“Our lives are full of portals, both literal and figurative. We’ve divided up the planet into nations whose conceptual boundaries are magically concretized in maps, in fences, and more dangerous barriers. We enclose museums and universities and laboratories in buildings whose doors truly lead to alternate worlds where new things become possible. Every time you walk over the threshold of a library, or through a door into a party, you open yourself up to the strange and previously unknown. That’s what makes the portal such a powerful and enduring metaphor. It’s based on our everyday experience.”
 

– Annalee Newitz