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Comment Re:Can you change the keybindings? (Score 1) 221

While being passive-aggressive and using is fine when you're having a personal conversation with one other person, but it's kind of rude to use it when other people who did nothing wrong might want to click your link. I was curious if the key binding change was done at the console or if it required editing configuration files somewhere. Sadly, all I learned is that people on the internet can be needlessly condescending.

Comment Re:Opposite. (Score 1) 841

I might be paid to teach, but it's a two way street. I have a curriculum that must be covered, so there is only so much time I can spend on any one topic. Additionally, different students learn at different rates and in different ways. And for things in math, things build up, so if you don't understand derivatives, you're not going to be able to optimize functions, and if you can't do optimization in one variable, you certainly aren't going to be able to do Lagrange multipliers. If a student slacks off all term, if they don't come to my office hours, if they won't talk to me after they bomb tests even when I specifically ask them to, there isn't anything that I can do about it.

My job is NOT to hold their hands, it is NOT to be a magical fountain from which they receive understanding and enlightenment without critically thinking about what I say, and it is NOT to make them happy and feel the world is beautiful. My job is to present the material in as clear and motivated way as I can, to assign exercises which I think will cement their understanding, and to evaluate their understanding of the material. I will do more than that if they let me, but at the end of the day, the student bears responsibility for learning.

Comment Re:In a perfect world (Score 1) 1797

This plays to a larger point that a free market is not the same thing as an unregulated market, and that very often times regulation is needed in order to keep a market free. Ron Paul has a point that we haven't done a perfect job at keeping markets free, but it isn't clear to me that he understands the difference between free and unregulated, and his fundamental belief that government cannot do anything right makes me wonder what he hopes to do as a congressman beyond burn the system to the ground.

That said, I have to respect that, in contrast to a lot of politicians, Ron Paul seems to have a sincere ideological backing for his beliefs, instead of using ideology to justify actions which are self serving and motivated elsewhere. I wish that we had more politicians out there who had ideologies which weren't completely based in greed and that these politicians followed their ideoloogies even when it went against their own interests (be they political, social, or economic). I think the left is better on this front than the right, as you have rich liberals calling on people to help the poor and raise taxes on the right, but both sides seem guilty of sacrificing principles in the name of political expediency.

Comment Re:Irrational Exuberance and Irrational Fears (Score 1) 209

...but I still think the people who keep the market even remotely stable and the people who make the market useful for it's true purpose (giving corporations a bond market and investors a place for potentially stable returns) are long term investors who follow the data.

The problem is that without the people who are speculating and taking bets, you wouldn't have nearly as many people that could make serious investments in companies. People invest in companies (in the sense that you want them to) because they expect them to grow. This is all well and good until an investor decides that he's done investing in the company. Maybe he's less certain about the future growth of the company. Maybe he just needs to free up capital for something else. Whatever the reason, he needs to know before he invests that, when he's ready to pull out, there is someone who will buy up his shares. This is where speculators come in handy. Because they are concerned with the short term effects on stock price and not long term effects on growth, there is generally someone willing to buy what the investor wants to sell, regardless of why he wants to sell. And because there are people constantly buying and selling, because there is a wide market, the investor doesn't have to worry (under normal circumstances) about a shortage of buyers driving down the price: If the market believes there is a true worth to a share, the sale price will be much closer to that price than if there were a small number of sellers who might hold out for a better price because the seller has no real alternative. The more buyers and sellers, the smaller margins people will be forced to accept between the price they buy/sell for and their own perceived value of the stock. Moreover, outside of certain exceptional circumstances, this should lead to a certain amount of price stabilization, as unless something happens to affect the true value of the share (i.e.. new information to suggest that the long term profitability of the company has changed), you have a wide arrange of buyers and sellers ready to buy/sell at a continuum of prices. The price of a share won't drop a dollar if there are people willing to buy the share for $0.25 less than the last sale.

The problem is that a large percentage of the market is speculation, and so the meaning of the stock price has changed. It has morphed from a measure of the value of the company to a measure of the perceived future value of the company to a measure of the perceived future value of the stock price. Of course, the underlying value (and expected future value) of the company still affect the stock price, but when your goal is short term profitability instead of long term allocation of capital, you are forced to be predominantly concerned with share price dynamics, which means that there are horrible feedback mechanisms which cause all sorts of undesired effects.

