Colosseum numbered entrances crowd exit

The name Saxony originally referred to a broad region of northern Germany associated with the Saxons. Over centuries, dynastic inheritance and the transfer of political titles shifted the name toward territories farther southeast. Today's German state of Saxony is therefore not centered on the early medieval Saxon homeland. Place names can migrate even when the land itself stays put.

Earth is the Solar System’s only known world with stable liquid water on its surface. Atmospheric greenhouse gases help keep that water liquid by retaining energy from sunlight.