- The Washington Times - Thursday, August 8, 2002

Today we're going to talk about how the Internet is magic and infallible sometimes, anyway and why the "digital revolution" actually is one.
The reason is that digital technology makes perfect copies. Maybe that doesn't sound too exciting, not up there with a tight game in the NFL. But it's important. It's the heart of the Internet.
Usually when you make a copy of anything, you lose something. If you photocopy a picture, then photocopy the copy, and copy the copy again, pretty soon it starts to get blurry. You are losing information. Eventually, you end up with a white piece of paper: You have lost all of the original photograph.
What has this got to do with the Internet? Bunches. Suppose your teen-age daughter wants to send some execrable music through the Web to Bobby in Seattle the latest hit from Grok Mortuary and the Gadarene Swine, say.
In electronic form, music can be either digital or analog. Analog in this case means in the form of a wave, the kind of funny complicated green line you see on science shows on TV.
To see why sending music in the form of a wave isn't a good idea, imagine that I gave you a drawing of a complicated wave perhaps an off-key guitar riff by Grok and the Swine and asked you to copy it with pencil and paper. Depending on how good an artist you are, you would get an approximation, but it wouldn't be an exact copy. If I gave your copy to someone else to copy, he would slightly miscopy your miscopy, introducing more error in electro-talk, "distortion." Before long, it would be unrecognizable.
So what happens if we send the music digitally? First we convert the Swine to zeros and ones. This is fairly complicated, which doesn't matter here. We now want to send the zeros and ones to Seattle without losing any quality. How can we do this?
For the sake of simplicity of explanation, suppose we decided to send a one as a brief 5-volt spike, and a 0 as a negative 5-volt spike.
This isn't a real complicated idea. The person on the receiving end would just watch the voltage he was getting. (Actually, of course, his computer would.) Every time a signal of positive 5 volts appeared, he would write down "1," and so on.
While it is simple in theory, in practice the signal would lose information. It would start out as a nice clean 5-volt spike, and arrive as a somewhat misshapen spike of maybe 4.6 volts. To get to Seattle it would go through many places, losing information each time.
So why is this better than sending a wave? Because, although the signal is starting to get blurry, it would still be obvious at each step that the messy spike had started out as a nice clean "1." The intermediate circuitry automatically replaces it with a new, perfectly formed spike, and sends it on its way. Nothing is lost. (If the equipment works.) This wouldn't work with a wave because the circuitry would have no way of knowing what the original looked like. It does know what a zero and a one should look like.
So digital information ends up absolutely unchanged at its destination. This is crucial because, on the Internet, information is constantly being copied and forwarded. When your daughter sends the abominable music to Bobby, it first goes over the phone lines to AOL or whatever. AOL then chops up the Swine (metaphorically speaking) into digital packets and sends them to Bobby.
Depending on where he is, the Swine packets may go through satellites, horrible Third World telephone systems or worse. In analog form, it just wouldn't work.
In digital form, Bobby can send the Swine on to other kids, who will send it to others, through hundreds of "hops," and nothing will be lost (or gained).
It is truly slick, and it's why the Internet works.

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