About Adjacent Possible

"The strange and beautiful truth about the adjacent possible is that its boundaries grow as you explore them. Each new combination opens up the possibility of other new combinations into the adjacent possible. Think of it as a house that magically expands with each door you open. You begin with a room with four doors, each leading to a new room that you haven't visited yet. But once you open one of those doors and stroll into that room, three new doors appear, each leading to a brand new room that you couldn't have reached from your original starting point. Keep opening doors and eventually you'll have built a palace."

- Steven Johnson, from Where Good Ideas Come From: The Natural History of Innovation.