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User: blueg3

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  1. Actual abstract on Researchers At Brown University Shattered a Quantum Wave Function · · Score: 5, Informative

    "An electron in liquid helium forces open a cavity referred as an electron bubble. These objects have been studied in many past experiments. It has been discovered that under certain conditions other negatively charged objects can be produced but the nature of these “exotic ions” is not understood. We have made a series of experiments to measure the mobility of these objects, and have detected at least 18 ions with different mobility. We also find strong evidence that in addition to these objects there are ions present which have a continuous distribution of mobility. We then describe experiments in which we attempt to produce exotic ions by optically exciting an electron bubble to a higher energy quantum state. To within the sensitivity of the experiment, we have not been able to detect any exotic ions produced as a result of this process. We discuss three possible explanations for the exotic ions, namely impurities, negative helium ions, and fission of the electron wave function. Each of these explanations has difficulties but as far as we can see, of the three, fission is the only plausible explanation of the results which have been obtained."

    Research group website
    Non-paywalled copy of paper

    TLDR: This research group studies exotic electron effects in superfluid helium. They see a particular effect that is not currently explained. There are a few possible explanations, and they argue that a particular one is probably true.

    Inaccurate "news" articles ensue.

    (The physics is subtle enough that, despite reading the abstract and bits of the paper, I would not venture to try to summarize it. You can smell a mile away, though, that this article is poor understanding mixed with hyperbole. The specific flavor is, "Quantum Mechanics is Philosophical Magic".)

  2. Re:Nonsense. Again. on Black Swan Author: Genetically Modified Organisms Risk Global Ruin · · Score: 1

    requires massive amounts of pesticides to live

    Since when is this true of any organism?

    because your dog Sniffles is actually the product of genesplicing of a dog and fish genes

    At the breeding level, no, your dog is the product of many generations of selective inbreeding, to the point that most purebred dogs have serious genetic defects and health problems. But your dog does undoubtedly have quite a bit of DNA from other species. Retroviruses are helpful like that.

  3. Re:'Regardless of... income and education level' ? on Soda Pop Damages Your Cells' Telomeres · · Score: 4, Informative

    They generally don't know that it's an organic process without controlling for those factors. You can't shove a microscope up someone's ass and just observe why a particular diet is having a particular effect.

    Remember how people always like to harp on how correlation is not causation? Well, it's said too often and too zealously, but it's still true. One of the most important lessons is that you need to control for confounding factors, or the effect you observe could simply be a correlation. It's very, very hard to control for the entire set of a human's behavior, though -- which is what you'd want to do in a classic, traditional experiment.

    There are a handful of confounding factors that are constantly problems -- they correlate with tons of things. Any good study about humans will control for them. Income and education level are two of them. So you will always see a paper controlling for these and, if they find an interesting effect, you will see a statement about how the effect is independent of income and education level -- because if that wasn't true, it's not a very valuable finding.

  4. Re: Objection One: on Password Security: Why the Horse Battery Staple Is Not Correct · · Score: 1

    I wasn't disagreeing with you. (Weird, for the Internet, I know.) I was just answering your semi-rhetorical question of "how would they think of random words"? The answer is that they can't.

    If you want some disagreement: while picking spots in a dictionary is random, it's not a uniform distribution and it's not as random as you might suspect. It's much safer to use a mechanical method that your brain has as little control over as possible to do the selection: dice, for example.

  5. Re:Objection One: on Password Security: Why the Horse Battery Staple Is Not Correct · · Score: 1

    Humans can't think of random words. There's not a sufficiently random process available. Humans can think of semi-random arbitrary words, which are totally different.

  6. Re:Fewer candidates to draw from... on FBI Says It Will Hire No One Who Lies About Illegal Downloading · · Score: 1

    "Seeding" is simply the mode BitTorrent is in when you no longer have any parts of the file that still need to be downloaded. Prior to that, even though you are not "seeding" yet, you are still transmitting the pieces that you *have* downloaded to any peers that ask for them.

    That's sort of the whole idea behind BitTorrent: peers trade pieces of partially-downloaded files with one another to reduce demand on seeders.

  7. Re:Fewer candidates to draw from... on FBI Says It Will Hire No One Who Lies About Illegal Downloading · · Score: 1

    Technically you could turn off all uploading, and hence not be distributing....

    True, though most BitTorrent clients don't support this.

  8. Re:Fermion that is its own antiparticle on Physicists Observe the Majorana Fermion, Which Is Its Own Antiparticle · · Score: 1

    Particles are interesting bundles of localized energy present in particular fields that happen to have a particular set of properties.

    Quasiparticles are interesting bundles of localized energy present in particular fields that happen to have properties similar to particles and also happen to be describable in terms of collective effects of what we call "particles".

    Particles simply aren't as "fundamental" as you seem to think they are.

  9. Re:Fermion that is its own antiparticle on Physicists Observe the Majorana Fermion, Which Is Its Own Antiparticle · · Score: 1

    Perhaps you think it's uninteresting because you mistakenly think that there's some deep, fundamental difference between a particle and a quasi-particle that makes one "real" and the other "not real".

