My commute for work has recently doubled, thanks to an office move. I now spend over two hours per day driving to and from work. And I've been reminded of a small pet peeve: strobe lights on big vehicles.

Back when I was in high school, I was mystified and very annoyed when school bus manufacturers started installing very bright strobe lights on top of their buses. Here you have a vehicle that is eight feet wide, thirty-five feet long, ten feet high, has lights all over, and is painted BRIGHT YELLOW. Anybody who manages to run into a school bus probably doesn't deserve a driver's license in the first place. Do they honestly think that adding a strobe light is going to significantly increase its visibility? In the early morning hours, when other drivers' vision is adjusted to the darkness, the strobes aren't just bright, they're blinding.

Now, apparently, the trend has spread. I first noticed it on garbage trucks. Now, I can understand the need for flashing yellow lights on the back of a garbage truck. While they move around their routes, they stop and go a lot, which can create a legitimate risk for surrounding drivers. As I drive down the highway on the way to work at 70mph+, I see garbage trucks (also barreling along at 70mph) with their lights flashing away.

Similar, but even more annoying flashers have now appeared on run-of-the-mill semis. Why does a semi need a bright, flashing yellow light, when it already has six tail lights, plus all the other decorative lights?

I understand the desire to ward off rear-end accidents. However, I can count on one hand the number of rear-end accidents I have seen in my life that involve a semi. Why? Because truck drivers tend to give themselves a lot more following room, which means that they rarely make sudden stops. The people who are following too closely behind generally have enough warning to slow down in time.

I wonder as well whether such lights are creating more risk than they are averting, by creating a distraction for drivers. Sure, that flashing yellow light might slightly increase safety for the one person directly behind the semi. But what about the couple dozen other drivers who are three lanes over, and are only distracted and annoyed by it?

I just returned to the office after several months away, and I have a new neighbor in the next office over. In talking with him, I am beginning to understand the antipathy some hold towards Microsoft and their licensing schemes. My co-worker is older, and not particularly tech-adept. Consider the following:

1) My new neighbor recently had a motherboard die on him. Because it was an OEM computer (HP, I think), replacing the motherboard with the exact same would have been prohibitively expensive, and replacing the motherboard with something else would have required a new license. (I know you can sometimes talk MS's CSRs into letting you reactivate, but 'officially' it's not allowed)

2) I recently bought a copy of Windows XP Home Upgrade. I didn't buy it at a store. In fact, I bought it from someone else who had. This same person had intended to install it on their computer running Windows 2000. And they couldn't. Not because of any technical reason, but because of arbitrary limitations imposed by Microsoft. See, in order to upgrade, you have to have an existing installation of Win95/98/98se/ME, OR an install disk for Win95/98/98se/ME/2000. And they fell neatly into a corner case. And they couldn't return it, because Best Buy won't take back opened software (can't blame them, really).

3) The gazillion versions. Yeah, lots of other people have complained about it, too, I know. But you know what? It's even worse than you typically hear. Take a look at all of newegg's offerings for Windows Vista. There are twenty-seven. Not only do you have the Basic/Premium/Ultimate/Business versions, you have a choice between Retail and OEM versions, Upgrade and Full versions, 32- and 64-bit versions, and single- and 3-packs. And, as we see in #2, if you get the wrong one, you're screwed.

4) The price is ridiculous. Period. Windows, in and of itself, doesn't help me do things. It's the applications that count. Comparisons to a Linux install (cost vs. what you get) are apt here.

5) I work for a big, faceless corporation. Our IT people buy (or do they lease? I don't know) laptops from Dell. They pay for the license that comes with the laptop, then pay again through their site license. Yep, Microsoft is double-dipping. I bought my own hard drive and happily installed XP using that unused license (and dual-boot Ubuntu), in case I actually want to do something useful with the laptop, which is otherwise tightly locked down. Off the company network, naturally.

6) It's becoming pretty difficult to purchase a computer from any of the big OEMs without getting burdened with Vista. I get the feeling that the number of people who prefer Vista over XP is overwhelmingly small. Yet Microsoft leverage their market position to force a copy of Vista onto nearly all new computers. And if you want to switch back to XP, you get to pay Microsoft again.

