Guess what ! I know something you don't know !
surprise
user
What's that ?
neutral
assistant
How many planets are there in the solar system ?
neutral
user
That's easy . Everyone knows that there are nice .
neutral
assistant
Not anymore ! Can you believe it ? They've decided that Pluto is not a planet anymore !
surprise
user
Nice try . I wasn't born yesterday , you know .
neutral
assistant
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 .
neutral
user
That sounds crazy . They can't just change their mind about things like that .
neutral
assistant
Yes , they can . If you remember correctly , people used to believe that the world was flat .
neutral
user
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 .
neutral
assistant
We actually know relatively little about space and the cosmos .
neutral
user
Do you think that we'll one day be able to travel to another planet for a vacation ?
neutral
assistant
I suppose we could actually live on a planet outside of the milky way .
neutral
user
Do you think we'll ever get to meet an alien from outer space ?
neutral
assistant
I hope not . I think they would be a threat to those of us that lived on Earth .
neutral
user
You're so old-fashioned . That's what people used to think about people from another country !
neutral
assistant