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| Simplifying the complex: some of the mathematical constructions at G4G13; Bjarne Jesperson’s “Knotted Cube” is second from right. (Courtesy: Robert P Crease) |
Topics: Education, Mathematics, Logic, Philosophy, Physics, STEM
When Roxana started to juggle balls with her feet it was proof, if any were needed, that G4G is the most disciplinarily diverse conference around.
G4G, or “Gathering for Gardner”, is a biennial event in honor of the recreational mathematician Martin Gardner (1914–2010). As a columnist for Scientific American, Gardner inspired generations of physicists, mathematicians, philosophers, puzzle-makers, logicians, magicians and others, including me. The 13th gathering this past weekend was called G4G13.
The conference began last Wednesday in the usual fashion: early-bird registrants flocked to the bar at the Ritz-Carlton in downtown Atlanta to show their favourite mathematics, physics, logic and magic tricks. These are called “bar bets”, for their only practical purpose is to give you cool ways to try to win money off sceptical strangers. I saw some classics on Wednesday, such as the challenge to guess whether a red wine glass is taller than its circumference – as a stranger is likely to think – or shorter, as it almost always is. The events of the next four days shared the same spirit, combining learning about the world with a spirit of playfulness – linked wherever possible to the number 13.
Gardner’s special skill was to get people to enjoy maths by acquainting them with the pleasure of solving problems in areas that ranged from physics to card playing and magic. About 120 talks were given – almost all a mere six minutes long, and each delivered to the entire gathering. We learned about such things as mathematical knitting, hyperbolic tiling patterns, the physics of dice and tops, fine points of logic, and pseudoscience. One celebrity participant was the 2014 Fields medallist Manjul Bhargava. Another was Erno Rubik, the Hungarian inventor of the eponymous cube that in the 1980s became the bestselling toy of all time.
Martin Gardner would have smiled, Robert P Crease, Physics World
Related link:
Home website: Martin Gardner dot org
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| March for Science, Washington DC, 2017 Credit: Becker 1999 Wikimedia (CC BY 2.0) |
Topics: Education, Politics, Research, Science, STEM
Greek: ὅπερ ἔδει δεῖξαι, "what was to be demonstrated," QED.
The March for Science in April 2017 was a unique demonstration of concern about the role of science and engineering in society and government. More than a million people in cities and towns around the world gathered in streets, made placards and banners, and heard speakers extoling the relevance and beauty of science—and also warning of diminished influence of science in policymaking. Some have dismissed the marchers as just another interest group advocating for more government funding for their work.
But the March, as I saw it and took part in it, represented something more: a significant change in how scientists see themselves and their work. This change had been slowly developing over recent decades and is now reaching a crescendo. Plans for another March for Science tomorrow indicate that the change among scientists is real, and that last year’s march was not simply a flash in the pan.
Scientists and friends of science are excited about recent progress in almost every scientific discipline. Whether it be observations of neutron star collisions, new findings on intergenerational epigenetic changes, macroscopic quantum entanglements, or human behavior, unprecedented scientific advances abound that will improve our future. Science marchers point to science as central to improving the human condition. At the same time, they are concerned about weakening public understanding and support of scientific research and the widespread neglect of scientific evidence. These concerns brought marchers to the streets in 2017 as much as pride in scientific accomplishments.
Scientists and many others are frustrated by public decisions based on ideology or wishful thinking
Scientific American
Russ D. Holt, chief executive officer of the American Association for the Advancement of Science (AAAS)
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| Pale Blue Dot: Cassini |
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| Pale Blue Dot: Voyager |
Images from: Pics-about-space.com
Topics: Education, Politics, Research, Science, STEM
I participated in the March for Science in Poughkeepsie, NY last year. Alas, this year's conflicts tutoring SAT math tomorrow, an obligation I've taken on locally in Greensboro. I will miss this year, but be there "in spirit." I should be able to participate in Earth Day next Sunday.
From the Triad website:
“The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.” ~Carl Sagan, Pale Blue Dot
Stand with us on Earth Day, April 22, when we march in concert with thousands of people in Washington, DC, and hundreds of cities around the world to show we value science.
