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Submission + - Why P-values cannot tell you if a hypothesis is correct (nature.com)

Submitted by ananyo
ananyo writes: P values, the 'gold standard' of statistical validity, are not as reliable as many scientists assume. Critically, they cannot tell you the odds that a hypothesis is correct. A feature in Nature looks at why, if a result looks too good to be true, it probably is, despite an impressive-seeming P value.

Submission + - Graphene conducts electricity ten times better than expected (nature.com) 1

Submitted by ananyo
ananyo writes: Physicists have produced nanoribbons of graphene — the single-atom-thick carbon — that conduct electrons better than theory predicted even for the most idealized form of the material. The finding could help graphene realize its promise in high-end electronics, where researchers have long hoped it could outperform traditional materials such as silicon.
In graphene, electrons can move faster than in any other material at room temperature. But techniques that cut sheets of graphene into the narrow ribbons needed to form wires of a nano-scale circuit leave ragged edges, which disrupt the electron flow. Now a team led by physicist Walt de Heer at the Georgia Institute of Technology in Atlanta has made ribbons that conduct electric charges for more than 10 micrometres without meeting resistance — 1,000 times farther than in typical graphene nanoribbons. The ribbons made by de Heer's team in fact conduct electrons ten times better than standard theories of electron transport they should, say the authors.

Submission + - India to build world's largest solar plant (nature.com)

Submitted by ananyo
ananyo writes: India has pledged to build the world’s most powerful solar plant. With a nominal capacity of 4,000 megawatts, comparable to that of four full-size nuclear reactors, the ‘ultra mega' project will be more than ten times larger than any other solar project built so far, and it will spread over 77 square kilometres of land — greater than the island of Manhattan.
Six state-owned companies have formed a joint venture to execute the project, which they say can be completed in seven years at a projected cost of US$4.4 billion. The proposed location is near Sambhar Salt Lake in the northern state of Rajasthan.

Submission + - Scientists reading fewer papers for first time in 35 years (nature.com)

Submitted by ananyo
ananyo writes: A 35-year trend of researchers reading ever more scholarly papers seems to have halted. In 2012, US scientists and social scientists estimated that they read, on average, 22 scholarly articles per month (or 264 per year), fewer than the 27 that they reported in an identical survey last conducted in 2005. It is the first time since the reading-habit questionnaire began in 1977 that manuscript consumption has dropped.

Submission + - Elsevier opens its papers to text-mining (nature.com)

Submitted by ananyo
ananyo writes: Publishing giant Elsevier says that it has now made it easy for scientists to extract facts and data computationally from its more than 11 million online research papers. Other publishers are likely to follow suit this year, lowering barriers to the computer-based research technique. But some scientists object that even as publishers roll out improved technical infrastructure and allow greater access, they are exerting tight legal controls over the way text-mining is done.
Under the arrangements, announced on 26 January at the American Library Association conference in Las Vegas, Nevada, researchers at academic institutions can use Elsevier’s online interface (API) to batch-download documents in computer-readable XML format. Elsevier has chosen to provisionally limit researchers to 10,000 articles per week. These can be freely mined — so long as the researchers, or their institutions, sign a legal agreement. The deal includes conditions: for instance, that researchers may publish the products of their text-mining work only under a licence that restricts use to non-commercial purposes, can include only snippets (of up to 200 characters) of the original text, and must include links to original content.

Submission + - Acid bath offers easy path to stem cells (nature.com)

Submitted by ananyo
ananyo writes: In 2006, Japanese researchers reported a technique for creating cells that have the embryonic ability to turn into almost any cell type in the mammalian body — the now-famous induced pluripotent stem (iPS) cells. In papers published this week in Nature, another Japanese team says that it has come up with a surprisingly simple method — exposure to stress, including a low pH — that can make cells that are even more malleable than iPS cells, and do it faster and more efficiently.
The work so far has focused on mouse white blood cells but the group are now trying to make the method work with cells adult humans. If they're succesful, that would dramatically speed up the process of creating stem cells for potential clinical applications.

