In previous blogs, I’ve discussed the possible impact and consequences of several “dimensions” of technology advances predicted by Moore’s Law — e.g., what happens if we see tenfold, or hundredfold, improvements in the speed and cost of computers? Today I’ll explore another such dimension: size, or “footprint.” What happens when computers get ten times smaller? A hundred times smaller?

We’ve certainly seen ample evidence of this trend during the past several decades. Relatively primitive computing machines (by today’s standards) once filled vast rooms, which had to be cooled with massive refrigeration units to keep the machines from overheating. I remember being in one such computer room, back in the mid-sixties, with a storage device known as a “high speed drum” (roughly akin to today’s hard disks, but by no means the same thing) that had a capacity of three megabytes. (Not gigabytes or terabytes, but just a few measly megabytes). The device was about the size of a family-sized washing machine, and it made just about as much noise; the scary thing, though, was that the bolts that anchored it to the floor suddenly snapped, and the drum began vibrating its way across the computer-room floor…

Well, from those ancient days, we went to refrigerator-sized minicomputers, and then desktop computers the size of a pizza box, and laptop computers the size of a notebook. Today, we’ve got smartphones that fit in our pockets; and we’ve got special-purpose computing devices the size of a postage stamp, if not smaller. So, 5-10 years from now, we’ll have … what?

Futurist Ray Kurzweil is not content to look ahead just 5-10 years. He says, “There will be a 100,000-fold shrinking of computer technology over the next 25 years.” (see “Microscopic computers may be managing human health by 2033“) Kurzweil goes on to argue that even today, we can put a pea-sized computer inside someone’s brain, ostensibly to replace the biological neurons destroyed by diseases like Parkinson’s. So perhaps in the next decade or so, we’ll see what he refers to as “blood cell-size devices … that can go inside our bodies and keep us healthy, and inside our brain and expand our intelligence.”

While such visions of the future may be reasonable in terms of just the size of the computing devices, I have no idea whether the field of biology will be able to take advantage of such “bionic” devices. But it certainly does create a great deal of incentive for such research to take place, and I’m optimistic that even if we don’t soon achieve the “bionic man” that we used to watch on science-fiction TV shows, we’ll definitely see some important improvements. Tiny embedded devices, for example, could arguably be used to augment physical sensations such as eyesight (for the near-sighted) or hearing (for people slowly becoming deaf) or smell or touch.

And as a complement or alternative to embedding devices inside the human body, we can easily imagine miniaturized computing devices being embedded into our clothing — e.g., in our shoes, our glasses, our shirts and dresses, even our underwear. Relatively primitive versions of such devices — sometimes known as “wearable computers” — have been discussed in the literature for at least ten years; see, for example, a 1997 paper titled “Smart Clothing: The ‘Wearable Computer’ and Wear Cam,” and a more recent (January 2010) report on “Computer Clothing.”

Assuming that such technology can be produced and sold at an economical price, it’s easy to imagine that while older generations of people might be terrified at the thought of computers inside their bodies — while younger generations might be more willing to accept the notion of computerized gadgets making them healthier, skinnier (what about microcomputers that gobble up fat cells?), and that help restore damaged or deteriorating physical capabilities.

Being healthy is important, and quite a few people obsess about it (we eat too much, but we also spend billions on diet pills and low-carb foods). But being slender, attractive, and sexy is even more enticing, and probably easier to sell. Wearing computer-enhanced clothing might also be easy to sell, if it can be made to seem “fashionable.” All of which suggests that companies like Microsoft might have a hard time making a successful product in this area, while companies like Apple might do much better.

There’s one other aspect of the likely trend towards miniaturization that we need to discuss: the impact on user interfaces (UI). Again, it’s something we’ve already begun to see, as computers have shrunk from mainframes to minis to PC’s to smartphones in the past decades. Keyboards have gotten progressively smaller; “tactile” keyboards are being replaced by “virtual” keyboards on a screen; and in more and more cases, keyboard-based input/output is disappearing completely. Sometimes the UI is simpler because our “tiny” computers are specialized, single-function devices rather than general-purpose computers; for example, we don’t expect to see 200,000 apps on our iPod shuffle, and all we really need is a button to start and stop the device.

We seem to be in the era of touch-sensitive UI’s now, and everyone is fascinated with Apple’s “multi-finger” combinations of swipes, flicks, pinching, and expanding. That may be okay for a while, and it might even last for a long time with certain applications (look how long the keyboard and mouse have lasted!), but as our computing devices continue to shrink, we’ll need something else. Voice recognition, which has long been a source of amusement and scorn, could become the next “big thing,” as we look for ways to communicate with tiny devices. Perhaps we’ll find applications where the computing device can track the motion of a user’s eye, or various other body characteristics (perspiration, body temperature, etc.)

Or maybe we’ll see progress in a different direction: instead of a computer that says, “Please tell me, in detail, what you want me to do,” the computers of the future will say something like, “From my analysis of you and the current situation, I think it’s likely that you want me to do one of the following five things. Please tap (or nod, or gesture, or sneeze) to indicate whether you want me to do A, B, C, D, or E.”

I think we’re still quite a few years away from the world of self-sustaining, self-reproducing “intelligent” nanoparticles that Michael Crichton described in his 2002 science fiction novel, Prey. But that might well just mean that it’s 20 years away, rather than only 5 or 10 years away…