From the brains behind brains on, this is the Moment of Um.

Moment of Um comes to you from APM Studios. I'm Ruby Guthrie.

Um.

One thing about me, I love to travel. I really like visiting places I've never been to before. I think it's so

exciting. Plus, it's a great way to try new foods, meet new people, and maybe even learn a new

language. I grew up traveling a lot, mostly because I have family that lives all over the world.

My grandparents are in Australia, and I also have

family in France. And can I let you in on a little secret? One of my goals in life is to visit

every continent. The continents are the different chunks of land here on Earth. There are seven

total. North America, South America, Africa, Asia, Europe, Oceania, which

includes Australia, and last but certainly not least, Antarctica. One of our listeners had a

question about this, too. How was the first piece of land created?

This is a really interesting question, and the correct answer to this question is we don't

know, and we don't know where it was.

Hi, my name is Annie Bauer.

I am a professor at University of Wisconsin in Madison, Wisconsin, and I am a geochronologist,

which means I date rocks, and I don't mean that I take them on dates.

I actually use radioactive decay of different elements to determine how old rocks are.

So the planet when it was first forming was actually probably mostly magma.

And whatever, when magma's at the surface, it's called lava.

And when it's at depth, it's called magma, which is a very confusing distinction.

But you can think of it as a big, like,

...