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User: Big_Oh

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  1. Bad Headline on Donald Trump Signs Pledge To Crack Down On Internet Porn (pcworld.com) · · Score: 3, Informative

    If you click deeply enough to read the actual pledge, it's about child porn and the use of the internet to groom and target children for sexual exploitation. There's something vague about keeping kids away from viewing porn, which could mean anything and so means nothing.

  2. Title doesn't reflect article on Human Limbs Evolved From Shark Fins Thanks To Sonic Hedgehog Gene (mirror.co.uk) · · Score: 5, Informative

    RTFA: from gills, not from fins.

  3. Self-reported on Tesla's NOx Problem: Model X Delay Explained? (dailykanban.com) · · Score: 3, Informative

    FTA: "In fact, Daily Kanban has discovered that Tesla has self-reported an NOx noncompliance at its Fremont, CA factory that may be contributing to delays in the production of the firm’s new Model X SUV."

  4. Never underestimate... on Chris Roberts Is the Least Important Part of the Airplane Hacking Story · · Score: 2

    Never underestimate the ability of non-security programmers and hardware people to overestimate their own security prowess.

  5. Re: Wait you mean the HQ for Dice isn't a casino? on How Google Map Hackers Can Destroy a Business · · Score: 1

    AAAAADDRRRIIIIIAAAANNNNNN!!!

  6. How D-Wave works on First Evidence That Google's Quantum Computer May Not Be Quantum After All · · Score: 1

    Remember analog computers? You would set up a circuit so that the voltage in one place was the answer to your computation, and then instead of calculating the answer you would *measure* the answer. We stopped thinking about them because it was tricky to set up the circuit for each calculation, but once you had it set up the computation would happen at the speed of electrons.

    The D-Wave computer is similar to this. Given a polynomial in many variables (with positive real coefficients, and the variables only take the values 0 and 1), you might like to find the assignment to the variables that minimizes the polynomial. So D-Wave sets up a thermodynamic system whose steady state can be *measured* and gives an assignment to the variables that makes your polynomial small. Systems will naturally try to minimize their energy, and so the assignment is likely to be your perfect minimum (repeat 100 times, and the best assignment is likely to have appeared).

    The question is whether the system minimizes its energy by classical thermodynamic flow (super fast), or by quantum effects (super-duper fast). It is, for that particular sort of problem, *much* faster than anything else ever. It had seemed to be so much faster and accurate that it had to be using quantum effects. But now somebody has found a faster way to do it classically, so that it isn't *that* much faster. For those of you in the know, the question isn't speed but the rate of growth of the speed: is the ratio of speed-up growing polynomially in the input, or exponentially?

  7. Re:S/T Ratio DOES matter on Three Unexpected Data Points Describe Elementary School Quality · · Score: 1

    As an instructor, I enjoy teaching a small class much more than teaching a large one. Presumably, teachers who are enjoying their work will do better than teachers who aren't. In my personal experience, the quality of the education I provide varies wildly from class to class and semester to semester. Within a classroom, there are always a few students who "get me" and vice versa, and always a few that I just don't jive with.

  8. Re:There is never a magic bullet on Three Unexpected Data Points Describe Elementary School Quality · · Score: 1

    SAT scores are bad to correlate with because they have nonobvious selection biases. For example, the state schools in Indiana don't require the SAT at all, so only those students who are hoping to leave the state for school take the SAT. This inflates the scores dramatically. In other places (Vermont, perhaps?) the SAT is required for all colleges, and so essentially all high school students take the SAT, deflating scores. Throw in the effect of guidance counselors recommending school A instead of school B, and SAT (by state, or by school) make very poor predictors. Even by student, it doesn't do very well, but that's another post.

  9. The Maps on Citation Map Shows Top Science Cities · · Score: 4, Informative

    Physics: http://www.leydesdorff.net/topcity/figure1.htm Chemistry: http://www.leydesdorff.net/topcity/figure2.htm Psychology: http://www.leydesdorff.net/topcity/figure1.htm And for the record, the authors refer to these as "fields of study", not "fields of science."

