Better understanding graphene

Yes, graphene is something of a miracle material (hit this link for my extensive graphene blogging), and yes it’s proving to be very vexing material as well. There’s a whole lot of promise, but not so much practice because graphene is proving to be a very fickle material. Research like this from the Georgia Institute of Technology is particularly important because unlocking the secret life of graphene will allow for increasing practical applications. Better understanding will lead to better utilization.

The release:

Study of electron orbits in multilayer graphene finds unexpected energy gaps

Electron transport

		IMAGE: Stacking of graphene sheets creates regions where the moiré alignment is of type AA (all atoms have neighbors in the layer below), AB (only A atoms have neighbors) or BA… Click here for more information.

Researchers have taken one more step toward understanding the unique and often unexpected properties of graphene, a two-dimensional carbon material that has attracted interest because of its potential applications in future generations of electronic devices.

In the Aug. 8 advance online edition of the journal Nature Physics, researchers from the Georgia Institute of Technology and the National Institute of Standards and Technology (NIST) describe for the first time how the orbits of electrons are distributed spatially by magnetic fields applied to layers of epitaxial graphene.

The research team also found that these electron orbits can interact with the substrate on which the graphene is grown, creating energy gaps that affect how electron waves move through the multilayer material. These energy gaps could have implications for the designers of certain graphene-based electronic devices.

“The regular pattern of energy gaps in the graphene surface creates regions where electron transport is not allowed,” said Phillip N. First, a professor in the Georgia Tech School of Physics and one of the paper’s co-authors. “Electron waves would have to go around these regions, requiring new patterns of electron wave interference. Understanding such interference will be important for bi-layer graphene devices that have been proposed, and may be important for other lattice-matched substrates used to support graphene and graphene devices.”

In a magnetic field, an electron moves in a circular trajectory – known as a cyclotron orbit – whose radius depends on the size of the magnetic field and the energy of electron. For a constant magnetic field, that’s a little like rolling a marble around in a large bowl, First said.

“At high energy, the marble orbits high in the bowl, while for lower energies, the orbit size is smaller and lower in the bowl,” he explained. “The cyclotron orbits in graphene also depend on the electron energy and the local electron potential – corresponding to the bowl – but until now, the orbits hadn’t been imaged directly.”

Placed in a magnetic field, these orbits normally drift along lines of nearly constant electric potential. But when a graphene sample has small fluctuations in the potential, these “drift states” can become trapped at a hill or valley in the material that has closed constant potential contours. Such trapping of charge carriers is important for the quantum Hall effect, in which precisely quantized resistance results from charge conduction solely through the orbits that skip along the edges of the material.

		IMAGE: This graphic shows electrons that move along an equipotential, while those that follow closed equipotentials (as in a potential-energy valley) become localized (right). The arrows denote the magnetic field,… Click here for more information.

The study focused on one particular electron orbit: a zero-energy orbit that is unique to graphene. Because electrons are matter waves, interference within a material affects how their energy relates to the velocity of the wave – and reflected waves added to an incoming wave can combine to produce a slower composite wave. Electrons moving through the unique “chicken-wire” arrangement of carbon-carbon bonds in the graphene interfere in a way that leaves the wave velocity the same for all energy levels.

In addition to finding that energy states follow contours of constant electric potential, the researchers discovered specific areas on the graphene surface where the orbital energy of the electrons changes from one atom to the next. That creates an energy gap within isolated patches on the surface.

“By examining their distribution over the surface for different magnetic fields, we determined that the energy gap is due to a subtle interaction with the substrate, which consists of multilayer graphene grown on a silicon carbide wafer,” First explained.

In multilayer epitaxial graphene, each layer’s symmetrical sublattice is rotated slightly with respect to the next. In prior studies, researchers found that the rotations served to decouple the electronic properties of each graphene layer.

“Our findings hold the first indications of a small position-dependent interaction between the layers,” said David L. Miller, the paper’s first author and a graduate student in First’s laboratory. “This interaction occurs only when the size of a cyclotron orbit – which shrinks as the magnetic field is increased – becomes smaller than the size of the observed patches.”

The origin of the position dependent interaction is believed to be the “moiré pattern” of atomic alignments between two adjacent layers of graphene. In some regions, atoms of one layer lie atop atoms of the layer below, while in other regions, none of the atoms align with the atoms in the layer below. In still other regions, half of the atoms have neighbors in the underlayer, an instance in which the symmetry of the carbon atoms is broken and the Landau level – discrete energy level of the electrons – splits into two different energies.

Experimentally, the researchers examined a sample of epitaxial graphene grown at Georgia Tech in the laboratory of Professor Walt de Heer, using techniques developed by his research team over the past several years.

They used the tip of a custom-built scanning-tunneling microscope (STM) to probe the atomic-scale electronic structure of the graphene in a technique known as scanning tunneling spectroscopy. The tip was moved across the surface of a 100-square nanometer section of graphene, and spectroscopic data was acquired every 0.4 nanometers.

The measurements were done at 4.3 degrees Kelvin to take advantage of the fact that energy resolution is proportional to the temperature. The scanning-tunneling microscope, designed and built by Joseph Stroscio at NIST’s Center for Nanoscale Science and Technology, used a superconducting magnet to provide the magnetic fields needed to study the orbits.

According to First, the study raises a number of questions for future research, including how the energy gaps will affect electron transport properties, how the observed effects may impact proposed bi-layer graphene coherent devices – and whether the new phenomenon can be controlled.

“This study is really a stepping stone in long path to understanding the subtleties of graphene’s interesting properties,” he said. “This material is different from anything we have worked with before in electronics.”

###

In addition to those already mentioned, the study also included Walt de Heer, Kevin D. Kubista, Ming Ruan, and Markus Kinderman from Georgia Tech and Gregory M. Rutter from NIST. The research was supported by the National Science Foundation, the Semiconductor Research Corporation and the W.M. Keck Foundation. Additional assistance was provided by Georgia Tech’s Materials Research Science and Engineering Center (MRSEC)

Advancing substrate-independent minds

Via KurzweilAI.net — if you are into futurism at all this blog post at KurzweilAI is worth the time for a full read.

