Is the World Flat?

My students LOVE basketballs, so when a story emerged about a Basketball player believing the world was flat came up, I thought it would be a great teachable moment.

http://www.espn.com/nba/story/_/id/18710759/kyrie-irving-cleveland-cavaliers-believes-earth-flat

The students unanimously agreed that the earth was round:

"Because I just saw the google Earth and google never lies"
"Because we read the story and the pictures the world was round" 
"Well if you look, you can see mountains poking up. That means that the worlds isn't flat"
"Because if the world was flat, then if you kept walking then you would fall off and be killed but that never happens" 
"Because I can see the moon and its round and I can see the sun and its round, so the earth is also round"
"We learned about the solar system, I wonder if he learned about the solar system"

I loved their reasoning and the point that they made wondering if he had learned about the solar system. Maybe some people weren't exposed to the knowledge. Early man believed the world was flat, so its not irrational to believe that the earth is flat. In our world of over-information and mis-information, its easy to forget why we know facts.

We looked at some pictures of early maps where the earth was flat and related it back to Columbus trying to sail to India. You can't just take knowledge for granted, you have to explore & understand.