Here's a Question!

Announcer: Frostbite Theater presents... Cold Cuts! No baloney!

Joanna and Steve: Just science!

Joanna: Hi! I'm Joanna!

Steve: And I'm Steve!

Joanna: Here's a question for you...

Steve: An unmagnetized steel rod is swiped along a permanent magnet.

Joanna: What happens to the steel rod?

Does nothing happen?

Steve: Does it become weakly magnetized?

Joanna: Does it become strongly magnetized?

Steve: Or, does it catch on fire?

Joanna: Pause the video now if you'd like to think it over before we show you what happens.

Steve: Although the steel rod contains iron, which is a magnetic material, it makes a lousy magnet because its atoms aren't aligned.

Joanna: Some are pointing up.

Steve: Some are pointing down.

Joanna: Some are pointing left.

Steve: Some are pointing right.

Joanna: Since they're all scrambled up, their magnetic fields cancel each other out.

Steve: Swiping the rod along the permanent magnet aligns some of its atoms. Once you get more atoms pointing in one direction than another, the fields add up and the rod behaves like a magnet.

Joanna: It's not a very strong magnet. But, as long as the atoms don't get shaken up, say by heating it or hitting it, it'll stay magnetized.

Thanks for watching. I hope you'll join us again soon for another question!