Here’s a taste from the link:

What might brains and minds look like in the future? It can be difficult to manage and organize ideas from many highly specialized fields of expertise that must necessarily converge to answer this intriguing question. Not only must one consider the areas of brain imaging, neuroscience, and cognitive psychology, but also artificial intelligence, nanotechnology, biotechnology, computational hardware architectures, and philosophy.

In the past, the transferal of minds into computer-based systems has been rather vaguely referred to as “uploading.” However, those hoping to advance this multidisciplinary field of research prefer to use the  term Advancing Substrate Independent Minds (ASIM), to emphasize a more scientific, and less science-fiction approach to creating emulations of human brains in non-biological substrates. The term ASIM captures the fact that there are several ways in which hardware and software may be used to run algorithms that mimic the human brain, and that there are many different approaches that can be used to realize this end goal.

Improving displays

And display improvements are increasingly important given the rapid evolution in types of consumer electronics — e-readers, smartphones, more complex touch screens, tablet/pad computers, et.al. — and the different types of high-performance displays needed to maximize these technologies.

The release:

Better displays ahead

		IMAGE: This is a prototype of the vertical stack multi-color electrowetting display device is shown in the photograph. Arrays of ~1,000-2,000 pixels were constructed with pixel sizes of 200 × 600… Click here for more information.

This release is also available in Chinese.College Park, MD (August 10, 2010) — Sleek design and ease of use are just two of the main reasons consumers are increasingly attracted to tablets and e-readers. And these devices are only going to get better — display technology improvements are on the way.

Several e-reader products on the market today use electrophoretic displays, in which each pixel consists of microscopic capsules that contain black and white particles moving in opposite directions under the influence of an electric field. A serious drawback to this technology is that the screen image is closer to black-on-gray than black-on-white. Also, the slow switching speed (~1 second) due to the limited velocity of the particles prevents integration of other highly desirable features such as touch commands, animation, and video.

Researchers at the University of Cincinnati Nanoelectronics Laboratory are actively pursuing an alternative approach for low-power displays. Their assessment of the future of display technologies appears in the American Institute of Physics’ Applied Physics Letters.

“Our approach is based on the concept of vertically stacking electrowetting devices,” explains professor Andrew J. Steckl, director of the NanoLab at UC’s Department of Electrical and Computer Engineering. “The electric field controls the ‘wetting’ properties on a fluoropolymer surface, which results in rapid manipulation of liquid on a micrometer scale. Electrowetting displays can operate in both reflective and transmissive modes, broadening their range of display applications. And now, improvements of the hydrophobic insulator material and the working liquids enable EW operation at fairly low driving voltages (~15V).”

Steckl and Dr. Han You, a research associate in the NanoLab, have demonstrated that the vertical stack electrowetting structure can produce multi-color e-paper devices, with the potential for higher resolution than the conventional side-by-side pixel approach. Furthermore, their device has switching speeds that enable video content displays.

What does all of this mean for the consumer? Essentially, tablets and e-readers are about to become capable of even more and look even better doing it. Compared to other technologies, electrowetting reflective display screens boast many advantages. The electrowetting displays are very thin, have a switching speed capable of video display, a wide viewing angle and, just as important, Steckl says, they aren’t power hogs.

###

The article, “Three-Color Electrowetting Display Device for Electronic Paper” by Han You and Andrew J. Steckl will appear in the journal Applied Physics Letters. http://apl.aip.org/applab/v97/i2/p023514_s1

Image Caption: A prototype of the vertical stack multi-color electrowetting display device is shown in the photograph. Arrays of ~1,000-2,000 pixels were constructed with pixel sizes of 200 × 600 and 300 × 900 µm.

ABOUT APPLIED PHYSICS LETTERS

Applied Physics Letters, published by the American Institute of Physics, features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, Applied Physics Letters offers prompt publication of new experimental and theoretical papers bearing on applications of physics phenomena to all branches of science, engineering, and modern technology. Content is published online daily, collected into weekly online and printed issues (52 issues per year). See: http://apl.aip.org/

ABOUT AIP

The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world’s largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.

Hawking looks to space for mankind’s future

Via KurzweilAI.net –

Stephen Hawking’s Warning: Abandon Earth—Or Face Extinction

August 10, 2010 by Editor

“Our only chance of long term survival is not to remain inward looking on planet Earth, but to spread out into space,” Stephen Hawking said in an interview Friday with Big Think. “We have made remarkable progress in the last hundred years. But if we want to continue beyond the next hundred years, our future is in space.”

“It will be difficult enough to avoid disaster on planet Earth in the next hundred years, let alone the next thousand, or million. The human race shouldn’t have all its eggs in one basket, or on one planet. Let’s hope we can avoid dropping the basket until we have spread the load.

“I see great dangers for the human race. There have been a number of times in the past when its survival has been a question of touch and go. The Cuban missile crisis in 1963 was one of these. The frequency of such occasions is likely to increase in the future. We shall need great care and judgment to negotiate them all successfully. But I’m an optimist. If we can avoid disaster for the next two centuries, our species should be safe, as we spread into space.

“If we are the only intelligent beings in the galaxy, we should make sure we survive and continue. But we are entering an increasingly dangerous period of our history. Our population and our use of the finite resources of planet Earth, are growing exponentially, along with our technical ability to change the environment for good or ill.  But our genetic code still carries the selfish and aggressive instincts that were of survival advantage in the past. It will be difficult enough to avoid disaster in the next hundred years, let alone the next thousand or million.  That is why I’m in favor of manned, or should I say ‘personed,’ space flight.”

Ten percent solar boost with a mere sticker

And these things can be applied to solar installations in the field. Talk about a simple improvement that goes a long, long way. Solar efficiency tends to go up in tiny increments unless it involves some sort of materials or process breakthrough. This news really is impressive.

From the link:

The power output of solar panels can be boosted by 10 percent just by applying a big transparent sticker to the front. Developed by a small startup called Genie Lens Technologies, the sticker is a polymer film embossed with microstructures that bend incoming sunlight. The result: the active materials in the panels absorb more light, and convert more of it into electricity.

The technology is cheap and could lower the cost per watt of solar power. Also, unlike other technologies developed to improve solar panel performance, this one can be added to panels that have already been installed.

