Forgot your password?

Comment: The failure mode is transformer core saturation. (Score 4, Informative) 43

by Ungrounded Lightning (#47536253) Attached to: The Truth About Solar Storms

High induced votlages in open wires are a problem, but they're not the big one.

The biggie is common-mode currents in long high-voltage transmission lines adding a strong DC component to the current in the substation transformer windings - high enough that when the same-direction peak of the AC's cycle adds to it, the core saturates. Then the inductance of the transformer drops to the air-core value and no longer substantially impeeds the current.

The current skyrockets. The resistive heating of the windings (and the force on the wires from the magnetic fields) goes up with the SQUARE of the current. The windings quickly soften, distort, form shorted turns, melt, open, short out to the frame, etc. The transformer is destroyed, or committed to a self-destructive progressive failure, in just a handful of such cycles - too fast for the circuit breakers to save them (even if they DO manage to extinguish the arcs with the substantial DC component to the current.) Even if the transformer doesn't explode and throw molten metal, gigawatt sustained arcs, and burning oil (or burning-hot oil replacement) all over the substation area, it's still dead.

This happens to MANY of the giant transformers in the power grid. Each set of three transformers that has one or more failed members means a high-voltage transmission line that is shut down until the transformer is replaced.

There are essentially no spares - these are built to order. Building one takes weeks, and there are few "production lines" so little parallelism is available. What is destroyed overnight will take years to replace, while each intercity power transmission line is not functioning until the transformers at its end ARE replaced.

The current occurs because the transformers are organized in a "Y" arrangement, and the center of the Y is grounded at each end (to prevent OTHER problems). The transformers have enough extra current handling capacity to avoid saturation from the DC through that center connection to/from ground from ordinary electrical and solar storms - just not a giant one like we get every couple centuries.

The solution is to put a resistor in that ground connection, to limit the DC in the lines (and dissipate the energy it represents). Indeed, a few lines have such resistors already.

But a suitable resistor is a box about the size of one of the transformers. It's very expensive. And it only makes a substantial difference to the operation of the lines in such a once-in-centuries event. So most executives don't spend the money (and get dinged for costing the company millions) to put them in, to prevent a failure mode that hasn't happened in the generations since Tesla and Westinghouse invented the three-phase long-line power grid.

Or at least they don't until the regulators or their stockholders require it. Which means said decision-makers need a little educational push to decide it's worth the cost and get it done.

Thus articles like this. B-)

Comment: Re:well (Score 1) 125

by Tom (#47535431) Attached to: The Psychology of Phishing

Ahh, so you work at one of those places with horrible culture.

I don't work there anymore, but I've been in the security industry long enough to know a number of companies, as well as the uncomfortable squirming that follows if you ask security training providers for independent evidence supporting their claims.

It's not a problem of IT security. Fire security trainings are quite similar, except that they have evolved thanks to decades of experience - in a modern company, those responsible know that the fire drill is primarily to drain the assigned helpers and floor supervisors, not the employees.

Instead of saying "this is stupid, I know this stuff" you could volunteer to help mentor people or simply grunt "yup, saw a guy get hacked by this once" instead of holding negativity.

I never said security is stupid. I am saying security awareness trainings are a waste of time, by and large. Tell me, how many people have you had in those trainings you thought before they went in that giving your password to random strangers is a good idea? 90% of the content of these trainings is either boring because everyone knows it already or boring because it's too technical and not interesting that they filter it out.

I've had the responsibility of writing or reworking existing IT security policies, and my advise has always been to make them as short and simple as possible. I've seen a multinational corporation vomit up a 300 page security policy, which was really great from an ISO 270xx POV, but aside from the guys in the security department who wrote it, I'm fairly certain I was the only other human being who actually read all of it, ever.

I love security. But I think our industries approach to users and security is fundamentally flawed and trainings are a band-aid on a broken arm - placebo treatments that don't even touch the real issues.

Comment: your reality is ludicrous (Score 1) 348

by Thud457 (#47532077) Attached to: Western US States Using Up Ground Water At an Alarming Rate
No joke.

