Tuesday, February 15, 2011

A simple handwave that makes The Matrix tolerable for the scientifically literate

Suppose that controlled fusion power requires real-time control computations which can be much more efficiently implemented in neurological hardware than in silicon.

(That Second Law of Thermodynamics thing was bothering the hell out of you, wasn't it?)

Note that neurological hardware really is exceptionally power-efficient for certain classes of computations. Common estimates of the human brain's power consumption are 20-25 watts; this is roughly the wattage of a Mobile Intel Core i5 processor, which (as far as we know) appears to be a much less powerful computer for many purposes. By contrast Watson runs on 90 IBM Power750 servers, filling ten racks, whose power draw is something like 80 kilowatts. In other words, Watson consumed about four thousand times more power than either of its meat-based competitors.

Here in reality, I think it's unlikely that any fixed class of computations can be efficiently implemented in neurons but not in silicon — see Carver Mead and his academic descendants' work on analog silicon circuits. But positing that such computations may exist seems within the realm of acceptable science-fictional handwaving.

UPDATE: Yes this is close to the standard handwave that the humans are being kept as computing devices, not power sources. But I think you need to draw the connection explicitly to power generation; otherwise there's just too much narrative in the film and animated shorts that makes no sense.

UPDATE': Never mind, I just remembered Morpheus's exact wording from the first film's voice over and I don't think it's salvageable. Oh well.

Sunday, February 06, 2011

Why iPads' role in education should be limited

This morning I came across this story about a Georgia state senator proposing replacing textbooks with iPads. This strikes me as a bad idea for several reasons.

First, the iOs developer agreement means that iOs will forever be a platform that teaches children to consume rather than to create, at least with respect to my discipline (computer programming).

If you think this doesn't matter because "kids don't program", I would like to disabuse you of that notion, hard. The iPad could have been a great device for running Squeak, which includes environments like etoys and scratch. These systems teach children to be producers rather than merely consumers of computing, which I think is no small matter given the importance of computers in society today. But, as a programming language interpreter and compiler, Squeak is prohibited by the iOs developer agreement

Many adults grew up as passive consumers of technology — for example, as television watchers or video game players, rather than people who shoot videos or program games. This blinds them to the possibility that things could be profoundly different. Ubiquitous digital video cameras and video sharing sites like YouTube have already transformed the relationship between people (especially young people) and video. Video is no longer solely the thing you sit on the couch and watch. It's something everyone can and does create. Despite the proliferation of astonishing banality on YouTube, I claim that this is a positive development. Making and editing a video of your cat is still more rewarding, and exercises more cognitive skills, than passively watching almost anything on television.* Programming could be the same way. No, the average person will never build complex software from the ground up. But the average person can, with appropriate support, learn to write small programs, and to modify big programs around the edges, and (crucially) to enjoy doing so. The iOs developer agreement simply shuts down this avenue of creativity, and that's the wrong thing to be doing to children.

Well, OK, so maybe you don't care about ideological issues like "freedom" and "creativity" (although I claim that if you do not, then you have no business working in education). Let's get down to practicalities.

The general attitude of Apple towards iOs device "owners" has been that the end-user does not truly own the device — Steve is just letting you hold it for a while. Note Apple's hostility to jailbroken devices and even its use of nonstandard screws for its cases. What does this mean in the education world? A school district that buys a thousand iPads will be completely at Apple's mercy w.r.t. software upgrades, hardware repairs, and general system maintenance.

The article notes that Georgia is "currently spending about $40 million a year on books [that] last about seven years". Apple is a consumer company and builds its products to last about 2 years. Ask people with vintage 2007 iPhones how well their devices are coping with iOs 4. Furthermore this 2-year product cycle is not an accident; it's built into the foundation of Apple's current business model, which is to ride the leading edge of technology so that they can always sell a device that's shinier than their competitors' devices (and even their own devices from a couple of years ago). Have the school districts really worked out the implications of this? I doubt it.

Furthermore, the article notes: "Textbook publishers are eyeing the potential for moving their content to the digital world, enabling them to update material rapidly and include interactivity." The unspoken subtext is that school districts will move from purchasing textbooks to purchasing subscriptions to textbook content. Ask university libraries with electronic journal subscriptions how well that's working out for them. And the iPad textbook age will, in the long run, be worse than that. Electronic journals at least distribute their articles as DRM-free PDFs: if you find a paper you need, you can save it to your local hard drive and have it forever. Does anyone think that grade school textbook publishers are going to release their iPad content without DRM? I laugh mordantly in your general direction. I pity the school district that has a budget crisis and cannot afford a textbook publisher's access fees for the year. I can only hope that most districts keep the old dead-tree textbooks in the basement for emergencies.

In summary, iPads in education will

  • Teach children to consume programs rather than to create them.
  • Lock schools into a closed computing ecosystem that they do not control.
  • Lock schools into a continual treadmill of costly hardware upgrades.
  • Lock schools into electronic subscriptions to DRM-encumbered textbook content.

All that said, dead tree textbooks are expensive and heavy and troublesome to update, and there's tremendous potential for electronic educational materials to improve the situation. And the iPad, being an excellently made device with an active developer community, is a fruitful context in which to experiment with new educational software. But until/unless some of the above features change, it's extremely premature for an entire state to make the iPad the center of its educational curriculum.

*Of course, there are a few great shows on television and people still watch those. Homemade video does not replace that and never will. But great shows constitute a tiny fraction of televisual content.