(techno music)
- [Announcer] This program
is brought to you by
BASF The Chemical Company.
- Hey, welcome to "stuff
to blow your kid's mind".
My name is Robert Lamb.
- And my name is Julie Douglas
and today we are talking
about magnets.
- You've played around
with a magnet before.
There's probably one on
your refrigerator right now
holding up some sort of important
document or piece of art.
And we're gonna play around
with magnets in this experiment.
But as we do so, and as we
witness the power of magnets,
we're gonna try to explain
exactly what's happening.
- Yeah, magnets are one of
the rare items on earth that
exert control over another
object without actually
touching it.
So let's have a look see here.
- Let's witness this force.
We have two magnets here.
Each one has a north and a south end.
Place that magnet here,
let's watch what happens
when I move this one in.
Attraction.
That's north to south.
Flip it around and what happens?
We see repulsion because
north is not gonna
attract to north and south is not gonna
attract to south.
- That's right.
You're chasing after it
and it is running away.
And the reason for this
is because we have a
magnetic field and within
this magnetic field,
we have atoms and we have a
bunch of electrons in these
atoms, and they're just
pretty hyperactive.
And they're creating
this activity which is
giving us this attraction and repulsion.
- Wouldn't it be cool if we
could see that magnetic field?
Well, there is a way.
And all you're gonna need,
is a magnet,
sheet of paper, and some iron filings.
Now iron filings are
basically little bitty pieces
of iron.
And you can buy them, just like this,
or you can make them if you have a little
parental supervision.
You're gonna need an iron
nail, a file, and then
you just file that iron nail down into
little pieces of iron.
So, if we pour these iron
filings onto this magnet,
we're gonna actually see the
shape of the magnetic field
that's surrounding that magnet.
- And it's really cool because
what you see happening here
are these little spikes in the
iron filings at either side
and these represent the
north and south poles.
And then everything between this,
is the magnetic lines
that those filings are
actually following.
- So there you have it.
The power of magnetism
right there on the table
in front of you.
- So in order to understand magnetism,
we actually have to travel to
the very center of the Earth.
- Yeah, and when we do,
what we find is this solid core of iron.
And the solid core of
iron is like a big ball
and its nearly the size of the moon.
- Right, this is the,
this solid lump is the
inner core of the planet.
And surrounding that, we
have a molten outer core.
- Yeah and this molten
outer core is really cool
because it's almost like an
ocean of iron swirling around.
And it's really chaotic.
- Right, it's basically
a magnetism engine.
And it's producing all of this
magnetism around the globe
which is why,
if you're lost on a summer day,
say out in the woods,
you pull out your compass
and no matter where you are,
you will be able to look
at it and see which way
points to the very top
of the planet, the north,
and which way points to the
very bottom of the planet,
the south.
- So think about a U shaped magnet, okay?
I'm holding it upside down
so you can see that the
north facing pole is on this side and
the south facing pole is on this side.
And everything in between
is the magnetic field.
And that's pretty much what's
happening here on Earth.
So not only does it create this magnetism,
but it also acts as a
shield for our planet.
- To understand how magnetism
actually protects our planet,
we have to travel into space.
- And when we do that, we
can look to the sun which
is actually pumping out
a ton of energy directly
toward us.
- This is solar radiation and
our planet actually needs this.
It heats our world.
It provides energy for all the plants that
thrive and grow here.
But too much of this
would be a very bad thing
for everybody.
It would be harmful to
our health and it would
strip off huge chunks of our atmosphere.
- Especially if you
consider something called a
solar flare.
And this is basically a
storm on the surface of
the sun.
And when this happens,
it actually emits a huge
electrical charge of particles on par of
one million megatons of TNT
and that's a lot of fireworks.
And it's a good thing that
we have this magnetic field
which kind of acts as like
an umbrella shielding us from
what would essentially take
out life here on Earth.
- So when you handle
just a household magnet,
you're toying with the
forces that are both
brooding at the very center of the planet,
and protecting us in space.
- [Announcer] This program
is brought to you by
BASF The Chemical Company.
(techno music)
