Through the earth mine communications

Okay, kiddo, let's talk about talking to people who are working in mines deep underground. You know how when you dig a hole in the sand, sometimes you can hear someone talking on the other side? That's because sound can travel through solid things like sand or rocks.

Well, people who work in mines figured out they can use this idea to talk to each other even when they're really far apart and deep in the ground. They have special devices called phones that they can use to talk to each other. These phones are connected to cables that go through tunnels and shafts in the mine.

Now, sometimes the mine can be so big that the cables can't reach from one end to the other. This is where it gets really cool, kiddo. The cables don't have to go all the way around the mine, they can go through the earth! This means they dig a hole straight through the middle of the earth and the cable goes all the way down one side of the earth and up the other side.

I know it sounds crazy, but scientists have done the math and it actually works! The cable goes through something called the earth's mantle which is like a thick layer of hot, gooey rock and then through the earth's crust which is the hard surface we walk on.

So, now the people in the mine can talk to each other no matter how far away they are from each other. That way they can stay safe and know what's going on all around the mine. Cool, huh?