* Posts by Nagle

2 posts • joined 23 May 2011

Startup claims 1W wireless charging at 10 metres


Exceeds safe limit for microwave exposure

Focusing a few watts of microwave power onto something about 5cm on a side results in a power density several times the accepted 0.01 watt per square centimeter safe limit for human exposure.

Geoffery Landis at NASA came up with this idea over a decade ago, and it's patented under US patent #6,967,462. The Ossia patent is just a few tweaks on the Landis patent. The safety issue was described in the Landis patent. That patent proposes detecting backscatter when the beam hit something other than a properly tuned antenna (such as a human) and reducing the power until the human gets out of the way. That might work, but it's iffy from a safety perspective.

At laptop scale, this might work, because the target area is bigger and the energy density of the beam can be reduced by using a wider beam. But charging phones while people are wearing them? Bad idea.

There's no problem doing this. Microwave power transmission has been demonstrated many times. It's just that you don't want people in the beam.

Google was 'warned repeatedly' about rogue drug ads


Vetting advertisers is technically possible. Now it's essential

If an ad service profits substantially from illegal ads, they have to expect to be viewed as participating in criminal activity. That's what's happening here.

Online ad services should be vetting their advertisers. They should be finding out who's behind the advertised web site and running a basic commercial background check. Is there a real business out there? Are they registered with Companies House (UK), or with the appropriate authorities in other countries? How long have they been in business? What's their annual revenue? How many employees? That's part of the due diligence routine for checking out a new commercial client.

Google just discovered that such checking isn't optional.

Advertiser and web site vetting can be done automatically. We do that at SiteTruth. There's no technical obstacle to doing this right.


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