  10. Re:Fermion that is its own antiparticle on Physicists Observe the Majorana Fermion, Which Is Its Own Antiparticle · · Score: 4, Informative

    That's hard to answer for a few reasons. I'm not a particle physicist, the subject is kind of complicated, and most people start off ill-informed (sorry!).

    Antiparticles are not particularly weird and particle-antiparticle interactions are, in particular, not some kind of physical witchcraft. I always have disliked that it's called annihilation. At the subatomic level, particle interactions are common and they generally involve the "creation" and "destruction" of particles. For example, maybe a neutron decays into a proton, an electron, and an electron antineutrino (by way of one of its down quarks changing into an up quark). Particle interactions are all sort of a shuffling of energy between the different flavors of bundles of energy we call particles. Lots of different physical quantities, like charge, are conserved, limiting what interactions can happen.

    In the interest of simplicity, a lot of what I'll say next is slightly wrong.

    Antiparticles aren't particularly weird. Particles all have a set of physical properties. It turns out that for each particle, there is another particle that is basically exactly the same, except all these physical properties are opposite. So an electron has charge -1 and an antielectron (positron) has charge +1. In fact, if you look at a legal particle interaction and replace all of the particles with their antiparticles, it's still a legal particle interaction.

    An implication of this is that if a particle and its antiparticle interact (not a particle and *any* antiparticle, but *its* antiparticle), the net total for any of their conserved quantities (like charge) is zero. That means the major legal interaction is that the two particles are destroy and produce photons. While photons are particles, we tend to think of them as just energy, so the particle-antiparticle interaction is an "annihilation": two particles go in, energy and zero particles come out.

    The "its antiparticle" bit is important. You don't see a lot of antielectrons because a free antielectron would easily encounter an electron and annihilate. But there are plenty of antineutrinos because they interact weakly with the rest of the world. An antineutrino interacting with, say, a proton does not cause annihilation. Even an antielectron interacting with, say, a proton doesn't do anything special.

    Oh, also, it turns out that, at least for the "normal matter" particles like electrons and protons, the universe seems to contain pretty much only the normal-matter particles and (relatively) no antiparticles. There doesn't seem to be any reason, in physics, for one to be preferred over the other. (It's just that in one region of space, you couldn't have a mixture and also have stable matter.) So that's weird.

    This is all a long-winded way of getting to the answer that particles that are their own antiparticles aren't particularly exciting. They all have the property that conserved quantities (at least, those that are negated in antiparticles) are zero. So they all naturally have annihilation interactions: when two collide, they can annihilate and form protons. But the annihilation interaction isn't particularly dramatic or weird, it just sounds interesting. The particles all probably also have interactions with all sorts of other types of particles, too, and it really comes down to what particle it happens to collide with first. Maybe a photon and an antineutrino interact with a proton and form a neutron.

    Most of the particles that are their own antiparticles are relatively neutral to normal matter (and consequently, also to normal antimatter). But they're all a very different kind of particle from normal matter. They're things like force-carriers (photons) and muons, and they interact with electrons and protons differently from how electrons and protons interact with each other.

    For some real fun, look up Feynman diagrams, a neat way of writing down different legal particle interactions. One axis is space (in one dimension) and one axis is time. Now, any 90-degree rotation of a legal interaction is still a legal interaction.

  11. Fermion that is its own antiparticle on Physicists Observe the Majorana Fermion, Which Is Its Own Antiparticle · · Score: 5, Informative

    The summary (and the article!) imply that it is rare and strange for a particle to be its own antiparticle. This is not the case. Plenty of boson and mesons are their own antiparticles: photons, gluons, pions, etc. This isn't a particularly weird situation.

    However, fermions are another story. Fermions and bosons are the two kinds of fundamental particles. They behave very differently. While there are bosons that are their own antiparticle, there are no known fermions that have this property. All the fermions we know of are Dirac-type. It's been long postulated that there could be Majorana-type fermions, which, among other things, are their own antiparticles.

    It's interesting, but not quite as crazy as implied.

  12. Re:Before the digital age ... on Obama Administration Argues For Backdoors In Personal Electronics · · Score: 2

    Before the digital age, they seized physical documents, which were usually trivial to access (with a warrant) and decipher.

  13. Re:Attention Slashdot Editors on iOS Trojan Targets Hong Kong Protestors · · Score: 1

    It doesn't just require a jailbreak. It also requires the user to install the software.

  14. Re:Idiot on David Cameron Says Brits Should Be Taught Imperial Measures · · Score: 1

    I think it also tends to be much faster, for the same reason. Add ingredient, zero, add ingredient, zero, etc. You can tear through measuring a complicated set of ingredients in no time.

    I tend to use grams unless the recipe actually specifies weight in US customary or if there is some particular motivation for using lb/oz. (Brewing supplies here, for example, are all sold by the pound or ounce, so it's useful to stick with those units.

  15. Re:Idiot on David Cameron Says Brits Should Be Taught Imperial Measures · · Score: 1

    Right. This is specifying the recipe by weight, though. It's just specifying it by relative weights, using a very convenient custom unit system.