The polymer film does three main things, says Seth Weiss, CEO and cofounder of Genie Lens, based in Englewood, CO. It prevents light from reflecting off the surface of solar panels. It traps light inside the semiconductor materials that absorb light and convert it to electricity. And it redirects incoming light so that rather than passing through the thin semiconductor material, it travels along its surface, increasing the chances it will be absorbed.

Power film: A thin plastic sheet covered with microscopic structures is applied to the front of a solar panel to increase the amount of light it absorbs.
Credit: Genie Lens Technologies

Is solar power cheaper than nuclear?

Surprisingly, maybe so.

From the link:

One of the issues associated with shifting from using fossil fuels to alternative energy sources is the cost. While adherents of alternative energy tout its benefits, many are skeptical, pointing out that such alternatives are just too expensive. Advocates of nuclear power point out that it is less polluting (if you don’t count storage of spent fuel) than fossil fuels, and that it costs less than alternatives like solar power.

A new study out of Duke University, though, casts doubt on the idea that nuclear power is cheaper than solar power. Using information from North Carolina, the study shows that solar power may be more cost efficient than nuclear power. With costs dropping on the production of photovoltaic cells, and with solar cells becoming increasingly efficient, it appears that — in North Carolina at least – solar installations offer a viable alternative to nuclear power, which is the source for about 20% of the electricity in the U.S.

A meeting of the photonic minds

Experts from three major photonic fields — solar photovoltaics, infrared (IR) photovoltaics and light emitting diode (LED) — met at the 2010 International Symposium on Optoelectronic Materials and Devices held on July 12 and 13, 2010, in Chicago. The conference was put together by the Quantum-functional Semiconductor Research Center of Dongguk University, the Microphysics Laboratory of the University of Illinois at Chicago (UIC) and Sivananthan Laboratories Inc. The symposium gave photonics leaders the opportunity to get together and discuss the current and future state of the industry and its materials and devices.

About the conference, Dr. Chris Grein, Professor of Physics and Director of Graduate Studies at the University of Illinois at Chicago, said, “The fields of solar and infrared photovoltaics and light emitting diodes have many common technical elements yet few conferences bring together experts from all three. One of the goals of the symposium was to facilitate the cross-pollination of many ideas that will benefit these technologies.”

The entire photonic space is rapidly evolving and conferences that put the different disciplines together can spur innovation from unseen sources. A material that imrpoves LED lighting could possibly improve solar cells, or a production technique lowering the cost of solar photovoltaics might also be applicable to IR photovoltaics. Another benefit of this meeting is it puts industry leaders, top researchers, students and other members of this business sector together in one place for a couple of days to speculate and share ideas.

Symposium topics included:

thin film solar cells

very high efficiency tandem solar cells

heteroepitaxial growth

antimonide- and HgCdTe-based infrared sensors

ZnO nanorods

The featured speakers were Dr. Martha Symko Davies of the National Renewable Energy Laboratory and Mr. Minh Le of the Solar Energy Technologies Program at the U.S. Department of Energy. This year’s conference was seventh in an ongoing series

ISS cooling system problem proving vexing

Looks like the International Space Station crew will have to undertake a third spacewalk to attempt to repair the faulty cooling system. Best of luck to current batch of space travelers, this is a challenging issue.

From the link:

Despite making one of the longest spacewalks ever, Douglas Wheelock and Tracy Caldwell Dyson had to give up trying to remove a broken ammonia pump and retreat inside.

Disappointed managers said two more spacewalks now will be needed to replace the pump and get the International Space Station’s cooling system operating normally again. The original plan called for two spacewalks.

Another spacewalk won’t be attempted until Wednesday at the earliest. Engineers huddled following Saturday’s eight-hour, three-minute effort – the sixth longest spacewalk ever – to consider their options.

“We will get through this problem,” said space station program manager Mike Suffredini. “The challenge is to get through this problem before the next problem hits the other cooling system.”

The pump failure knocked out half of the space station’s cooling system last weekend, leaving the orbiting lab with only one good cooling loop. Another breakdown could leave the station in a precarious situation.

In this image taken from video and made available by NASA astronaut Doug Wheelock, foreground begins the first of two spacewalks to replace a broken ammonia pump Saturday Aug. 7, 2010. (AP Photo/NASA)

Bill Gates on educating yourself online

Via KurzweilAI.net — This sounds great, and actually does sound feasible given the sheer quantity and quality of transcripts and video of incredible lectures (TED talks, anyone?), but I do wonder if this might be the educational equivalent of representing yourself in court, you know the old, “a lawyer who represents himself has a fool for a client.”

Bill Gates: In Five Years The Best Education Will Come From The Web

August 9, 2010

Source: TechCrunch — Aug 6, 2010

“Five years from now on the web for free you’ll be able to find the best lectures in the world,” says Bill Gates. “It will be better than any single university.”

He believes the $50,000 a year university education could be done via the web for as little as $2,00

The particle accelerator as power generator

Not as far fetched as you might think.

From the link:

Using this back-of-an-envelope calculation, Wilson worked out that a single 1000 GeV proton could lead to the release of 12,000 GeV of fission energy. Of course, this neglects all the messy fine details in which large amounts of energy can be lost. For example, it takes some 20MW of power to produce an 0.2MW beam in the Energy Doubler.

But even with those kinds of losses, it certainly seems worthwhile to study the process in more detail to see if overall energy production is possible.

Wilson’s conclusion is this: “There are probably better ways of producing plutonium, but it does appear that it would be feasible to construct an intense proton accelerator that would produce more energy than it consumes.”

SEC knocking at the door? Cooperate

Well, unless you’re certain you’ll be found innocent of any charges the SEC is bringing to bear. If you’re eventually going to get nailed, cooperating will garner a lower penalty.

From the link:

A new study finds that it may pay — at least in dollar terms — to help the SEC by sharing results of internal investigations and keeping the public informed when something has gone awry. Rebecca Files, an accounting professor at the University of Texas at Dallas, claims that while cooperating with the SEC increases a company’s likelihood of getting sanctioned, being both cooperative and forthcoming in information shared with investors can result in lower penalties. “It’s just like going to the cops and turning yourself in,” she says. “You’ll still have to pay some cost for your actions, but the penalty will be significantly reduced.”

