Bob McHenry, my mentor at Britannica, takes me gently to task in re: my post on Lyman and Varian’s measurement of the amount of information produced in the world:

This sort of thing merely perpetuates on of the great errors of our time. Apparently word has yet to get around that there is no such thing as “information.”

Sounds nuts, right? Of course information exists. I just burned a CD this morning with a few hundred pictures of my kids; there are now 620 MB of JPEGs on that CD– in other words, 620 MB of information.

Well, not so fast. Bob makes his case in an essay, “Content with Content” (not sure how to pronounce it? That’s kind of the point), which argues:

Information has no physical existence. What exists are myriad arrangements of objects and energy in the world, and brains that are wired to detect and respond to certain patterns in them…. [I]nformation is not put in, as is usually said to be the case; nor is it sent; nor is it somehow detected or extracted. It has no being whatever, out there in the world.

In short, information is a mode of perception, just as is sound, just as is color. There is no sound in nature; sound is how we humans perceive compression waves in air. There is no color in nature; color is how we humans perceive wavelength in electromagnetic radiation. There is no information in nature; information is how we humans perceive patterns. The word “information” as it is used in “information science” – to designate some substance, some aspect of substance, in the physical world – is a figure of speech, another metonymy…. It’s a useful figure, of course, as figures of speech usually are – else we would not have them – but it is important for us shamans who pretend to work with it in various ways to understand it for what it is.

In a simple information theory-engineering sense, information can be said to exist: it’s pits on a CD, magnetic bits on a Zip drive, that sort of thing. Claude Shannon, the father of information theory, called it “a difference that makes a difference.” (At least I think that was Shannon; maybe it was Eric Ashby, or Ludwig von Bertalanffy.) But how does it make a difference? A bunch of ones and zeroes don’t, in themselves, make a difference; they have to be decoded and interpreted, whether by a machine (which converts those ones and zeroes into other things– words, pictures, programs, etc.) or a person (who makes sense of the products of that conversion).

In other words, “information”– or more accurately, knowledge– really only exists when those decoding and intepreting functions are going on. It is created by the exchange; it isn’t a thing that is exchanged. The CD doesn’t contain information; it contains instructions that, if acted on by the right computer running the right software on the right operating system, can become knowledge. Or as Bob puts it, “Our friend Thoreau said ‘It takes two to speak the truth – one to speak, and another to hear.’ This captures nicely the notion that what is really happening in communication happens in two brains and not somewhere in the middle.”

You can also see this a little more clearly if you think about the disconnect between quantities of data and the importance of the knowledge that they contain. Classicist Gregory Crane, a professor at Tufts who runs the Perseus project, once pointed out that “While we have, for all practical purposes of data storage and computation, an infinite amount of art and archaeological materials, the corpus of Greek and Roman texts that survives is relatively small — well under a gigabyte by any estimate.” But that’s damn important stuff, by any estimate. Likewise, you can get the Bible onto a CD with plenty of room to spare; but that doesn’t mean that it contains less “information,” in any social sense, than a double CD from N’Sync or Emerson, Lake and Palmer. Finally, MP3s definitely have less “information” (meaning data in this case) than traditional CDs; but most of us can’t hear the difference between a CD and an MP3. As Warren Weaver noted,

Information must not be confused with meaning. In fact, two messages, one of which is heavily loaded with meaning and the other of which is pure nonsense, can be exactly equivalent, from the present [strictly technical] viewpoint, as regards information.