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Semiconductor Defects...

Configuration coordinate diagram, showing important energies and optical transitions. For this example, Etherm gives the acceptor level relative to the CBM.

Citation: J. Appl. Phys. 119, 181101 (2016); http://dx.doi.org/10.1063/1.4948245


Topics: Education, Nanotechnology, Semiconductor Technology, STEM


Abstract

Point defects affect or even completely determine physical and chemical properties of semiconductors. Characterization of point defects based on experimental techniques alone is often inconclusive. In such cases, the combination of experiment and theory is crucial to gain understanding of the system studied. In this tutorial, we explain how and when such comparison provides new understanding of the defect physics. More specifically, we focus on processes that can be analyzed or understood in terms of configuration coordinate diagrams of defects in their different charge states. These processes include light absorption, luminescence, and nonradiative capture of charge carriers. Recent theoretical developments to describe these processes are reviewed.

Introduction

Every material contains defects; perfect materials simply do not exist. While it may cost energy to create a defect, configurational entropy renders it favorable to incorporate a certain concentration of defects, since this lowers the free energy of the system.1 Therefore, even in equilibrium, we can expect defects to be present; kinetic limitations sometimes lead to formation of additional defects. Note that all of these considerations also apply to impurities that are unintentionally present in the growth or processing environment. Of course, impurities are often intentionally introduced to tailor the properties of materials. Doping of semiconductors with acceptors and donors is essential for electronic and optoelectronic applications. In the following, we will use the word “defect” as a generic term to cover both intrinsic defects (vacancies, self-interstitials, and antisites) and impurities.

Since defects are unavoidable, we must consider the effects they have on the properties of materials. These effects can be considerable, to the point of determining the functionality of the material, as in p- or n-type doping. Point defects play a key role in diffusion: virtually all diffusion processes are assisted by point defects. Defects are often responsible for degradation of a device. Even in the absence of degradation, defects can limit the performance of a device. Compensation by native point defects can decrease the level of doping that can be achieved. Defects with energy levels within the band gap can act as recombination centers, impeding carrier collection in a solar cell or light emission from a light-emitting diode. Sometimes, these effects can be used to advantage: luminescence centers in wide-band-gap materials can be used to emit light at specified wavelengths; or single-spin centers (such as the nitrogen–vacancy (NV) center in diamond) can act as an artificial atom and serve as a qubit in a quantum information system.2,3 Finally, sometimes, one deliberately wants to grow materials with many defects. Examples are materials for ultrafast optoelectronic switches or semiconductors used to optically generate THz pulses, where defect densities should be large enough so that carrier lifetimes are as short as a few picoseconds.4

Journal of Applied Physics:
Tutorial: Defects in semiconductors—Combining experiment and theory
Audrius Alkauskas1, Matthew D. McCluskey2 and Chris G. Van de Walle3,a)

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Book suggestions for a work endeavor

Yeah! I have something I'm trying to do for work. Kind of inspired by a forum topic about why black speculative fiction isn't popular. I started getting emails about it recently and it got my brain ticking.

At the large bookstore chain where I work, we do have a few shelves of African American fiction. But they're mostly urban fiction about gangs, or slave narratives. Nothing wrong with either, but my hypothesis is that  if you don't have a way of knowing that there's sci fi written by black people, then you're not going to find it on the shelf labeled 'African American fiction' in our bookstore. For a reader looking for something more, they will not find it there.

One of my co-workers didn't know who Octavia Butler was- that she was black and female and one of the most prolific sci-fi writers around. And that's not their fault at all, but it does prove my point. I'm trying to convince the higher ups at my job that expanding those shelves, or at least including books from the massive sections in sci fi, fantasy and horror, written by black people is important.

People going to those shelves, looking for something other than romance novels and 'urban' fic are going to think that these books don't exist for us. And that's the problem. The sci fi section of the store is MASSIVE. So easy to get lost in, so easy to never know black people are there. My manager said she'd help me create the proposition, and while she said it's a very long shot (not just this idea, but most changes to the system) she is still going to help. She wants a list, and I need suggestions!

I need author, title, ISBN- 13 (or 10), along with publishing date and any other info you can get me. I will take anything and everything, especially repeat suggestions. I want popular stuff. I want to convince these businessmen that black sci fi, black fantasy, that it sells, that it is worthwhile. I don't know if this is going to work, but I am going to try.

Help me!

Thank you for your time.

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Simpler, Faster, Cheaper...

