[speaker001:] Guess what! I know something you don't know!
[speaker002:] What's that?
[speaker001:] How many planets are there in the solar system?
[speaker002:] That's easy. Everyone knows that there are nine.
[speaker001:] Not anymore! Can you believe it? They've decided that Pluto is not a planet anymore!
[speaker002:] Nice try. I wasn't born yesterday, you know.
[speaker001:] I'm dead serious. They've decided that it's too small to be a planet, but actually they haven't yet agreed on how big something has to be in order to be a planet anymore.
[speaker002:] That sounds crazy. But they can't just change their mind about things like that.
[speaker001:] Yes, they can. If you remember correctly, people used to believe that the world was flat.
[speaker002:] I suppose you're right. They also used to think that they were so important that the sun revolved around them, not the other way around.
[speaker001:] We actually know relatively little about space and the cosmos.
[speaker002:] Do you think that we'll one day be able to travel to another planet for a vacation?
[speaker001:] I suppose we could actually live on a planet outside of the milky way.
[speaker002:] Do you think we'll ever get to meet an alien from outer space?
[speaker001:] I hope not. I think they would be a threat to those of us that lived on the Earth.
[speaker002:] You're so old-fashioned. That's what people used to think about people from another country!
[speaker001:] Point taken. Hopefully one day, we'll live in an interplanetary society.