Reginald L. Goodwin's Posts (3028)
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| A cross-sectional image is shown of a silicon-based optical fiber with solar-cell capabilities. Shown are the layers -- n+, i, and p+ -- that have been deposited inside the pore of the fiber. (Image: Badding lab, Pennsylvania State University) |
University Park, PA and Southampton, England--Researchers at Pennsylvania State University and the University of Southampton have created a silicon-based optical fiber with solar-cell capabilities that is scalable to many meters in length and has a bend radius of about 400 microns. Possible in the future: weaving together solar-cell silicon wires to create flexible, curved, or twisted solar fabrics. The findings are posted in an early online edition of Advanced Materials and will be published on a future date in the journal's print edition.
The team's new findings build on earlier work addressing the challenge of merging optical fibers with silicon chips. Rather than merge a flat chip with a round optical fiber, the team found a way to build a new kind of optical fiber with its own integrated electronic component, bypassing the need to integrate fiber-optics with chip-based electronics. To do this, they used high-pressure chemical vapor deposition to deposit semiconducting materials directly into holes in optical fibers.
Laser Focus World:
Silicon p-i-n junction optical fibers could lead to photovoltaic fabrics
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Artist's impression of a protostar, with its jets of outflowing matter, protoplanetary disk, and envelope of gas and dust. |
In their early stages of formation, the objects that will eventually become stars are small. They grow by gathering material from the surrounding cloud of gas. At least, that's what current theories tell us what happens. Due to the difficulty of resolving star systems during their formative years, most observations have been from later periods of their evolution, after the protostar has reached a substantial fraction of its final size and mass.
A new observation has revealed the youngest protostar yet observed. John J. Tobin and colleagues measured the properties of the newborn star and its environment, determining that it had only accreted about 20 percent of the matter surrounding it, and hasn't even begun nuclear fusion. Based on this, the protostar was likely no more than 300,000 years old at the time of observation, with the distinct possibility that it was even younger.
Ars Technica: Astronomers discover youngest protostar yet observed, Matthew Francis
I pulled the scheduled post on p-i-n diode technology. It will appear on Monday.
Nigerian Novelist Chimamanda Adichie spoke at TED on a subject from which I title this posting (and give her credit), related to the tragedy in Newtown, Connecticut yesterday. It is east of Danbury, for me merely 30 - 45 minutes drive from me in New York.
Ms. Adichie was speaking on the power of ignorance with respect to stereotypes. Linda Christensen, following this theme as well, encouraged her African American and Latino students to express their experiences in personal essays.
We are getting bits and pieces of a story and calls for reactions; bills. All that may come to pass eventually, but some things to consider, as a single story isn't the full picture:
- Doomsday: a lot of angst and hype about next Friday being suddenly 10^100 years into the future with imminent, hypo thermal death to the universe. At least that's the conventional science regarding the universe's end -- and NOT the hype. The good news is by THAT distant time, we'll all be gone (and I no longer blogging) when this occurs: just not next Friday.
- Active shooter training: we're going to have to think about this. Places like Israel search you before you enter...the mall. That's not comfortable for US residents to think about, just as taking off our shoes and pat searches in airports still are not comfortable post-9/11, but we may have to think about and earnestly consider things we'd rather not.
- Mental health: it amazes me that we'd never think of walking about with an obviously broken arm, pierced skin, blood streaming out of an open wound, yet we HIDE mental health issues. We stigmatize those that want to seek help as if admittance of a problem would be "career limiting." We spend more time on Facebook and "words with friends" when we need to speak to one another; see a play versus a movie; go to dinner at a restaurant and talk to one another.
- Gun control: we're going to have to debate this (unlike both candidates' dodge in the last election cycle). Debate: A formal discussion on a particular topic in a public meeting or legislative assembly, in which opposing arguments are put forward. Instead of dismissing occurrences as "isolated"; this is becoming too frequent to ignore.
And one in particular, who can no longer...