To prevent cores of single-wall carbon nanotubes from filling with water or other detrimental substances, the NIST researchers advise intentionally prefilling them with a desired chemical of known properties. Taking this step before separating and dispersing the materials, usually done in water, yields a consistently uniform collection of nanotubes, especially important for optical applications.
Credit: Fagan/NIST
View hi-resolution image

Topics: Carbon Nanotubes, Electrical Engineering, Nanotechnology, Semiconductor Technology

Just as many of us might be resigned to clogged salt shakers or rush-hour traffic, those working to exploit the special properties of carbon nanotubes have typically shrugged their shoulders when these tiniest of cylinders fill with water during processing. But for nanotube practitioners who have reached their Popeye threshold and “can’t stands no more,” the National Institute of Standards and Technology (NIST) has devised a cheap, quick and effective strategy that reliably enhances the quality and consistency of the materials—important for using them effectively in applications such as new computing technologies.

To prevent filling of the cores of single-wall carbon nanotubes with water or other detrimental substances, the NIST researchers advise intentionally prefilling them with a desired chemical of known properties. Taking this step before separating and dispersing the materials, usually done in water, yields a consistently uniform collection of nanotubes. In quantity and quality, the results are superior to water-filled nanotubes, especially for optical applications such as sensors and photodetectors.

The approach opens a straightforward route for engineering the properties of single-wall carbon nanotubes—rolled up sheets of carbon atoms arranged like chicken wire or honey combs—with improved or new properties.

“This approach is so easy, inexpensive and broadly useful that I can’t think of a reason not to use it,” said NIST chemical engineer Jeffrey Fagan.

NIST:
Simpler, Faster and Cheaper: A Full-filling Approach to Making Carbon Nanotubes of Consistent Quality, Mark Bello

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Wearable Photovoltaics...

Ultra-thin solar cells are flexible enough to bend around small objects, such as the 1mm-thick edge of a glass slide, as shown here.
CREDIT: Juho Kim, et al/APL

Topics: Consumer Electronics, Electrical Engineering, Materials Science, Photovoltaics, Solar Power

WASHINGTON, D.C., June 20, 2016 -- Scientists in South Korea have made ultra-thin photovoltaics flexible enough to wrap around the average pencil. The bendy solar cells could power wearable electronics like fitness trackers and smart glasses. The researchers report the results in the journal Applied Physics Letters, from AIP Publishing.

Thin materials flex more easily than thick ones -- think a piece of paper versus a cardboard shipping box. The reason for the difference: The stress in a material while it's being bent increases farther out from the central plane. Because thick sheets have more material farther out they are harder to bend.

“Our photovoltaic is about 1 micrometer thick,” said Jongho Lee, an engineer at the Gwangju Institute of Science and Technology in South Korea. One micrometer is much thinner than an average human hair. Standard photovoltaics are usually hundreds of times thicker, and even most other thin photovoltaics are 2 to 4 times thicker.

AIP: Ultra-thin Solar Cells Can Easily Bend Around a Pencil, Catherine Meyers

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Fotoman

I photographer friend sent me a video about a 1200mm camera lens. It looked like a mini bazooka, the case was carried by two persons. They compared it to a 50mm and a 400mm lens. I could stand on a mountain with my arms raised and you could count the hairs on my arm pits (eh, strike that image) from the valley below.

As a young man I had an idea of an imaginary super hero Fotoman who could snap your picture with an Instamatic and beat you by folding, spindling and mutilating the paper photo. His arch nemesis was a crazed copy machine technician. You've seen him xeroxing his behind to send smell-o-grams to business execs.

Fotoman gets the upgrade with digital cams, tablet and drones. If he can get a clear shot, he can alter your image on the fly and delete you if necessary. And don't let him get the green screen drop on ya, LOL! Have to get him a cool helmet with heads-up display and hologram projector. Fotoman uses common technology but is really a home-brewed quantum scientist having had several deep flash encounters of the 4th dimensional kind. He gets flashbacks that seem so real and wears makeup and disguises in public to prevent his real face from being photographed.

Canon's monster 1200mm lens

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Exciton Condensate...

Figure 1: A Coulomb drag experiment measures the interactions between charges in two closely spaced layers. The experiment entails running a current through the “drive” layer (here, the top layer) and measuring the resulting flow of charge in the “drag” layer (the bottom layer). The panels indicate three (of many) possible drag scenarios associated with two sheets of bilayer graphene (grey). At left, exciton pairs form between holes (red) in the drive layer and electrons (green) in the drag layer, giving rise to a large drag effect. At center, holes drag electrons in the same direction (positive drag) because of momentum transfer between the charges in different sheets. At right, holes drag electrons in the opposite direction (negative drag), an observation in bilayer graphene that is yet to be explained.

