This post is the result of a conversation with Majo Carrasco, who is going to be a T.A. in my data visualization class next semester. She’s from Quito, Ecuador (which means Equator).

The Mitad Del Mundo (Middle of the World) monument, near Quito, sits on the dividing line between the Northern and Southern Hemispheres.

Well, almost. The real position is about 250 yards (229 meters) away at the Intiñan Solar Museum. GPS has provided a more accurate location than the one that was fixed by a French expedition in 1736. The Prime Meridian in Greenwich is also not in the right spot. It’s really 111 yards (102 meters) away from it’s marked location. Below, at the more accurate site. Photograph by C.T.Johansson.

Some differences between the hemispheres:

I thought that the rotation principal also applies to water draining from a sink, but there seems to be considerable disagreement on this assertion: goo.gl/yRzjRr

Night sky The Southern Cross cannot be seen from most of the Northern Hemisphere, and Polaris, the North Star, cannot be seen from almost all of the Southern Hemisphere. But from the Equator, both are visible.
Below, the Milky Way from the Southern Hemisphere (La Silla Observatory in Chile).

Photograph by ESO/H.Dahle.