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| To verify entanglement among the three photons, the physicists measured the times that the photons arrived at a detector. This 2D histogram shows that groups of three photons are all localized to a small region, indicating strong correlations in the arrival times of the three photons. Image credit: L. K. Shalm, et al. ©2012 Macmillan Publishers Limited |
The physicists, from the University of Waterloo and the University of Calgary, have published their paper on three-photon energy-time entanglement in a recent issue of Nature Physics. As the physicists explain, this new form of entanglement is the three-photon version of the famous EPR correlations for continuous variables (e.g., position and momentum) between two particles. The EPR thought experiment, published in 1935, raised questions about the fundamental concepts underlying the young theory of quantum mechanics. "The Heisenberg uncertainty principle forbids one from simultaneously discovering both the position and momentum of a particle with arbitrary accuracy," lead author Krister Shalm of the University of Waterloo told Phys.org. "EPR pointed out that, if you create a pair of entangled particles, it is possible to measure both the position and momentum of both of them with arbitrary precision. It is still impossible to learn both the position and momentum of each of the individual particles, but, instead, we can learn information about the total position and momentum they share. Entangled particles, in some sense, are the ultimate team players. They lose their own individual identity with all the information in the system contained in the correlations."
Phys.org: Physicists extend entanglement in Einstein experiment, Lisa Zyga
12.12.12: The last time this date, or repetition of dates will occur again until January 1, 2101 (the 01.01.01 of the 22nd Century). The Astronomical Society of the Pacific proclaims today Anti-Doomsday Day. There's a concert for Hurricane Sandy relief.
AGU is the American Geophysical Union. Yesterday, I posted Scientific American's assertion that we've become essentially two camps: scientists and non-scientists, or (I think) more accurately: those who trust The Scientific Method and its conclusions, and those -- for various reason -- who do not.
Dan Satterfield is the author of the blog (link below). He is a meteorologist/weatherman with 32 years of experience.
He advises: read the blog post, then watch the embed Carl Sagan lecture from AGU's annual meeting.
"We've arranged a global civilization in which the most crucial elements — transportation, communications, and all other industries; agriculture, medicine, education, entertainment, protecting the environment; and even the key democratic institution of voting — profoundly depend on science and technology. We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces." Carl Sagan
American Geophysical Union: IPCC Climate Forecast from 1990 - Amazingly Accurate
Astronomical Society of the Pacific: Anti-Doomsday Day
Related links:
#P4TC: Missing In Action
Utopia Planitia (Latin: "Nowhere Plain") is the largest recognized impact basin on Mars and in the solar system with an estimated diameter of 3300 km,[1] and is the Martian region where the Viking 2 lander touched down and began exploring on September 3, 1976. It is located at the antipode of Argyre Planitia, centered at 49.7°N 118.0°E. It is in the Casius quadrangle and the Cebrenia quadrangle of Mars.
Many rocks at Utopia Planitia appear perched, as if wind removed much of the soil at their bases.[2][3] A hard surface crust is formed by solutions of minerals moving up through soil and evaporating at the surface.[4] Some areas of the surface exhibit what is called "Scalloped topography," a surface that seems to have been carved out by an ice cream scoop. This surface is thought to have formed by the degradation of an ice-rich permafrost. (Wikipedia) Also known in Star Trek lore, the place for building Federation starships.
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| Utopia Planitia shipyards |
Hence, the appropriate title for the following from Scientific American:
In 1993, Americans elected the first physicist to Congress: Vern Ehlers, a Republican from Michigan. Just six years later, former assistant director of Princeton’s Plasma Physics Laboratory, Rush Holt, a Democrat from New Jersey, joined him. And in 2008, Fermilab physicist and Illinois Democrat Bill Foster joined them, only to lose re-election in 2010 before regaining his seat this year. At that rate, Holt joked to an audience of mostly chemists at Princeton University on November 9, “By mid-century, the population of Congress would be physicists.”
But that’s a “slow way” to inject scientific thinking into the political process, Holt argued. “I wish we could get more Americans and, hence, their representatives thinking like scientists, which means basing our conclusions on evidence,” he said.
That laudable goal may prove even more challenging than turning a physicist into an electrifying political speaker. Because humans are not born statisticians, thinking scientifically is both technically and psychologically challenging . We prefer a story (anecdote!) to a compilation of statistics (data!). The modern world, as Holt observed of C.P. Snow’s famous analysis decades ago, has become divided into two disparate camps: scientists and non-scientists.
This may be most apparent currently on the subject of climate change...“The evidence for climate change is strong enough that we should be taking very bold and very expensive action because the costs of not taking action will be even more expensive,” Holt argued, suggesting that legislation to combat climate change “probably will be undertaken again, I would guess relatively soon in the next Congress.”