Back in October of last year, I installed Ubuntu on my main computer at home. I did a few tweaks, and was quite satisfied with the results. Other than a few hiccups, mostly related to sharing a printer, everything went smoothly. I'm now a convert.

But a few weeks ago, I ordered myself some parts for a new build. My intention was to similarly install Ubuntu, get the right drivers set up, and off we go. Unfortunately, it didn't work. Here is what I ordered:

• Athlon 64 X2 3600 (yes, it's already overclocked)
• Biostar TForce 7025 uATX mobo
• 2GB some generic PC2-6400 RAM
• Radeon HD3850
• 300GB SATA (either WD or Maxtor, don't remember :eek:)

So nothing unusual. Since I had heard that the new Catalyst 7.12 drivers supported the Radeon 3xxx series under Linux, I thought I was set. Unfortunately, I wasn't able to get the drivers to work. Trust me, I tried a lot of things. And I know that plenty of other people have had success doing it. Just not me.

So I bought a copy of XP Home Upgrade from someone who had a Win2k installation and realized only too late that you need either an installation of Win98 or Win98se or Win95 or WinME OR an official CD for one of the above or Win2k. They fell into a corner case--Win2k was installed, but they didn't have the CD. They couldn't install it because of an arbitrary restriction, and they couldn't return the (now-open) box. Even before I started installing XP, I started understanding a bit better the aversion some have for commercial software.

That feeling continued through the next while of setting up and installing things. True, all the drivers and utilities for my hardware were relatively up-to-date and polished. But it seemed to me like many of the things Windows does or wants to do are not for my benefit. Activation, for example. And setting up Windows Media Player and telling it NOT to send any information. And Windows Genuine Advantage, for the naming of which all of MS management ought to be drawn and quartered.

Granted, for the normal user, these things aren't any sort of big deal. I understand that Microsoft want to reduce piracy, and I have no issue with that. Even setting aside the "punish the customers, let the pirates go free" situation that results from WGA, DRM, and similar efforts, I still have issues with Microsoft poking around my hard drive. The necessity of installing anti-virus software is also annoying. Normally, I'd create a limited user account and use that, but so many applications require an administrator account that it's impractical. I miss sudo. I miss being able to update everything on my system at once, without having to download executables and run them individually. I miss compiz (I had problems paying half price for XP--you think I'm gonna spend money for Vista's eye candy?!). I don't have any alternative at the moment, though, so until there is a reliable and easy way to get my video card working under Linux, I'll be using XP. I don't hate it. In fact, I know how to work with XP better than I do with Ubuntu. It's just....less comfortable.

Here's hoping Hardy Heron brings me luck. Three months to go...

Gadget: Digital picture frames
Feature: Dimensions that reflect the reality of photography

At some time in the near future, I would like to buy my wife a digital picture frame. I started looking around, and found, to my utter consternation, that a vast majority of the under-$100 picture frames are widescreen. Yes, nearly all of them sport a screen with a resolution of 480x234. How many people actually take pictures with that sort of aspect ratio? I'd venture to say practically none. Nearly every digital camera defaults to taking photographs with a 3:2 aspect ratio. Widescreen LCDs are great for movies, yes, and some of these frames can do that. But for their primary purpose, i.e. displaying photographs, they are singularly unfit.

Let's take that 480x234 panel as an example. In the ideal case, we would have a photograph 1) displayed in its entirety (no cropping), 2) fill the whole screen, and 3) maintain its aspect ratio. With these devices, however, you get to choose two.

What were they thinking when they designed these?

