From: Ryan Leavengood <mrcode@...>
Date: 2005-05-08T03:10:46+09:00
Subject: Re: What sound does no duck make?

John Carter wrote:
> Imagine a flock of ducks in the sky. Listen.
> Now remove the ducks. Listen.
> 
> What is the sound of no duck quacking?
> 
> What should nil respond_to?

Imagine a large steel box with a small hole, through which you can push 
a stick. Inside the box there is supposed to be a duck. This duck is 
your dinner, and you are very, very hungry. But before you can open the 
box to retrieve the duck for dinner, you have to use the stick and hole 
to prove that there is a duck inside (by poking in...poor Mr. Duck.) If 
poked the duck will quack rather loudly. But since this is a big box, 
the duck can hide sometimes, so it won't always quack when you push in 
the stick. Also the proof of duck existence is needed because opening an 
empty box will release a deadly gas (it is a dangerous world.)

In addition, this is a smart box, and on the back, where you cannot see 
or access it (the box is against a wall), there is a switch which turns 
on "smart mode." In smart mode, an empty box will complain when you push 
the stick in the hole. Unfortunately some clever guy thought this was 
dumb, and he turned off smart mode ("eh, it is a waste of electricity" 
was his logic.)

So you spend hours, poking and poking and poking, never really sure if 
there is a duck inside, because the box just never told you it was 
empty. Eventually you die of starvation, all because that clever guy 
turned off that switch.

Ryan