Here's a fun one.
When lava or molten metals cool, the particles in the metals align themselves to the earths magnetic north pole.
It's been found that the magnetic north pole has not always been in it's current location. (In fact it's currently moving quite quickly...)
In fact, it's been noted that in periods of ancient history, the south pole has/was the north. Or at least, it was the strongest source of a magnetic north on the planet.
If the earth is not round, and doesnt converge back into a point on the bottom, how could all the rock particles line up to point at is as if there were a bottom to the earth?
Really hoping to weed out the smart people with some of these questions.