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### At Oxford, a Battery That's Lasted 175 Years -- So Far

Actually, you can kill yourself with a single 9 V battery -- or the 12 V battery of your car. One man did:

http://darwinawards.com/darwin...

The computation goes as follows. The issue, as several people have pointed out, is that it is current across the heart that causes defibrillation (basically interrupting the heart's natural rhythm so that it pulses chaotically), not a matter of cooking the person (which will also work, BTW, but isn't the most common cause of electrical shock deaths). It isn't even the case that more current is always worse -- there appears to be a range of currents that are more toxic than others. A brief explanation of this is here:

https://www.physics.ohio-state...

The maximally toxic range of currents across the thorax is empirically 0.1 to 0.2 amps. Below that it isn't enough to defibrillate, above that the heart muscle clamps all the way which means that when the current is removed it is actually more likely that it can with help or will on its own restore a normal rhythm.

The internal resistance of the human body once you introduce probes through the comparatively insulating skin is around 100 ohms. A 9V battery across ~100 ohms makes a thoracic current of roughly 0.1 amp, right at the start of the maximally fatal range. The Darwin above was given because an idiot didn't believe this and stuck probes through his skin to "prove" that it wasn't so.

Personally I've experienced shocks from 12 V car batteries when screwing around with them on rainy nights with salt water on my hands. That's another good way of reducing skin resistance. I didn't take the hit across the torso, but it was every bit as painful as a 110V shock through dry skin -- more so, actually -- and caused my muscles to contract like lightning.

None of this is actually news -- it has been known as long as there has been electricity, because people have been killing themselves accidentally with electricity just that long. My scout leader 50 years ago worked for GE (as an inventor, actually -- one of the people who invented the photodiode controlled light). He taught me that long ago to ground one finger and then brush another finger of the same hand against any possible hot wire so that you find out with a jolt across your hand, not through your torso. Hand to foot, hand to hand, not so good. People used to kill themselves all the time touching hot electrical switches while standing in wet feet on bathroom floors before ground fault circuits were invented and mandated by code.

None of which has much to do with TFA, but it is good to know if you work at all with electricity. Physicists need to know it just to be able to teach it to their students so THEY don't kill themselves accidentally one day. It isn't the voltage that kills you, it's the current, and it doesn't take much current to do the job (or much voltage to create a fatal current).

2 days ago
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### SOTU: Community Colleges, Employers To Train Workers For High-Paying Coding Jobs

I'm not convinced it is that simple. Like it or not, the information economy is going global, and programmers in India are often just as good as programmers in the US, cost far, and it doesn't matter whether or not they live in the same hemisphere with the company they work for or not. So it isn't just H1B's. It is the fact that finding competent people who can support small US business computing and IT needs at a reasonable (for small business) cost is not trivial. Competence is rare, even with a global workforce to draw on, and that makes it expensive anywhere, but expensive in India is cheap in the US and will remain so until the cost of living and quality of life in the two countries are comparable.

Even the computation of "300,000 jobs lost" is a bit glib. Are there 300,000 out of work software engineers in the US who are competent, employable, reliable, etc? Maybe. But I doubt it. That's 0.1% of the US population and would constitute a rather large percentage of all unemployment. It also doesn't reflect the fact that many companies that get a start using offshore computation labor end up making money and stimulating MORE jobs, not fewer, with MORE money going into pockets to spend in the US. And sure, they help out the Indian or Chinese or Korean or Irish economies too! Which isn't a totally bad thing. It's not a zero sum game.

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3 days ago
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### Rare Astronomical Event Will See Triple Moon Shadows On Jupiter

Really? Don't say that so loud, you'll hurt its feelings. Besides, I thought it was a rare star type called a "black dwarf", sort of the theoretical limit of a brown dwarf with its teensy but measurable gravitational heating...

Well, maybe not so rare...;-)

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(And I'm just kidding, yeah, black dwarfs are dark white dwarfs and brown dwarfs may or may not have had to undergo fusion at some point yadda yadda, but the point is that Jupiter is on the spectrum that includes brown dwarfs emitting only from gravitational collapse and so in some sense is an extremely boring star too small to have ever ignited or just large enough to have barely and briefly ignited -- like all of the other visible or invisible brown dwarfs out there in the Universe. And Pluto is not a planet and shares its name with a Disney dog, and it's feeling bad about that, too.)