Topics: Atomic Physics, Bose-Einstein Condensate, Condensed Matter Physics, Quantum Mechanics

Superfluids (fluids with zero viscosity) and superconductors (materials with zero resistance) have a common ingredient: bosons. These particles obey Bose-Einstein statistics, allowing a collection of them at low temperatures to collapse into a single quantum-mechanical state, or Bose-Einstein condensate. Bosons in superconductors consist of two paired electrons, but the pairing is weak and only occurs at low temperatures. In a quest to build devices that carry electricity with low dissipation at higher temperatures, researchers have therefore explored the possibility of engineering electrical condensates [1] out of strongly bound pairs of electrons and holes, or excitons. Now, two research groups have, independently, fabricated and characterized a graphene-based device that is thought to be a promising platform for realizing an exciton condensate [2, 3]. Neither group has yet found evidence for such a condensate—the ultimate goal of such experiments. But their measurements lay the groundwork for future searches.

Excitons form in semiconductors and insulators. The binding energy between the exciton’s electron and hole can be quite strong, greatly exceeding their thermal energy at room temperature. Unfortunately, excitons recombine quickly, too fast to allow a condensate to form. Although excitons coupled to light confined within a cavity can form hybrid particles (exciton-polaritons) that do live long enough to condense [4], such condensates require a continuous input of light.

APS Viewpoint: Chasing the Exciton Condensate
Michael S. Fuhrer, Alex R. Hamilton

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Well, that's a great question. I'll try to answer. You know your favorite scene in your favorite movie? You could watch it over and over again, and for those few minutes, you ARE the badass/lover/giant robot on the scene. You live that character's life, feel what they feel, and the words they say come naturally to your lips because they just fit the moment.

Each of my stories is like that. I become each character, male or female or other, I live their lives, I feel what they feel. And I do that everywhere - on the drive to work, when I have a few moments to space out at my desk, before I go to sleep at night. I live many lives, love multiple people, and the really good ones, the lives I love the most, I write down. And when the scene or moment runs out, I try on the next one. Sometimes I want to be the tragic, tortured loner, desperately seeking his love. Sometimes I want be the innocent lover, feeling her first kiss, her first moment of passion. I love my present live and my spouse, but before I met them, these other lives filled the loneliness, took away the empty hours in the middle of the night, when I had no one. It became addictive, and I haven't given it up. Today I am a mage, rescuing an innocent girl, a princess fighting to keep my land from conquest, and an alien species, holding back infected hordes with only my will.

For drawings - I see each scene in my head, like a movie, sometimes, and at a particularly good place I can freeze the moment, and then I look for source material, that is, a picture in my reference pose books that fit the image in my head as closely as I can. It is rare to find just the right pose, but when I do, I draw my best approximation of it. But sometimes, the image is so strong, I don't need reference pictures. Those come out the best.

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I have been writing and imagining stories since I was little, and still afraid of the dark. I also read incessantly, and my favorite books I would read over and over.

“But Ako, what does that have to do with anything? Get to the world building, already!”

I will, I will. I only mention those two things because they are pertinent. The first, imagining my own little stories, is relevant because they always reached a point where I could not drive them forward... it was as if there were no more ground to lay a road on, no foundation.

The second, reading books over and over, is relevant because the stories I loved so much and the writing styles in them that I admired taught me how to make a story do what I wanted it to do.

The culmination is this: a good story has to have a good back story, one that makes sense, is logical, even, in some cases, scientifically feasible. The story has to have a good history to give it foundation.

So here it is... the way I build a world, a whole universe, to support a story, because when all else fails, and the characters themselves cannot drive a story forward, the world that the story is based on can.

So. There are several pieces to consider. And please – these are not set in stone, this is just my process. It won’t work for everyone – I just hope it helps as a jumping-off point.

1) The world itself. And by the world, I mean the planet that the story takes place on, the star it circles, some of the nearby planets that may influence it, and of course, its moon or moons. Is there anything unusual about the planet itself? Does it have some unique quality that gives rise to the cool things in the story that I am writing? Remember, nature rarely wastes anything. If a people or a select group have an ability, in my mind, there should be something driving it, some need or use for it. I put that unusual thing into the planet itself, so that there is a logical reason that the extraordinary people can do what they do.

Is the planet Earth-type? It doesn’t have to be. Remember, the seasons are determined by the axial tilt, and not all planets will have the same tilt as Earth. Change the tilt, and you change the seasons, the kind and arrangement. And not all regions, even here on Earth, have the typical four – where I am from, the tropics, there is no winter or autumn.

Does the planet have several moons, or more than one sun? Moons influence not just the tides, but also the people. The sun or suns influence the kind of diurnal system and circadian cycle (the length of the “day” has an effect on the body of a living thing) the people have.

What is the cool new aspect that makes this world unique? Is it extra dense, making the people heavyworlders? Is it being constantly bombarded? Is it shrouded in nebulae?

