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Comment Re:Remember TEMPEST? (Score 2, Insightful) 264

The "audio" in question is most likely all below 24 kHz, that being the Nyquist limit for the 48 kHz sampling hardware, unless it happens that some phones can actually sample faster, and have microphones that can respond to higher frequencies.

The instruction rate of the CPUs in question is many times that frequency.

It doesn't sound likely.

Comment Remember TEMPEST? (Score 5, Interesting) 264

TEMPEST was a details-secret government requirement meant to defeat means of eavesdropping on classified computer data from its electromagnetic emissions. I guess they need to include audio too.

My impression is that the noise comes from the power supply, not the CPU. I can certainly hear it with some computers, and it is related to work on the video card in my experience. I'm astonished that you can actually pull data from that, and in fact I'd like to see independent confirmation before I believe it.

Comment Drinking Water Isn't So Easy As You Think (Score 3, Interesting) 247

When I was a kid I did Unicef collection every Haloween. We got an orange cardboard coin box at school, and collected donations to it along with our trick-or-treat. Unicef used these funds to build water wells for people in Africa who had only access to contaminated surface water.

A decade or two later, we found that many of these wells accessed aquifers that were contaminated by arsenic. And that thus we kids had funded the wholesale poisoning of people in Africa, and that a lot of them had arsenic-induced cancers that were killing them.

OK, we would not make that mistake again, and today we have access to better water testing. But it caused me to lose my faith that we really do know how to help poor people in the third world, no matter how well-intentioned we are.

And we had better not go around curing disease withoput also promoting birth control. Despite what the churches say, and the local dislikes and prejudices. Or we'll just be condemning more people to starve.

Comment Re:Er, wait, what? (Score 5, Insightful) 140

Well, nuclear reactions that we can turn off like laser-initiated fusion are a lot nicer than the alternatives. The inside of your car engine is a raging inferno shot with electric sparks and compressed with inexorable steel cylinders. That doesn't keep you from going on a nice drive with your sweetie.

Comment IOMMU (Score 4, Informative) 125

Yes, when I saw this I thought that this was a reason to make motherboard IOMMUs a security feature. Also, the DMA destination memory pages should not have the executable bit turned on. Recent generations of Intel/AMD CPUs have provided the ability to turn that bit off.

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