3 days ago
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### SOTU: Community Colleges, Employers To Train Workers For High-Paying Coding Jobs

Well, one could also understandably confuse "programmer" with building a content page with html. Writing in a markup language -- even in a raw markup language as opposed to using a GUI to build one as many/most "web developers" are prone to do nowadays -- isn't exactly programming. Programming sort of starts when one includes at least some kind of conditionals, with something other than a graphical chooser, and goes up from there.

That is, writing in raw php, java, or maybe even javascript probably counts. But is building a website with Joomla using a mouse plus filling in a bit of content programming? Even if you have to drop in a shopping cart? Not so much.

Of course, being an Old Guy (tm) I tend to think of "real programming" as involving compilers somewhere along the way, and view interpreted scripting languages and interactive languages, especially ones run primarily inside IDEs (e.g. matlab or octave, maybe R) as wussy programming-lite. I know, I know. Fighting words for many young folks these days.

(Besides, I'm kidding. I actually think one can write real, highly functional programs in these languages/environments, as long as you don't mind paying the performance penalty. In cases where the tradeoff between development time and run time favors it, it is even the right thing to do even for the best programmer in the world.)

5 days ago
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### SOTU: Community Colleges, Employers To Train Workers For High-Paying Coding Jobs

High paying coding jobs are also tough to get when India is metaphorically just outside of your internet door. In India the job really IS high paying. In the US, rates that can compete with Indian coders are starvation wages.

Even entrepreneurial coding is ever more likely to be shipped overseas, as it isn't even worth it to invest personal serious coder skills as sweat equity in a new company compared to just having a team in India build out ideas to spec (and maybe then tweaking them). Of the last three companies building software to support all or part of the business plan I've been involved with, one had core code worked out by a local real coder (me) that was eventually abandoned in favor of a mix of commercial and open source stuff that could also span the work to be done, one hired an India team for 2/3 of the programming (most of the external interface) and only used me and one other person for a nubbin of mostly database and algorithmic stuff, and the third farmed all of the programming out as the principles didn't even know how to code (and I didn't get involved enough to do something deep in the core of the product before it went away, bought out).

It would be lovely if it were TRUE, and one could make a living doing things like interface work or intermediate algorithmic stuff with a community college education in coding, as a code "plumber" as opposed to a code "architect", but the sad fact is that most people would starve at US code plumber wages, with a few exceptions in mid-sized established businesses where e.g. they maintain their own website and have a team of maybe 5-6 people, only two of whom know what they are doing. But those two aren't going to be CC grads, and the do as you are told code-plumbers won't even make as much as real plumbers make.

Still, it isn't a completely crazy idea. Code plumber wages still beat working as a shelf-stuffing wage-slave employee at Barnes and Noble, or as a line chef in a small restaurant, or as a barista, or as a checkout person in a grocery, or... And the jobs are likely to come with full benefits. And who knows? With enough coders trained at the plumber level, maybe they will self-organize into shops that can compete with India and still pay a living with benefits. A lot of the ability to do so is a matter of scale and backing by enough real programmers who (as noted above) learned to code by coding, coding some more, and then sitting down to really get to work coding (usually with mentoring and some purpose in mind).

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5 days ago
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### Entanglement Makes Quantum Particles Measurably Heavier, Says Quantum Theorist

Re:Particle physics is easy ... (109 comments)

:-)

BTW, nice recursively demonstrative 1337 handle...;-)

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### Text Editor Created In Minecraft

Re:the whole things an editor if you're brave enou (114 comments)

Everybody would at least be trying to be a net positive part of the solution instead of neutral to net negative. As I said elsewhere in the thread, the ideal is probably neither Charles Manson or Mother Teresa, it is probably more like the Boy Scouts -- do a good turn daily and try to be no worse than neutral otherwise. And don't be a butt. Very important that.