I don’t’ think of all of this at the beginning of a story, of course. An interesting idea, a scene, will come to me, and I’ll just start writing, but sooner or later I knuckle down and build the world to fit the story.

2) The timeline and culture. The world and the history of your people will make a difference. Were there wars, upheavals, diaspora? Have they been in the same place for untold generations, or were they driven away, to find a new home?

How technologically advanced are they? Stone-age equivalent, medieval, modern, future, far future? What is their level of technology? Metallurgy? Are they agrarian, or industrial? Rural, urban, or nomadic?

What system of government do they have? A monarchy? A duarchy? A council? An elected body? A dictatorship?

3) The map. It is imperative to draw a map of your world, the different land-masses, the different nations, geographic types. I found out the hard way that geography influences people, culture, even the way people think. Coastal people don’t just eat fish, they worry about storms, tsunamis, invaders by sea, trade by sea. Mountain people can be hardy, isolated, and if the mountains are tall, used to the cold – probably. They are probably good at protecting their trade routes, and may have dominion over the only pass through their demesnes. You get the idea. Rivers move from high places to low land, and influence trade in a preindustrial society.

The map also shows where everyone is in relation to each other. Vague descriptions can work for a while, but sometimes the story needs the fine detail to give it depth. The sharing of borders can be significant.

This is just a snap-shot of what goes into world-building. I am sure I have not included a lot of things that others may consider. Different stories can have emphasis on different aspects.

 

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https://studios.amazon.com/projects/121410

Check out the new ethnic sci-fi children's series called THE TIME TELESCOPE. JIM DAVIS is an agent for the Bureau of Historic Investigations. He investigates missing information to their historic files of the future. He uses a Time Telescope to go back to the past to show eight year old genius, TASHA JONES, the importance of history first hand.

Please rate so this can be greenlighted by Amazon Studios. Make your voice count. 

We are only going to get on the networks/internet if we push for diversity on screen.

Thank You, Chris Love

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A New Migration...

Topics: Climate Change, History, Octavia Butler, Politics, Science Fiction


It's been a breathtaking seven days that puts into context what a president has to do: gather information, calm fears for now the second police shooting - the first generated by Alton Sterling and Philando Castile's executions; a terrorist attack by truck in Nice, France in the backdrop of two political conventions poised to pick this president's successor in a volatile world. This election will be a reflection of our fears and our character, beyond our own self-deluding mythology, who we really are.

Some context: "The Great Migration" was of approximately six million African Americans from the rural south to northern cities for opportunities in the budding industrial revolution and (hopefully) AWAY from the De Jure and De Facto segregation, Jim Crow and racial terrorism they were all fleeing. Notable ex-patriots: The ancestors of First Lady Michelle Obama (documented in "The Warmth of Other Suns" by Isabel Wilkerson); James Lee Boggs, deceased husband of Grace Lee Boggs and author of "The American Revolution: Pages from a Negro Worker's Notebook," in which he predicted the impacts of automation and what he referred to at the time "cybernation" that we recognize as the advent of computers in what were once jobs done by humans and less robotics or apps.

Note the plot synopsis from "Parable of the Sower" written by Octavia Butler in 1993:

Set in a future where government has all but collapsed, Parable of the Sower centers on a young woman named Lauren Olamina who possesses what Butler dubbed hyperempathy – the ability to feel the perceived pain and other sensations of others – who develops a benign philosophical and religious system during her childhood in the remnants of a gated community in Los Angeles. Civil society has reverted to relative anarchy due to resource scarcity and poverty. When the community's security is compromised, her home is destroyed and her family murdered. She travels north with some survivors to try to start a community where her religion, called Earthseed, can grow. Wikipedia

Now look at the plot of the US as it relates to a heating climate (I'm sure the same applies overseas as well):


The previous migration was a drive for opportunity and fairness; the next one will be for the first level of Maslow's hierarchy: comfort. The strain on resources will split humanity along tribal and factional lines like never before. Those who "have" will hoard and build up walled cities; defended castles to maintain their bounty from the hungered herds of "have not's." For those youth that will still be around (I'm not anticipating I will), as 2050 approaches they will see how far we've actually migrated...from the caves.

Scientific American: U.S Cities Are Getting Dangerously Hot [Graphic]
A dramatic rise in “danger days” is underway, Mark Fischetti

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Scientism...

Source: izquotes.com

Topics: History, Physics, Philosophy, Science


Scientism: It's an old word, so old it has to be added to your online dictionary almost everywhere you might type it. It also at first glance sounds reasonable, and in my own oft-used urban descriptor: "science-y."

