"Digital" Explained

Submitted by Bill St. Clair on Mon, 10 May 2004 12:00:00 GMT
# I printed, signed, put in an envelope, and intend to mail today the following letter answering Jeff Cooper's question about the meaning of "digital":
Col. Jeff Cooper
Gunsite Ranch
Paulden, AZ 86334

Colonel Cooper,

In the last two editions of your Commentaries, which I look forward to reading each month on my computer, you asked about the meaning of "digital", and why it's better. I have worked with digital computers and digital electronics for the last twenty-five years, so I consider myself qualified to answer.

"Digital" is an adjective meaning roughly "represented as numbers". The opposite of "digital" is "analog". So a "digital" watch displays the time as numbers, whereas an "analog" watch has the conventional big hand, little hand, and second hand (though most "analog" watches are actually digital inside these days, keeping time with precise tiny rotations of a stepper motor controlled by a computer chip).

The difference between digital and analog is easily understood in the world of audio recording. The LP records that we used before Compact Discs (CDs) took over are analog. They store sound as bumps in the spiral groove cut in the vinyl. Cassette tape recorders, likewise, store sound as variations in the magnetization of the ferrous surface of the tape. CDs on the other hand, store music digitally. The voltage of the signal is sampled 44,000 times a second, and each sample is converted into a number between -32,768 and 32,767 (16 bits, able to represent 2**16 = 65,536 different numbers). That string of numbers is recorded as tiny holes in the metal film that is under the CD's plastic surface.

There are a number of different ways to store these strings of numbers. MP3 files compress the audio to fit in a shorter string of numbers, trading off a small reduction in quality for a large reduction in size. Images are also recorded digitally these days, three numbers representing each pixel in an image and using JPEG and MPEG compression. And you have of course seen the plethora of digital powder scales, which use the same sort of analog-to-digital (A/D) converter used to make digital music to convert to a number the voltage drop across a piezoelectric material in response to gravitational force exerted by the powder being weighed.

So what's the advantage of digital storage? Digitally recorded music usually has more dynamic range than analog, with no tape hiss or record scratches whatsoever, but many audiophiles still think that analog recordings sound better. The real advantage, however, is that digital recordings don't degrade. Yes, your CD surface can be scratched or dirtied so that the bits are unreadable, but as long as they are readable, the string of numbers will be read, and can be copied, exactly, time after time.

As with anything the advertisers get their hands on, the "digital" adjective is abused to convince people that they must buy something new to replace or augment the tried and true. Just as the gun manufacturers create new calibers every year, even though, as you often say, the venerable .45 ACP, .30-06 Springfield, and .22 LR suffice for most uses. But I find it nice that the CDs I bought twenty years ago sound as good today as they did then. My LP records got scratchy sounding in only a few years. But I still prefer a simple balance beam scale to the fancy digital versions for measuring my powder. Simple, effective, nothing to burn out.

# The Libertarian Enterprise - Letter from e.j.totty - why the idea L. Neil Smith expressed last week, You Go First: The Peace Amendment, won't happen until the eagles come home to roost. [tle]

# L. Neil Smith at The Libertarian Enterprise - Torturing the Truth -

There is a common chemical test in which a small portion of the stuff being tested is heated to incandescence and the resulting light put through a prism device that spreads it out for examination. Dark "absorption lines" in the spectrum indicate what elements the stuff contains.

War is like that, especially idiotic, unjust, and illegal wars like the one the United States government has chosen to fight now in Iraq, Afghanistan, and enough other places around the world to boggle what few remaining minds on the planet haven't been boggled already. War heats the populace, leaders and followers alike, to a kind of incandescence, until it becomes fairly easy to see what they're made of. In the present case, the experimental results are pretty damned discouraging.


I stopped listening to conservative talk radio on September 11, 2001, because I knew that, for all their mouthings about liberty, what they're really all about is punitive, paternalistic socialism. Now that I'm compelled to listen to them again, I see that I was right. The commentators issuing their pronouncements from inside my fireplace have certain characteristics in common. To begin with, they refuse to acknowledge the single most important truth of the last three years, since the fall of the New York towers, indeed the most important truth of the last thousand years regarding western dealings in the Middle East.

That truth is simply this: it isn't the Moslems who came to the west to push us around, steal our resources, sneer at our customs and beliefs, depose our leaders and replace them with puppets, reshape our political institutions, or redraw our national borders to suit their own foul purposes. No, that's what we Europeanoids have been doing to them.

Get this through your head right now, because it's not going to go away, no matter how much you may hate being compelled to recognize it. It's a fact that will largely determine the shape of the 21st century. Americans and Europeans are the aggressors in this conflict, and what happened in New York on September 11, 2001, was an act of long-delayed retaliation.

# Lady Liberty at The Libertarian Enterprise - Damned if You Do, Dead if You Don't - carry the best defensive weapon known, that is, after learning how to use it effectively and when to do so. [tle]

# Ron Beatty at The Libertarian Enteprise - "Wasting" your vote? - in case you've decided you prefer pulling a lever (or touching a computer screen) to voting from the rooftops, Mr. Beatty reminds you that the way to truly waste your vote is by voting for either branch of the Boot on Your Neck Party. [tle]

If you want this country to become the next incarnation of Nazi Germany, the next Soviet Union, the next Imperial Rome, vote Republican't.

If you want this country to be a poverty stricken third world nation, with it's citizens taxed into poverty and submission, no more than a minor satrapy in a UN global hegemony, vote Democrap.

If you believe that no government has the right to tell you whom to love, who to associate with, when or how you can travel, vote Libertarian. If you believe that you do not need 'permission' to defend your life, to start a business, or to get married, vote Libertarian. If you believe that government employees are no better than anyone else, vote Libertarian.

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