|Authored by: Anonymous on Friday, July 20 2012 @ 03:30 PM EDT|
|Plugging a microwave into an electrical outlet turns it from a doorstop into a|
machine with the capability of cooking food.
Feeding data (e.g. the Firefox program) into a computer turns it from a doorstop
into a machine with the capability of browsing the World Wide Web.
Neither of these acts makes a new machine. Neither of them even *improves* an
existing machine. They are both examples of *using* the machine. You feed
inputs into it, and it does its thing, and outputs come back out. Even when you
plug your microwave into the wall, it won't cook any food until you press some
buttons on it, giving it the inputs it needs: how long do you want it to cook?
on what power setting?
For a general-purpose computer, the "thing" that it does is
"execute the instruction cycle". Because this is a universal
algorithm, it allows the computer to compute *literally anything* that we can
figure out how to describe to it in program form. That's what it was designed
to do, and it arrives from the factory ready to do it. Giving it instructions
is simply *using* the machine, not improving it.
Pressing 1+1= on your calculator causes it to display the answer, 2. But it
doesn't give the calculator any new capability. It was always capable of
performing that calculation if you fed it the proper input. A general purpose
computer is just a far, far more complicated example of the same thing. It is
programmed with millions, even billions of instructions, but it still does the
exact same thing as your desktop calculator does: accept some inputs, do some
mathematical calculations, and produce some outputs.
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