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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 Just Blackberry? (Score 1) 278

This might as well be how Blackberry, Nokia, and Palm blew it. And I'm probably leaving off a few companies.

IMO it all comes down to arrogance about your own platform. In Nokia's case that was Symbian.

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.

Comment Where is it practical? (Score 1) 127

But it does not allow rockets to reenter the Earth's atmosphere at orbital velocities, slow down, and land.

How about the Moon and Mars? It seems to me that the fuel capacity of Dragon isn't enough to do both lunar descent and ascent just on the Super Draco thrusters and the trunk's fuel capacity.

Comment What's really impressive (Score 2) 127

The impressive part is that they do it with an actual rocket that is 106 feet tall, and that they have launched it 7 times with 0 failures.

Using the same engine, rather than treating the engine as a disposable object that only performs one burn in its lifetime. Most rocket engines can't be throttled, can't be shut down and then restarted in flight or otherwise.

The tricky part is going to be for any stage to have enough delta-V to return to the pad after lifting a payload to orbit. Also, as far as I can tell, this takes a drag chute for lower stages, and a re-entry shield for upper ones.

Bruce

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