Of course, this is a problem with how the market works, devoid of any of the newer concerns like algorithmic or high frequency trading. There are plenty of things to be said (on both sides) about their value, but that is outside the point I want to make, which is this:

There are benefits to having some amount of speculation in stock markets, as they add liquidity, which makes non-speculative investors more willing to participate in the system. Problems arise when there is too much speculation, but that doesn't mean all speculation is bad or unhealthy. Unfortunately, putting limits on speculation is hard, and unlikely to ever be done in an optimal way. This is the natural outgrowth of that speculation, and while I personally believe it is more harmful than some other computer-based techniques (e.g. instead of algorithms which identify and then participating in the emotional binges in the market, algorithms which identify when the market has been irrational and set themselves up to profit when they course correct), it is a part of a necessary evil.

Comment Re:The judge is an idiot (Score 1) 400

Its pretty clear that these people were not the sinister criminal masterminds behind the riots - they're just a couple of irresponsible tw@ts who needed to spend their weekends sorting garbage for the next six months

The riots, at first, might have been an organic occurance. What happened as it went on was a horrible mix of anger, opportunism, and the less savory. The "riots" as a whole had no mastermind. But what these tw@ts, as you call them, did was to try to set themselves up as masterminds to a part of the riot. It wasn't two people saying "I'm angry, I'm going to loot to teach someone a misdirected lesson," it was "Let's see if we can convince other people to engage in wanton destruction! That would be awesome!"

They may not have caused the riots as a whole, they may not have thought to cause riots if there weren't any going on already, and they might not be geniuses, but they made a serious attempt to cause other people to do widespread damage. Had they succeeded, they would have been criminal masterminds behind the rioting in their area (while most of the rioting had no masterminds). Four years may be excessive, but six months of community service for people with that little disregard for society, who desire to do that much harm to their community seems too light.

Comment Re:It's a crime to attempt a crime, or incite othe (Score 2, Insightful) 400

In this particular case, it wasn't a call to fix or change the system, but that doesn't negate the point: it's important to clarify what limits we are willing to place on free speech and to understand the consequences of those limits. I agree that this instance seems reasonable, but I think it's important to have guidelines so that we don't have to consider everything on a case by case basis. A call to riot for the sake of destruction is a crime. A call to protest is not. But what about a call for civil disobedience, to ignore laws deemed unjust? You are still inciting people to break the law, but the character of the crime is much different. Of course, even in the US, where there is a codified right to free speech, there are definite limits. You aren't allowed to shout fire in a public building, and you aren't allowed to make credible threats against a person. But what makes a threat credible?

There are other examples which are even less clear. How should we handle the publishing a list of abortion doctors' addresses, with a vague call to arms? Is the call to arms just rhetoric, or is it a true incitement to violence? If we make the determination by the wording, people will just find euphemisms to use. With these facebook posts, not only was intent clear, but given the nature of current events, it was more likely that people would act (and a belief that someone will actually take your call to arms seriously seems like it should factor into things). However, it is a call to an even worse crime, and even though intent can't be proven, it is hard to believe that someone would publish such a list without hoping someone else would act.

Free speech is a great ideal, but we've never had completely free speech, and that's the way it should be. However, if we want to balance our idealism with practicality in a consistent and even handed way, it's important to understand exactly what society will and will not accept.

Comment Re:Economies of scale? (Score 2) 350

The competitors can only get better economies of scale if they were all using the same components from the same manufacturers, and even then, only if they use group purchasing: individually, they don't have the sales to justify the quantities required to get cheap manufacturing, and even if the manufacturer can afford to sell cheaper, it won't sell much below its other competitors unless the tech manufacturers can negotiate a collective deal. Even if they did all standardize on the components they were using, this has the disadvantage of picking winner and losers among the production companies, which could lead to some manufacturers shutting down, and hence to decreased competition which would raise prices in the long run.

Or was collusion not what you had in mind? And this also only works on commodity items that Apple doesn't have patents on. Explain why Apple would always get a rate of return unless their competitors were stupid and mismanaged, because if the people whose business it is to get good those rates don't see it, chances are neither will any other slashdotters with similar tech/econ/business backgrounds.