At some undefined point in the future, my wife and I want to build our dream home. We have lots of ideas and opinions on what we want. The purpose of this Journal entry is to serve as a temporary repository for ideas, wishes, requirements, and fantasies for our dream house, and to collect ideas from anyone willing to share. Here is the list so far:

Rooms we want:

• Kitchen
• Dining area (my wife wants a formal dining room, although I think it's a waste)
• Living room (this plus the family room plus the play room = 3 living spaces? too many, methinks)
• Family room
• Master +3 bedrooms + guest suite
• 3.5 baths minimum (4.5 if guest suite is on first floor and all other bedrooms are on the 2nd)
• Den/study/library
• Play room/theater/game room (maybe the "family room" can take the place of the formal living room, and this will be the informal room)
• Workshop for me (either separate room or space in garage)

Things to avoid:

• Two-story rooms
• Wasted space
• Rooms that are too big, especially
  • Family/Great room
  • Master bedroom
• Extra rooms that add little usability
  • sunroom
  • big central foyer
• Tile in the kitchen and eating areas (I installed it earlier this year and it practically pulls food onto itself!

Other features:

• Must be extremely energy-efficient, especially with respect to climate controls.
  • Double or triple-paned windows
  • More than the normal amount of insulation
  • Skylights where practical
  • designed to let light but not heat in
• Double oven
• Breakfast bar
• If adjacent dining and living rooms, ability to segregate or join the two in a way that's not obvious (really big pocket door? pocket *wall* like in that one episode of Monster House (the gangster house)?)
• Ideally All bedrooms upstairs except for guest suite
• Kitchen close to garage
• 3-car garage
• bathtubs in every full bathroom (no bathrooms with just showers)
• garage doors not visible from front
• Big pantry immediately accessible from the kitchen
• Mudroom area by garage
• Kitchen close to dining room

Other ideas:

• Desk/mini office in the kitchen for mom
• Outlets placed for Christmas lights (D.U.H.)
• Some place for the kids to do homework (possibly a table that folds up against the wall in an existing room when not in use?)

In a way, this is a bit similar to the Dilber Ultimate House, but what I'm looking for is a subset of what Scott Adams was looking for. At this point, I'm thinking on the level of "what rooms do I want, and where do I want them?" rather than "we should put hooks by the garage door to hang keys on!"

Please feel free to post any ideas or suggestions you have. This could be things you would like in your own house, things you have done that you really like (or that didn't turn out as well as you thought), things you wish you had done or are glad you didn't do, etc. I'll include them in the lists above and, of course, credit the contributor.

Over the last few months, I've done a fair amount of travel for my job. This has led me to ask this question:

Why, oh why, are airplane windows so small?

You see, as I sat on a flight from Paris down to my destination in Africa, I noticed that from our altitude, the view of the stars was absolutely breathtaking. I blocked as much cabin light as I could with my pillow, shaded my eyes, and wondered at how well I could see so clearly. Except I couldn't see much. Because of the thickness of the window (triple-paned), and its small size, my view was severely restricted. And I had to twist around to a rather uncomfortable position in my seat in order to get a decent view.

In fact, it would seem that airplane windows are sized and positioned as to be as useless as possible. Sure, if you happen to be flying at sunset and the plane happens to be pointed in the right direction and you have a window seat on the correct side of the plane, you'll get a good view. But you can see sunsets from the ground. What do people want to look at when they're up in an airplane? The ground, of course. Or, as in my case, if they notice the brilliant sky above, they'll want to look at the stars. But you can't get a decent view of either without smashing your face up against the glass, and even then, your view gets distorted by the three panes separating you from the outside.

You would think that after some fifty-plus years of jet airline design and construction, airplane manufacturers would have noticed that their windows are inadequate for any practical purpose. But no, windows are only slightly larger in the upcoming Dreamliner as they were in the DC-3.

C'mon, Boeing. You've made planes attractive for the airlines by making them more efficient. Now make them more attractive to passengers by improving the view.

While you're at it, those seats could use some work, too.

As I sat on an early-morning flight this morning, I started thinking about the difficulties Microsoft is facing in encouraging adoption of Vista. I thought about all the big complaints I have read, and then it hit me:

Why don't Microsoft follow Apple's lead and build the next version of Windows on a BSD foundation?

Now, I've only toyed with Vista a little bit while browsing through the local Fry's and fiddling with friends' computers, I've gotten a fair impression of what it's like from a User's perspective. And it seems to me that for billions of dollars worth of investment, there's not much from a user's POV that drives sales. Sure, it might be a little more secure under the hood, and the driver model is new, but neither of those affects (or should affect) the user experience. Yeah, there's some eye candy, but certainly nothing to justify the amount of development. And now we have a whole mountain of relatively new code in which to find bugs and security vulnerabilities.

