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


Forgot your password?

Comment Re:This wasn't an engineering decision... (Score 2) 569

I'm willing to bet not much of that pollution comes from VW diesels, in America.

That depends on what you consider to be "not much". There were about 500,000 cars affected by this issue in the US, and they are producing as much as 40 times the legal limit. That would mean they produce as much pollution as 20 million cars that meet the emissions standards, which is a meaningful percentage of the 250 million or so cars on the road in the US. That doesn't make them the dominant source of pollution or anything, but it does mean they're contributing far out of proportion to their numbers. They're certainly not something we can afford to ignore.

That figure of up to 40x the legal limit also shows why it's so important to catch cheaters. Pollution controls can bring emissions down to far below the level they were before the controls were implemented, but that also means a comparatively small number of cheaters can have a disproportionate effect on total pollution.

Comment Re:Speaking as an engineer... (Score 1) 569

The test doesn't rely entirely on trust; it also relies on there being a substantial penalty for getting caught cheating. That's an important reason not to reduce the fines VW is facing. They and other car companies need to know that trying to cheat the emissions tests has real consequences.

Comment Re:This wasn't an engineering decision... (Score 2) 569

but if the current regulations are already to a point where the amounts being released have a negligible impact on health, pollution, etc. then making them more strict does not amount to much real good, but adds potentially significant costs.

But we aren't at that point yet, so you're engaged in sophistry. The best recent estimate is that air pollution causes about 200,000 early deaths each year in the United States, of which about 53,000 come from road transportation- more than any other source. FWIW, that means that pollution from cars and trucks kills more people every year than traffic accidents. So we still have a very long way to go before we can claim we've reached standards that make automotive exhaust safe.

Comment Re:Speaking as an engineer... (Score 5, Informative) 569

It seems to me that at least some of this finger pointing should go towards the idiots who created the circumstance where the item under test was informed it was under test.

It doesn't actually work that way, i.e. the EPA doesn't tell the car that it's being tested now. What happens, though, is that the tests are under carefully controlled conditions in the interests of reproducibility. The car is placed on a chassis dynamometer and run at a constant speed. VW programmed their engine computer to look for a combination of constant speed and zero steering input, which would never happen during normal driving, and switched into low emissions mode when it detected that combination.

Comment Re:23% of the company (Score 1) 471

If ozone's so nasty, why all the hysteria about the missing ozone layer

On the off chance that you actually are this ignorant and aren't just trolling, the difference is that we don't have to breathe the ozone layer. Ozone is a mixed bag. On the one hand, it burns your lungs at quite low concentrations, so it's bad to breathe it. On the other hand, it absorbs some nasty UV radiation that would otherwise cause problems like skin cancer and cataracts (and damaging crops and wildlife, so don't think sunscreen is an adequate substitute). The ozone layer is conveniently located in the stratosphere, where we don't have to breathe it and would suffocate from low pressure long before the ozone could do much damage anyway. So we get the benefits of protection from UV without having to worry about lung damage. Ground level ozone, though, gives us all the problems of destroying our lungs at a concentration that's too low to do much good for UV protection.

Comment Re:23% of the company (Score 2) 471

At least, that's what our own goverment says; out of one side of their mouth they say this is a public health issue, and out of the other side they tell us that the owners have not been exposed to anything harmful as a result. So which is it?

It's both. The diesels in question produce up to 40x the emissions standard for oxides of nitrogen. Oxides of nitrogen at those levels aren't especially toxic, but in the presence of sunlight they slowly react to produce ozone, which is nasty. High levels of ozone- levels that were regularly produced in the most polluted cities until we instituted smog controls- cause severe respiratory problems in people with existing respiratory problems like asthma. Ozone pollution certainly can kill. So even if the problem isn't so severe that the drivers have to stop driving immediately for their own safety, it's not something we want to allow in the long term.

Comment Re:23% of the company (Score 1) 471

Apparently VW doesn't have what it takes.