Scientific American:
Representative Rush Holt's Advice to His Fellow Scientists on Politics
David Biello
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| Optics and Photonics |
Usually, if you blast enough light into an insulator, it will blow up quickly or break down slowly. But today, a pair of papers published in Nature describe using very intense femtosecond laser pulses that not only do not damage the material, but also induce electrical currents in an otherwise insulating dielectric—specifically a fused silica prism (Nature, DOI: 10.1038/nature11567; Nature, Advanced DOI: 10.1038/nature11720).
The work is exciting because insulators that can quickly change into conductors (and back into insulators again) could be used for signal switching. Today's fastest semiconductor switching is measured in terahertz, but light-induced switching in insulators, such as demonstrated in these papers, could work at petahertz rates—more than 10,000 times the rate of current electronics. In the near-term, it could also make possible petahertz (1015 hertz) metrology.
Optics an Photonics: Ultrafast Light Turns Insulator into a Conductor, Yvonne Carts-Powell
In 12 days...it will be the Winter Solstice for the northern hemisphere.
It will be the shortest day on the calendar; five days before Christmas/Saturnalia/Yuletide, Kwanzaa: it will be three days post the end of Hanukkah. It will be as it's always been.
Then, as it always has (and always will for some time), the days will start getting incrementally longer. Spring will arrive, temperatures will warm and flowers will blossom. We'll have to deal with the weather: post Katrina, post Rita, post Irene, post Sandy.
There is an eventual end of things just as there is an eventual end of us as living creatures.
Times arrow is orchestrated by entropy: the tendency for things to go from order to disorder, from hard, strong and young to the latter opposite as we age. Due to entropy, you can smell perfume sprayed out of a bottle (otherwise, it would either drop ungracefully in a lump on the floor, or never leave its container).
I am concerned...and saddened that so many young are led by this media hype to dread the future; to contemplate Hamlet's soliloquy. You have so much to live for...discover...enjoy. I lived with doomsday clocks and duck-and-cover drills due to a Soviet threat that now no longer exists.
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| Merry-go-round |
I urge educators and parents to share the contents of the link below with your children. When the young are injured by myth as credible as Y2K was for spin, sport or ratings...it is no longer a game!
The surest cure to manipulated ignorance...is knowledge.
David Morrison
Director, Carl Sagan Center for the Study of Life in the Universe
NASA Senior Scientist
There is widespread and unnecessary fear of doomsday on December 21, 2012. Some people worry about a Maya prophesy of the end of the world, others fear a variety of astronomical threats such as collision with a rogue planet. Opinion polls suggest that one in ten Americans worry about whether they will survive past Dec 21 of this year, and middle-school teachers everywhere report that many of their students are fearful of a coming apocalypse.
SETI Institute: Doomsday 2012 Factsheet
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| Physics World - a 'solar energy funnel' |
Computer simulations by researchers in the US and China could lead to solar cells that work efficiently across a broad range of the solar spectrum. Dubbed a "solar energy funnel", the new concept offers a way of using strain to modify the band gap of a semiconductor so that it responds to light within a range of different wavelengths. However, the funnels have yet to be made and tested in the lab – some researchers suggest using them in practical devices could prove problematic.
The basic operating principle of a solar cell is that an electron in the valence band of a semiconductor material absorbs a photon and jumps across an energy "band gap" into the conduction band. The result is an electron and a positively charged hole, which do not move separately through the semiconductor but instead form a bound state called an exciton. To extract electrical energy, the electron is collected at one electrode and the hole at another.
Light from the Sun comes in a range of wavelengths and therefore an ideal solar cell should be very efficient at converting this broad spectrum into electricity. Unfortunately, semiconductors with a fixed band gap are not very good at doing this. In particular, longer-wavelength photons do not have enough energy to make an electron to jump the band gap and will not be converted into electrical energy. Photons with energies greater than the band gap will be converted, but regardless of their energy they will only create just one electron–hole pair. Any excess energy will be dissipated in the semiconductor as heat.
Physics World: Semiconductor funnel could boost solar cells
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| Physics World - How ULAS J1120+0641 may have appeared |
For the first time, astronomers have determined the chemical composition of gas from the first billion years of the universe's life. The gas consists mostly of neutral hydrogen atoms, which means that it may mark the era before stellar radiation began ionizing the universe. Furthermore, the gas shows no signs of the heavy elements that are forged in stars so it may contain only the light elements produced by the Big Bang.