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### Text Editor Created In Minecraft

Re:the whole things an editor if you're brave enou (114 comments)

Amen. Line by line, actually. Especially your summary sentence. Although I'd take issue with "become" -- it has always been that way. It is arguably "un-becoming" fucked up, but a glacial pace compared to our capabilities and opposed by the MIC sociopaths and organized crime, who are not necessarily disparate groups.

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### Text Editor Created In Minecraft

Re:So let's work toward world peace. Here. Now. (114 comments)

Oh, don't worry. This is /. I'm a nerd/geek. I've spent far, far too many hours over the last two weeks playing the Android Icewind Dale remix. And I did my time with the e-cocaine known as minecraft, only quitting when I had built towers from the bottom of the world to its top and realized suddenly that I was bored to tears. Even now I can't get myself motivated to revisit it.

That's how I know that it is doing nothing but skipping sleep.

As for the vanity of the world and the pit of existential despair, hey, minecraft is a better way to cope with it than some I can think of. But I think not the best way.

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### Text Editor Created In Minecraft

Re:the whole things an editor if you're brave enou (114 comments)

And the Sudoku puzzle is good for your brain, and hence isn't all that bad for society to the extent that people with healthy logical brains are better than the alternative. Probably true of minecraft as well -- I certainly enjoyed it for a month or three, just as I enjoyed second life more briefly, World of Warcraft in its day, and am currently enjoying the rebirth of Baldur's Gate and Icewind Dale on my tablet. But at some point all of these things -- even Sudoku -- become a form of e-crack, a means of withdrawal from the world, a kind of meditation that replaces the struggle with a dirty scary largely unknowable world with something clean and relaxing.

In the end, it's a matter of ethical balance. If you are working long and hard enough to support yourself, far be it from me to criticize what you do with your elective time outside of that (and vice versa) as long as it isn't things like torturing puppies or crafting kiddy porn. Also, as many have pointed out, one individual probably can't fix all of the ills of the world, and so in a sense it is wasteful of your life to devote all of your elective energy in trying at the expense of all joy and diversion. Still, I think that in between spending all of one's life in a drug or mindcraft-induced haze of complete avoidance of the real world and becoming Mother Teresa there is an ethical optimum, probably quite broad, of doing no particular harm, being as responsible for supporting your own personal life and its self-assumed obligations (like children and pets) as circumstance and ability permits, and yeah, out of sheer self-interest if nothing else spending some of your elective energy on making the world a better place for everyone because that makes it a better, safer place for you yourself. It needn't even be false or religious altruism, in other words, even if your personal ethos is a single life to live, no god, no afterlife, most of us would prefer to live in a world that minimized the personal risk of being burned alive by religious zealots, being beaten or killed by thugs and bullies, starving to death because some accident robbed us of the ability to work for and feed ourselves -- and so in a very deep sense fulfilling a "social obligation" to help others is part of an optimized selfish ethic, a way of buying "insurance" through one's actions insuring others.

So how much Sudoku, or Minecraft, or WoW/BG/IWD or Diablo II Expansion is too much, compared to doing something more constructive with some part of that time? That's the choice of each individual, but I think that it is arguable that if you get to where you are building word processors out of Minecraft you m-i-i-g-h-t be a hair over the line...;-)

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### Text Editor Created In Minecraft

Re:So let's work toward world peace. Here. Now. (114 comments)

Thank you for so effectively demonstrating the existential ennui that paralyzes our entire civilization. Of course if you look carefully at your replies and actually think for a moment, the answers to each and every one are obvious and there are a rather large number of talented individuals who demonstrate this every day by their actions.

The tragedy is the many competent persons who would rather build giant virtual word processors or make armor to sell in WoW than to take up arms against the world's sea of trouble and, by opposing, end them. All that it takes for evil to prevail is for good persons to do nothing, and honestly, building Minecraft engines is as close to doing nothing as it is possible to do and still breathe.

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### Text Editor Created In Minecraft

Re:the whole things an editor if you're brave enou (114 comments)

The really important question is whether or not at the Planck scale one finds that we are all one really, really big version of Minecraft, being played by beings that look strangely like turtles. All the way down.