Files based her findings on a study of 1,249 restatements made between 1997 and 2005, 10% of which resulted in a sanction against the company or its managers. She drew her conclusions on how forthcoming companies were about their problems in press releases and 8-Ks, as well as how quickly they came forward after a problematic reporting period. Since the SEC’s dealings with these companies occur behind closed doors, she could not know how fully cooperative they were in any investigation.

Beautiful space image — the Antennae galaxies

A space image two-fer today!

Enjoy …

From the link:

The X-ray image from Chandra shows huge clouds of hot, interstellar gas that have been injected with rich deposits of elements from supernova explosions. This enriched gas, which includes elements such as oxygen, iron, magnesium and silicon, will be incorporated into new generations of stars and planets.

The bright, point-like sources in the image are produced by material falling onto black holes and neutron stars that are remnants of the massive stars. Some of these black holes may have masses that are almost one hundred times that of the Sun.

The Spitzer data show infrared light from warm dust clouds that have been heated by newborn stars, with the brightest clouds lying in the overlap region between the two galaxies. The Hubble data reveal old stars in red, filaments of dust in brown and star-forming regions in yellow and white. Many of the fainter objects in the optical image are clusters containing thousands of stars.

An argument against online privacy regulation

I ran a muli-part post covering some of the more chilling aspects of online privacy last weekend, largely quoting the excellent Wall Street Journal series on the subject. This weekend here’s the best, and really most difficult, solution to the issue. I’m never for un- or even quasi- necessary regulation, so keeping the government out of online privacy oversight should remain the goal of anyone interested in the future of online freedom.

The key point from the second link (emphasis mine):

If a central authority such as Congress or the FTC were to decide for consumers how to deal with cookies, it would generalize wrongly about many, if not most, individuals’ interests, giving them the wrong mix of privacy and interactivity. If the FTC ruled that third-party cookies required consumers to opt in, for example, most would not, and the wealth of “free” content and services most people take for granted would quietly fade from view. And it would leave consumers unprotected from threats beyond their jurisdiction (as in Web tracking by sites outside the United States). Education is the hard way, and it is the only way, to get consumers’ privacy interests balanced with their other interests.

The latest on NASA’s CubeSat missions

I’ve done a little blogging on CubeSats and here’s the latest news from NASA.

From the second link, the release:

RELEASE : 10-188

NASA Announces Next Opportunity for Cubesat Space Missions

WASHINGTON — NASA has announced a second opportunity for small satellite payloads to fly on rockets planned to launch in 2011 and 2012. These CubeSats could be auxiliary cargo on previously planned missions.

CubeSats are a class of research spacecraft called nanosatellites. The cube-shaped satellites are approximately four inches long, have a volume of about one quart and weigh less than 2.2 pounds.

CubeSat investigations should be consistent with NASA’s Strategic Plan or the Education Strategic Coordination Framework. The research should address aspects of science, exploration, technology development, education or operations.

Applicants must submit proposals electronically by 4:30 p.m. EST, Nov. 15. NASA will select the payloads by Jan. 31, 2011, but selection does not guarantee a launch opportunity. Collaborators may be required to provide partial reimbursement of approximately $30,000 per CubeSat. NASA will not provide funding for the development of the small satellites.

NASA recently announced the results from the first round of the CubeSat Launch Initiative. Twelve payloads have made the short-list for launch opportunities in 2011 and 2012. They are eligible for launch pending an appropriate opportunity and final negotiations. The satellites come from 10 states: Alabama, Alaska, California, Colorado, Michigan, Montana, New Hampshire, New York, Utah and Vermont.

For additional information on NASA’s CubeSat Launch Initiative program, visit:

http://www.nasa.gov/directorates/somd/home/CubeSats_initiative.html
For more information on NASA’s Strategic Plan, visit:

http://www.nasa.gov/budget
For more information on NASA’s Education Strategic Coordination Framework, visit:

http://www.nasa.gov/offices/education/performance/strategic_framework.html

- end -

Beautiful space image — the sun in a solar flare

A solar flare from August 1, 2010 no less (last Sunday).

Enjoy …

Great Ball of Fire

On August 1, 2010, almost the entire Earth-facing side of the sun erupted in a tumult of activity. This image from the Solar Dynamics Observatory of the news-making solar event on August 1 shows the C3-class solar flare (white area on upper left), a solar tsunami (wave-like structure, upper right), multiple filaments of magnetism lifting off the stellar surface, large-scale shaking of the solar corona, radio bursts, a coronal mass ejection and more.

This multi-wavelength extreme ultraviolet snapshot from the Solar Dynamics Observatory shows the sun’s northern hemisphere in mid-eruption. Different colors in the image represent different gas temperatures. Earth’s magnetic field is still reverberating from the solar flare impact on August 3, 2010, which sparked aurorae as far south as Wisconsin and Iowa in the United States. Analysts believe a second solar flare is following behind the first flare and could re-energize the fading geomagnetic storm and spark a new round of Northern Lights.

Credit: NASA/SDO/AIA

Bush tax cuts find foe in Greenspan

Alan Greenspan’s post-Fed chair economic line has been quite different from how he wielded power for almost twenty years. His latest seeming apostasy is to call for repealing the Bush 43 tax cuts. I’ll have to admit I agree with the sphinx here. I’m certainly fiscally conservative, but I’m not fiscally stupid, and I’m certainly not one of those fiscal hardliners (hardheaders?) who would prefer to see the United States go completely bankrupt than to implement a serious monetary policy that matches the facts on the ground.

From the link:

It was not enough, it seems, for Alan Greenspan, the former Federal Reserve chairman and a self-described lifelong Republican libertarian, to call for stringent government regulation of giant banks, as he did a few months ago.

Now Mr. Greenspan is wading into the most fierce economic policy debate in Washington — what to do with the tax cuts adopted, in large part because of his implicit backing, under President George W. Bush — with a position not only contrary to Republican orthodoxy, but decidedly to the left of President Obama.

Rather than keeping tax rates steady for all but the wealthiest Americans, as the White House wants, Mr. Greenspan is calling for the complete repeal of the 2001 and 2003 tax cuts, brushing aside the arguments of Republicans and even a few Democrats that doing so could threaten the already shaky economic recovery.