This description at the beginning of the article from The American Association for the Advancement of Science is instructive and concise:

Historian Richard G. Olson defines scientism as “efforts to extend scientific ideas, methods, practices, and attitudes to matters of human social and political concern.” (1) But this formulation is so broad as to render it virtually useless. Philosopher Tom Sorell offers a more precise definition: “Scientism is a matter of putting too high a value on natural science in comparison with other branches of learning or culture.” (2) MIT physicist Ian Hutchinson offers a closely related version, but more extreme: “Science, modeled on the natural sciences, is the only source of real knowledge.” (3) The latter two definitions are far more precise and will better help us evaluate scientism’s merit.

A History of Scientism

The Scientific Revolution


The roots of scientism extend as far back as early 17th century Europe, an era that came to be known as the Scientific Revolution. Up to that point, most scholars had been highly deferent to intellectual tradition, largely a combination of Judeo-Christian scripture and ancient Greek philosophy. But a torrent of new learning during the late Renaissance began to challenge the authority of the ancients, and long-established intellectual foundations began to crack. The Englishman Francis Bacon, the Frenchman Rene Descartes, and the Italian Galileo Galilei spearheaded an international movement proclaiming a new foundation for learning, one that involved careful scrutiny of nature instead of analysis of ancient texts.

Descartes and Bacon used particularly strong rhetoric to carve out space for their new methods. They claimed that by learning how the physical world worked, we could become “masters and possessors of nature.”(4) In doing so, humans could overcome hunger through innovations in agriculture, eliminate disease through medical research, and dramatically improve overall quality of life through technology and industry. Ultimately, science would save humans from unnecessary suffering and their self-destructive tendencies. And it promised to achieve these goals in this world, not the afterlife. It was a bold, prophetic vision.

From the seeds of this formed the basis for utopia: H.G. Wells was the first science fiction writer to tackle it; Utopia was written I think before the genre was invented by Mary Shelly ("Frankenstein," fairly dystopian to say the least). Star Trek and the proclivities of Gene Roddenberry (an atheist) embodied it in Mr. Spock and the planet Vulcan: human contact with an entire species of beings supposedly led fully by logic and reason. The Earth - post Armageddon - surviving its own hubris and learning to cooperate beyond borders, languages, religions and the previous things that separated the human tribe and made "Mutually Assured Destruction" (M.A.D.) possible in a hopefully fictional Trek timeline.

New Thought: It apparently started in the 19th century originating from Phineas Parkhurst Quimby - imitated ad nauseum by opportunistic others, branching into several realms via modern communications (radio, television, Internet) from faith healers, prosperity gospel, pseudoscience and general quackery. As the link indicates, the enduring appeal is humans feeling empowered in an unpredictable and often cruel cosmos. Many traditional, non denominational, modern and/or New Age gurus have cashed in on this uncertainty quite lucratively. You can see its sustained and prosperous modern incarnations with a simple exercise of channel-surfing.

I would say scientism in its modern expression would be (a representative off-the-top-of-my-head trio) Richard Dawkins, Sam Harris and Neil deGrasse Tyson. They ARE scientists, but have made a lucrative living speaking and writing about the virtues of science; how if we all thought more rationally we wouldn't have to wait for heaven on Earth: we could design it ourselves. Sociologist Jeffrey Guhin in New Scientist challenged the idea that Tyson forwarded of a nation totally run by logic, reason and science (sounds familiar? \\//_). He posits the very simple question that gives one pause: what does "rational" mean? Things that "sounded" rational and science-y like Eugenics was used for wholesale discriminatory behavior by Hitler's Third Reich (you know: concentration camps and gas chambers). If we just "follow-the-data" of standardized test scores, then the often debunked thesis behind "The Bell Curve" sounds rational, because one does not have to take into account generations of poverty vis-à-vis slavery; sharecropping (a word that is a contradiction in terms on its own); racial terrorism; Jim Crow; De Facto and De Jure segregation; bank red lining; differentiated education (for me, torn and outdated books supplemented by xeroxed copies my teachers purchased at their own expense) and no career opportunities to climb the economic ladder to a better life. The better correlation is wealth of parents and guardians to academic achievement, most of which happens to be the dominant culture.

The National Science Foundation (I think) was right to commission a study on Science Literacy and the public good, as more than anything that will determine the outcome of nations as we share and contest resources on this Earth, or prepare as a species to inhabit other worlds to extend us beyond the fate of the dinosaurs.

The broad brush of "all we need is science" is the proportional equivalent to its antithesis: "all we need is (fill in the blank): Buddha, Chia Pets, Gaia, Jesus, Odin, Mood Rings, Mood Rocks, Positive Thinking, Possibility Thinking, Prayer Cloths, Quantum Physics (since we travel < c, highly doubtful), Holy Water; Thor."