  10. One dimensional cubicles on America's Cubicles Are Shrinking · · Score: 1

    "...cubicles have shrunk to ... 49 feet". That *is* small.

  11. Re:Johnny's Mom Has 3 Kids... on The Tuesday Birthday Problem · · Score: 1

    If slashdot had a like button, I'd be giving you some rapid-fire love now.

  12. "having a plan" is not the same as "planning" on US Intelligence Planned To Destroy WikiLeaks · · Score: 1

    The story isn't that they planned to do this, and it is unreasonable to conclude that the plan was ineffective. The story is that they developed a plan to do this. I'd be shocked if China didn't have a plan (or a dozen plans) for the conquering of Taiwan. I'd be horrified if they actually planned to invade Taiwan. Military people need to practice between real action, and drawing up contingency plans is a way to do that. It's healthy, and prevents much stupidity from seeing the light of day. For example, from thinking about this, they may be led to realize that net censorship is ineffective and counterproductive unless it is undertaken on a brazen scale. That would be good, and IMHO more likely than that it will lead to real attacks on Wikileaks.

  13. Re:The way math is structured is disconnected from on A Mathematician's Lament — an Indictment of US Math Education · · Score: 1

    You've missed the point: it isn't mathematicians who've made it overly complicated. It is people responsible for /teaching/ math. Mathematicians have made it exactly as complicated as it needs to be, no more and no less. But many textbook authors have taken that complicatedness and introduced it into areas where it isn't needed, out of a lack of understanding as to why it was needed in the first place. An example from TFA: mathematicians prefer "|x-5|2" over "x is between 3 and 7" because the former generalizes naturally to arbitrary metric spaces (like R^n). But until somebody is ready to talk about distance in R^2, and circles and such, the latter should be preferred. It uses less notation, and requires less thought to really grok.

  14. Betelgeuse on First Evidence of Supernovae Found In Ice Cores · · Score: 1

    The crab nebula is 6500 light years away. The SN1006 event was 7200 light years away. The Betelgeuse supernova could appear to earthlings at any moment, and it's only 640 light years away.

  15. GNU TeXmacs on Modern LaTeX Replacement? · · Score: 1

    GNU TeXmacs (http://www.texmacs.org/) attempts to be exactly what the poster is asking for. For research math, though, there is no real option. Journals require submission in TeX or a standard variant.

  16. Related news: Perfect number on New Possible Record Prime Number Found · · Score: 1

    In related news, a new perfect has been found. It has roughly twice as many digits as the most recent Mersenne prime. Like all other known perfect numbers, this one is also even.

  17. Origin of Cryptography on Preview of New Block Cipher · · Score: 2, Funny

    "...This implies that cryptography may come ultimately from the infantile sexual pleasure that children obtain from the muscle tension of retaining the feces." From Kahn's "The Codebreakers".

  18. Re:Overreaction. on Automated Sentry Robots · · Score: 1

    Never mind tracking the target, the sales blurb ends with "The Room Defender comes with a remote control so you can control it from anywhere in the room. " I think it doesn't even have a light sensor.

  19. 127 meters is exactly 5000 inches on Our Friend, The Meter · · Score: 1

    No roundoff!

  20. The reputation of de Branges on Mathematician Claims Proof of Riemann Hypothesis · · Score: 1

    No serious mathematician would suggest that de Branges is a kook or crank. He has solved important and difficult problems in the past by introducing creative approaches and developing new tools. When he first announced that he had proved the RH, he was taken seriously.

    As I understand it, his first attempt was awfully written, and it took quite some effort to figure out what he was saying, let alone if it was correct or not. A hole was found, the hole was patched. Another hold was found, another hole was patched. Like a bubble under the carpet, each correction created another error. At this point, no serious mathematician thinks that his attack on the RH is viable. Not because committees didn't plan for it, as he suggests, but because it has been looked at and simply doesn't work.