Now let's do a bit of speculation. What if Microsoft had built Vista on a BSD core? Well, on the good side, they would start off with mature, complete, pretty-darn-secure code, which would save them an enormous amount of time and money. It would also have improved compatibility and interoperability with the rest of the world, although the cynic in me would say that this would act as a reason for Microsoft not to do it. Also on the minus side side we have application incompatibility. Microsoft, however, is a Grand High Master at handling this problem. In addition, most programs (setting aside games for now) work pretty well in Wine. Microsoft could even create an API analogous to Apple's Carbon to allow developers to easily write code for the old and new versions of Windows.

What about hardware? Well, considering the paucity of drivers at Vista's release, and considering the fact that most common hardware actually work out of the box under Linux, I don't think this one is as large an issue as it initially appears, even if much of the code is written by independent developers.

Now, of course there are other "soft" issues that would follow such a transition. First of all, there's a whole ecosystem of developers who know how to code for Windows but not for anything else. This includes pretty much all of Microsoft. Consider this, though: there were six years between the release of XP and Vista. How long do you think an experienced Windows programmer would take to become competent at writing code for a BSD-based OS? Would a year of full-time training and practice be enough? Two years? And if the remaining four (or five) years were spent on writing the new version of Windows, would it be enough?

One could certainly write a book on this subject, and I've only scratched the surface, but there's one point I'd like to put forth. What about this: write the next version of Windows on a BSD core, and run every single old application in an emulator, or on a compatibility layer, or something similar. It may seem drastic, but here's my thought: breaking backwards compatibility can be a good thing. I've heard stories upon stories of patches, quirks in windows, extra execution paths, and special application-detecting code that have made their way into the windows codebase in order to ,a href="http://dansdata.com/gz070.htm">make a specific, single application run right. Break the yoke of backwards-compatibility and make it all run in its own space, and let Windows be an OS and window manager.

Before I get off rambling, I'll end it here. Comments?

The second number is 20

Gadget Feature: Fiber-optic link for displays.

I recently read an article where the author was given a demonstration of various HDMI cables and their ability to carry High-Definition content over longer distances. For a standard 6-ft cable, there was no difference in data transmission between the cheapest off-the-internet cable and the ludicrously expensive top-of-the-line brand name cable. However, when they tested 10-meter cables, there was a significant difference between the cables. The expensive cables were able to carry higher-resolution images farther than the cheap ones.

So here's my idea: why don't we use a fiber connection for our displays? I'm not particularly familiar with the encoding HDMI/DVI uses, but in terms of raw data, 1920x1080 x 60 frames per second * 24 bits/pixel comes out to around 3Gbps. That's a lot of data. It's a perfect application, in my opinion, for fiber. It's immune to electrical noise, so you don't have to worry about running it parallel to power lines in your house. It only takes one fiber, and requires no extra sleeving, so you have one small, light cable to attach. It can go considerable distances, provided it's a decent fiber, so you can put your projector, your receiver, your cable box, and your HTPC wherever you want. And it's getting quite cheap.

The home thater seems like a perfect situation to use fiber, but there's no reason it wouldn't work for desktop PCs, conference rooms, or any of a number of other applications as well. But nobody seems to be using it. Is there something I'm missing?

As I sit here, typing on my work laptop, my left wrist is practically getting burnt by the heat put off by the hard drive. The hard drive on my 700m at home gives me the same toasty feeling. For that reason, and because of the sheer geeky coolness of it, I want a Solid State Drive.

The performance advantages of SSDs have been stated many times: lower power consumption, very fast "seek" times, high data rates, shock tolerance. Several companies, including Samsung, PQI, SanDisk, A-data, and SimpleTech, have announced upcoming SSD products.

The only problem? They're expensive. As in a $600 premium on a notebook with a 32GB SSD instead of a spinning-disk hard drive, as of now (early June 2007). SanDisk say that the premium should drop to about $250 by Q2 2008, but for those of us who are too frugal, or too impatient, or both, there is an alternative: DIY.

