...and that's coming up after this.
[recorded tagline]: 96.3!
--As a radio DJ, I'm surrounded by permanent magnets all the time--
like this one here, found in my headphones...
and these, found in the big speakers.
And there's even one in this microphone.
[birdsong]
--And would you believe
there's a link between cows and magnets, as our vet explains?
--The cow magnet will sit in the front stomach of the cow,
where it can attract hazardous pieces of metal--
like this bit here, which the cow may eat by mistake.
While this piece of metal can roam free in the cow's stomach,
it could puncture the stomach wall and cause the cow a lot of harm...
but while it remains attached to the magnet, it can cause no harm at all.
--Permanent magnets are useful,
but sometimes you need a magnet that can be controlled:
a magnet that can be switched on and off, like the one at the scrap yard.
It helps to move bits of metal from one place to another.
Doctors use temporary magnets, too.
--As an eye surgeon, sometimes we have to remove tiny bits of metal
which become embedded in the backs of people's eyes.
And if you look at this x-ray, you can see this tiny little fragment
here at the back of this person's eye; and this could cause serious damage.
And we remove those fragments using an electromagnet, like this one.
Now here we see, with the electromagnet off,
it's not able to lift up a bit of metal like this paper clip.
But when I turn the magnet on, we're able to lift up that paper clip.
And that's how, as an eye surgeon, we use electromagnets
to remove bits of metal from the eye.
--Magnetism gets everywhere!
--There's a magnet in anything
that has a motor, like your hair dryer or microwave.
There's a magnet in your telephone!
In a computer!
In a video recorder--and your TV!