Another really important question is just how much of the world's creative potential is devoted to creating meta-inventions on top of rulesets intended for something else entirely rather than, say, bringing about world peace, curing cancer, feeding the hungry, or just plain moving out of your mom's basement. Not that I am entirely without sin in this regard myself, but it is a sad commentary on the state of the world (virtual or not) that we appear to live in when solving vast and pointless artificial problems in a virtual reality is more appealing than tackling the real and serious problems that surround us.

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### Entanglement Makes Quantum Particles Measurably Heavier, Says Quantum Theorist

Re:Particle physics is easy ... (109 comments)

So you're/they're saying mass-energy in any form doesn't have a "weight"? Einstein was even wronger? Rearrangements at constant mass-energy can have different weight? At the Planck scale you can say pretty much anything you like and not have much chance of your words being falsified, and while I'm not a falsificationist and agree that a consistent hypothesis can have meaning even if it can't be verified or falsified, this falls into the same scientific category that magnetic monopoles do, only tens of orders of magnitude worse. At least in the case of monopoles, I can understand all sorts of observationally true sequellae -- like charge quantization -- and they should be easy enough to observe subject only to their Bayesian prevalence and looking in the right places with the right tools. It wouldn't surprise me in the least if magnetic monopoles are eventually observed, adding a really, really important building block to our incomplete TOE. But in the meantime, I accord them only a weak degree of belief because I cannot rule out from a near infinity of hypotheses human have not thought of -- yet -- alternative explanations of the same sequellae that don't involve monopoles and because it becomes increasingly difficult to explain why we haven't observed at least one monopole yet unless there is some truly enormous energy barrier or symmetry breaking that we do not understand.

So I think that there is a very reasonable chance that monopoles exist and that physics completes in that general direction and that we'll eventually be able to take that "chance" (far too weak to call a "true fact") and turn it into a probably true fact through observation. I think that there is almost no chance that the hypothesis that entanglement alters weight at what amounts to the Planck scale ever gets any experimental validation either way. In its own way, it is like hypothesizing that dynamics at that scale is all due to neurotic invisible fairies. Which is, of course, very nearly a perfect metaphor for quantum field theory anyway.

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### Bill Gates Endorses Water From Human Waste

Hmm, is that true? Granted that many of the water molecules in my body have been inside many, many living animals and passed through one way or another, surely there are (a LOT of) water molecules being made and unmade every day through ionic dissociation. It might be more accurate to say that every atom of H and O in your body has been through a creature, but not necessarily bonded into water. Then there is "new water" produced when primordial hydrogen or methane are oxidized. Finally, I haven't done the statistical mechanics of it, but the ocean (or total volume of existing water) is pretty big, turnover is pretty slow, diffusion is even slower -- I could believe that a significant fraction of "old" water molecules (or the old constituents of younger molecules) in the world haven't been through an animal yet, and of those a few are making their first pass through me. But that's difficult for me to visualize well enough even to do a Fermi estimate of the probabilities, certainly not before my coffee.

The real problem is dissociation of water into H+ and OH-, followed by the formation of H_3O+ and OH-, followed (quite rapidly) by recombination into H_2O with (probably) different H, though. When that happens (and it happens all the time and rapidly in ordinary water) it is almost certain that the H+ that leaves a water molecule in one second is not the one that rebonds to it a moment later, so water molecules have a comparatively short half-life as a unitary identity, two specific H's and one specific O have been one specific water molecule for less than a day (models indicate order of 10 hours). So in that sense, almost none of the water in my body has been in the body of any other animal, as little of the water I drink was in another animal within ten hours of when I drink it, and even it it was, if it persists in my own body for a single day very little of it is still the same water at the molecular level that it was when I drank it.

In the end it is as useful as noting that we are all stardust, that is to say, the excreta of a dying star. That too is more poetically true than literally true, but it sounds way cooler than saying that we are all made of shit (starshit or otherwise:-).

And yes, we suffer from the same dissociation problem. I am not the same me (in terms of physical constituents) instant to instant as I'm a large, complex, organism and the worldlines of all of the matter that is arguably "me" for at least some brief time if "I" am defined either in terms of chemistry or some physical envelope are a whirling blur around my macroscopic worldline, constantly being spun into my envelope and then spinning out again, with every thread tied to the threads of many, many other living beings by the will of the Norns. Quite a romantic picture, even though sure, the bulk of the ins pass through my nostrils and mouth and the outs pass through many channels including anus and urethra.

