“The only unit of time that matters is heartbeats. Even if the world were totally silent, even in a dark room covered in five layers of foam, you’d be able to count your own heartbeats. When you get on a plane and travel you go 15 heartbeats per mile. That is, in the time it takes to travel a mile in flight your heart beats 15 times. On a train your heart might beat 250 times per mile. And we count this up and we make sense of it.” — Paul Ford, on the role that our frame of reference for time plays in our lives in relation to the technology humans create and use.