Submission + - Stephen Hawking claims "there are no black holes" (nature.com)

Submitted by ananyo
ananyo writes: Stephen Hawking has proposed a new solution to the black-hole firewall paradox, which has been vexing physicists for almost two years, after its discovery by theoretical physicists Joe Polchinski at the Kavli Institute for Theoretical Physics in Santa Barbara, California, and colleagues. The paradox troubles physicists because if the firewall scenario is correct, Einstein’s general theory of relativity is flouted. But the classical theory black hole cannot be reconciled to the quantum mechanical prediction that energy and information can escape from a black hole.
Now Hawking has proposed a tantalizingly simple solution to the paradox which allows both quantum mechanics and general relativity to remain intact--black holes simply do not have an event horizon to catch fire. The key to his claim is that quantum effects around the black hole cause spacetime to fluctuate too wildly for a sharp boundary surface to exist. As Hawking writes in his paper, "The absence of event horizons mean that there are no black holes — in the sense of regimes from which light can't escape to infinity."

Submission + - Why 'irrational' choices can be rational (nature.com)

Submitted by ananyo
ananyo writes: Organisms, including humans, are often assumed to be hard-wired by evolution to try to make optimal decisions, to the best of their knowledge. Ranking choices consistently — for example, in selecting food sources — would seem to be one aspect of such rationality. If A is preferred over B, and B over C, then surely A should be selected when the options are just A and C? This seemingly logical ordering of preferences is called transitivity.
Furthermore, if A is preferred when both B and C are available, then A should ‘rationally’ remain the first choice when only A and B are at hand — a principle called the independence of irrelevant alternatives (IIA).
But sometimes animals do not display such logic. For example, honeybees (Apis mellifera) and gray jays (Perisoreus canadensis) have been seen to violate IIA, and so have hummingbirds (Selasphorus rufus).
Researchers have now used a theoretical model to show that, in fact, violations of transitivity can sometimes be the best choice for the given situation, and therefore rational. The key is that the various choices might appear or disappear in the future. Then the decision becomes more complicated than a simple, fixed ranking of preferences. So while these choices look irrational, they aren’t necessarily.

Submission + - Physicists explain 'gravity-defying' chain trick (nature.com)

Submitted by ananyo
ananyo writes: Leaping up out of a jar in an arc before falling to the floor, the fountain-like motion of a chain of beads has puzzled millions around the world with its apparently gravity-defying behaviour. Now physicists think they have an explanation.
British science presenter Steve Mould, who made the experiment famous, explained the phenomenon as simply one of inertia: the falling chain has downward momentum, causing an upward momentum in beads leaving the pot. This, in turn, makes them leap before gravity can slowly reverse their momentum.
Mould’s explanation was clever, but wrong, says physicist John Biggins of the University of Cambridge, UK. The only way to account for the rise is for the chain to receive a 'kick' from the pot from which it is being pulled. This challenges not only the explanation given by Mould, but the conventional mathematics of chains, Biggins says.

Submission + - Ampere could be redefined after experiments track single electrons crossing chip (nature.com)

Submitted by ananyo
ananyo writes: Physicists have tracked electrons crossing a semiconductor chip one at a time — an experiment that should at last enable a rational definition of the ampere, the unit of electrical current.
At present, an ampere is defined as the amount of charge flowing per second through two infinitely long wires one metre apart, such that the wires attract each other with a force of 2×107 newtons per metre of length. That definition, adopted in 1948 and based on a thought experiment that can at best be approximated in the laboratory, is clumsy — almost as much of an embarrassment as the definition of the kilogram, which relies on the fluctuating mass of a 125-year-old platinum-and-iridium cylinder stored at the International Bureau of Weights and Measures in Paris.
The new approach, described in a paper posted onto the arXiv server on 19 December, would redefine the amp on the basis of e, a physical constant representing the charge of an electron.

