Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror

Comment Re:regarding constitutions (Score 5, Interesting) 413

If you're not starting with a good constitution, preserving it isn't going to help. Egypt's most recent constitution was drafted entirely by Islamists after the secularists and Christians walked out when it was clear it was going to embody Sharia law and other Islamist practices at the expense of human rights.

Comment Re:Bring on the earthquakes (Score 1) 109

Energy is energy. The difference between an explosive detonation and compressed air being released from a ruptured container is the amount of time it takes for it to escape. An atomic warhead lets it all out within milliseconds (the historic Trinity test showed a 300 meter fireball at 25 milliseconds, and that was estimated to be 84 terajoules.) A ruptured pressurized tank would let the energy out much more slowly than a detonation, but still very fast. And we're talking about petajoules of energy.

Let's say there was a crack that led to the surface, and the air started escaping. It would quickly erode the walls of the crack, opening a progressively larger hole. At some point the surrounding earth would be weakened and give way, releasing the bulk of the air in a very short amount of time. I'm guessing that once the hole is big enough, it would likely take less than a second for the bulk of the air to escape.

It might not be nearly as powerful as the shockwave generated by a hydrogen bomb, but it might be close to the destructive power of an atomic bomb.

Comment Re:Issues? (Score 0) 109

207 megawatt-hours times 24 hours/day times 40 days represents the storage of over 7 petajoules of energy. By comparison, a one megaton hydrogen bomb releases about 4 petajoules. That means this chamber will be continuously containing the equivalent energy of a city-leveling nuclear blast. It better be really big, because it's going to be really stressed. It's not like salt is nature's pre-made engineered compressed gas cylinder.

And what happens if the salt chamber ruptures and the air finds its way to the surface? This would go off like a compressed air volcano. I would be afraid to live or work within 10 miles of this thing.

Comment Re:What if car companies care about out safety? (Score 1) 317

Ah, I think I understand what you're getting at. The core concept I think you're missing is that there is no "car computer". There isn't a single central computer running everything, with just wires to remote sensors and actuators. Instead, the car is built from of dozens of distributed systems, all interconnected via the CAN bus. The engine has its own computer, and its tasks include firing spark plugs, monitoring engine sensors, etc. The ABS has its own computer, and all it does is to monitor and modulate the brakes. The dashboard is its own computer, and simply displays data coming from the various other systems. And the infotainment system is its own computer, and is hideously complex, and does no end of crap. I believe my car has over 140 individual systems on the bus.

Each device on the bus has an independent processor that does whatever the device is supposed to do, a CAN controller, and a transceiver that isolates the device from the bus (thus preventing a wonky stereo from shutting down the engine.) Some devices transmit data constantly, such as the engine controller continuously sending RPM and exhaust gas temperature. Some devices only transmit data when they do something "interesting", like the seat belt detectors or the tire pressure sensors. Others don't normally transmit much data, but instead read from other sources of data and do something with it. The remote control mirrors are an example of a device that doesn't send much of anything, but constantly listens for other information.

Each system works independently, talking to and from the bus as required. The bus protocol arbitrates amongst itself to figure out who is sending the highest priority message, so things like airbag deployment can take precedence over changing the radio station. The CAN bus is that standard interface you were asking about.

The "infotainment" system has expanded beyond sound and is becoming the center of control for things like climate and navigation. When you tap the "A/C" icon on the screen to turn on the air conditioning, it'll send an "calling for cabin A/C" message over the bus. But it's not in charge of your car. Your car will continue to work even if someone pries it out of the dashboard, (as long as they didn't steal the security system, too.) You maybe won't be able to adjust the climate, you won't have a satnav system, but your car will still work. And you could replace that panel with a different panel. The horrible "MyTouch" control panel is an option in Ford cars (unfortunately standard on their higher end packages), but you can get simpler option packages that don't include it, and instead have a panel with actual tactile controls. Both panels use the same CAN bus and interface to talk to the rest of the car's systems.

Comment Re:The guy has no clue (Score 1) 314

Yeah, this guy couldn't make it past the third sentence without tagging himself as technologically illiterate. I can't believe he tried to cite GPS as a benefit of the internet.

Any organization that does not want the risks that come from connecting systems to the net can disconnect theirs.

I fundamentally agree with you ten-million percent.... but to be fair critical systems connected to the internet is not a an easily solved technological problem.... and that's because it's not a technological problem at all. It's a people problem. If you can figure out a fix for people problems then there's about a half-dozen Nobel Prizes soon to arrive at your doorstep.

-

Comment Re:Oh, look! Just what the economy needs! (Score 1) 600

The prices are not set because that's what they need to be to keep service, they prices are currently set to as high as possible. You only need to look at the profitability of the industry to see that. A large part of the reason it works (keeping prices to high) is that there are not enough practitioners in the US (look at doctors per capita for developed countries). It's a market, but it's a strongly manipulated market, as those that benefit from the lack of doctors are the ones that set the numbers.

Comment Re:Oh, look! Just what the economy needs! (Score 1) 600

Agreed, there's a lot of greedy doctors working to artificially limit the supply of doctors (look at how many they (the doctors) allow per capita in the US vs other countries). We pretend that the US healthcare system is a market, but it's clearly not, it's regulated (both self and by the government) to be specifically expensive.

Comment Re:Oh, look! Just what the economy needs! (Score 1) 600

Technology is making an individual mandate a requirement for a functional system going forward.

As more things become testable, less people will be incentivised to be in a group at all, this will drive up the cost for those at risk for various diseases. Insurance works best if everyone participates, medical tests will reduce participation.

Comment Re:Oh, look! Just what the economy needs! (Score 1) 600

If the $8k/year/citizen number is correct, it still seems likely that the UK is less expensive per a taxpayer.

Additionally, for the 16% uncovered in the US system, I'd assume the UK is definitely better. Also, having had a few different insurance plans in the US, I'd point out that the UK system was better than 2 out of the 3 plans I've had. It is true that for a small portion of the population the US system is dramatically better, and many it's slightly better though. This is also why the US system is making moves more towards a system like the French, or the Swiss, where the coverage is 100%, the cost (per citizen, which should proportionally be about per tax payer) is $5k, vs the $8k in the US (and as good as low end insurance is here in the US at a minimum).

Slashdot Top Deals

"Lead us in a few words of silent prayer." -- Bill Peterson, former Houston Oiler football coach

Working...