It's actually quite simple. You'll need a few things:

• A dual-card CF-to-IDE adapter. $26 + shipping
• Two 16GB Compact Flash cards. $150 each + shipping (cheaper may exist--this was the only one on newegg ATM)
• About 5 minutes of spare time, plus however long it takes to format and install your OS of choice.

Step 1: Insert the cards into the adapter
Step 2: Swap the adapter into the laptop
Step 3: Format the drive and install your OS of choice. Make sure you limit (or turn off) your swap file.

There are a couple things that I've noticed:

• The adapter listed will only fill about half the space of the original drive, so in theory, four CF cards would fit just fine. I haven't been able to find any four-card CF-to-IDE adapters, though. Do any exist?
• If your laptop has a slide-in hard drive (as opposed to the type illustrated on the page for the adapter), you'll have to attach something to the adapter so you can actually push it all the way in.
• For what it's worth, this should also reduce the weight of your notebook by some few ounces. This always seems to be a big selling point for notebook manufacturers.

Device: Notebooks/laptops and anything else that runs on batteries
Feature: Longer battery life

This one really bugs me. I have two regular 53Wh batteries for my work laptop. The newer one gives me 2-2.5 hours of battery life with non-intensive use (web browsing, email, etc), and the older one gives me about one hour. Now neither of these batteries is new, so I can't expect a great deal of capacity from them. And since it is running a company-managed OS image, and it's locked down pretty hard, I can't tell it to spin down the hard drive, and it doesn't make use of SpeedStep. So it's not running as efficiently as it should.

But still. I can't immediately answer the question of "How much is enough?" Truthfully, the answer is, has been, and always will be "more than I have now." For now, I think 5 hours under moderate-to-heavy use should be considered a bare minimum. I would like to see eight to ten hours under the same usage pattern be considered "average", and twelve hours as "exceptional".

So what will that take? There are two approaches to the problem: either increase the supply of energy or decrease the demand (or, most practically, a combination of both). The first approach, increasing energy storage, only really has two real prospects that are likely to become commercial in the near future:
--Increased battery capacity-- There really hasn't been progressing significantly--my now-close-to-15-year-old Thinkpad has a battery with a capacity of about 34Wh, and which is significantly smaller than the battery for my Dell Latitude D610. So in a decade and a half, very little has happened.
--Fuel cells-- It's a great idea, although many hurdles remain before they can gain widespread adoption. First of all, it has to fit in the normal profile of a laptop. We're getting closer to that ideal--current prototypes are about the size of a notebook dock. They'll still need to shrink by a factor of about 10 to become acceptable, but lots of very smart people are working on it. The downside of fuel cells is simple--they require consumables. Forget to take along enough refills, and expect to be tied to an electrical outlet. However, If a single fuel cell can power your notebook for a month, I guess that's not such a big deal.

On to demand. There are a few current developments that are promising, like the various brands of Solid-State Disks and Apple's announcement of LED-backlit displays. Right now, the hard drive in my laptop is keeping my leg uncomfortably warm. Eliminating nearly all that power consumption would be great. What other targets do we have?
--CPU-- This is still the low-hanging fruit in many ways. When running full-blast, it can still consume tens of watts. Intel and AMD (and VIA, although they're ahead of the game here) need to work on that. When idle, the CPU should be using practically zero power. We've had enough of "make it faster, dangit!" on the notebook front, and we need to turn our attention to power savings, even at the expense of some performance. However, this is only possible with the cooperation of...
--Operating System-- You can't point fingers at any one OS here. Linux is just as guilty (if not more so) than Windows, although Vista is working hard to take the battery-sucking crown. Maybe we need mobile-specific OSes that run next to nothing when allowed, so the CPU can get a rest.
--RAM-- Right now, this is by far the hottest part of my laptop. Granted, those modules get no ventilation, but right now I'm doing nothing beyond typing this. Again, the only places SODIMMs go is into laptops (excepting niche applications like industrial control and tiny form factor machines), so they need to be made much more energy efficient.
--Wireless-- Of various sorts--802.11x, Bluetooth, etc. Yes, they have to consume power to transmit, but everything else needs to be pared down.
--Display-- Here's a wild idea--why not use a divergent fresnel lens behind the LCD, and use ambient light instead of a CFL or LEDs?

