Star Trek is, of course, a world full of ubiquitous computing, although it’s rarely portrayed in those terms exactly. We see communicators, tricorders, flat-panel displays everywhere…and, for portable information access and messaging, the PADD.

Of course, these are really all just non-functional props. But the ideas behind them have long-since fired the imagination of real-world engineers. Communicators have already completely infiltrated our real-world lives–we call them cellphones. Flat panel displays are now so common it’s getting hard to remember when televisions took up significant cubic volume and not just rectangular area. Tricorders…well, we’ve got a way to go on that one, because we’re nowhere near the necessary technology for that kind of magical scanning. But they’re working on it.

PADDs, however, are in reach of our real-world technology, and the iPad seems to be consciously trying to make them a reality. The way PADDs have been portrayed, even as far back as Classic Trek¹ gives us some insight, I believe, into how Apple envisions the iPad being used.

Memory Alpha describes a PADD thus:

“Consisting of a large touchscreen display and minimalistic manual interface or control panel (generally only one or two buttons), the typical PADD is used for a variety of functions including logging manifests, compiling duty rosters or diagnostic reports, entering personal data, and/or accessing library computer systems.”²

OK, so, let’s translate that into real-world terms.

“…large touchscreen display…”

Check.

The common PADD in Star Trek (not counting the big boat anchor they schlep around in the Classic series) maybe half-again as large as an iPhone or iPod Touch. To be honest, a lot of the early PADDs we saw aren’t very practical for the heavy, every-day use that we see. Their split design–screen on top, large but sparse control area on the bottom–eats a lot of real estate and leaves the screen itself about iPhone sized. And if you’ve ever done any really serious reading on the iPhone, you know that’s not really all that comfortable.

However, there are other PADDs that sort-of point the way to something more usable. One notable device I saw rewatching DS9: “Penumbra” was being used essentially as a large digital picture frame, and a moment’s examination of the prop shows it was only lit because there was a light box affixed to the back, marring its sleekness. As a concept, however, it’s much closer to something actually usable, because it’s almost all display screen. The same basic device is also shown in an earlier episode being used to manipulate images to identify a suspect. The effects, of course, were composited in later, but that shows that, even in 1997, someone was really starting to think about how you’d use one of these things.

The iPad fits this model handily. It’s almost entirely screen, with a bezel less than  half-inch thick³. It’s a multi-touch screen, to boot, which enables all of the abilities we’ve already seen on the iPhone, and should also make typing with the on-screen keyboard feasible⁴.

Some people think the screen is too large, some too small. Some the wrong proportions. I read a lot of complaints about it being 4:3 rather than 16:9, but I think 16:9 would be a very awkward form factor to hold and rotate. Apple wants a device that works at any orientation, and the longer (or taller) you make it, the more you bias it to a specific orientation, just based on what will be comfortable to hold. Granted, widescreen content will suffer a bit, but this isn’t intended to replace your widescreen TV, any more than a PADD replaces the main screen on the bridge.

“…minimalistic manual interface…”.

Check.

Again, the earlier PADD designs were less realistic in this regard, with their minimalistic interfaces taking up a surprising amount of space. Later PADDs are almost all display, and some don’t have an obvious, dedicated control area at all.

The iPad, like the iPhone, has exactly five actual, physical buttons–the power button, a screen rotation lock switch (originally intended to be a mute switch like the iPhone), two volume buttons, and the Home Button. With current technology, we really do need at least a few actual, physical buttons, but I can see that changing fast.

There are two things we see people doing to provide input on a PADDs that will not be possible with an iPad, and I really wish were: handwriting and voice. Jake Sisko’s probably the only one we ever see using a stylus with a DS9-era PADD, but it still points at a use case Apple’s being rather stubborn about: some people still like handwriting. Granted, it’s not a huge market–else, Tablet PCs with handwriting capability would sell better than they do–but it’s still a market. Voice is also a niche market, but there’s some very good voice recognition software out there (mainly made by Nuance) that could probably be made to work on the A4 CPU.

“…used for a variety of functions including logging manifests, compiling duty rosters or diagnostic reports, entering personal data, and/or accessing library computer systems.”

Check. And here’s where the big controversy really seems to focus right now.

Critics insist that something this powerful (and this pricy) is and of right ought to be a general purpose computer. It should not be locked down to mere consumpion–and limited production–of media, information, and messaging, and possible game playing.

But that is not Apple’s use case. Apple’s primary use case is the one described here for a PADD. A PADD, in story context, probably has a processor that makes the most powerful multicore processor today look like a clay tablet.  You probably could make a PADD do all kinds of things if you wanted to⁵.

That’s not what a PADD is for. It’s for accessing, and sometimes composing, information, messges, and media. Composition can take the form of voice, typing with predictive text, or pen input–sadly, the iPad will only allow the middle of these three, although I hold out hopes of eventual extensions or evolution to permit voice and handwriting. Access can take the form of locally stored or synchronized data, or data retrieved or synchronized over the ship’s ubiquitous, wireless network (and, by extension, Star Fleet’s Federation-wide subspace network).

And it just works. In a story-universe where random technological malfunction often leads to zany hijinks, you never hear anyone complain that their PADDs are on the fritz, causing random artificial personalities to be spawned or multiple transporter duplicates or sudden appearance of tapioca pudding in the mess hall. PADDs just work.

That is more or less the intention for the iPad.

So what will happen in the real world?

Well, of course, nobody really knows yet.

In the Star Trek universe, PADDs are ubiquitous tools, indispensable as a class, but individually disposable, given as much thought as we give pads of lined yellow paper or Post-it® notes. They’re limited purpose, limited function, but nobody seems to be concerned about their limitations, because they do what they’re supposed to do. You can create content on them, and even fairly well, but they’re not computers. They are, essentially, terminals or, if you prefer thin client machines. The same is really true for every tricorder and for that matter every console on the ship. The real brains are the never-seen computer cores, just as the real brains of the current Internet are mostly unseen server farms.

The iPad is similarly limited by design. A lot of people look at it, look at what it’s theoretically capable of, and insist that it’s a general purpose computer. It isn’t. It probably could be, but it isn’t. Apple is betting that the iPad’s focus on web browsing, e-mail, media consumption (including text, audio, and video), light content-creation capabilities (through iWork, for example), and tightly controlled extensibility through its App Store will become just as ubiquitous. They’ve isolated almost all of the things people actually do with their netbooks–and to a large extent with their full-sized “general purpose” computers–and they’ve wrapped it all up in one of the slickest, easiest to use user interfaces out there.

From a usability standpoint, they probably do have a winner. But will the limitations be a turn-off, long-term, for the consumer market? Or will the easy-to-use “appliance” nature of the device catch the imaginations of people weary of wrestling with the daily hassles of “general purpose” systems?

In a few days, we’ll begin to see. Cellphones have made the Star Trek communicator a ubiquitous reality. Now, we’ll see if the iPad and the copycat devices that are already lining up to compete with it will do the same for the PADD.