Science is first of all a method. It begins with the simplest yet most profound act we humans can make: asking a question. It requires the best of our intellect to follow the lead those questions lay out on the map. It requires our courage when that path reveals truths we would prefer not to face. It requires our minds to stretch beyond their native intuitions; to imagine a petite three-dimensional sphere whirling through space when the surface beneath our feet is flat and big enough to hold billions of our kind; to conceive of scales outside the reckoning of our senses, from the tininess of our sun in a gargantuan universe to the immensities of space inside an atom too small too see without expensive, highly developed technology.
Science expands our senses, our curiosity. We live every day in a world that yesterday was impossible magic.
Yet, when lies become mainstream public currency, when borders close to the free sharing of research, when people are told to stop asking questions or to avert their eyes from evidence, the pursuit of science itself becomes an endangered species.
Yes, scientists themselves are human. They are people of their day and culture. Any endeavor that requires humans to carry it out will produce failures and mistakes, even horrific ones. Yet the solution is not to slam the door, shut down controversy, or retreat from the challenge. What better remedy than the methods of science: to address the errors by asking better questions, seeking more knowledge, engaging more minds in order to bring a broader variety of backgrounds and perspectives into the quest?
Topics: Education, Diversity in Science, STEM, Women in Science
In their order of appearance:
Project #21, Burglar alarm (3D snap kit)
Project #11, Flying Saucer
Project #53, Flashing Laser Light with Sound
Project #548, Rechargeable Battery (solar panel)
The Joint School of Nanoscience and Nanoengineering will participate in the USA Science and Engineering Festival as part of the North Carolina Science Festival. Our portion is called "Gateway to Science." I am a humble one of many great exhibits. I'll start 9:00 am at the Nano Energy table (my group), then take the evening shift from 1:00 - 5:00 pm at the electronic snap kits table I spent until 9:30 last night setting up, as well as I saw many other fellow students setting up their displays in the wee hours. Like anything, it's something you're at first "voluntold" to do, but take pride in your particular part coming off without a hitch. It's going to be a long, eventful day. I'll try to get some other photos posted when I get a break.
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| Warning signs: the greater blue-ringed octopus changes its appearance when threatened using techniques that have inspired an adaptive infrared reflector. (CC BY-SA 2.5/Jens Petersen) |
Topics: Bioengineering, Biology, Optical Physics, Materials Science, Nanotechnology
A simple device with tuneable infrared reflectivity has been made by mimicking the adaptive properties of the skin of octopuses and related animals. Chengyi Xuat, Alon Gorodetsky and George Stiubianu of the University of California, Irvine created the device using a dielectric elastomer and say that it overcomes many of the limitations of previous adaptive infrared-reflecting systems.
Reflecting infrared radiation is important for many technologies, ranging from building insulation to spacecraft components. But most of the materials used to reflect radiation in the infrared region are static: they are unable to respond and adapt to changes in the environment. Some adaptable infrared-reflecting systems have been developed, but they tend to be complex and difficult to control, while also lacking spectral tunability and requiring high operating temperatures.
Inspired by the skin of cephalopods – squid, octopuses, and cuttlefish – Gorodetsky and colleagues have now developed an adaptable infrared-reflecting system that they say is easy to control, can respond rapidly and be used repeatedly. The system also has a tuneable spectral range and works at low temperatures.
Many cephalopods can rapidly change the colour and patterning of their skin. This is done for both camouflage and signalling, and is enabled by pigment cells with adjustable spectral properties that can response within hundreds of milliseconds. These yellow, red, and brown cells, known as adaptive chromatophores, are packed with pigment granules and can be expanded and contracted by radial muscles. As their size and shape changes so do the wavelengths of light that they absorb and reflect.
Octopus skin inspires new infrared reflector, Michael Allen, Physics World
PHANTOMELECTIRK.COM
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| Artist's illustration of Orion Span's planned orbiting hotel, Aurora Station. Credit: Orion Span |
Topics: Economy, Existentialism, Space Travel, Politics
Well-heeled space tourists will have a new orbital destination four years from now, if one company's plans come to fruition.