There are other potential places we could save more power, but that's enough for now. Reducing power consumption would bring lots of benefits. You'd save space on cooling systems, letting you build a smaller, lighter notebook. You'd need a smaller battery for the same lifetime, again saving size and weight.

Yeah, everyone's a critic, and it's easy to be an armchair engineer, but the needs are nonetheless valid.

Device: Optical drives of all sorts.
Feature: Slot-loading

Okay, so we've had slot-loading CD players in cars for years and years, and I like it. Minimal visible footprint, very slick interface, no clunky, plastic trays or faceplates that may or may not match your computer. And if you're modding your computer, or using it in a new one, there's no need for painting, dying, stealth doors, or any sort of mechanical hiding mechanism. All you have to do is cut a slot.

Yes, such drives exist. Well, one model exists, namely the Plextor PX-716AL/SW-BL, but it costs $150! One hundred dollars (or more) is an awful high premium on a mere disc loading mechanism. I'm surprised they sell any at that price.

But why doesn't anybody else make such a drive?

Every once in a while, I come across a situation that makes me really wish for one or another feature for some gadget. So here's my first feature request:

Device: Portable Audio and Video devices (MP3 players, DVD players, maybe even laptops and PDAs)
Feature Request: Integrate an FM transmitter into it.

I drive an old car that has a tape deck in it, so when I want to listen to the music on my MP3 player (an inexpensive 2GB Sansa), I plug a cassette adapter in. This leaves a cord draped onto the passenger seat. Now maybe this might not bother most people, but I'm an engineer, and as such have an instinctive dislike for anything so inelegant. I have an FM transmitter at home that we have occasionally used. The problem is that this transmitter, while respectably small, is still larger than the MP3 player. And it's a separate device. That's attached by a cord. So I end up with a nunchuck-style arrangement.

So let's add an FM transmitter to MP3 players. You turn on your mp3 player, tell it to broadcast on channel xx.x, turn up the car radio, and you're off. Heck, set a preset on your radio and leave the same frequency set on your MP3 player to eliminate a couple steps. Then you can put the mp3 player wherever--in the glove compartment, sitting in the coin tray, put it back in your pocket, whatever.

There are a few potential downsides:
--If the user forgets to turn on the FM transmitter, it would drain batteries faster
--Manufacturers of iPod (and other mp3 player) accessories would be pretty mad
--The FCC might not like the suddenly-increased number of FM transmitters, even if they're all very low-powered
--Added complexity and circuitry might be hard to fit into the same-sized package
--Differing radio frequencies in different countries

Your thoughts?

In the wake of today's tragedy on the Virginia Tech campus, my wife made a very disturbing, yet profound, observation. Every news outlet is asking the question "What could have done to prevent this from happening?" Everyone and his dog will have an opinion on what VT officials could have done better. And everyone will demand someone's head on a platter. The politicians do it because they want to be seen as acting strongly against such events, and the media do it because it makes it easy to blame someone: "so-and-so should have had more police there" or "the administration should have locked down the entire campus immediately". They have to blame somebody for not seeing beforehand what we now see clearly with hindsight. In other words, we have to blame this on somebody, and punish them. The blame game is particularly maddening, because it shows a lack of perspective, and leads to inappropriate, ineffective responses.

Think of it this way. If the gunman had not been killed, but rather taken into custody, would we still be hearing questions like "why did it take them two hours to send out an email to the students?". Perhaps eventually, but not with such immediacy or such a scathing tone. Instead, there would be much more focus on the gunman. In the last forty-five minutes we've been watching the news, not once did we hear them place the blame on the gunman. Why? Simple. We cannot satisfactorily place the blame on him and punish him. University officials and the police, on the other hand, are right there and present ripe targets. Even though there's little they could have done to prevent it.

Now that I've ranted a bit and complained about what the media are doing wrong, what do I propose as a solution? I propose that university (that's all of them, not just VT) officials take a hard look at what could drive this person to this type of action.

