I'm also curious how the sun could move overhead along the tropic of capricorn so much faster than it does over the tropic of cancer and no one has ever noticed this variation in speed from the ground.
i've wondered about this as well.
all i could come up with is that time passes slower-- only at ground level-- in the southern planisphere, and so when people look up the sun seems to move at the same speed.
this makes no sense these days, now that we can talk to people across the planispheres in real time.