"We are starting to look back to the epoch that is probably when the first stars were turning on," says Robert Simcoe, an astronomer at the Massachusetts Institute of Technology who built the instrument that acquired the spectrum of the far-off gas. "This is the very first [chemical] measurement that anybody has made in any environment at these early times."
The Big Bang, which occurred 13.7 billion years ago, showered the cosmos with hydrogen and helium. Aside from a trace of primordial lithium, heavier elements – which astronomers call metals – arose later, after stars formed and exploded, casting oxygen, iron and other metals into space. Furthermore, the first stars radiated extreme ultraviolet light that ionized gas, tearing electrons from the hydrogen nuclei. The universe is still ionized today.
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"And we who embody the local eyes and ears and thoughts and feelings of the cosmos we've begun, at last, to wonder about our origins. Star stuff, contemplating the stars organized collections of 10 billion-billion-billion atoms contemplating the evolution of matter tracing that long path by which it arrived at consciousness here on the planet Earth and perhaps, throughout the cosmos."
Physics World: Ancient gas sheds light on universe's first billion years
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| Physics arXiv |
Part of science is the point/counter-point of differing views. It is part of the process of the Scientific Method. Famous recollection: the argument between Einstein and Bohr on Heisenberg and Quantum Mechanics. Now an accepted part of physics, Einstein ultimately lost.
To the Google-it-downloading public, this can be confusing and frustrating. However, this is science: examination leads to different theories; theories are vigorously debated, verified or refuted. Then, everyone in the science community decides to go in the direction of the new paradigm. Probably why a lot of scientist (at least in the US) don't go into politics.
One of the driving forces in modern science is the idea that the Universe “computes” the future, taking some initial state as an input and generating future states as an output. This is a powerful approach that has produced much insight. Some scientists go as far as to say that the Universe is a giant computer.
Is this a reasonable assumption? Today, Ken Wharton at San Jose State University in California, makes an important argument that it is not. His fear is that the idea of the universe as a computer is worryingly anthropocentric. “It’s basically the assumption that the way we humans solve physics problems must be the way the universe actually operates,” he says.
What’s more, the idea has spread through science without any proper consideration of its validity or any examination of the alternatives. “This assumption…is so strong that many physicists can’t even articulate what other type of universe might be conceptually possible,” says Wharton.
Physics arXiv: Why The Universe Is Not a Computer
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| Curiousity - AAAS Science Mag |
SAN FRANCISCO, CALIFORNIA—The first full analysis of martian soil by the Curiosity rover has detected simple carbon compounds that could be the first traces of past martian life ever found, NASA scientists announced here today at a press conference at the annual fall meeting of the American Geophysical Union. The catch is that Curiosity team members can't tell yet whether the organic matter was once alive, was never alive and drifted onto Mars from space, or was simply cooked up in Curiosity's analytical instrument from lifeless bits of soil. Figuring out the ultimate source of the carbon in this organic matter—biological or not—will take time. "Curiosity's middle name is Patience," cautioned Curiosity project scientist John Grotzinger of the California Institute of Technology in Pasadena.
AAAS Science Mag: The First Signs of Ancient Life on Mars?
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| Nature |
A global team of researchers has come up with the 'most accurate estimate' yet for melting of the polar ice sheets, ending decades of uncertainty about whether the sheets will melt further or actually gain mass in the face of climate change.
The ice sheets in Greenland and Antarctica are melting at an ever-quickening pace. Since 1992, they have contributed 11 millimetres — or one-fifth — of the total global sea-level rise, say researchers. The two polar regions are now losing mass three times faster than they were 20 years ago, with Greenland alone now shedding ice at about five times the rate observed in the early 1990s.
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| Water ice is abundant in Mercury's dark polar craters. NASA/Johns Hopkins Uni Applied Phys Lab/Carnegie Inst of Washington |
Talk about a land of fire and ice. The surface of Mercury is hot enough in some places to melt lead, but it is a winter wonderland at its poles — with perhaps a trillion tonnes of water ice trapped inside craters — enough to fill 20 billion Olympic skating rinks.
The ice — whose long-suspected presence has now been confirmed by NASA's orbiting MESSENGER probe — seems to be much purer than ice inside similar craters on Earth's Moon, suggesting that the closest planet to the Sun could be a better trap for icy materials delivered by comets and asteroids. Three papers detailing the findings are published today in Science.
