Yet another Tab Dump

August 9, 2011

Invasion of the Viking women unearthed – Science Fair – USATODAY.com

So, the study looked at 14 Viking burials from the era, definable by the Norse grave goods found with them and isotopes found in their bones that reveal their birthplace. The bones were sorted for telltale osteological signs of which gender they belonged to, rather than assuming that burial with a sword or knife denoted a male burial.

Overall, McLeod reports that six of the 14 burials were of women, seven were men, and one was indeterminable. Warlike grave goods may have misled earlier researchers about the gender of Viking invaders, the study suggests. At a mass burial site called Repton Woods, “(d)espite the remains of three swords being recovered from the site, all three burials that could be sexed osteologically were thought to be female, including one with a sword and shield,” says the study.

“These results, six female Norse migrants and seven male, should caution against assuming that the great majority of Norse migrants were male, despite the other forms of evidence suggesting the contrary. This result of almost a fifty-fifty ratio of Norse female migrants to Norse males is particularly significant when some of the problems with osteological sexing of skeletons are taken into account,”

Sun-free photovoltaics – MIT News Office

The solution, Celanovic says, is to design a thermal emitter that radiates only the wavelengths that the PV diode can absorb and convert into electricity, while suppressing other wavelengths. “But how do we find a material that has this magical property of emitting only at the wavelengths that we want?” asks Marin Soljačić, professor of physics and ISN researcher. The answer: Make a photonic crystal by taking a sample of material and create some nanoscale features on its surface — say, a regularly repeating pattern of holes or ridges — so light propagates through the sample in a dramatically different way.

“By choosing how we design the nanostructure, we can create materials that have novel optical properties,” Soljačić says. “This gives us the ability to control and manipulate the behavior of light.”

The team — which also includes Peter Bermel, research scientist in the Research Laboratory for Electronics (RLE); Peter Fisher, professor of physics; and Michael Ghebrebrhan, a postdoc in RLE — used a slab of tungsten, engineering billions of tiny pits on its surface. When the slab heats up, it generates bright light with an altered emission spectrum because each pit acts as a resonator, capable of giving off radiation at only certain wavelengths.

Silver pen has the write stuff for flexible electronics

While it looks like a typical silver-colored rollerball pen, this pen’s ink is a solution of real silver. After writing, the liquid in the ink dries to leave conductive silver pathways — in essence, paper-mounted wires. The ink maintains its conductivity through multiple bends and folds of the paper, enabling devices with great flexibility and conformability.

Metallic inks have been used in approaches using inkjet printers to fabricate electronic devices, but the pen offers freedom and flexibility to apply ink directly to paper or other rough surfaces instantly, at low cost and without programming

Breaking News from BBC: Fashion Industry Does Not Exist

June 17, 2011

BBC News – Flashy sports cars are male ‘short-term mating signal’

Although men used spending on luxury items as a short-term mating signal, women did not spend to attract men.

What they’re talking about, apparently, is that women don’t [tell researchers that they] buy big flashy luxury items to attract men for hookups and flings. Because makeup, designer clothes, personal trainers and plastic surgery are, y’know, free.

This pretty much encapsulates the traditional post-1980 rules on feminine versus masculine behavior: women have to make it all seem effortless. It also contradicts previous research results.

Getting the apodizing phase plate out of my tabs

May 12, 2011

Get ready to see lots more exoplanet images soon | Bad Astronomy | Discover Magazine

What the new technique does is steal a bit of light from the core and use it to suppress some of those ripples. It interferes with them, damping them down. It only works on half the image, as you can see: on the right the ripples are obvious, and on the left they are essentially gone. If you’re looking for a planet, it means you have to observe it several times rotating the detector so you can clean up the halo all the way around the star.

Planet hunters no longer blinded by the light

The Steward Observatory team used a machined piece of infrared optical glass about the size and shape of a cough drop to introduce the ripples. Placed in the optical path of the telescope, the APP device steals a small portion of the starlight and diffracts it into the star’s halo, canceling it out.

I really like this because it’s a hack. Astronomers have been trying for hundreds of years to get rid of excess diffracted light, and you can’t do it. You just can’t. But what you can do is get rid of some of it, and shove the rest into parts of the image that you don’t care about looking at. And that turns out to be better than good enough. (Technically, what they’re doing is trading spatial resolution for time, since you have to observe for much longer to image all angles around a star, but that’s OK too. And, as with most things that have thresholds, you’re not going from mediocre signal to slightly better signal, but from no signal to signal at all…)

At last: e-paper that’s actually like paper

May 5, 2011

Video: E Ink Shows Off Rollable, Scrunchable, and Video Screens | Popular Science

These demos show that e-ink displays can be embedded into other materials–the video below shows it sewn right into a bit of Tyvex cloth, the super-tough, paper-like cloth used in shipping envelopes.

It’s easy to see the uses for that kind of thing: Envelopes could be sturdy and reusable, with shippers simply changing the shipping address on the screen rather than tossing the envelopes.