The Famous Senate Restaurant Bean Soup Recipe

2 pounds dried navy beans
four quarts hot water
1 1/2 pounds smoked ham hocks
1 onion, chopped
2 tablespoons butter
salt and pepper to taste

Wash the navy beans and run hot water through them until they are slightly whitened. Place beans into pot with hot water. Add ham hocks and simmer approximately three hours in a covered pot, stirring occasionally. Remove ham hocks and set aside to cool. Dice meat and return to soup. Lightly brown the onion in butter. Add to soup. Before serving, bring to a boil and season with salt and pepper. Serves 8.

You are correct, they like it with a lot of pork. /snrk

Comment: Re: surpising (Score 5, Interesting) 165

by Frobnicator (#47531905) Attached to: Amazon's Ambitious Bets Pile Up, and Its Losses Swell

How long do long term investors have to wait for consistent profitability?

Math time... $126M loss / $19B revenue = 0.66%, less than one percent loss for a quarter. The company is worth about $140B, so the quarter's drop is less than a tenth of a percent, meaning absorbing a the loss is a tiny decrease in a large bucket. In contrast, the skittish investors yesterday cost the company about $12B compared to the $126M business loss. The skittish investors who cause huge overnight drops like this create opportunities.

We're not talking about a company that is hemorrhaging money. It isn't a company plagued by mismanagement. It is a company that since their first day built a track record of tinkering with models. That is all Amazon has ever done. They have the resources to continue operating when they discover unprofitable ones. It takes money to make money, and many tests and changes cost time and money. Yes, some investors refuse to see the long term and demand a profit every single quarter. Other investors see this as an opportunity to buy or to hold.

Last night they took a 10% drop because short-term investors are skittish. Today you can buy it at a 10% discount; so thanks skittish investors!

Comment: bigger than Steve Jobs. ? (Score 0) 174

Did you see dear leader on The Colbert Report last night?!!! /swoon

I'm sure that story will wander its way to /. in a few days.

(Just poking fun at /.'s mancrush on EM. I think it's nice that a few billionaires are willing to spend a little of their money on nerd projects like Musk, Bezos, Cameron.)

Comment: Re:name and location tweeted... (Score 1) 786

You're a really sorry loser, posting ad hominem attacks against people you know nothing about as an AC. 20 years of online experience tell me one thing: There's a 95% chance that you are in fact the exact opposite of the man you pretend to be if you act like that.

Comment: Re:name and location tweeted... (Score 0, Troll) 786

Men really need to start to stand up for equal rights.

While I agree with your main point, equal rights is not the problem. Equal treatment is. We have the same rights, feminism has won long ago. But in many areas men and women are still treated very differently. Sometimes the women are treated badly, and there are many feminists making a big scandal of it, and sometimes the men are treated badly, and almost never anyone says a word.

Comment: Re:What?!? (Score 1) 786

Blame Twitter. If you had more than 140 characters available, you could properly voice your opinion in a way they cannot find fault with, for example by lauding them so excessively that anyone with three working brain cells understands what you really want to say.

Twitter is a free SMS broadcast service and public link sharer, nothing more. People use it for stuff that they really should take a minute of calm and a slightly longer text format for. Brevity is a virtue, but only really good writers can properly convey a complete thought in a short sentence.

Comment: Re:Customer service? (Score 1) 786

I completely understand why airlines do NOT let families on early, because they now charge people extra for those privileges. But if they were trying to maximize efficiency instead of profits, it would definitely make sense to move the families on when fewer people are obstacles on the plane.

If efficiency were your policy, you'd stop applying special rules based on arbitrary distinctions. While deeply engrained in our culture, there's no reason to treat families differently from other people travelling together, who may (or may not) have equally compelling reasons to want to sit in one row.

Airlines have destroyed their own customer friendliness by collectively fighting a price war until the point where they need to make you pay for napkins so they can operate profitably. I personally find it insulting that some arbitrary rules give some people priviledges that other people have to pay for. Do it 100% or don't do it at all.

Comment: Re:Elective surgery on a critical organ (Score 3, Interesting) 521

by Tom (#47526479) Attached to: Laser Eye Surgery, Revisited 10 Years Later

If you must, do the surgery that is reversible - they insert a small piece of plastic that corrects the lens shape.

Do you have a name, link or any other information on this? I'm seriously interested, because I would love to get rid of my glasses (haven't had them for very long, so I'm still getting used and I don't really want to), but even without medical advice I understand that irreversible surgery on an eye is not a good idea.

"Confound these ancestors.... They've stolen our best ideas!" - Ben Jonson