“I’m in favor of tax cuts, but not with borrowed money,” Mr. Greenspan, 84, said Friday in a telephone interview. “Our choices right now are not between good and better; they’re between bad and worse. The problem we now face is the most extraordinary financial crisis that I have ever seen or read about.”

Get ready for the Perseid Meteor Shower

The Perseids are always worth a trip away from the lights of the city to get a better look. The action happens around midnight August 12th-13th.

From the link:

The show begins at sundown when Venus, Saturn, Mars and the crescent Moon pop out of the western twilight in tight conjunction. All four heavenly objects will fit within a circle about 10 degrees in diameter, beaming together through the dusky colors of sunset. No telescope is required to enjoy this naked-eye event: sky map:

Enlarge
The planets will hang together in the western sky until 10 pm or so. When they leave, following the sun below the horizon, you should stay, because that is when the Perseid meteor shower begins. From 10 pm until dawn, meteors will flit across the starry sky in a display that’s even more exciting than a planetary get-together.

The Singularity and rationality

Via KurzweilAI.net –

Singularity and Rationality: Eliezer Yudkowsky speaks out

August 5, 2010 by Thomas McCabe

Eliezer Yudkowsky is a Research Fellow at the Singularity Institute for Artificial Intelligence and founder of the community blog Less Wrong. We discussed his coming talk at the Singularity Summit on August 15, his forthcoming book on human rationality, his theory of “friendly AI,” and the likelihood of the Singularity and how to achieve it.

What are you working on currently?

I’m working on a book on human rationality. I’ve got… let me see… 143,000 words written so far. There’s been a lot of progress lately in fields contributing to human rationality, and it hasn’t made its way down to the popular level yet, even though it seems like something that should be popularizable. The second part of the book is on how to actually change your mind, and all the various biases that have been discovered that prevent people from changing their minds. Also, with reference to the Singularity, we’ve discovered in practice that you can’t just sit down and explain Singularity-related things to people without giving them a lot of background material first, and this book hopes to provide some of that background material.

Singularity Irrationality

What’s the most irrational thing you’ve heard regarding the Singularity?

That’s sort of a fuzzy question, because as the word “Singularity” gets looser and looser, the stuff you hear about it gets more and more irrational and less and less relevant. For example, for the people who think that the invention of hallucinogens was a Singularity… I forget who exactly that was [Terence McKenna].

The Singularity Institute once received an email saying, “This entire site is the biggest load of navel gazing stupidity I have ever seen. You are so naive, and clueless as to the inherent evil that lurks forever. A machine is no match for Satan.” I don’t know if that counts as the *most* irrational thing people have said about the Singularity, but…

In terms of what the public accepts as the Singularity, I think that the sort of more naive, “Well, people are still walking around in their biological bodies even after there are superintelligences around, and they’re just sort of being cool and futuristic but it hasn’t completely shattered life as we know it” — that sort of conservatism — may be the silliest thing. I think that’s a failure to understand superintelligence as something that becomes real and will have a real effect on the world.

Flexible display news

The latest step in flexible displays is looking toward large-scale production a la roll-to-roll printers (think newsprint) to get costs down. I can’t wait to see the applications of bendable displays once they become relatively cheap and innovators, inventors and artists can start playing around with the material.

From the link:

Applied Materials is trying to solve this problem–and get an early foothold in a potentially huge market–by standardizing equipment that makes flexible displays. The company, the world’s dominant maker of equipment for manufacturing computer chips and liquid-crystal displays, is developing a process that could print flexible transistor arrays that perform just as well as those on rigid substrates. That would be required if flexible displays are to be viable.

Flexible and rugged electronics with plastic displays are likely to entice consumers. Nick Colaneri, head of the Flexible Display Center at Arizona State University, points out that devices like the iPad could be bigger, and take on new functions, if they could shed their breakable glass screens. But there’s also an appeal for manufacturers. Flexible displays could cost much less to make. They could be produced on roll-to-roll machines that operate continuously at high volumes, which is more efficient than the batch methods used to make conventional electronics.

Regrowing human limbs

I came across this news a few times in the last couple of days. Maybe not quite limb regeneration, or in humans at the moment, but it’s still  just amazing.

From the link:

To figure out why mammalian muscle cells can’t regenerate, Blau’s team looked for proteins known to block cell division, focusing specifically on those that are found in mammals and birds but not in amphibians capable of regeneration. They identified one candidate, called ARF. Blocking both this protein and a similar protein, Rb, identified in previous research, enabled cells isolated from mouse muscle to begin dividing. When transplanted back into mice, the engineered cells integrated with existing muscle fibers, but only if Rb was turned back on. The scientists haven’t yet shown that this muscle works properly.

Researchers ultimately hope to develop ways to regenerate tissue damaged via injury or disease. The ability to precisely re-grow cells in the pancreas or the heart, for example, could provide new therapies for diabetes or heart disease. The team now plans to examine whether the same approach will work in these types of cells.

Google Wave, RIP

A few months and a year after announcing Google Wave, the Mountain View behemoth pulls the plug. (Note: it will remain live through the end of the year) Looks like parts of Google Wave will live on in some fashion nestled in products and indicatives to-be-named. You can find my previous blogging on Google Wave here, here and here.

From the link:

While very few of you may be shedding tears over the demise of Google Wave, or even knew what it was, we probably haven’t seen the last of this service. The search giant says the technology behind its ill-fated collaboration tool will live on in new products that have not yet been announced. Google isn’t giving any hints about what new those new products might be or how they would benefit from Wave features. But company CEO Eric Schmidt recently said the Wave team would be moving over to other products that are “like Wave but applied in some other areas,” according to a YouTube video posted by TechCrunch’s MG Siegler.

And:

Wave was also a platform for third-party developers to extend Wave’s functionality with Web-based applications. If Wave’s extensibility could be folded into the rumored Google Me that would go a long way to appeasing developers who’ve already put time and energy into developing for Wave. Extensions that might fit in with a social network could include apps for travel or event planning, games and image editing.

Jimmy Carter saved microbrews and craft beer

Who knew?