This makes me happy, but what I particularly want to see is the next step: e-ink displays where most of the driver electronics have been separated from the display. Because for the kinds of e-ink applications they’re talking about, you don’t want the display changing a lot, and you don’t want just anybody to be able to change it. For instance, you don’t want the routing or delivery folks at the shipping company to be able to change the label…

Figuring out the right partitioning for this kind of thing is difficult; maybe you could have some kind of scrambling section that would reroute all the rows and columns according to a key known only by authorized people. Or maybe real crypto somewhere. Or just something that measured how much current had been passed through the drivers and encoded it with some kind of checksum…

But none of that is necessary for what I want: a pile of e-paper and a printer that will erase and reprint each sheet whenever I want, so that I can spread out as much reference material as I can see, just like I used to be able to do with books.

A certain naive charm

May 5, 2011

File-Sharers Await Official Recognition of New Religion | TorrentFreak

The church has its own set of axioms, most of which revolve around free access to knowledge and the sharing of information. They include:

# Reproduction of information is ethically right.
# The flow of information is ethically right.
# Remix Spirit is a sacred kind of copying.
# Copying or remixing information conveyed by another person is an act of respect.

Gereat Idea — Because there’s no way it could go wrong

April 22, 2011

BBC News – GM mosquitoes offer malaria hope

Research groups have already created “malaria-resistant mosquitoes” using techniques such as introducing genes to disrupt the malaria parasite’s development.

The research, however, has a great challenge – getting those genes to spread from the genetically-modified mosquitoes to the vast number of wild insects across the globe.

Unless the gene gives the mosquito an advantage, the gene will likely disappear.

Scientists at Imperial College London and the University of Washington, in Seattle, believe they have found a solution.

They inserted a gene into the mosquito DNA which is very good at looking after its own interests – a homing endonuclease called I-SceI.

The gene makes an enzyme which cuts the DNA in two. The cell’s repair machinery then uses the gene as a template when repairing the cut.

As a result the homing endonuclease gene is copied.

It does this in such a way that all the sperm produced by a male mosquito carry the gene.

The idea is really fairly elegant. And getting mosquitos that disrupted the transmission of malaria would be a pretty wonderful idea (even if the cost of the research would probably buy a year’s worth of bed tents for the entire continent).

And yet a tool that guarantees an inserted gene — any inserted gene — will spread fairly rapidly throughout an entire reproductively connected insect population makes me feel just the tiniest bit nervous. Like the biological equivalent of grey goo.

Technological genres and market illogic

April 19, 2011

Poor Colonized Ezra

April 15, 2011

Paul Ryan is not pro-competition, and his critics are not anti-competition – Ezra Klein – The Washington Post

Ryan, Brooks says, believes that “health care costs will not be brought under control until consumers take responsibility for their decisions and providers have market-based incentives to reduce prices.” It’s true that Ryan does believe that. But it’s not true that that’s what’s worrying so many about his budget proposal.

[italics added]

If Ryan actually did believe that old rightwing canard, wouldn’t he, you know, introduce a proposal that made it possible for medical consumers and to actually control their costs, and for effective lower-cost providers to gain share. But unless he’s a complete drooling moron, Ryan knows that’s not what his proposal does, hence he doesn’t really believe the canard (or doesn’t care about his beliefs) and has been pretty much feeding Ezra and all the other young village wonks a charming access-laced line of bullsh*t.

And this comes right after a sentence gently chiding Brook for giving Ryan too much credence.

Random robot gripping improvements tab dump

March 25, 2011

At some point we’re going to turn around and this kind of stuff will actually be useful, especially with improvements in vision so that machines can see the orientation of the things they’ve picked up.

DARPA fashions miracle robotic attachment from balloon, coffee • The Register

The manipulator works by pressing the soft balloon full of loose coffee grounds down on the object to be gripped. Then the air is sucked out of the balloon, causing the coffee granules to press together and lock into a rigid shape – just as they do when vacuum-packed. The object is now securely grasped by the manipulator, and can be released as desired by ending the suction on the granule-filled bulb.

Grip-Happy Compliant Electroadhesion Sneaking Into Everyday Usage

Today, they’ve moved onto bigger and better things, like gripping a banana using the same technique. Meet “compliant electroadhesion.”

As was the case back in 2008, electroadhesion still requires very little power to function. According to SRI, 11 square feet of electroadhesive material will support about 440-lbs. using 40mW.

This is why you test your new formulas first

March 24, 2011

The First Law of Development Stats: Whatever our Bizarre Methodology, We make Africa look Worse

The biggest change in method was that the new HDI is a geometric average rather than a normal (additive) average. Geometric average means you multiply the separate indices (each ranging between 0 and 1) for income, life expectancy, and education together and then take the cube root (I know your pulse starts to race here…)

Now, students, please notice the following: if one of these indices is zero, then the new HDI will be zero, regardless of how great the other indices are. The same mostly applies if one of the indices is close to zero. The new HDI has a “you’re only as strong as your weakest link” property, and in practice the weakest link turns out to be very low income (and guess which region has very low income).

You can see why the geometric average might have been attractive: by multiplying and then taking a root, it avoids the Bill-Gates-Walks-Into-A-Bar problem that besets arithmetic averages. But instead it makes errors in scaling or in linearity much worse. You gains on the swings, but you loses on the roundabouts.

And ultimately it’s always going to be about the scaling. $2 may make you twice as happy as $1, but $2 million is unlikely to make you twice as happy as $1 million, much less a million times as happy as $2.

It’s much, much easier, both mathematically and politically (because you get to avoid claims of subjectivity) to measure utility or development in linear terms of clear quantities like dollars or years of life or bushels of food. Too bad all you learn is ever more precisely where the house keys aren’t.


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