Obviously they do have what it takes, since they can program their engine computers to pass the smog test. The problem is that they take a performance hit when they do it, and they decided they wanted the higher performance even if it wasn't legal. Chances are the performance difference isn't enough to make the car impractical, but it would make it less attractive.

Comment Re:The Nazis Could Have Won (Score 1) 295

If Hitler had not betrayed Stalin, he could have held mainland Europe indefinitely.

Or until Stalin decided to betray him first. Long-term peace between Nazi Germany and the USSR was not going to happen; Communism and Fascism were too strongly opposed ideologies for them to avoid war for very long.

Comment Re:most don't do phd studying, and houses need pai (Score 1) 143

Spending $100,000 teaching someone Homer before they get to work spraying for bugs doesn't make their pest control services more valuable. It just wastes their time and our money.

An exterminator may not need to know about Homer for his job, but neither do the vast majority of people whose jobs do require a university education. The reason universities teach about those "unimportant" subjects is because an education is supposed to be about more than just preparing people for a life of work. It's supposed to be preparing them for their entire lives- as workers, yes, but also as friends, parents, citizens, and whatever other roles the may choose to take on in their lives. Maybe we would have a better society and a better polity if we tried as hard as possible to give everyone a first rate education.

Comment Re:Slower, Same range, within 5 years?!? (Score 1) 213

But 10 kW, which would recharge in 8 hours, would be entirely feasible with a special circuit wired up to the garage. Thats only 42 amps at 240 V 3-phase. It's a bit more than a fair size electric oven/range with the oven and all burners working full, but not crazy more.

Actually, that's 42 amps at 240V single phase. You may be confused because many 50A home circuits (under NEC, at least) are 4 wire, single phase 120/240V circuits. They have 2 hot wires, a neutral, and a ground wire, so they can provide either 240 V (between the hot wires) or 120V (between one hot wire and neutral). That's the same kind of circuit that's typically used to supply an electric range, which are often rated at about 12kW (240V x 50A). A true 3-phase, 50A 240V circuit would be able to provide just under 21 kW peak power (240V x 50A x sqrt(3)). Note that those kW ratings are for non-continuous operation; circuits intended for continuous (i.e. >3 hours at a stretch) operation may not operate at over 80% of the nominal capacity. A range can get away with using full circuit power because it's practically impossible to operate all the burners and the oven at maximum capacity for very long, but the expected 8-10 hour charging times would classify the car charger as continuous and prevent it from operating at more than 80% of nominal power.

Comment Re:1.21 gigawatts? (Score 1) 213

The 15 minutes to 80% charged is not for the home charger; it's for the Porsche equivalent of Tesla's superchargers. I would assume they'll be fed from the local medium voltage distribution system- typically around 10kV to ground- rather than from household voltage. Home charging will probably be with a conventional 240V/50A system, which should be able to get the car fully charged overnight.

Comment Still playing catch-up (Score 2) 213

Big deal. Porsche is unveiling a prototype of a car that can compete with what Tesla has been doing for a few years. That's great, except that Tesla is a moving target. If Porsche wants to get some excitement going, they need to put out something that will compete with where Tesla will be in a few years when this thing actually makes it into production.

Comment Re:Poor example (Score 1) 451

it will be always be a challenge to have these control systems anticipate what human drivers intend to do.

It would help if more human drivers used their turn signals regularly. There's a device specifically designed to let other drivers know what you're intending to do, but most drivers refuse to use it.

Comment Re:But this is California, so of course it's stupi (Score 3, Informative) 135

California requires warnings about metal concentrations on virutally ALL FOOD

No, it doesn't. There are two requirements for labeling. Individual food items that require labels have to have them, and anyone shopping can see that only a tiny fraction of the items are labeled. There's also a requirement that the entrance to the store have a label if any food item requires one. Since most food stores carry at least one item that requires a warning, almost all stores require one. That might make you think that all food requires labeling, but that impression is incorrect.

The generation of random numbers is too important to be left to chance.