From the Jon Chait link:

To make a long story short, prohibition led to the dismantling of many small breweries around the nation. When prohibition was lifted, government tightly regulated the market, and small scale producers were essentially shut out of the beer market altogether. Regulations imposed at the time greatly benefited the large beer makers. In 1979, Carter deregulated the beer industry, opening  back up to craft brewers. As the chart below illustrates, this had a really amazing effect on the beer industry:

The above blockquote and chart come from an E.D. Kain link in Chait’s post.

Here’s Chait’s take on the topic:

It’s worth noting that Carter got no political credit for this move, and that the benefits didn’t appear until long after he departed. Some policy successes — like a successful war or peace treaty — yield immediate political dividends. But others produce little change until many years later, by which time everybody has forgotten your policy had anything to do with it.

In related news (and the reason for the linked posts — today is International Beer Day (well at least for another hour or so.)

House may still vote on middle class tax cut extension …

… before the election adjournment in October.

From the link:

The House could consider an extension of the 2001 and 2003 tax cuts for middle-income households prior to the chamber’s Oct. 8 target adjournment, House Majority Leader Steny Hoyer (D-Md.) said Aug. 3.

Hoyer said he would like the legislation to move before lawmakers adjourn to campaign for the midterm elections. But it is possible that the House will not reach an agreement on how to proceed, he told reporters during a conference call hosted by the Center for American Progress.

“I think many in our caucus and many on the Senate side would like to see us address it and to give confidence to working Americans that their taxes are not going to be increased, and I fall under that category,” Hoyer said.

Additionally, “we have to deal with the Senate,” he said, adding that it is not a requirement that the Senate move the extension first. Some House leaders have previously said that they would wait until the Senate acts.

Kagan confirmed

Senate vote came down 63-37 to mostly yawns all around. There was no realistic way Elena Kagan wasn’t going to be confirmed to the Supreme Court.

Environmental Graffiti

I’m doing some posting at Environmental Graffiti on solar and other alternative energy sources. You can check out my first effort here. That post was built from one appearing here a couple of days ago.

Separating and sizing nanoparticles

A useful nanotech development.

The release:

NIST nanofluidic ‘multi-tool’ separates and sizes nanoparticles

		IMAGE: A 3-D nanofluidic “staircase ” channel with many depths was used to separate and measure a mixture of different-sized fluorescent nanoparticles. Larger (brighter) and smaller (dimmer) particles were forced toward the… Click here for more information.

A wrench or a screwdriver of a single size is useful for some jobs, but for a more complicated project, you need a set of tools of different sizes. Following this guiding principle, researchers at the National Institute of Standards and Technology (NIST) have engineered a nanoscale fluidic device that functions as a miniature “multi-tool” for working with nanoparticles—objects whose dimensions are measured in nanometers, or billionths of a meter.

First introduced in March 2009 (see “NIST-Cornell Team Builds World’s First Nanofluidic Device with Complex 3-D Surfaces”, the device consists of a chamber with a cascading “staircase” of 30 nanofluidic channels ranging in depth from about 80 nanometers at the top to about 620 nanometers (slightly smaller than an average bacterium) at the bottom. Each of the many “steps” of the staircase provides another “tool” of a different size to manipulate nanoparticles in a method that is similar to how a coin sorter separates nickels, dimes and quarters.

In a new article in the journal Lab on a Chip*, the NIST research team demonstrates that the device can successfully perform the first of a planned suite of nanoscale tasks—separating and measuring a mixture of spherical nanoparticles of different sizes (ranging from about 80 to 250 nanometers in diameter) dispersed in a solution. The researchers used electrophoresis—the method of moving charged particles through a solution by forcing them forward with an applied electric field—to drive the nanoparticles from the deep end of the chamber across the device into the progressively shallower channels. The nanoparticles were labeled with fluorescent dye so that their movements could be tracked with a microscope.

As expected, the larger particles stopped when they reached the steps of the staircase with depths that matched their diameters of around 220 nanometers. The smaller particles moved on until they, too, were restricted from moving into shallower channels at depths of around 110 nanometers. Because the particles were visible as fluorescent points of light, the position in the chamber where each individual particle was stopped could be mapped to the corresponding channel depth. This allowed the researchers to measure the distribution of nanoparticle sizes and validate the usefulness of the device as both a separation tool and reference material. Integrated into a microchip, the device could enable the sorting of complex nanoparticle mixtures, without observation, for subsequent application. This approach could prove to be faster and more economical than conventional methods of nanoparticle sample preparation and characterization.

The NIST team plans to engineer nanofluidic devices optimized for different nanoparticle sorting applications. These devices could be fabricated with tailored resolution (by increasing or decreasing the step size of the channels), over a particular range of particle sizes (by increasing or decreasing the maximum and minimum channel depths), and for select materials (by conforming the surface chemistry of the channels to optimize interaction with a specific substance). The researchers are also interested in determining if their technique could be used to separate mixtures of nanoparticles with similar sizes but different shapes—for example, mixtures of tubes and spheres.

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* S.M. Stavis, J. Geist and M. Gaitan. Separation and metrology of nanoparticles by nanofluidic size exclusion. Lab on a Chip, forthcoming, August 2010

Selenium improves solar efficiency

I like the “anti-sunscreen” intro to this news on improving the efficiency of photovoltaic solar cells with selenium.

The release:

Selenium makes more efficient solar cells

This release is also available in Chinese.

		IMAGE: This is a sunset over the Pacific Ocean as seen from Highway 1 south of Monterey, Calif. LBNL’s Marie Mayer, who took the photo, calls sunlight and water “two sustainable… Click here for more information.

College Park, MD (August 3, 2010) — Call it the anti-sunscreen. That’s more or less the description of what many solar energy researchers would like to find — light-catching substances that could be added to photovoltaic materials in order to convert more of the sun’s energy into carbon-free electricity.

Research reported in the journal Applied Physics Letters, published by the American Institute of Physics (AIP), describes how solar power could potentially be harvested by using oxide materials that contain the element selenium. A team at the Lawrence Berkeley National Laboratory in Berkeley, California, embedded selenium in zinc oxide, a relatively inexpensive material that could be promising for solar power conversion if it could make more efficient use of the sun’s energy. The team found that even a relatively small amount of selenium, just 9 percent of the mostly zinc-oxide base, dramatically boosted the material’s efficiency in absorbing light.