So I think I'll stick with stardust woven by the Norns, not a pile of recycled shit.

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### Entanglement Makes Quantum Particles Measurably Heavier, Says Quantum Theorist

Re:Particle physics is easy ... (109 comments)

Sure, and consider that we do not yet have direct experimental confirmation that antiparticles fall down, instead of up. There's a reason for that, and it is 30 orders of magnitude.

The antiparticle experiment actually might be doable. And it is the thing that is a mere 37 orders of magnitude short of measuring the difference in weight of entangled quantum antiparticles.

So yes, you are right, one cannot be certain that there is no supremely clever way to measure Planck-length scale phenomena without using experimental probes with the energy of a freight train per particle and so on. What we can say with certainty is that at this particular moment, there is no justification for the use of any "measurable" variation of weight. No, there is no measurable variation of weight in particular, and probably no measureable variation of mass. The same laws of quantum mechanics that produce the supposed entanglement make it impossible to measure things at that resolution on a particle scale.

Now, if you could entangle whole planets, or even entire cats, matters might be different. I'd suggest building a scale and put Schrodinger's diabolical apparatus (plus a volunteer cat) onto it. Tell us what you measure regarding the difference in weight of the entangled vs non-entangled cat, bearing in mind that measuring weight is measuring so don't be surprised if the cat's state is collapsed to the classical one of live or dead but not both while you perform the measurement.

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### Entanglement Makes Quantum Particles Measurably Heavier, Says Quantum Theorist

Re: It's even easier (109 comments)

Excuse me? E^2 = p^2c^2 + m^2c^4 is the correct statement (or to be pickier, the four vector P = E/c - \vec{P} has conserved length equal to mc). Photons have zero mass, so for them E^2 = p^2c^2. You are thinking of E = \gamma m_0 c^2, which works fine for massive particles where m_0 \ne 0, not so well for light where \gamma = \infty because light travels at the speed of light.

BTW, does /. grok latex if one wraps it, that is, does $$E = \gamma m_0 c^2$$ work? Might as well try it...

No, apparently not. I suppose I'll have to look at actual documentation to see if there is any way to make it work.

Hey /. Dudes! You keep changing the site, improving it and so on! A 21st century website that cannot speak latex is so, not-even-20th century, and when that site is devoted to technology, it is vaguely insulting. Even wordpress can often understand $latex E = \gamma m_0 c^2$.

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### Entanglement Makes Quantum Particles Measurably Heavier, Says Quantum Theorist

Re:Particle physics is easy ... (109 comments)

You saved me from having to reply. I do not think that this "measurably heavier" means what you think it means (or rather, they think that it means), to quote Inigo Montoya. Let me 'splain. No, there is too much, let me sum up. In addition to the fact (as you have so ably pointed out) that we will never, in the future course of the universe, be able to measure the effect predicted, it is a theoretical prediction based on assumptions in a particular circumstance. If the assumptions turn out not to be correct, it might not be any more correct than the assumptions. And since we will never, ever, ever be able to verify the prediction of measurable changes in weight -- where I am pretty certain that they meant to say "mass" and not "weight", since the former is an intrinsic property of particle configurations and the latter describes the macroscopic Newtonian force between two objects where traditionally at least one of the two is rather large, say a planet or a star -- of two quantum entangled microscopic particles in a Universe where the other forces acting on them are tens of orders of magnitude larger under pretty much all circumstances, we cannot even use this to demonstrate the empirical consistency of the unproven theory.

I'll have it done by lunch time, as long as the lunch is held in the restaurant at the end of the Universe, which I will get to via an infinite improbability drive using the plausibility of measuring the difference in weight of quantum entangled states.

Oh, one last thing. Everything is in a quantum entangled state. Literally everything. All of the time. After all, there is no "outside" of everything to perform a classical measurement and force the system to disentangle. Something to think about, while contemplating the Nakajima-Zwanzig equation -- for the Universe:

http://en.wikipedia.org/wiki/N...