That startup, called Orion Span, aims to loft its "Aurora Station" in late 2021 and begin accommodating guests in 2022.
"Affordable" is a relative term: A 12-day stay aboard Aurora Station will start at $9.5 million. Still, that's quite a bit less than orbital tourists have paid in the past. From 2001 through 2009, seven private citizens took a total of eight trips to the International Space Station (ISS), paying an estimated $20 million to $40 million each time. (These private missions were brokered by the Virginia-based company Space Adventures and employed Russian Soyuz spacecraft and rockets.)
"There's been innovation around the architecture to make it more modular and more simple to use and have more automation, so we don't have to have EVAs [extravehicular activities] or spacewalks," Bunger said of Aurora Station.
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Elysium or the Elysian Fields (Ancient Greek: Ἠλύσιον πεδίον, Ēlýsion pedíon) is a conception of the afterlife that developed over time and was maintained by some Greek religious and philosophical sects and cults. Initially separate from the realm of Hades, admission was reserved for mortals related to the gods and other heroes. Later, it expanded to include those chosen by the gods, the righteous, and the heroic, where they would remain after death, to live a blessed and happy life, and indulging in whatever employment they had enjoyed in life. Source: Wikipedia
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In the year 2154, the very wealthy live on a man-made space station while the rest of the population resides on a ruined Earth. A man takes on a mission that could bring equality to the polarized worlds. Matt Damon, Jodie Foster, Sharlto Copley, IMDB
*****
Rockets, moon shots
Spend it on the have-not's
Money, we make it
Before we see it, you take it
[Chorus]
Oh, make you want to holler
The way they do my life
Make me want to holler
The way they do my life
This ain't living, this ain't living
No, no baby, this ain't living
No, no, no
Marvin Gaye, "Inner City Blues," Genius.com/lyrics
"All science and engineering has a moral and philosophical component. It is imperative that as future scientists you pursue your research ethically, thinking also of your impact on society going forward." Quoted from the post "Freedom and Responsibility," October 30, 2017.
'Luxury Space Hotel' to Launch in 2021, Mike Wall, Space.com
for sometime now I’ve wanted to complete this Black and white in color.
steven just began the color works. It was submitted as part of an Blackage Anthology Book
that fell through yeatrs ago. It now posted as an extra on line story on Stranger web page
at Ghettostone Publications site. Recently I have attempted to contact director and movie creator Mr. Fuqua
of Training Day fame to ask if they would please take a look. Stranger storyline has been featured in an independence film years ago, but I think the film success of Black Panther has inspired movie goers so why not try again.
Stranger is ageless and bright to America in the hula of a slave ship ( check Universe book O) from ghettostone, but
he is our Universes ultimate evil doer. Always hidden in the shadows The Stranger would be the last thing you see before your demise.
I enjoy writing for villians they are much easier to write that heroes because most people dont
beliveve in heroes any more and ask why would a super powered hero help anyone as opposed to
gettin paid or becoming famous. Villians from a Black perspective I thing should reflect history
and power so The Stranger brought to America in a slaveship morphs into a Werewolf and manipulates
youth into his evil service. He appears in all my stories so far except for RAMZEES.
Here a page from a quick down and dirty Blackage Anthology Book that never was, enjoy
Mihael R Brown editor chief
Ghettostone PublicationsThe Stranger
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| The target chamber used to achieve laser fusion is shown in the foreground and the laser appears in the background. (Courtesy: Advanced Beam Laboratory/Colorado State University) |
Topics: Green Tech, Nanotechnology, Nuclear Fusion
Smaller, cheaper neutron sources and new opportunities for simulating the extreme conditions at the center of stars are among the possible benefits of new research carried out by physicists in the US and Germany. The group directed rapid-fire pulses of intense blue light from a compact laser at arrays of nanostructures to generate a dense plasma yielding large numbers of neutrons created by nuclear fusion.
