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Comment Re:Deepwater Horizon non sequitur (Score 5, Interesting) 290

Ash = ash.
Coal ash is different from volcanic ash.

I used to do ash analysis on coal samples - coal ash is pushing 95% silica and alumina. The rest of the elemental analysis are trace elements, which can be made to sound super-scary when you scale up the quantities to thousands of tons. OMG! There's 100,000 pounds of this KILLER element released! Yes, but it's spread out evenly though 10 million tons of slurry over 100 square miles. You could probably strip-mine the top 5 feet of the same area in a city and find higher concentrations.

The biggest problem is not all the toxic waste, it's all the bloody inert sludge that's everywhere.

Comment Re:"Back to the launch site"? (Score 2) 73

It seems that the quantity of fuel required to fly an nearly empty 1st stage is negligable. That is, the amount that they normally leave behind as reserve in case of issues getting to orbit is enough for the 1st stage to land with - you basically just fall/parachute as far as you dare and then fire the engines at the last second to steady/cushion the landing.

Comment Re:SpaceX (Score 2) 73

If I were SpaceX, the first thing I would have done is tossed an engine in the water, recovered it, and studied it. Landing legs and cushioned landing are sexy and the whole process is very impressive on paper to the less well educated space fanboy (I.E. 99% of them)... but engine refurbishment is the key to the whole process.

Well, the goal is to eventually land them on, er, land so that they don't get dunked. Then you end up with 9 engines and a first stage in fairly good nick with 5 minutes of flight time on it.

I don't know of their timeline, but I'd expect a couple of sucessful water landings, then it'll be time to land somewhere on terra firma. Or a big-ass barge, that might do the job.

Comment Re:Rebooting (Score 1) 305

Have a read through the "technical notes on EEC IV MCU" document on this page

This was for a ecu used in the 80's to early 90's - it had things like the "limited output strategy" where basically if the CPU didn't get its act together in time to tickle the hardware watchdog, a very basic set of logic IC's take over which give you a fixed squirt of fuel for every engine revolution and static timing. Which would make your car run like a piece of crap, but still run (sorta).

Comment Re:Umm safety? (Score 2) 305

Let's imagine you could buy a car that was $2000 cheaper without airbags - Would people buy them?

No need to imagine. People did. And people still do. I bought plenty of cars that didn't have airbags or abs or stability control or seatbelt pretensioners or emergency brake assist or power steering,even (the horror!).

But nowadays, people do give serious thought to their safety, which is why even the base model crapbox has ABS and airbags. If I had a choice between a car advertised as "5 STAR crash rating" and one without that was 5 grand cheaper, the one with the 5 stars gets my money every time. If one of those features saves me in an accident - or even better, helps me to avoid one - it's worth it.

Comment Re:brick your car (Score 2) 305

, because of an unexpected register state, well, ooooooooooooooops.

oooooooooooops indeed, that'll be at least 50 milliseconds while the system watchdog reboots into previous firmware version.

These are not the people that do your phone updates. These are people that deal with real-time embedded systems that are safety-criticial. There will be something like a hardware watchdog set that is used for the next 100 times of vehicle operation that triggers the 'fail safe' option of returning to the previous firmware.

Comment Re:If that wasn't crueal and unreasonable... (Score 1) 1038

The problem with this is the person who is being executed can't come back and give an account of their execution.

Well, not if they're completely dead. If they're only mostly dead, they can be revived and recount their experiences.
People have experienced pretty much all of the current methods of execution in other circumstances and have survived when given medical care. So yeah, you can ask them what it's like to be strangled / shot multiple times / gassed / shocked / etc and from what I've heard, there's not too many things that are actually free of some sort of suffering.

Comment Re:Time travel is not possible without (Score 3, Insightful) 465

Depends on how your time machine works.
If it's a 'jump' or sudden discontinuity between one time and another, you're in trouble.

If it's a 'linear' style time machine (a-la H.G. Wells) and you're merely pulling the 'flow of time' lever from it's rest postion of "Forwards at 1x speed" to something like "Backwards at 200x speed"..... then you're much more likely to remain attached to whatever continent you happen to be in.

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