons come in
pairs with protons which have an equal positive
charge and the two cancel each other.
-How
is it that electrons get charge? They are born
with it, so to speak. Charge is something that
cannot be created or destroyed, so there has been
the same amount around today as when the universe
began (we think!). It is a good thing that there
is a lot of it, or we wouldn't get to listen to
music very often and it would all be classical!
Every worse, we wouldn't be around at
all!!
-But where did this charge come from,
how did it get here? I wish that I knew. But,
science hasn't come to understand this question
yet!
I hope that this answers some of your
questions about electricity. If nothing else I
hope you learn to keep your fingers out of
electrical outlets! Click Here to return to the search form.
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