Tag Archives: wi-fi

Airnergy! Snake-oil gadget recharger debuts at CES, gulls Gizmodo blogger

Oops, looks like someone slipped up here. SlashDot points us to a Gizmodo report from the Consumer Electronics Show about a device called the RCA Airnergy, which purportedly soaks up wi-fi signals into an internal battery, which you can then use to recharge your iPod, phone, satnav or whatever. Read the following excerpt from the report carefully; there’ll be a test afterwards. šŸ˜‰

It’s not exactly new tech, as ohGizmo notes, but it’s the first application that’s of any real use to consumers. Put simply, Airnergy takes the energy created by wi-fi signals and stores it in a rechargeable battery. At CES, the device’s battery, which I believe was precharged with Wi-Fi power, was able to charge a BlackBerry from 30% power to full power in about 90 minutes.

Now, anyone with the most basic of engineering or physics educations probably found their brows furrowing before the quote, but the excerpt couldn’t have portrayed its writer as any more gullible. The comments thread after the post is a litany of people explaining exactly why the Airnergy is (at best) the subject of exagerrated claims or (at worst) an out-right scam or spoof. This is the sort of reportage that hands ammunition to the “online reporting is inferior to dead-tree journalism” lobby… even though the dead-tree outfits are getting pretty shabby at fact-checking themselves in these times of shrinking budgets and receivership.*

What interests me most about this story, though, is that it shows we’re still suckers for snake-oil, even in this technology-saturated age, and that seems weird to me – some part of my brain wants to believe that, because we’re more dependent on technology, we should be more clued-up as to the basics of the science behind it. That’s obviously a fallacy – just typing it out is enough to make me snort in self-derision – but it’s a remarkably persistent one, leaving outfits like RCA (or rather whoever has current ownership of that particular defunct brand name) able to fool gadget geeks with the eternally-gilded promise of something for nothing.

But you have to wonder how much of it is self-delusion – what about Steorn, the Irish company that still insist they’ve built a perpetual motion machine? You’d think that, after being so thoroughly debunked, a charlatan on the make would just pack their bags and head for the hills of obscurity. What keeps them coming back? Are they so cynical that they plan around monetising that small percentage of the desperate-to-believe, or have they just drunk too deeply of their own kool-aid? [image by stallio]

[ * And before anyone beats me to it, yeah, I’ll hold my hands up – I’ve been spoofed before, and reported things here inaccurately, sensationally or uncritically. In my defence, however, I’m not paid to blog, and hence my research time is fitted around the stuff I do to pay the bills… and I’ve always ‘fessed up to my goofs when they’ve been brought ot my attention. ]

Wi-fi makes walls see-through

wi-fi routerRemember me mentioning the special paint for making wi-fi cold-spots?

Well, here’s a reason you might want to invest in some – via Bruce Schneier we discover that some folk at the University of Utah have found a way to surveil the inside of a building using wireless signals:

The surveillance technique is called variance-based radio tomographic imaging and works by visualizing variations in radio waves as they travel to nodes in a wireless network. A person moving inside a building will cause the waves to vary in that location, the researchers found, allowing an observer to map their position.

The researchers, electrical engineering graduate student Joey Wilson and his faculty advisor Neil Patwari, have tested the technique with a 34-node wireless network using the IEEE 802.15.4 wireless protocol, according to the MIT Technology Review. By ā€œinterrogatingā€ the space with signals and multiple receivers, the researchers found they were able to read the waves to detect the location of a moving object within a meter of accuracy.

OK, so it’s not quite kit you can buy from the local Electronics Barn… but you can pretty much guarantee that now the proof-of-concept has been done, all sorts of smart types will be looking at making affordable homebrew versions. [image by delta_avi_delta]

Wi-fi cold-spots and hot-boxes

No wi-fi logoI’ve been saying for a few years now that once we reach a saturation point with wireless internet access, cafes and other establishments will start advertising the absence of wi-fi in the same way the currently advertise its availability. Even an always-online geek like myself sometimes feels the urge to retreat from the cloud, after all, even if only so I can sit down in peace with a book for an hour or two.

But there are plenty of other reasons why you might want to spend time somewhere that wi-fi can’t reach you… or alternatively somewhere where there’s wi-fi available which can only be accessed by someone inside the building or room in question. The classical way to make a room impermeable to high-frequency signals is a Faraday cage, but that’s neither cheap or architecturally simple. Now there’s a much simpler option which may aid the proliferation of wi-fi cold-spots in urban areas – a special paint based on an aluminium-iron oxide that resonates in the same frequency range used by wi-fi routers.

And not just cold-spots. I can definitely see a market for wi-fi hot-boxes – rooms with carefully controlled physical access (think burly doormen and surly cashiers) wherein you and a bunch of, er, associates can set up an ad-hoc LAN connected to the web through a heavily encrypted router. No one outside that room – even the establishment’s proprietors – could know what data had been passed around within it.

If you’ll excuse me, I’m off to book a one-way ticket to Mexico City and draw up a business proposal…