  16. Re:Size of a cup on David Cameron Says Brits Should Be Taught Imperial Measures · · Score: 1

    Weren't "words with multiple meanings" like "mile" exactly what crashed that Mars lander?

    The Mars Climate Orbiter was never intended to land, but it did.

    And no. It had nothing to do with words with multiple meanings. Nobody in the US in engineering (or science, really) should be confused about what pound-seconds are. (This is despite the fact that both "pound" and "second" have multiple definitions.) What crashed the Mars Climate Orbiter is that the spec for a piece of software required that it produce results with one unit, and it instead produced results with a second unit. That's going to be a problem, regardless of whether the incorrect unit it produces is kN-s, dyn-s, lbf-s, cm-g/s, or kg-km/hr. (And if you think that scientists and engineers who use metric always use the SI base unit, you clearly don't do science or engineering.)

  17. Re:Size of a cup on David Cameron Says Brits Should Be Taught Imperial Measures · · Score: 1

    Now you're misstating the precision of the measurement and using units that aren't necessarily marked on the measuring devices. (Dry-measure cups are not often not graduated.)

    The ambiguity doesn't really exist. People are either being intentionally difficult or users of the metric system are too stupid to handle words with multiple meanings.

  18. Re:Idiot on David Cameron Says Brits Should Be Taught Imperial Measures · · Score: 1

    Note that they are actually measuring by weight, using a custom unit system.

  19. Re:Idiot on David Cameron Says Brits Should Be Taught Imperial Measures · · Score: 1

    Basically, no, the kitchen is exactly the place I want metric measurement

    You are confusing two issues: metric vs. US customary units, and measurement by volume vs. by mass.

    I assure you that both metric and US customary unit systems have units for volume and mass, so you can measure either way using either system. It's also the case that neither unit system specifies how one is to measure ingredients in the kitchen.

    It is European convention to measure many kitchen dry ingredients by weight. It is, unfortunately, US convention to measure many dry ingredients by volume. This is okay, even convenient, for some things where the real quantity doesn't particularly matter. (While cherry tomatoes will vary, you could probably use twice as much or half as much without any trouble.) For precision measurements, you need to use weight. This is what's used by professional cooks in the US already and is becoming increasingly common in cookbooks.

    Incidentally, if you buy your butter in sticks, it's easy to measure a cup of butter. Otherwise, it's convenient to post a list of standard densities for things like butter.

  20. Re:Idiot on David Cameron Says Brits Should Be Taught Imperial Measures · · Score: 1

    While cup is a standard and precise unit of measurement, there are lots of materials in cooking you should not measure by volume (whether that volume is in cups or mL).

  21. Re:Size of a cup on David Cameron Says Brits Should Be Taught Imperial Measures · · Score: 1

    I can see when my coffee cup is full and I could fill it with water to get 1 cup.

    This is equivocation. The word "cup" denotes both a standardized unit of measure (volume) in the US customary units and also an object for holding and consuming liquids. They have only a historical relationship to one another.

    Whenever the word "cup" is used in the context of measurement, it means the unit of measure.

  22. Re:Idiot on David Cameron Says Brits Should Be Taught Imperial Measures · · Score: 1

    In the US, "cup" is a capacity measurement, just like fluid ounces. You don't measure with any sort of arbitrary cup, you do it with a calibrated measuring cup (which is generally marked in fl oz and mL as well). You could use any graduated container, though. I like beakers.

    Same goes for teaspoons and tablespoons, which are volume measurements that are only historically linked to any of the spoons one might eat with.

    The one European cooking convention that's actually useful here is using weight for dry measure instead of volume. Most dry-measure materials pack well (like flour) or have nonstandardized grain sizes (like salt), so you cannot make a precise measurement by volume. We're converting, though -- most good cookbooks will list both. (Professional cookbooks will only list weight.) People on TV will generally tell you to stop measuring by volume. Etc.

  23. Re:OMFG, stupid on Microsoft Announces Windows 10 · · Score: 2

    Chemical potential energy.

  24. Re:Fucked both ways on Scientists Seen As Competent But Not Trusted By Americans · · Score: 1

    If they don't believe the science, then by the very definition they are not scientifically literate.

    That's a tautology, then. It's strictly true that, if you define "the scientifically literate world" as "places that [believe] climate change science", then all of the scientifically literate world believes* climate change science.

    It seems you are confusing "deciding which steps to take to counter the issue" and "deny the issue exists while keeping on making it worse".

    I'm not looking at all at how any particular state is taking steps (or not) to address climate change. That's highly variable and also is very sensitive to what you count as "taking steps". But I'm not concerned with that.

    I was looking only at to what extent the population of a nation agrees with some of the most basic scientific facts about climate change.

    By that definition, large chunks of the developed world, the US included, sits around 50%. There's another big cluster around 60-65%.

  25. Re:Fucked both ways on Scientists Seen As Competent But Not Trusted By Americans · · Score: 0

    Which I guess doesn't include countries like the Netherlands or the UK.