...albeit a little long winded (12 minutes?): most poetry slams are at a 3 minute limit, unless you consider Haiku slams, which by its very structure are...brief.
Sigh! What exposure to too many fumes in the lab will do...
Fermilab Lecture Series Presents: Physics Slam
The supermassive black holes occupying the centers of most galaxies have a close relationship with their galactic hosts. Galaxies with large central bulges have massive black holes, while the relatively lightweight black holes live in galaxies with smaller bulges. This link has been observed in enough cases to raise it nearly to a principle: black holes and galactic bulges grow together, as part of a single process.
A new observation has revealed a galaxy that isn't just bending the rule, but completely breaking it. In most systems, the black hole's mass is about 0.1 percent of the mass of the galaxy's central bulge. Remco van den Bosch and colleagues identified a black hole with a mass that's about 59 percent of the mass of the central bulge. In fact, this black hole is one of the most massive ever observed, a striking discovery in a galaxy much smaller than our own. The galaxy itself is a bit on the small side, and the researchers suggest that we might want to look at the black holes in more galaxies this size.
Ars Technica:
Violates established relationship between black holes, galactic bulges masses.
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Fort Davis, Texas — Astronomers have used the Hobby-Eberly Telescope at The University of Texas at Austin's McDonald Observatory to measure the mass of what may be the most massive black hole yet — 17 billion Suns — in galaxy NGC 1277. The unusual black hole makes up 14 percent of its galaxy's mass, rather than the usual 0.1 percent. This galaxy and several more in the same study could change theories of how black holes and galaxies form and evolve. The work will appear in the journal Nature on Nov. 29.
NGC 1277 lies 220 million light-years away in the constellation Perseus. The galaxy is only ten percent the size and mass of our own Milky Way. Despite NGC 1277's diminutive size, the black hole at its heart is more than 11 times as wide as Neptune's orbit around the Sun.
McDonald Observatory:
Using Hobby-Eberly Telescope
12-years-old: from the BRONX!
According to Grandmaster Larry Christiansen, chess is more than a strategy game — it’s a “mental war” involving sharp mental faculties and efficient cognitive processing. Christiansen gave a simultaneous exhibition at a Cornell Chess Club event on March 30th. At a simultaneous exhibition a highly ranked chess player plays multiple games at the same time with a number of different players. In this event, Christiansen faced more than 20 opponents without suffering a single loss. Prior to the exhibition, Christiansen shared a few secrets of the trade with other avid chess players.
Cognitive Science, Computer Science and Chess: Grandmaster Christiansen Visits C.U.
Scientists have found through a computer simulation that the universe grows like a giant brain.
This research has been published online in the November 16th issue of the journal Nature’s Scientific Reports.
Scientists have found that there are some single basic laws, which are still unknown, are working from the tiny electrical firing of neurons to the expansion of the universe.
“Natural growth dynamics are the same for different real networks, like the Internet or the brain or social networks,” said study co-author Dmitri Krioukov, a physicist at the University of California San Diego.
Researchers made a computer simulation of the early universe by breaking it to the tiniest possible units even smaller than the sub-atomic particles. They linked any quanta – the smallest discrete quantity of a physical property – in the huge celestial network and found that more and more space-time was added to the universe as the simulation progressed showing that the “network” connections between the matter in the galaxies also grew.
Researchers found that the growth of social networks and brain circuits follow the same path as the growth of universe i.e. their networks expanded in the similar way. They maintain a balanced links between similar nodes with the ones that had already many connections.
Say People: Single unknown fundamental laws are controlling everything
The looming possibility of deep, across-the-board budget cuts-know as sequestration-poses historic risk for U.S. research and development, experts said at a Capital Hill briefing organized by AAAS. Unless lawmakers find a compromise by year's end to avert the cuts, the crippling impact could be felt for a generation, they warned, even as other nations are increasing R&D investments.
Without an agreement, sequestration would be imposed automatically beginning in the first week of January. It could slash the U.S. R&D investment by 8.4%--some $58 billion--over five years. That would mean laboratory closures and layoffs, the experts said, and it would jeopardize current research in areas ranging from genetic medicine and advanced manufacturing to batteries that could allow a 10-fold increase in the range of electric cars. It might also discourage a new generation from careers in science and engineering.
AAAS: "Sequestration" Budget Cuts Would Cripple U.S. Scientific Progress, Experts Warn