Submission + - First recorded observation of freshwater fish preying on birds in flight (nature.com)

Submitted by ananyo
ananyo writes: The waters of the African lake seem calm and peaceful. A few migrant swallows flit near the surface. Suddenly, leaping from the water, a fish grabs one of the famously speedy birds straight out of the air.
“The whole action of jumping and catching the swallow in flight happens so incredibly quickly that after we first saw it, it took all of us a while to really fully comprehend what we had just seen,” says Nico Smit, director of the Unit for Environmental Sciences and Management at North-West University in Potchefstroom, South Africa.
After the images did sink in, he adds, “the first reaction was one of pure joy, because we realized that we were spectators to something really incredible and unique”.
  Rumours of such behaviour by the African tigerfish (Hydrocynus vittatus), which has been reported as reaching one metre in length, have circulated since the 1940s. But this is the first confirmed record of a freshwater fish preying on birds in flight, the team reports in the Journal of Fish Biology (PDF).

Submission + - Swarms of small satellites set to deliver close to real-time imagery of Earth (nature.com) 1

Submitted by ananyo
ananyo writes: A swarm of small satellites set to deliver close to real-time imagery of swathes of the planet is launching today. San Francisco-based Planet Labs, founded in 2010 by three former NASA scientists, is scheduled to launch 28 of its ‘Doves’ on 9 January. Each toaster-sized device weighs about 5 kilograms and can take images at a resolution of 3–5 metres.
Meanwhile Skybox Imaging plans to launch a swarm of 24 satellites, each weighing about 100 kilograms, which will take images of 1 metre resolution or better. Skybox launched its first satellite on 21 November (and captured the first HD video of the world from space) and plans to launch another this year, followed by the remainder between 2015 and 2017. In a first — at least for civilian satellites — Skybox’s devices will also stream short segments of near-live high-resolution video footage of the planet. So, too, will UrtheCast, a start-up based in Vancouver, Canada, whose cameras will hitch a ride on the International Space Station.
Because the swarms are still to be launched, scientists have yet to fully assess the quality of the imagery. But the satellites’ spatial resolutions of 1–5 metres are much higher than those of most scientific satellites. Landsat, NASA’s Earth-observation workhorse, for example, has a resolution of 15–100 metres depending on the spectral frequency, with 30 metres in the visible-light range.

Comment Re:Meaningless values are meaningless. (Score 1) 134

by ananyo (#45898691) Attached to: China Tops Europe In R&D Intensity

Proportion of GDP spent on research is not a 'meaningless' number. The EU spent a great deal of time trying to (unsuccessfully) urging its member states to push their total spending up to 3%. They've since realized that no single metric can adequately measure a nation's capacity to innovate in science - but this measure is still part of a basket of metrics that it's perfectly reasonable to use to examine a country's commitment to science.
To be clear - there's little evidence that spending a lot of money science will get you a Google or a Genentech, but on the other hand, a fair bit of evidence that spending nothing will make it extremely unlikely. ie science spending is necessary but not sufficient.

Submission + - China tops Europe in R&D intensity (nature.com)

Submitted by ananyo
ananyo writes: By pouring cash into science and technology faster than its economy has expanded, China has for the first time overtaken Europe on a key measure of innovation: the share of its economy devoted to research and development.
In 2012, China invested 1.98% of its gross domestic product (GDP) into R&D — just edging out the 28 member states of the European Union, which together managed 1.96%, according to the latest estimates of research intensity, to be released this month by the OECD.
The figures show that China’s research intensity has tripled since 1998, whereas Europe’s has barely increased (see graph). The numbers are dominated by business spending, reflecting China’s push in the manufacturing and information- and communication-technology industries.

Submission + - Bizarre star could host a neutron star in its core (nature.com) 1

Submitted by ananyo
ananyo writes: Astronomers say that they have discovered the first example of a long-sought cosmic oddity: a bloated, dying star with a surprise in its core — an ultradense neutron star.
Such entities, known as Thorne-Zytkow objects, are theoretically possible but would alter scientists' understanding of how stars can be powered. Since Thorne-Zytkow objects were first proposed in 19751, researchers have occasionally offered up candidates, but none have been confirmed.

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