Computer programs are the most complicated things that humans have ever created.
Software and hardware
Butler Lampson, recipient of the Turing Award for his contributions to computer science, relates the followi ng anecdote about software:
There’s a story about some people who were writing the software for an early avionics computer. One day they get a visit from the weight control officer, who is responsible for the total weight of the plane.
“You’re building software?”
“How much does it weigh?”
“It doesn’t weigh anything.”
“Come on, you can’t fool me. They all say that.”
“No, it really doesn’t weigh anything.”
After half an hour of back and forth he gives it up. But two days later he comes back and says, “I’ve got you guys pinned to the wall. I came in last night, and the janitor showed me where you keep your software.”
He opens a closet door, and there are boxes and boxes of punch cards.
“You can’t tell me those don’t weigh anything!”
After a short pause, they explain to him, very gently, that the software is in the holes.
It is amazing how these holes (Fig. 3.1) have become a multibillion-dollar business and arguably one of the main driving forces of modern civilization.