What we could all use is a return to actually teaching civics to our respective populations, and leave proselytizing to family units. Methinks both camps need to step back and consider a true "separation of church and state" (& science). It will benefit both camps better to stay in their lanes, without either one harmfully denigrating the other. We need to survive together as a species, or in the words of Dr. King "perish together as fools." The Earth does not need us to circumnavigate the sun, and the universe if we were so foolish wouldn't blink at our hubris...or departure.
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Kollege Kids Update & Relaunch

Hello BSFS members; I am Ricardo H the co founder and creator of Kollege Kids. I am the visual/animation coordinator and  co-producer of this show.  As you know we are making major changes to Kollege Kids. We are introducing a new show called "Professor Holmes" which will be the prelude to Kollege Kids. In Professor Holmes; he will be the main character to explain the characters story and background. He will come in contact with other Kollege Kids parents as well.

We will add in a virtual world called Chessman/Africa America which will we will explore and know the story behind the world. The Kollege Kids videos have been removed off YouTube because we going to relaunch it in the fall.  We want to give you a better quality product and we plan on relaunching it this fall. Be on the lookout for Professor Holmes/ Kollge Kids in the Fall.

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Neural Networks and H2O...

Schematic showing water molecules in the denser water phase (left) and the ice phase. (Courtesy: Tobias Morawietz)


Topics: Artificial Intelligence, Computer Engineering, Computer Science


Artificial neural networks have been used to simulate interactions between water molecules and provide important clues about the remarkable properties of this live-giving substance. The study has been carried out by physicists in Germany and Austria, who used the networks to perform simulations 100,000 times faster than possible with conventional computers. Their work offers explanations for two key properties of water – its maximum density at 4 °C and its melting temperature – but the technique could be expanded to include other aspects of this ubiquitous substance.

Physicists and chemists have long found water's unusual properties difficult to explain. Its density, for example, peaks at around 4 °C, which means that frozen water floats on liquid water – a property that is vital for aquatic creatures that have to survive in cold climates. Massive computer simulations have shown that hydrogen bonds between water molecules play a key role, but these simulations do not tell the whole story.

One key challenge is understanding the role of van der Waals interactions, which arise from quantum fluctuations in the electrical polarizations of water and other molecules. Van der Waals interactions have traditionally been hard to include in computer simulations, but Tobias Morawietz and colleagues at the Ruhr-Universität Bochum and the University of Vienna have now used artificial neural networks (ANNs) to model them in water. ANNs are computer algorithms that "learn" how to perform a specific task by being fed data related to that task. An ANN could, for example, learn how to recognize an individual's face by being fed photographs of people and being told which images are of the target person.

Physics World: Neural networks provide deep insights into the mysteries of water
Hamish Johnston

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Join DJ International TV This Sunday night in Berwyn and meet Bill McCormick, one of the authors of Legends Parallel.

Bill will be discussing his transition from being a DJ on Z-95 to being a professional sci-fi writer and and how odd things can get in the real world. There will be cheap drinks, good food, and lots of fun.

Nine 30 Ten Sports Lounge - 5:00 PM / 07/17
6710 W Cermak
Berwyn, IL 60402

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Genesis Planet...

Image Source: Daily Galaxy link below


Topics: Astronomy, Astrophysics, Big Bang, Cosmology, White Dwarfs


I took the title from the Daily Galaxy's original post. It seemed apropos and succinct, but I am aware of the strong feelings it may generate.

Science strives mightily to fight "confirmation bias" : "the tendency to interpret new evidence as confirmation of one's existing beliefs or theories." The way scientists try to weed out minutiae is through peer review. Feelings are bruised, but truth is winnowed from social and preconceived chaff. Previous theories once held in high regard are thrown away. As new technology and instruments become available, this disciplined process is repeated. A scientific discovery may or may not confirm already preconceived notions. It's usually the latter. Such is not science, but the seeds of the boondoggle, pseudoscience and superstition; it is the natural tendency in an ever-changing world to reach for the comfortable instead of lighting "a candle in the dark" (Carl Sagan).

“There are more things in Heaven and Earth, Horatio, than are dreamt of in your philosophy.”

William Shakespeare, Hamlet

"I would rather have questions I can't answer, than answers I can't question."

Richard Feynman

In 2015, NASA's Hubble Space Telescope precisely measured the mass of the oldest known planet in our Milky Way galaxy. At an estimated age of 13 billion years, the planet is more than twice as old as Earth's 4.5 billion years. It's about as old as a planet can be. It formed around a young, sun-like star barely 1 billion years after our universe's birth in the Big Bang. The ancient planet has had a remarkable history because it resides in an unlikely, rough neighborhood. A few intrepid astronomers have concluded that the most productive to look for planets that can support life is around dim, dying stars white dwarfs.