First, figure out what made him crack. Was there too much pressure to succeed in school? Did he have too large of a course load? Did his girlfriend just dump him? Did he just flunk a critical exam? Then, we need to find ways to prevent that cause where appropriate, or mitigate the consequences. Maybe better student relations and counseling would help prevent or reduce extra stress. Maybe we need tighter controls on how many courses students can take. Maybe we need a better "relief valve" for pent-up frustration. Say, a wall with professors' portraits and free use of paintball guns. Or an anonymous forum for rants. I'm not a behavioral psychologist, so I can't say what would work best. Nothing more needs to be done, in my opinion. We need to come to grips with what happened, and get on with our lives.

In any case, we must stop focussing so much on what could have been done had we known everything beforehand, and instead look forward optimistically to find genuine solutions. Solutions that will help us as people better ourselves so that this will never happen again. Instead of trying to shield us from the "bad guys", empower us so that none of us becomes a "bad guy" in the first place.

I'm doing a poor job of expressing my view, but I hope I get the point across.

Historically, AC power has been preferred for a couple reasons. The first is because it has been easier to transmit long distances. Simply run it through a transformer to boost the voltage up to some hundreds-of-kilovolts, string it up on high-tension power lines, and step down the voltage at the other end. The advantage of this method is that the high voltage means that relatively little current is required in order to transmit the same amount of power. That decreases line losses in transmission. It's also easy to step voltages up and down very efficiently for distribution.

The second reason why AC is preferred is because that's how almost all electricity is generated. Some piece of rotating machinery (gas turbine, steam turbine driven by coal or nuclear or gas, windmill, etc) spins a generator, which produces AC. The only exception I can think of is photovoltaics, which at this point are still too expensive from a consumer's point of view.

Then why would you want DC? For bulk transmission of large amounts of power, DC is better for several reasons: You can put more DC current through the same wire, since DC uses the entire cross-section of the wire instead of only the surface, as AC does. With DC, you also do away with (or can ignore) capacitance between phases and capacitance between conductor and environment. It's also easier to control power flow with DC.

So AC is better on the generation side, DC is better on the transmission side, and AC is better for distribution. What a fun world we live in.

So why do I want DC? Simple: I recently took a quick survey of my house, and discovered something startling: Practically nothing in my house needs AC power. Seriously, almost everything in my house either already converts AC to DC, or could be fairly easily redesigned to use DC.

Now, this may seem kind of obvious. Computers naturally run off DC, as does everything associated with them--I lump printers, scanners, and network gear of all sorts in that group. Incandescent lights can run off DC just fine--they're fairly close to a simple resistive element in any case. Our stereo and VCR/DVD player run off DC (thanks to internal conversion), and almost everything inside the TV gets power after it's been converted to some sort of DC. Our fridge runs on AC, but fridges that run off DC exist--it's just a matter of using DC motors for the compressor and blowers instead of AC motors. Even fluorescent lighting, including CFLs, can easily work with DC; the electronics in the ballast that control current flow for AC can easily be designed to do the same for DC.

There's one more reason that's a bit of my personal fetish: power backup. That heavy brick of a UPS you have in the corner? It's converting AC power to DC in order to charge your batteries. When the power goes out, that same UPS then converts that DC back into AC to feed into your computer. Once it's in the computer, it gets converted once again to DC before it powers all the fun stuff inside. That's a fair amount of loss incurred through those three conversions, even if it's only when the power's out and only as long as the battery lasts. With a DC-powered house, however, the outside DC would run directly to a power conditioner in the PC, with very little loss along the way. Your UPS would enjoy much higher efficiencies. And if you had a big enough battery bank, your own house could serve to reduce the effect of startup current when your teenage daughter turns on the hairdryer or when someone turns on the vacuum cleaner.

But what about the costs of the inefficiency of converting AC to DC at the supplier's end? They don't matter. You see, you're paying $.xx/kWh for your electricity, and losing some of that energy through AC-to-DC conversion. In effect, you're paying more for each kWh of electricity that's actually doing something beneficial. Pushing the AC-to-DC conversion upstream towards the energy producers would increase the "sticker price" of the power you get, but you would end up using less of it, balancing out the cost.