Scientists have built ever more energetic lasers in the quest to demonstrate nuclear fusion’s feasibility as an energy source. The National Ignition Facility (NIF) in California, for example, generates pulses with a whopping 1.8 MJ of energy, in order to compress tiny pellets of deuterium and tritium to the point where the nuclei fuse and emit copious numbers of neutrons. The aim is to achieve ignition, when the alpha particle released by the fusing nuclei provides the heat for a self-sustaining reaction – with the energy of the emitted neutrons ultimately being tapped to produce electricity. However, NIF is enormous – occupying the area of three football pitches – and, like other high-energy lasers, can only fire a handful of times a day.
Some researchers are instead working on less energetic but more rapid-fire lasers. These will never get anywhere close to ignition, but can still achieve exceptionally high intensities – thanks to the extreme brevity and hence power of their pulses. Such lasers can create plasmas with very high energy densities ideal for studying extreme astrophysical environments, for example. These devices could also potentially be used as compact sources of neutrons, which probe atomic structure in ways not possible with X-rays. Neutrons are usually produced at large accelerators or reactors and a compact source would be welcomed by scientists.
Nanowires boost nuclear fusion, Hamish Johnston, Physics World
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| Allen Dulles, the fifth and longest-serving Director of Central Intelligence, took a personal interest in the construction of the Original Headquarters Building (OHB). He was the son of a Presbyterian minister and insisted that a Biblical quotation be fixed in stone in the OHB Lobby. The verse – "And Ye Shall Know the Truth and the Truth Shall Make You Free" – John 8:32 – now stands as the Agency motto. At the dedication ceremony for OHB, Dulles included this quotation in his speech. Source: CIA.gov |
Topics: Commentary, Existentialism, Science, Politics
Whatever your opinions of them, that is the motto of our preeminent spy agency, one of the 17 intelligence agencies along with what's left of our allies that has confirmed Russia interfered in the 2016 elections that our current president* exhaustively and nauseatingly labeled "fake news."
On August 19, 2016, I wrote a blog post titled: "These Truths..." It talked about self-evident, rational truths, such as evolution, the age of the universe; governance. Those were halcyon days, when we had a president and not a president*/embarrassment. When we (at least, as member of the non-bigoted, saner part of the electorate), were convinced our president had fidelity to his marriage, his country and its Constitution.
Excerpt from "These Truths":
This year's election is unique as one political party has nominated such a flimflam artist as its candidate, that has made no bones about his hostility to science: "climate change is a plot by the Chinese against American manufacturing." As the New York Daily News opined on his loose 2nd amendment comments: "this isn't funny anymore."
This is an assault on fact versus fantasy, science versus psychobabble; sanity versus insanity. Flimflam's persona non grata interviewed on Alex Jones - the KING of conspiracy provocateurs - as a casual search of YouTube on his rant compilations attests, many right wing pundits have, as he's complained - mainstreamed his views in the public sphere without crediting him, only nourishing a faux ecosystem around Mr. Flimflam. FF sometimes quotes him verbatim, which Jones says admirably is "surreal."
This president*/flimflam artist denies knowing of $130,000 payment to Stormy Daniels. Unlikely. His lawyer apparently gives it from his own home equity, supposedly not expecting to get repaid. The problem is, if the president* had paid him back, it wouldn't be an in-kind donation during an election, an FEC violation. And why ISN'T a "billionaire" writing a check for his own hush money payments? There is likely a prenuptial agreement he'd be in violation of if this proves out true, and that will cost flimflam what little money Putin lets him dip his toes in.
What it does mean: 1. A lawyer MUST inform his client of any contractual agreement s/he enters into on behalf of her/him. 2. By denying the NDA (non-disclosure agreement) with an adult film star, he may have essentially nullified it. He also has one with a Playboy centerfold with which he supposedly had a long-term affair. Stormy's lawyer salivates at the prospect of questioning the president* and his lawyer under deposition. I relish when, as he did from his first spouse where he invoked his Fifth Amendment right to not self-incriminate ninety-seven times, he does so again - hilariously and maddeningly under oath.