"In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs," said Avi Loeb, theorist at the Harvard-Smithsonian Center for Astrophysics (CfA) and director of the Institute for Theory and Computation. Even dying stars could host planets with life - and if such life exists, we might be able to detect it within the next decade.

The ancient planet orbits a peculiar pair of burned-out stars in the crowded core of a cluster of more than 100,000 stars. The new Hubble findings close a decade of speculation and debate about the identity of this ancient world. Until Hubble's measurement, astronomers had debated the identity of this object. Was it a planet or a brown dwarf? Hubble's analysis shows that the object is 2.5 times the mass of Jupiter, confirming that it is a planet. Its very existence provides tantalizing evidence that the first planets formed rapidly, within a billion years of the Big Bang, leading astronomers to conclude that planets may be very abundant in our galaxy.

The Daily Galaxy:
Hubble Space Telescope Reveals "The Genesis Planet" --The Oldest Known Planet in the Milky Way (Today's Most Popular)

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cQED...

A. Houck/Princeton

Figure 1: Scanning defect microscopy provides a map of photons in a resonator lattice. Houck and colleagues demonstrated the technique using 49 resonators (grey lines) that were coupled together to form a kagome lattice. This configuration consists of a triangular arrangement of three resonators at each point in a honeycomb lattice.

Topics: Electrical Engineering, Nanotechnology, Quantum Electrodynamics


A scanning probe detects the quantum states of photons in a microwave circuit, providing the information needed for quantum simulations.

Quantum mechanics rules the dynamics of light and matter. Yet performing a quantum-mechanical simulation of a material from first principles is practically impossible on a classical computer because the complexity of the simulation increases exponentially with the number of particles involved. The solution, according to Richard Feynman, was to build a machine out of quantum building blocks that could directly emulate the material itself [1]. Prototypes of such quantum simulators that are based on ultracold atoms, ions, photons, and superconducting microwave circuits are now available [2], with the latter, in particular, having attracted Silicon Valley’s interest. The challenge with these circuit-based simulators, however, is that they are 2D, which complicates the readout of their constituent elements. Andrew Houck from Princeton University, New Jersey, and colleagues have now delivered an attractive solution by developing a technique [3], called scanning defect microscopy (Fig. 1), that determines the number of photons occupying each mode of a 2D microwave circuit. It is this information that would serve as the fundamental input and output for certain quantum simulations.

Superconducting microwave circuits combine electronic and photonic degrees of freedom [4, 5]. The main element of the circuit is a transmission line, which is made up of a central superconducting wire separated by a gap from two grounded plates. All of these structures are on a single plane, as if one had taken a 2D slice through a coaxial cable. When truncated, the transmission line becomes a resonator, which can host discrete photon modes within its gaps. Large lattices of resonators can be engineered in various 1D or 2D geometries by coupling two, three, or more resonators together via a capacitive interface. In many ways, photons in such devices behave similarly to electrons in a solid.

To make microwave circuits that can simulate quantum phenomena faster than a classical computer, however, resonator lattices have to be integrated with superconducting qubits. Such qubits are controlled with electrical currents in a Josephson tunnel junction, and in many respects, they behave like artificial atoms, which couple to the photons in the circuit. As a result, superconducting microwave circuits can be used to explore the coupling between the quantum states of light and matter, the regime of circuit quantum electrodynamics (cQED). Photons in these devices often exhibit striking matter-like behavior [6, 7], providing the basis for the simulation of complex materials. Such circuits can be fabricated on a substrate using standard lithographic techniques, with qubits and resonators that are hundreds of micrometers or even millimeters in size.

APS Viewpoint: A Bird’s Eye View of Circuit Photons
Sebastian Schmidt, Institute for Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland

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CFP: Afrofuturism in Time and Space

Sharing this post from the Science Fiction Research Association (SFRA-L) Listserv:

Dear Comrades:

 

I'm delighted to announce that Isiah Lavender III and I seek essay proposals for an anthology called "Afrofuturism in Time and Space." Please see the CFP below and attached for more details. Also, please note that we thought we'd posted this sooner, and so the deadline in is just a few weeks.... If you are interested and need a bit more time to develop your proposal, please contact either me or Isiah off list.

 

Thanks, enjoy, and please pass along the good word. I hope to see proposals from some of you soon!