“Researchers are exploring ways to make solar cells both less expensive and more efficient; this result potentially addresses both of those needs,” says author Marie Mayer, a fourth-year University of California, Berkeley doctoral student based out of LBNL’s Solar Materials Energy Research Group, which is working on novel materials for sustainable clean-energy sources.

Mayer says that photoelectrochemical water splitting, using energy from the sun to cleave water into hydrogen and oxygen gases, could potentially be the most exciting future application for her work. Harnessing this reaction is key to the eventual production of zero-emission hydrogen powered vehicles, which hypothetically will run only on water and sunlight. Like most researchers, Mayer isn’t predicting hydrogen cars on the roads in any meaningful numbers soon. Still, the great thing about solar power, she says, is that “if you can dream it, someone is trying to research it.”

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The article, “Band structure engineering of ZnO_1-xSe_x alloys” by Marie A. Mayer, Derrick T. Speaks, Kin Man Yu, Samuel S. Mao, Eugene E. Haller, and Wladek Walukiewicz will appear in the journal Applied Physics Letters. See: http://apl.aip.org/applab/v97/i2/p022104_s1

ABOUT APPLIED PHYSICS LETTERS

Applied Physics Letters, published by the American Institute of Physics, features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, Applied Physics Letters offers prompt publication of new experimental and theoretical papers bearing on applications of physics phenomena to all branches of science, engineering, and modern technology. Content is published online daily, collected into weekly online and printed issues (52 issues per year). See: http://apl.aip.org/

ABOUT AIP

The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world’s largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.

Will the WikiLeaks issue close military/intelligence doors?

Michael Hayden hopes not. The relationship between intelligence agencies and the military is always pretty fragile and the WikiLeaks incident over posting classified video of a 2007 Baghdad helicopter attack a couple of months ago threatens to shut down a lot of communication between the government entities.

From the first link:

The recent publication of classified military documents on the whistleblower site WikLeaks should not be allowed to chill information sharing that’s been going on within the military and intelligence communities, the former director of the CIA said Tuesday.

In an interview, retired Gen. Michael Hayden, who led both the CIA and the National Security Agency (NSA), expressed concern over the potential for knee-jerk restrictions on data sharing in response to the incident.

“Senior leadership in the country will have to guard against over-reaction,” Hayden cautioned. “Clearly, we need to be careful. We have to pay more attention to security,” he said.

Wikileaks last week posted more than 90,000 military and intelligence documents on the ongoing war in Afghanistan. Bradley Manning, an Army intelligence analyst already charged with supplying WikiLeaks with a video allegedly showing a deadly U.S Apache helicopter attack in Iraq, is the prime suspect in the leak of the Afghanistan war documents.

Invisibility cloak update

It’s been several months since I’ve come across any news on invisibility cloak technology, something of a pet subject around here, but here’s the very latest — findings on transformation optics.

From the second link, the release:

New findings promising for ‘transformation optics,’ cloaking

WEST LAFAYETTE, Ind. — Researchers have overcome a fundamental obstacle in using new “metamaterials” for radical advances in optical technologies, including ultra-powerful microscopes and computers and a possible invisibility cloak.

The metamaterials have been plagued by a major limitation: too much light is “lost,” or absorbed by metals such as silver and gold contained in the metamaterials, making them impractical for optical devices.

However, a Purdue University team has solved this hurdle, culminating three years of research based at the Birck Nanotechnology Center at the university’s Discovery Park.

“This finding is fundamental to the whole field of metamaterials,” said Vladimir M. Shalaev, Purdue’s Robert and Anne Burnett Professor of Electrical and Computer Engineering. “We showed that, in principle, it’s feasible to conquer losses and develop these materials for many applications.”

Research findings are detailed in a paper appearing on Aug. 5 in the journal Nature.

The material developed by Purdue researchers is made of a fishnet-like film containing holes about 100 nanometers in diameter and repeating layers of silver and aluminum oxide. The researchers etched away a portion of the aluminum oxide between silver layers and replaced it with a “gain medium” formed by a colored dye that can amplify light.

Other researchers have applied various gain media to the top of the fishnet film, but that approach does not produce sufficient amplification to overcome losses, Shalaev said.

Instead, the Purdue team found a way to place the dye between the two fishnet layers of silver, where the “local field” of light is far stronger than on the surface of the film, causing the gain medium to work 50 times more efficiently.

The approach was first developed by former Purdue doctoral student Hsiao-Kuan Yuan, now at Intel Corp., and it was further developed and applied by doctoral student Shumin Xiao.

Unlike natural materials, metamaterials are able to reduce the “index of refraction” to less than one or less than zero. Refraction occurs as electromagnetic waves, including light, bend when passing from one material into another. It causes the bent-stick-in-water effect, which occurs when a stick placed in a glass of water appears bent when viewed from the outside.

Being able to create materials with an index of refraction that’s negative or between one and zero promises a range of potential breakthroughs in a new field called transformation optics. Possible applications include a “planar hyperlens” that could make optical microscopes 10 times more powerful and able to see objects as small as DNA; advanced sensors; new types of “light concentrators” for more efficient solar collectors; computers and consumer electronics that use light instead of electronic signals to process information; and a cloak of invisibility.

Excitement about metamaterials has been tempered by the fact that too much light is absorbed by the materials. However, the new approach can dramatically reduce the “absorption coefficient,” or how much light and energy is lost, and might amplify the incident light so that the metamaterial becomes “active,” Shalaev said.

“What’s really important is that the absorption coefficient can be as small as only one-millionth of what it was before using our approach,” Shalaev said. “We can even have amplification of light instead of its absorption. Here, for the first time, we showed that metamaterials can have a negative refractive index and amplify light.”

The Nature paper was written by Xiao, senior research scientist Vladimir P. Drachev, principal research scientist Alexander V. Kildishev, doctoral student Xingjie Ni, postdoctoral fellow Uday K. Chettiar, Yuan, and Shalaev.

Fabricating the material was a major challenge, Shalaev said.

First, the researchers had to learn how to precisely remove as much as possible of the aluminum oxide layer in order to vacate space for dye without causing a collapse of the structure.

