Saturday, May 30, 2015

journey to the center of the laptop

The last time I described how ideas from my software career shaped my present thinking, the topic was the interdependency between the meanings of data and code. The effective meaning of data was rooted in the details of "information systems" behind it: purposeful sequences of computer code and human labor to methodically record it, construct it, augment it, alter it, mix it with more data, etc. But the same observation could be reversed: the effective meaning (and correctness) of the information system was no more than its demonstrated transformations of data.

This viewpoint appeared to apply in other domains as well. For a wide range of candidate concepts, probing the equivalent of the concept's supporting "information system" usefully sifted its detectable meaning. How did the concept originally arise? How could the concept's definitions, verifications, and interpretations be (or fail to be) repeated and rechecked? Prospective data was discarded if it didn't have satisfactory answers to these questions; should pompous concepts face lower standards?

However, not all the software ideas were at the scale of information systems. Some knowledge illuminated the running of a single laptop. For instance, where does the laptop's computation happen? Where's the site of its mysterious data alchemy? What's the core of its "thinking"—with the precondition that this loaded term is applied purely in the loose, informal, metaphorical sense? (Note that the following will rely on simplified technological generalizations too...) The natural course of investigation is from the outside in.
  • To start with, probably everyone who regularly uses a laptop would say that the thinking takes place inside the unit. The ports around its edges for connecting audio, video, networking, generic devices, etc. are optional. These connections are great for enabling additional options to transport information to and from the laptop, but they don't enable the laptop to think. The exceptions are the battery slot and/or the power jack, which are nonetheless only providers of the raw energy consumed by the laptop's thinking.
  • Similarly, it doesn't require technical training to presume that the laptop's screen, speakers, keyboard, touchpad, camera, etc. aren't where the laptop thinks. The screen may shut off to save power. The speakers may be muted. The keyboard and touchpad are replaceable methods to detect and report the user's motions. Although these accessible inputs and outputs are vital to the user's experience of the laptop, their functions are like translation rather than thinking. Either the user's actions are transported to the laptop's innards as streams of impulses, or the final outcomes of the laptop's thinking are transported back out to the user's senses. 
  • Consequently, the interior is a more promising space to look. Encased in the walls of the laptop, under the keyboard, behind the speakers, is a meticulously assembled collection of incredibly flat and thin parts. Some common kinds of parts are temporary memory (RAM), permanent storage (internal drives), disc drives (CD,DVD,Blu-Ray), wireless networking (WiFi). By design this group receives, holds, and sends information. Information is transported but not thought about. So the thinking must occur in the component that's on the opposite side of this group's diverse attachments: the main board or motherboard.
  • To accommodate and manage the previously mentioned external ports and internal parts, the motherboard is loaded with hierarchical circuitry. It's like a mass of interconnected highways or conveyor belts. Signals travel in from the port or part, reach a hub, proceed to a later hub, and so forth. As a speedy rest stop for long-running work in progress, the temporary memory is a frequent start or end. The intricacy of contemporary device links ensure that motherboards are both busy and sophisticated, yet once more the overall task is unglamorous transportation. There's a further clue for continuing the search for thinking, though. For these transportation requests to be orderly and appropriate, the requests' source has to be the laptop's thinking. That source is the central processing unit (CPU).
  • Analysis of the CPU risks a rapid slide into complexity and the specifics of individual models. At an abstract level, the CPU is divided into separate sections with designated roles. One is loading individual instructions for execution. Another is breaking down those instructions into elemental activities of actual CPU sections. A few out of many categories of these numerous elemental activities are rudimentary mathematical operations, comparisons, copying sets of bits (binary digits, either zeros or ones) among distinct areas in the CPU's working memory, rewriting which instruction is next, and dispatching sets of bits in and out of the CPU. In any case, the sections' productive cooperation consists of transporting bits from section to section at the proper times. Again setting aside mere transporting, the remaining hideout for the laptop's thinking is somewhere inside those specialized CPU sections completing the assigned elemental activities.
  • Also considered at an abstract level, these CPU sections in turn are built from myriad tiny "gates": electronics organized to produce differing results depending on differing combinations of electricity flowing in. For example, an "AND" gate earns its name through emitting an "on" electric current when the gate's first entry point AND the second have "on" currents. Odd as it may sound, various gates ingeniously laid out, end to end and side by side, can perfectly perform the elemental activities of CPU sections. All that's demanded is that the information has consistent binary (bit) representations, which map directly onto the gates' notions of off and on. The elemental activities are performed on the information as the matching electric currents are transported through the gates. And since thinking is vastly more intriguing than dull transportation of information in any form, the hunt through the laptop needs to advance from gates 
This expedition was predictably doomed from the beginning. Peering deeper doesn't uncover a sharp break between "thinking" and conducting bits in complicated intersecting routes. No, the impression of thought is generated via algorithms, which are engineered arrangements of such routes. The spectacular whole isn't discredited by its unremarkable pieces. Valuable qualities can "emerge" from a cluster of pieces that don't have the quality in isolation. In fact, emergent qualities are ubiquitous, unmagical, and important. Singular carbon atoms don't reproduce, but carbon-based life does.

Ultimately, greater comprehension forces the recognition that the laptop's version of thinking is an emergent quality. Information processing isn't the accomplishment of a miraculous segment of it; it's more like the total collaborative effect of its abundant unremarkable segments. An outsider might scoff that "adding enough stupid things together yields something smart", but an insider grasps that the way those stupid things are "added" together makes a huge difference.

Readers can likely guess the conclusion: this understanding prepares someone to contemplate that all versions of thinking could be emergent qualities. Just as the paths in the laptop were the essence of its information processing, what if the paths in creatures' brains were the essence of their information processing? Laptops don't have a particular segment that supplies the "spark" of intelligence, so what if creatures' brains don't either? Admittedly, it's possible to escape by objecting that creatures' brains are, in some unspecified manner, fundamentally unlike everything else made of matter, but that exception seems suspiciously self-serving for a creature to propose... 

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