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


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. ×

Comment Please stop and think (Score 5, Insightful) 359

You live in a country with a wildly corrupt government that repeatedly lies to you and regularly unburdens you of your basic human rights. Then one day, officials from this government force you and everyone you know at gunpoint to submit to a series of "tests." You notice that, all of a sudden, many of the most social and/or eldest (therefore vocal, therefore most likely to be community leaders/government dissenters) among you go missing and later mysteriously die. For good measure, a number of kids randomly disappear and die as well. The ones that survive tell horrible stories about the dismal conditions in which they were held, where they were injected with any number of things and only a few days later, became sick . The government (the same government that lies to you and considers you subhuman) tells you that the cultural practices that have been with your group for a thousand years are all of a sudden, just now, for reasons they don't have time to explain, causing you to get sick and die, and it just happens to selectively be wiping out the kids and the community leaders.

If it were the US doing this, I conjecture that at the very least, this comment thread would have a radically different tone. Less "these guys are idiots," and more "these guys are heroes." What we're witnessing in Liberia is a tragic consequence of a corrupt power structure attempting, maybe for the first time, to legitimately help people that it has previously subjugated. The whole thing smacks of people acting in their and their community's best interests based on many many previous data points telling them government=bad, therefore avoid government. Unfortunately, it takes time to build a relationship of trust between a government and its citizens, and in the face of the calamity that Liberia is confronting, neither the government nor its citizens have any time to spare.

Comment Re:Graphene is awesome! (Score 1) 34

Isolation of nanotubes (1991, Iijima) preceded isolation of graphene (2004, Geim & Novoselov) by over a decade. It's likely that the first commercial applications of graphene will be exfoliated graphite used as a component in polymer composites. It's cheap and the materials prep is straightforward and scalable. Electronics quality graphene (CVD-grown or SiC-derived epitaxial) is still fairly expensive, about $10/sqcm on Cu, though the price is plummeting as the bigger players (Samsung, IBM) get involved.

Comment Re:Let's be fair (Score 2) 561

Disclaimer: I am not an expert in mental/intellectual disorders.

From Wikipedia (and cited to boot!):

The last table in that section states that adults with an IQ of 60 "...can harvest vegetables, repair furniture."

In early childhood, mild intellectual disability (IQ 50–69) may not be obvious, and may not be identified until children begin school.[7] Even when poor academic performance is recognized, it may take expert assessment to distinguish mild intellectual disability from learning disability or emotional/behavioral disorders. People with mild intellectual disability are capable of learning reading and mathematics skills to approximately the level of a typical child aged nine to twelve.[7] They can learn self-care and practical skills, such as cooking or using the local mass transit system.[7] As individuals with intellectual disability reach adulthood, many learn to live independently and maintain gainful employment.

So not quite a carrot.

Comment Re:Wormholes + a flat universe (Score 1) 358

Please see my response to slashmydots.

Empty space is globally flat, but because gravity is a force with unlimited range no universe with any mass in it is globally flat.

The Friedmann equations assume that the universe is homogeneous, meaning that it has a uniform density. This is a pretty good approximation at length scales on the order of the visible universe. Space containing mass can be flat, as long as the mass is uniformly distributed throughout the universe and its density equals the critical density parameter, which, according to our best observations, seems to be true within experimental error.

At small enough scale every spacetime is locally flat, although that scale may be very small near a black hole. Only at the location of the singularity is it impossible to find a locally flat reference frame.

You're absolutely right. I clarified this in my response to slashmydots. Sorry about the confusion.

Comment Re:Wormholes + a flat universe (Score 1) 358

Ok, I wasn't clear. That's my fault. There are several different length scales at work here. General relativity operates on spaces that are locally Euclidean (technically speaking, Lorentzian) meaning that at each point in the space, there exists a neighborhood in which distance can be described by a Euclidean (technically Minkowski) metric. But this neighborhood is arbitrarily small (this is part of the reason that GR and QM don't get along). We'll call this length scale 1. On a larger scale, say the scale of galaxies, space bends in a way that is described by the stress-energy tensor in the Einstein field equations. We'll call this length scale 2. On an even larger scale, that of the entire universe, as far as we can observe, the density of the universe is within a hair's breadth of the critical density of the universe. This means that the overall curvature of the hypothetical universe, if the density were homogeneous, is almost zero. We'll call this length scale 3.

At length scale 1, the space is Euclidean by definition, and therefore "flat." This is always true in GR independent of everything else.

At length scale 2, the space is curved in a manner which is determined by the matter/energy in that space. This was the length scale that I was referring to when I used "locally" in my first post.

At length scale 3, because the overall curvature is very close to zero, space appears flat to within experimental error. This was the length scale that I meant when I said "globally" in my first post.

I apologize for my lack of clarity before. I agree that "bowling ball on trampoline" is an inadequate description of the theory. But of course, I never said anything about that in my first post, or about space being 2 dimensional.

Comment Re:Wormholes + a flat universe (Score 5, Interesting) 358

Space appears flat on a global scale, but locally, it is highly curved around massive objects, especially around objects like black holes. Nothing we've observed so far strictly prohibits our universe having some sort of locally nontrivial topology like a wormhole. Keep in mind, also, that our observable universe is what appears globally flat. If cosmic inflation is right (and it's looking like it probably is), the actual extent of the universe could easily be 20-30 orders of magnitude larger than what we see, in which case, the universe could be highly curved on those scales and still appear quite flat to the best ability of our observations.

Comment Re:Even higher! (Score 2) 1040

I take it you assume this person has no kids. It might surprise you to learn that if you're single and childless and making minimum wage ($7.25/hr at 2000 hrs/year=$14500 yearly income), you aren't part of Romney's 47%. Yep, you pay taxes to the fed, and presumably to the state as well. Here's a story about a woman making $12000/year and paying about $1300 in fed/state/ss/medicare. And that was before the payroll tax break expiration.

So how do you get out of paying taxes if you're making minimum wage? Well, it helps to have kids/be older/have a mortgage. But of course, if that's the case, then the balance sheet you've provided above is wildly obfuscatory, with childcare/medical expenses taking up the bulk of whatever's left after you pay your mortgage.

That's not to mention the fact that you're also assuming that this minimum wage job is a full-time gig. Usually they're part time, and the people holding them work two or more of them, meaning they're spending a decent chunk of money commuting. All this adds up to the most important fact: no savings. The reason that's so damn important is that one little slip-up (car runs over a nail, you slip a disc in your spine, etc.) and all of a sudden, you're running around to high-interest predatory creditors, which isn't exactly a path to financial freedom. That, and since minimum wage jobs are so replaceable, if any emergency happens, you're likely to be unceremoniously fired.

I could go on about how being poor isn't all sunshine and rainbows, but frankly, I think it's kind of ridiculous that I should have to. If it's really as cozy as some people say it is, they certainly have the option of trying it on for size. Hell, it's much easier to become poor than it is to become rich. So why isn't everyone doing it? Because secretly, waaaaay deep down in their heart of hearts, they know it's a shit deal. I think that speaks volumes enough.

Comment Re:"Science" == "Argumentum ab auctoritate" ?!?!?! (Score 1) 247

IANAL, but as I recall, in the practice of law (at least in the US), you don't add anything new. Unless you're a Supreme Court Justice. A lawyer's job is to piece together relevant laws and cases for precedent to provide a legal framework for whatever argument they're presenting.

Slashdot Top Deals

Don't tell me how hard you work. Tell me how much you get done. -- James J. Ling