 

Best, Lisa

 

CFP: Afrofuturism in Time and Space

 

Co-editors Isiah Lavender III and Lisa Yaszek seek essays on black speculative art across

centuries, continents, and cultures for a new collection called “Afrofuturism in Time and Space.” When Mark Dery coined the term “Afrofuturism” in 1993 to describe art that explores issues of science, technology, and race from technocultural and science fictional perspectives, he did so primarily in reference to postwar African-American art, music, and literature. Over the past decade, however, scholars and artists alike have begun to redefine Afrofuturism, pushing its temporal boundaries back to the 17th-century roots of modern science and industry while expanding its geographic boundaries to include diasporic black and pan-African speculative fictions. As editors, we seek scholarly essays and artists’ case statements that demonstrate how to productively rethink Afrofuturism as a globe-spanning tapestry of creative voices and aesthetic practices linking historic African American, contemporary black Atlantic, and pan-African authors together in provocative new ways. That is to say, we are looking both backward through

history and outward from the U.S. At the same time, we also welcome works that treat what we might now call “classic” Afrofuturist authors and themes from new methodological perspectives.

 

While we, of course, welcome proposals on Samuel R. Delany, Octavia E. Butler, and Nalo

Hopkinson, we also seek essays that address:

 

• Early African American literature

• Slave narratives and neo-slave narratives

• Jim Crow and Apartheid

• Poetry, film, graphic narrative, and sonic fictions

• Black Atlantic and other black diasporic aesthetic traditions

• Pan-African and regional African speculative fictions

• Little-known artists, understudied artists, emerging artists, and mainstream artists

working with Afrofuturist themes

• Occult or native scientific practices as they inform Afrofuturist texts

 

The editors invite submissions that respond to the focus of the volume and also welcome general inquiries about a particular topic’s suitability. Please submit 250 word abstracts, a working bibliography, and a brief CV electronically as MS Word attachments to Isiah Lavender III at isiahl@lsu.edu and to Lisa Yaszek at lisa.yaszek@lmc.gatech.edu by July 30, 2016.

 

Accepted articles should be between 5000 and 6500 words in length, including “Works Cited,” and prepared in MLA style, and forwarded as MS Word attachments.

 

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Fuels and Futures...



Figure 1. The correlation between hydrocarbon-based power consumption and economic output for most countries on Earth. A power-law fit finds that annual GDP per person is G = $10 500 (C/kW)0.64, where C is hydrocarbon-based energy consumption per second per person. The tight power-law relationship indicates that economic prosperity is not currently feasible without consumption of hydrocarbon fuels. The power law is reminiscent of scaling laws in biology; 15 the flow of petroleum through economies resembles the flow of blood in mammals. On average, the hydrocarbon power consumed in the US is 8 kW per person, the same as 80 incandescent 100 W bulbs burning continuously. If the US were to rely only on its currently available renewables—biomass cogeneration, wood, hydropower, geothermal, wind, passive solar, and photovoltaics—power consumption would drop to four bulbs per person; eliminating hydropower and biofuels would reduce the number to one or two. The reduction would entail such a change in lifestyle as to make the US unrecognizable. 16 (Data source: Central Intelligence Agency, World Factbook, 2015; DOE/Energy Information Administration, 2015.)



Citation: Phys. Today 69, 7, 46 (2016); http://dx.doi.org/10.1063/PT.3.3236



Topics: Alternative Energy, Economy, Green Energy, Green Tech, Politics


President George W. Bush famously said: "we're addicted to oil." That's an understatement, as it is evident this is the underpinning of the planetary economy.

The sad part is, without physics to give an intervention of sorts, the kind of utopia envisioned by Gene Roddenberry in Star Trek is highly unlikely. We're already showing the strains of automation, globalization and trade deals without a forethought on the impacts with populations at the bottom of societal ladders. It makes way for demagogues in the US, the UK and elsewhere that don't quite have a clue how to solve the problem, but play into xenophobic fears (as evidenced) to their advantage.

To contend with the challenges of fueling modern society, the physics community must collaborate with other disciplines and remain broadly engaged in research and education on energy.

For how long and in what ways can humans sustain the energy-intensive way of life we take for granted? That consequential question is one that physicists must help answer. As we pass the middle of 2016, oil prices are at a 10-year low, partly because of the surge in production of oil and natural gas from fracking. The current fracking boom may ease the transition to a new mix of energy resources. Conversely, it may make us complacent and delay the transition or incite popular resentment and impede the transition.

The physics community must participate in shaping how energy issues play out over the coming decades. The development of fusion reactors, photovoltaic cells, and other potential energy sources clearly requires contributions from physicists. As educators, many of us occupy the central position of teaching students the very definition of energy and the fundamental limits on extraction of free energy from heat. Beyond the classroom, we should all be concerned with the public’s understanding of what energy means. Even in the specific case of fossil fuels, there is room for our increased technical engagement through collaboration.

Physics Today: Physics, fracking, fuel, and the future
Michael Marder, Tadeusz Patzek and Scott W. Tinker

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