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Medicine

Submission + - Landmark Health Insurance Bill Passes House 1

theodp writes: A hastily-crafted amendment imposing tough new restrictions on abortion coverage in insurance policies helped pave the way for the House to approve the Democrats' bill to overhaul the nation's health insurance system. "It provides coverage for 96 percent of Americans," said Rep. John Dingell. Rep. Candice Miller disagreed, calling the legislation "a jobs-killing, tax-hiking, deficit-exploding" bill. The 1,990-page, $1.2 trillion legislation passed by a vote of 240-194 and moves on for Senate debate, which is expected to begin in several days.

Comment Re:how does a magnetic field line just stop somewh (Score 5, Informative) 256

(Disclosure: I'm a physicist)

You could just as well ask: "how can an electric field line just stop somewhere?", and thereby conclude that there can be no such thing as an "electric monopole" (a positively- or negatively-charged particle). As long as the universe has no net electric or magnetic charge, all lines will terminate somewhere. If the universe did have a net charge the point is subtle, but that's irrelevant: the paper talks above pairs of opposite-pole monopoles created together, like a particle and its antiparticle. So this argument doesn't hold water.

Monopoles aren't impossible in principle (it would just be an extra term in Maxwell's equations) and are predicted in some theories, but fundamental-particle monopoles have never been observed. The summaries of this paper are confusing a lot of people: the authors are describing a crystal system with excitations that look like monopoles. They are NOT describing discovery of a new fundamental particle, but rather a new kind of solid-state phenomenon.

Comment Re:Another Job well Done (Score 1) 121

It's worth noting that Planck doesn't actually use a lot of liquid helium to cool itself down. It's cryogenic system is based upon "cryogen-free" mechanical refrigerators - the satellite launches warm, then cools itself down electrically and by radiating to space. The satellite lifetime isn't limited by running out of liquid helium.

Herschel, in contrast, does have a giant liquid helium tank. It launches full of helium, and eventually warms up when the tank runs out.

Comment E- and B-modes (Score 4, Informative) 50

The "E-modes" and "B-modes" referred to in the article aren't quite the same as electric and magnetic fields. Here's the basic story.

Suppose you try to map the polarization of the microwave background across the sky. Each direction on the sky has some polarization magnitude and direction, which we can represent by a little headless arrows on the sky (headless because flipping the polarization 180 degrees doesn't change it). A map of the CMB polarization thus looks like a bunch of little line segments of varying sizes and orientations all across the sky.

Now imagine looking at the pattern of polarization directions near some point on the sky. This arrangement of lines can be "curl-free" if the lines are oriented radially or circumferentially around the central point; this is called an "E-mode" pattern. The polarization pattern might instead have a curl component, which is called a "B-mode" pattern. another way of looking at it: an E-mode pattern looks locally the same when mirror-reversed, while a B-mode pattern does not. Any field on the sky can be written as the sum of an E-mode pattern and a B-mode pattern.

This technicality is important because of how polarization is generated in the microwave background. It turns out that all kinds of relatively mundane processes can generate E-modes - they're still very interesting and informative, but we know they're there (and have even detected them). B-mode patterns are much more unusual - it turns out that normal CMB physics cannot generate large-scale B-modes. Inflation, however, generates a background of gravity waves in the early universe that produce a B-mode contribution to the CMB. This is incredibly tiny and difficult to detect, but it's a smoking gun for inflation.

Comment This is not the only such experiment (Score 3, Informative) 50

It's worth noting that more than one such telescope hopes to probe CMB polarization on a similar timescale. Caltech and JPL are leading the BICEP2 and SPIDER collaborations (also with NIST), which will also be deploying in a few months (the former at the South Pole, the latter on a high-flying balloon) to probe E-mode and B-mode CMB polarization. The Princeton experiment mentioned in this article isn't that different - it just apparently has better press!

Comment Re:Its NOT E=mc^2 (Score 3, Informative) 268

That's true: E=mc^2 is valid for moving particles if m is interpreted as the relativistic mass.

The grumbling comes about because physicists themselves almost never talk about relativistic mass in this sense anymore. Nowadays we usually say that a particle has an invariant mass m (its rest mass) which determines the relationship between its energy and momentum; E^2 = (mc^2)^2 + (pc)^2. That way a particle's mass has a single, well-defined value regardless of how fast it's moving. What you might call the "relativistic mass" I just call E/(c^2).

The two formalisms are completely equivalent, of course, but modern notation has swung toward defining "mass" as the rest mass only.

Comment Why must "fair" mean "equally positive"? (Score 2, Insightful) 1601

I'm generally bothered when folks trot out statistics claiming that the news media ran more negative articles/clips on one side of an argument than the other, and thus is hopelessly biased. What law of nature says that "fair" coverage has to have a balance between positive and negative for the two sides? If one side strays farther from reality on verifiable, important things, the news media should call them on that. The media shouldn't pick a side a priori, but it also has a responsibility to speak up when the facts are clear (which, admittedly, they aren't always).

That said, I'm not going to argue that there is no bias in the media, nor that the recent election cycle was completely fair. If nothing else, Obama had a huge structural advantage in news coverage because he was vastly "newer" in numerous different ways. I'm sure the personal views of the news staff play some role as well. This study of the Washington Post is unusually comprehensive and interesting.

The above should be taken as a more general rant about this kind of tit-for-tat comparison, whether trotted out by Fox News to attack the "liberal media" or in "balanced" science pieces where a crackpot gets as much airtime as legitimate science. I just don't find this general metric for judging bias particularly compelling.

Earth

Carbon-Neutral Ziggurat Could House 1.1 Million In Dubai 393

Engadget is reporting that a new pyramid-shaped city of the future, dubbed a "Ziggurat," is being touted by Dubai-based environmental design company, Timelinks. Claiming that their design allows for an almost self-sufficient energy footprint and, obviously, economy of space, the real trick would be getting 1.1 million people to live in such close proximity. "Martijn Kramer, managing director of The International Institute for the Urban Environment told WAN: 'As a general reaction the Ziggurat Project is viable from a technical point of view. However reflecting from a more sustainable holistic approach we do wonder if the food supply and waste system are taken care for, as the concept seems rather based upon carbon neutrality and energy saving.' Kramer's initial reaction to 'Ziggurat' also raises a very important issue: are people willing to live in a mega building of 2.3 sq km? Will the thought of living in a machine comfort people?"

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