[♪ INTRO]
Oh, hi, everyone!
Squeaks is supposed to meet me here in the lab, but he’s not here yet!
I wonder what’s taking him so long.
I’m super excited to see him, because he promised
he’d show me his new magnet!
Oh! There you are, Squeaks!
Is everything okay?
[Squeaks answers]
Oh, I see!
Squeaks was trying out his new magnet by the river, and the path there
is really long and windy.
So, it took him a while to find his way back to the Fort.
Hm.
The river is directly south of here.
If only you’d had a compass!
Then you could have taken a shortcut.
[Squeaks squeaks quizzically]
A compass!
It’s a tool that can tell you what direction you’re going.
And if you know what direction you’re going,
you can find your way around without getting lost!
People have been using compasses for thousands of years
to explore the world.
They can be big or small, fancy or plain.
But they have an important thing in common:
They have some kind of arrow or needle that points north.
So, if we had a compass right now, its needle would point...
… this way!
Because that’s north!
In fact...
We can use your magnet to make your own compass,
right here at the Fort!
What do you say, Squeaks?
[Squeaks is all in]
All right!
Let’s do it!
You can make a compass, too — just make sure
you get a grownup to help you!
To make a compass, you’ll need...
... a sewing needle
… a piece of aluminum foil
... and a clear container of water with a flat bottom...
Oh yes!
And a magnet.
This is definitely where you’ll want help from a grownup.
First, carefully pick up the sewing needle,
and hold it by the end that has the hole in it.
Now, drag the magnet along the needle slowly from the end
with the hole to the pointy end—like this.
You’ll need to do this about fifteen or twenty times.
And always make sure you’re doing it the same way, from the hole end
to the needle point!
Next, we’ll need to fold our foil into a little boat of sorts...
… And then poke the needle through it.
Again, make sure a grownup helps you with this!
Trust me, poking your finger with a needle hurts.
Now we’re ready to finish our compass!
All we have to do is gently float the foil on the water in our bowl,
wait a second, and...
Look!
The needle turned, and it is now pointing north!
We did it!
[Squeaks squeaks]
Good question, Squeaks!
But before I explain what happened in this experiment,
let me explain how compasses work in general.
The reason why a compass points north is really cool:
It’s because the pointy part inside is a magnet!
And magnets have two ends, called poles.
One end of the magnet is called the north pole,
and the other is called the south pole—
no matter which direction they’re facing.
And opposite poles of two different magnets attract.
That means they pull on each other.
Meanwhile, similar poles repel each other.
Repel means push away.
Now, here’s the really awesome part: our planet, Earth,
is basically one huge magnet.
So it also has magnetic poles!
That means, the Earth’s poles act the same way that a magnet’s poles do.
They attract and repel the poles of other magnets!
And they just so happen to line up pretty well with the parts of the planet
we call the North and South Pole.
[Squeaks squeaks excitedly]
You’ve got it!
The Earth’s magnetic poles pull and push a compass needle’s
magnetic poles, and that’s what causes the compass to point north!
So… why do you think our sewing needle pointed North?
[Squeaks squeaks]
That’s right!
I said the needle of a compass is a magnet.
So…?
[Squeaks finishes his thought]
Yeah!
That’s it!
Our sewing needle became a magnet!
That first step we did, where we rubbed the needle with your magnet,
actually magnetized the sewing needle—in other words,
it turned it into a magnet!
The pointy end became the north pole of a magnet,
and the other end became the south pole!
[Squeaks is impressed… then confused]
You know, Squeaks, you’re absolutely right!
It seems like the north pole of the Earth should repel
the north pole of our compass needle.
But here’s the weird thing: the Earth’s north magnetic pole
is actually in the south, and it’s south magnetic pole is in the north!
So the Earth’s south magnetic pole is pulling the north pole
of our needle to the north!
And the Earth’s north magnetic pole is pulling the south pole
of our needle to the south.
Which is weird and confusing, I know.
But hey, I didn’t name these things.
[Squeaks squeaks excitedly]
Exactly Squeaks!
Since the Earth’s magnetic poles are always pulling on the poles
of other magnets, all we had to do to get our magnetized needle to
point north was let it freely spin about in response to those forces!
Which is what the foil and water were for!
Cool, huh?
Whoa, look at the time!
We told Jessi we’d meet her in the garden
to help pull weeds, so we’d better get going!
And we’ll look into getting you a compass that’s a bit easier
to carry around than this bowl.
That way, you can make your way to and from the river
a little quicker next time.
Thanks for bringing your magnet to show me!
And thank you for joining us here at the Fort.
If you want to keep learning and having fun with Jessi, me,
Squeaks, and all our friends, be sure to hit the subscribe button,
and we'll see you next time on SciShow Kids!
[♪ OUTRO]