NatGeo cartographer takes to the airwaves

I didn't hear the segment in question, but apparently the folks at NPR's "Talk of the Nation" erroneously discussed that the Nile is the only river that flows south to north. To respond to their error, they invited Allen Carroll, Chief Cartographer for National Geographic, to talk about "why people tend to think that rivers run south." The discussion came at the end of Hour 1 today, 11/28, which is located at this link. Not every day that a cartographer appears on the radio. He talked a little about map layout, and our perceptions of which way North is. It was cool to hear his comments after taking this course.