“You remove it almost completely but leave a little bit to act as pillars to support the structure, and then you spin coat the dye-doped polymer inside the structure,” he said.

The researchers also had to devise a way to deposit just the right amount of dye mixed with an epoxy between the silver layers of the perforated film.

“You can’t deposit too much dye and epoxy, which have a positive refractive index, but only a thin layer about 50 nanometers thick, or you lose the negative refraction,” Shalaev said.

Future work may involve creating a technology that uses an electrical source instead of a light source, like semiconductor lasers now in use, which would make them more practical for computer and electronics applications.

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The work was funded by the U.S. Army Research Office and the National Science Foundation.

Hit this link for the related image (it’s just too big for this blog and I didn’t feel like doing any resizing), and here’s the accompanying caption for the image:

This illustration shows the structure of a new device created by Purdue researchers to overcome a fundamental obstacle in using new “metamaterials” for radical advances in optical technologies, including ultrapowerful microscopes and computers and a possible invisibility cloak. The material developed by the researchers is a perforated, fishnet-like film made of repeating layers of silver and aluminum oxide. The researchers etched away a portion of the aluminum oxide between silver layers and replaced it with a “gain medium” to amplify light. (Birck Nanotechnology Center, Purdue University)

NFL television ratings, here comes the science

Research from the University of Illinois.

The release, er, story:

Winning record, team longevity, prime-time games influence NFL TV ratings

8/4/10 | Phil Ciciora, News Editor

CHAMPAIGN, Ill. — Legendary Green Bay Packers coach Vince Lombardi once said, “Winning isn’t everything; it’s the only thing.” For NFL teams, especially small-market franchises seeking to increase their fan base, winning does help, but so does team longevity in the market as well as the number of games played in prime time, according to research by a University of Illinois sports economist.

Scott Tainsky, a professor of recreation, sport and tourism at Illinois, says that many of the same factors that influence whether fans attend a game in-person also influence a team’s television ratings.

“Sports economists have traditionally relied on attendance figures as a proxy for demand in order to figure out what’s motivating fans to go to games,” Tainsky said. “Even though the NFL is priced just a little bit below where it could maximize revenue at the gate, it still requires a large income or at least a large outlay of money for the average fan to see a game in-person.”

According to Tainsky, whose research was published in the Journal of Sports Economics, since the vast majority of fans watch the games on TV instead of in-person, and with the NFL generating over half of its revenue through TV contracts, TV ratings might actually function as a better proxy for consumer demand in both the home and road teams’ markets.

“We have a long history of studying consumer demand for major league baseball, but there’s very little research done on the NFL, even though it’s the largest revenue, most popular sport in the U.S.,” he said.

Of the three factors that positively influence demand, fielding a winning team is the most difficult variable to account for on a year-to-year basis, especially for small-market teams.

“From the first day of training camp, winning is the goal for every team in the league,” Tainsky said. “But that’s going to be somewhat cyclical, since the league has a pretty hard salary cap. If the spending on player talent is virtually equivalent for all 32 teams, there’s going to be parity, meaning that some teams will have good years while other teams will have bad years.”

Since it’s easier for the big-market teams such as Dallas and Chicago to weather the year-to-year swings in their win-loss records, small-market teams need to be even more proactive in courting fans when they’re muddling through a losing campaign.

One way to do that, Tainsky says, is to promote the experience of going to the game.

“When you’re a small-market team and you’re having a down year, you have to promote other things besides the quality of the team,” Tainsky said. “You have to market the tradition of sports being passed down from generation to generation, this notion of, ‘I went to the game with my dad, and he went with his dad,’ or the ‘On any given Sunday…’ mythology that the NFL likes to cultivate. If you can get this to be a habit of consumption on Sundays, that’s ideal, because it’s easier to take it on the chin when they’re not doing so well.”

Small-market teams mired in a rebuilding year are also at risk of having their broadcasts blacked out as a result of poor attendance. But Tainsky discovered that ratings for telecasts in those markets – Atlanta, Buffalo, Jacksonville, Oakland, St. Louis and Tennessee – were on par with the remaining 26 franchises. He blames market size rather than market demand for the teams’ failure to sell out games.

“There are three different ways that Nielsen collects ratings, and one of them is the percentage of TVs in the area that are on, and those aren’t appreciably lower in cities that experience blackouts,” Tainsky said. “In fact, the per capita demand is often higher in small markets; they just have trouble filling 60- and 70,000- seat stadiums. A place like New York City has a low market share, but the sheer number of people it has in its surrounding metropolitan area allows it to sell out games.”

In that respect, it may not be the fault of the smaller market cities that they can’t get a larger percentage of a viewing audience, Tainsky says.

“The team might be doing everything it can do to attract fans, but because of the smaller population size, it has to be that much more popular to avert blackouts.”

Although there was a slight ratings bump for games played in prime time, Tainsky said that sharing a home market with another team, as the San Francisco 49ers and the Oakland Raiders do in the Bay Area, represented a significant drag on consumer demand. The socioeconomic status of fans was also negatively associated with ratings. Tainsky noted that other research has shown that lower-income fans engage in homebound and sedentary activities, further indicating that TV ratings might be a better measure of consumer demand.

Using TV ratings to analyze demand also allows sports economists to look at the size of viewership in cities that don’t have a home game that weekend, or in cities that don’t have teams. There’s also the “diaspora effect,” where fans have been displaced either by the team moving to a different market (the Baltimore Colts moving to Indianapolis, for example) or the fans themselves moving from their home markets (for example, displaced Pittsburghers living in suburban Chicago).

“Population flow from city-to-city does seem to have an effect on ratings for games,” Tainsky said. “If more people from western Pennsylvania have moved to the Chicago suburbs, the game featuring the Steelers will be popular but only if the game is being played at Heinz Field in Pittsburgh.”

Tainsky said displaced fans won’t watch in great numbers if the Steelers are playing on the road at, say, Jacksonville, which may indicate that viewers aren’t necessarily tuning in for the game itself, but rather for the feelings of nostalgia that watching a football game on a Sunday evokes.

“It makes them think back to where they’re from, and the good times they had watching those games in the past,” he said. “So there’s more to it than just the game itself.”