Dial the number, let it ring. That’s usually all it takes to contact anyone else in the world in possession of a telephone. We take this simplicity for granted, but for some time towards the end of the 20th century, there was serious concern that the rapidly increasing demand on telephone networks was not going to be met.
We live in a world where phones are smart, mobs are dumb and Justin Timberlake is famous. If any of this strikes you as mysterious, you might have use for a steadily growing branch of science out there that aims to explain how all of it can be possible.