WebGL Flaw Leaves GPU Exposed To Hackers 120

recoiledsnake writes "Google spent a lot of time yesterday talking up WebGL, but UK security firm Context seems to think users should disable the feature because it poses a serious security threat, and the US Computer Emergency Readiness Team is encouraging people to heed that advice. According to Context, a malicious site could pass code directly to a computer's GPU and trigger a denial of service attack or simply crash the machine. Ne'er-do-wells could also use WebGL and the Canvas element to pull image data from another domain, which could then be used as part of a more elaborate attack. Khronos, the group that organizes the standard, responded by pointing out that there is an extension available to graphics card manufacturers that can detect and protect against DoS attacks, but it did little to satisfy Context — the firm argues that inherent flaws in the design of WebGL make it very difficult to secure."

The Future of In-Car Computing 112

Barence writes "PC Pro is running a collection of articles looking at the future of in-car computing technology. They discuss how smartphones will become the primary means of in-car entertainment, how satnavs will be integrated into fighter-jet style heads-up displays, and how cars will create wireless mesh networks that warn each other of upcoming delays and collisions. The also explore the issue of integrating driverless cars onto the roads. 'It's one thing having smart cars that can talk to each other and react accordingly, but if half of the cars are dumb, it's another issue.'"

Comment Re:Here's one for advanced students (Score 1) 680

This one fails because indefinite integrals don't give you functions, but equivalence classes of functions, all of which differ by a constant. That is why in calculus class you wrote Integral[x dx]=x^2/2 +C. So there are two solutions. The first is that you say that both sides are in the same equivalence class. The second is that you get out of equivalence class land by turning all the integrals into definite integrals on some interval [a,b]. If you do this, you get

1 |_a^b +Integral_a ^b tan x dx = Integral_a^b tan x dx

where 1|_a^b means that we evaluate the function 1 at the points b and a, and we take the difference. 1[b]-1[a]=1-1=0, and so both sides simplify to Integral_a^b tan x dx


Using the Web To Turn Kids Into Autodidacts 230

theodp writes "Autodidacticism — self-education or self-directed learning — is nothing new, but the Internet holds the promise of taking it to the masses. Sugata Mitra, an Indian physicist whose earlier educational experiments inspired the film Slumdog Millionaire, is convinced that, with the Internet, kids can learn by themselves so long as they are in small groups and have well-posed questions to answer. And now, Mitra's Self-Organized Learning Environments (SOLE) are going global, with testing in schools in Australia, Colombia, England and India. On their own, children can get about 30% of the knowledge required to pass exams, so to go further, Dr. Mitra supplements SOLE with e-mediators, amateur volunteers who use Skype to help kids learn online."

Comment Re:Size of FB is frightening (Score 1) 218

Except that there is a lot more to do on facebook than status updates (e.g. looking at other people's status updates, playing games, and slowly eroding your privacy in ways you can't even fathom). The number of status updates on FB is NOT the number of searches people do. For the marketing people, a better metric would be "amount of time spent on the site", which is proportional to how much time you spend look at adds. For direct search comparison purposes, status updates is not a good stand in.

So maybe there are only 2% as many status updates as there are google searches, but what about page views or time spent? They say there are "lies, damned, lies, and statistics" because there are lots of different statistics that let you "prove" all sorts of competing points. Don't be that guy who compares apples to oranges. Facebook might not be as big as google by any reasonable measure, but this is not a reasonable way to compare.

Comment Re:Practical Joke? (Score 1) 525

No, transfinite means "beyond finite". As in infinite. There are techniques for working with "infinite numbers" (more correctly called ordinals or ordinal numbers), and these techniques usually have the adjective transfinite, like transfinite induction. To make things more complicated, even if one ordinal number is bigger than another, they can still have the same size (or cardinality), but since this was probably a troll, I've said too much.

Comment Re:Holy Cow (Score 1) 256

Yes, this time, but how do you think that the world changes with technology? Sometimes, we find better ways of doing things, and with a fair bit of luck, those better ways become the popular ways, and then become the tried and true ways. Things that survive the test of time tend to be good, but you shouldn't conflate "good" with "better than the new thing". I mean, if not for technology finding better ways to do things, you would be forced to peddle your sarcastic remarks at the local bar, where you risk being punched in the face. Are the old ways really that much better?

Comment Re:idea != fact (Score 1) 269

Yeah, though it's a common problem that reporting on science is overblown and inaccurate. Scientists make subtle claims, and reporters will simplify and exaggerate them. Whether this is through ignorance, a desire to make things more palatable for their readers, or a desire to make the article more punchy and widely circulated, I cannot say, though the further it goes through the news cycle, the worse it gets. This is a large reason why people don't trust science: when you oversell your case, people can tell.

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