Hey guys it's Jade here and welcome to your introduction to electricity.
This tutorial is mainly going to focus on electric charge because they are the
building blocks of all of electricity
whether you're learning about lightning or light bulbs they are electricity. So
we're going to start by talking about some of the history about how
electricity was discovered.
Now I know what you're thinking... Snoozeville right but i'm really going
to try and make it fun and turns out there's some pretty wacky stuff in there
anyway and studies show that a story is good for your memory so I'll try and keep it
brief. And then we're going to talk about some of the really basic but fundamental
ideas you're going to have to know about like what electricity is how electric
charges behave, that kind of thing.
Then we're going to end by talking about some of the more sciency technical stuff
you're going to need for the classroom.
So if you're ready to embark on a journey come with me back to ancient
Egypt.
So before anyone knew anything about electricity
the ancient Egyptians found these weird mystical fish swimming in the Nile where
every time you touched one you got this shock.
So the ancient Egyptians didn't know these were electric fish they just
thought they were magical. They called them the thunders of the Nile and
thought that they were the protectors of all other fish. They thought that they
were so magical in fact that they were used as a cure for headache
so if a patient came in with a headache they were often asked to touch one of
these magical fish and the shock was thought to cure the headache.
So my original plan for this video was to make fun of this idea because it
sounds pretty crazy right?
But then I thought you know the ancient Egyptians they are pretty clued on, they
built the pyramids!
So I decided to google "does electric shock cure headache?" and it turns out
that there's this recent treatment for curing headache
where you run an electric shock across your brain
so yeah that showed me I mean maybe they're onto something.
I've liked the article below if you want to check it out and hey next time you
have a headache try touching an electric fish
I'm actually curious now. But anyway back to the point:
the first recording of electricity where these wonders of the Nile that were
thought to cure headache
back in ancient Egypt. Skipping forward a couple of millennia to the Mediterranean
the ancient Greece discovered that if you rub certain objects like amber with
cat's fur
if it starts to attract other lighter objects like feathers. And this is
actually where the word electricity comes from the greek word electron which
means amber. So that was the second recording of electricity in history
people still didn't really know what it meant but they did know about this
weird mysterious force that existed between objects. So it wasn't until
around the 18th century that people discovered
that force between objects with actually because of the electric charge. The
balance or imbalance of electric charge largely dictated how an object behaved
with another object.
So the first most important thing you need to know if you want to understand
electricity is there are two types of charges: positive and negative. So before
we go on I just want to make clear that the words positive and negative don't
actually mean anything.
They were coined by the ex-US president Benjamin Franklin, and he was just trying
to demonstrate that there are two types of charges and they do opposite things.
So it could easily have been another pair of opposites like black and wite or
cat and dog.
He just decided on a positive and negative and it works. So that's the
first most important thing,
there are two types of charges: positive and negative.
The second most important thing is how these charges interact with one another.
Through experiment
it was found that like charges repel and opposite charges attract. I'll say that
again,
like charges repel and opposite charges attract! So two positive charges repel
two negative charges repel one positive charge and one negative charge attract
you get the idea.
So it turns out everything has a charge. You have a charge,
I have a charge, your cat has a charge, your mom has a charge,
everything has a charge.
So you might be wondering why isn't everything
rappelling or attracting everything else? Even though every object has individual
charges on it
most of the time there's an equal amount of positive and negative charge
leaving the overall charge of the object neutral
so even though there are positive and negative charges on the object the
object itself isn't positively or negatively charged it is neutrally
charged
ok so now that we know a little bit more about charge and how it behaves
let's try to figure out what was going on back in ancient greece with the amber
and the feather.
So before there was any rubbing all the objects, the amber, feather, and cat's fur
were all electrically neutral just like any other normal object.
So when the cat's fur was rubbed onto the amber, negative charge was
transferred from the cat's fur to the amber, which left the amber with an
overall negative charge because it was started at neutral and it just got
negative charge transferred to it.
So now the amber is negatively charged. So when a neutral object like the
feather was brought near the amber, because the feather was negatively charged it
repelled some of the negative charges in the feather
because like charges repel. So this left the feather positively charged, so now
that we have one negatively charged object, the amber, and one positively
charged object, the feather, they attract because opposite charges attract. And the
only reason that the feather moved toward the amber was because it was lighter.
Did you get that? So you guys have a pretty good idea about what charges are now,
so I just want to go over a couple of the more technical things that your
teacher or lecture are going to
want you to know. So I just really want to stress that charge is not an object,
charge is a property of an object, just like mass or color.
You can't really be like "hey check out my eight kilograms" or "I'm holding this
red", it's like a kilograms of what? Red what? Charge is the same,
it can't exist without an object. It is a property of an object.
The second thing is that because we're usually trying to measure charge it
needs a unit and the SI unit for charge is the Coulomb, and that's it!
So the take-home messages of this video are: if you're ever going to make fun of
the ancient Egyptians make sure you really done your research.
Electric charges are the building blocks of all of electricity.
There are two types of charges: positive and negative. Like charges repel and
opposite charges attract. Charge is a property of an object not an object
itself. The SI unit of charge is the Coulomb,
and if you ever have a headache try touching an electric fish and let me
know how it goes!
Thanks bye!