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### How We'll Program 1000 Cores - and Get Linus Ranting, Again

Re:Torvalds is half right (449 comments)

Note well that historically, MOST parallel computers have profited the MOST from parallelizing totally linear tasks. Not the tasks themselves -- embarrassingly parallel tasks, simply running many instances of completely independent code or many instances of code that is extremely coarse grained so that one can run almost all of the task as linear code with only infrequent communications with a "central" controller. Classic examples are plain old multitasking of the operating system with code that doesn't make heavy use of bottlenecked resources (the reason most users see some small benefit from e.g. quad core vs single core processors, as there is enough often enough work being done to keep 3-4 cores busy at least some of the time without much blocking, and this keeps the processor itself from thrashing by providing the illusion of parallelism through multitasking with time slices. It works best if the cores have independent caches and contexts and if there is sufficient task affinity. Also, classic "master-slave" parallel computing, where e.g. a Monte Carlo computation might spawn N slaves, each one with its own random number generator seed, and run N "independent" samplings of some process that are only infrequently aggregated back to the master. Again, the characteristic is lots of nearly independent serial computation with only short, infrequent, non-blocking, non-synchronous communications back to some collection point. Two programs that often were used to demonstrate the awesome advantages of scaling at the limits of Amdahl's law were parallel povray (rendering can be broken up into nearly independent subtasks in master-slave) and a parallel Mandlebrot set generator/displayer (where each point has to be tested independently, so whole subsets of the relevant parts of the complex plane could be distributed to different processors and independently computed, with the master collecting and displaying the results.

Sadly (well, not really:-) modern processors are so damn fast you can get to the accessible bottom of the Mandlebrot set with almost no perceptible delay from rubber banding even with a single core, so the latter isn't so dramatic, but the point remains -- quite a lot of work that can be done with multiple cores (arguably MOST of the work that can efficiently and easily be done with multiple cores) is trivial parallelism, not parallel programming. Instance 1 is the richest source of advantage for a parallel system, and tasks that will scale out to 1000 cores are almost certainly ONLY going to be trivially/embarrassingly parallel tasks because Amdahl's law and the complexity of unblocking communications between subtasks is a royal bitch at 1000 processors no matter how you architect things. SETI at home, maybe. Solving a system of partial differential equations on a volume with long range interactions not so much.

The fundamental problem with 2 and 3 is that they have to be hand coded. Really pretty much period. Sure, you can get away with getting some advantage from using e.g. a parallel linear algebra program as a link step in a program that can run on serial resources, but typically the gains you can get are limited and will not scale well, certainly not to anywhere near 1000 cores, even for case 2. To use 1000 cores for a tightly coupled parallel computation where every core talks to every other core per step of the computation -- well, that just isn't going to happen without an incredible (literally) boost in interprocessor communication speed, reduction in communication latency, elimination of resource blocking at both the hardware and kernel level. The problem at some point becomes NP complete (I suspect, of course pending the issue of whether P = NP etc) and simply working out ways for the communications to proceed in a self-avoiding pattern to eliminate collisions or delays due to asynchronicity is itself a "hard problem", forget the problem you're actually trying to solve.

So I'm largely with Linux on this one. Advantages to parallelism at the OPERATING SYSTEM level probably saturate in almost all contexts long before one can put 1000 cores to use. Even if you provision every core with its own L1, its own L2, its own L3, even if you have unprecedented mastery at the hardware level of locking in parallel pathways to main memory, you have some serious hardware limitations and economic tradeoffs to consider. Here is a nice little article outlining some of the tradeoffs between comparatively expensive L1 and less expensive L2:

http://www.extremetech.com/ext...

I can believe that 64 cores can still be manipulated in ways that are beneficial, in server environments where there are likely to be 64 semi-independent threads (that only rarely seek to access shared blocking resources) that can be kept on-chip and in both chip context and and cache. 128 cores I start to get to be very skeptical. By 1024 cores, there just isn't going to be MUCH benefit except for a tiny fraction of the work people might buy CPUs to do, and the effort of writing sufficiently efficient code to put all those cores to work is itself a daunting, expensive thing to consider.

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