Power in numbers

  • Illustration by HEADCASE DESIGN
  • (A) DLP Conventional DLP hi-def sets use a mercury lamp and a rotating colour wheel to illuminate the microdisplay. (B) LED DLP Because they use three light sources of different colours "“ red, green and blue "“ LED DLPs need no colour wheel. Image credit: DOGO
Date:31 August 2007 Tags:,

Power in numbers
Q
I’ve heard about programs that can use the processing power of your computer for scientific research. How does this work, and will it slow down my PC?

A You’re thinking of “distributed computing”, which combines the unused processing power of multiple Internet-connected computers for scientific number crunching. (Distributed computing could be used for anything, really, but most projects have been science-related.)

Your PC rarely employs 100 per cent of its processing capability, and it uses very little while sitting idle. Distributed computing applications sit in the background, waiting for the times when your CPU isn’t doing all that much. They use those “spare cycles” to run data-crunching routines, such as simulating the folding of proteins or scanning radio telescope data for extrasolar communications.

The program on your computer connects to the project’s master servers, grabs a bit of data and works on it in the background, then uploads the result. Since it is designed to operate as the lowest priority on your PC, it will always defer CPU time to programs you run yourself, such as a Web browser or media player.

However, since the distributed computing programs are running your CPU at or near 100 per cent utilisation all the time, your PC will be using more electricity than it would if it were left idle, and it will generate the maximum amount of heat.

But this extra heat and power is going to a good cause. The dominant distributed application these days is Stanford’s Folding@Home, which aims to use the power of millions of participant PCs – and PlayStation 3s! – to work toward cures for diseases such as Alzheimer’s, Parkinson’s and cancer. If you’d like to participate, go to http://folding.stanford.edu/

Screen sickness
Q
Occasionally, when I play video games, I get motion sickness. Why is that?

A The accepted term for that particular variety of motion sickness has been called “simulator sickness”, and despite a few studies to determine its cause, nobody is quite sure why it happens.

It doesn’t affect just video-game players. A 1995 report by the US Army Research Institute found that almost half the military pilots who used flight simulators developed after-effects – and 10 per cent of those respondents had symptoms lasting more than 4 hours.

Like motion sickness brought on by planes and boats, simulator sickness seems to occur when there is a disagreement in the brain between what you’re seeing and what your inner ear reports is actually happening. One theory about motion sickness posits that it occurs because the area postrema portion of the brain associates the visual/balance discrepancy with hallucination. Since seeing things that aren’t there is often a sign of poison in the body, the brain tells the body to purge, unleashing the, um, hot dogs.

How can you fix it? You might try sitting further away from the screen so that it doesn’t fill your field of vision. Also, experience often helps you get over it. It seems that after enough exposure to dizzying graphics, your brain learns that you don’t die from poison every time you play a first-person shooter, and it lets you enjoy your fun.

iPod plead bargain
Q
Recently my house was burgled and someone stole both my computer and my iPod. I had over R7 000 worth of iTunes music on those machines. Is there any way to get it back?

A According to the iTunes Terms of Service: “Apple does not represent or guarantee that the service will be free from loss, corruption, attack, viruses, interference, hacking, or other security intrusion Apple disclaims any liability relating thereto. You shall be responsible for backing up your own system, including any products purchased from the iTunes store that are stored in your system.”

But the reality is that Apple has allowed many people to re-download their music, usually with a warning such as, “We don’t have to do this, but we understand your issue, so we’ll let you do it once.” Because of Apple’s legal relationships with content owners – that is, the music and movie industry – the company cannot let everybody re-download music whenever they want.

So while I can’t promise you that Apple will let you download everything again, I can tell you that it won’t hurt to ask. I can also tell you that backing up your purchases is very wise, either by burning songs to music CDs (which you could re-rip), or by backing up the song files themselves to DVDs or to a secondary drive.

Internet eyeball
Q
I have a webcam on my PC. Is it possible for a hacker to hijack it and see me?

A I hate to be the bearer of creepy tidings, but it is possible. Anything that is connected to a computer on the Internet is at risk of being compromised, whether it’s a file sitting on a hard drive or a peripheral device such as a webcam or microphone. A computer programmer was arrested in Madrid, Spain, in 2005 for writing a virus that allowed him to take over webcams to record pictures and videos of his victims – while he was also stealing their bank account passwords, among other things.

The good news is that your virus protection software should eliminate these webcam worries right alongside other outside threats. As long as your software’s virus profile database is up to date, you’re as safe as possible.

In addition to virus-scanning software, a good firewall might help more network- savvy people determine if their webcams are streaming data to an outside source. Then again, if a computer has been compromised by a virus or Trojan, the firewall might be as well.

Of course, the most secure piece of hardware is the one that isn’t plugged in, so if you’re really freaked by the idea that someone might be spying on you, simply unplug your camera from the USB port. If, like me, you have an unpluggable webcam embedded in your laptop screen, you may want to blindfold it with a piece of tape.

On the other hand, I wouldn’t worry too much about Internet Peeping Toms. Relatively few webcam-controlling viruses have appeared, at least partly because the hardware varies from PC to PC. Writing one virus that works with all those models would be a programming challenge.

Keep it going
Q
I’m planning to go bike trekking. Based on the principle of “he shall have music wherever he goes”, I’m planning to take my iPod. Of course, I’ll also have to drag along the GPS and I might as well take the cellphone. Problem is, these power-hungry gadgets don’t have replaceable batteries. How do I keep them running out in the sticks?

A Although advances in battery technology keep improving runtimes, ironically enough advances in microprocessor capacity and functionality often eat up those hard-won advances. Even if your gadgets aren’t power-hungry, the quest for compactness often means a trade-off in battery capacity.

Carrying spare batteries not only adds weight, in your case it’s not even an option.

There are a couple of alternatives that our resident gearheads regard as worth exploring, though.

Flexopower (www.flexopower.com) sells a variety of chargers that collect their juice in the form of solar energy and store it in a li-on battery. The SolarPouch provides power outputs in USB or DC form, and comes with a bunch of cellphone adapter plugs.

More compact, and not necessarily as elegant (though inventive in its own way) is a charger powered by off-the-shelf dry cells. We’ve seen 9V versions of this kind of charger, but we liked Lady Ada’s Mintyboost so much we ordered it (www.ladyada.net) and built it ourselves. It uses 2 AA batteries and a clever digital circuit to deliver a couple of refills to a range of gadgets from iPods to Garmin Forerunner GPSes. And besides, it looks way cool, enca
sed in its Altoids chewing gum tin. You can buy components separately and construct the hardware yourself, if you like, but we ordered the full kit including tin. All you need is some basic tools, a half-decent soldering technique, and that’s it. Power out is via a USB socket.

 

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