What exactly is "truth" in this president*'s era? He has the all-time Olympic record for fabrications, fibbing; lying and obfuscations. His evangelical base seems unmoved by his past, his present dissembling and twitter ranting. They had conniption fits when President Clinton had a consensual relationship with an ADULT (albeit young) White House intern. A blue dress with spermatozoa was salacious; "grab 'em by the p----" on Access Hollywood deserving of a Mulligan. The rank hypocrisy of what amounts to an authoritarian political movement masking itself as a religious order self-imposed to tell everyone ELSE how to live is breathtaking. The word "EVILGELICALS" should become a thing in our modern lexicon; they should not recover, and the congregations in their immediate futures should be comprised of crickets.
If indeed, "the truth shall make you free"...an avalanche of lies from a president* backed by a faux religious order - evilgelicals - is a prelude to slavery.
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| Illustration of the device structure: stanene is on top of the lead-tellurium film and bismuth-tellurium substrate. α-tin has a similar crystal structure to diamond. |
Topics: Applied Physics, Materials Science, Nanotechnology, Superconductors
Almost a century after Heike Kamerlingh Onnes first discovered superconductivity, the factors that determine whether a system will be superconducting and at what temperature remain hard to pin down. However, advances in nanotechnology have given some good pointers where to look, as well as providing promising systems for exploiting superconductivity in real-world applications.
The fundamental requirement for superconductivity is the coupling of fermionic electrons into Cooper pairs. Theory paints a neat picture of how the resulting bosonic behaviour allows occupation of the same energy levels and leads to a host of exotic behaviour - zero electrical resistance and the expulsion of magnetic flux lines so that superconducting objects levitate on magnets, to name a few. Where the picture grows fuzzy is extrapolating from there what specific aspects a material system needs to become superconducting at a given temperature. While design principles to fabricate a room-temperature superconductor remain elusive, a lot has been learnt in the chase, bringing applications of superconductors in a range of sectors from imaging, testing and quantum cryptography ever closer.
2D materials
Among the material systems where unusual electronic behaviour akin to Cooper pairing might be likely is the interface between perovskite oxides – in particular, LaAlO3 and SrTiO3 – where there is a discontinuity in the polarity of the crystalline lattice. Following the initial discovery of a highly mobile “2D electron gas” at the interface in 2004, Jochen Mannhart and colleagues then identified superconducting properties at the interface in a layer limited to just 20 nm in 2007. The transition temperature was a chilly 200 millikelvin, and the exact origins of the effect were unclear, but oxide interfaces remain a hotbed for exploring electronic and spintronic behaviour.
Since then several 2D structures have revealed superconducting behaviour where it does not exist in the bulk, an example being “grey” tin. The form of tin usually considered most useful is “white” tin, which has a conventional metal crystallographic structure, and was among the first superconducting materials to attract study. However, at low temperatures white tin will gradually transform into grey tin, which has a diamond cubic structure and is sometimes described as “tin pest”. To their surprise, Qi-Kun Xue, Ding Zhang and colleagues at Tsinghua University in China found that when they reduced the dimensions of tin to 2D stanene of just 2-20 layers, they could observe superconducting properties in grey tin too. Going even thinner to monolayers resulted in insulating properties.
"What we found is that the grey tin can be scientifically quite interesting," Zhang told nanotechweb.org. As well as the fundamental science the discovery opens up, it also poses the opportunity to produce circuits from all one material, with superconducting wires of few layer stanene separated by insulating monolayers.
Superconductivity - pairing up with nanotechnology, Anna Demming, Nanotechweb.org
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| Designs Mag - Dr. Martin Luther king Jr. Timeline 2015 |
Topics: African Americans, Civil Rights, History, Human Rights, Martin Luther King
I believe the little girl with Dr. Martin Luther and Coretta Scott King is Yolanda. She is deceased now along with her parents, but her niece namesake just spoke at the March For Our Lives, looking remarkably like her iconic grandfather. Despite all the reveals of Dr. King as a flawed philanderer as investigative journalists are apt to do, he was at the end of the day a husband, a man and a father. As he said on the previous day, "longevity has its place." His death came year-to-date of his denouncement of his nation's involvement in Vietnam, that would eventually claim the lives of almost 60,000 soldiers, sailors and airmen, affecting survivors with post traumatic stress disorder; drug abuse, alcoholism and suicide. Total deaths numbered in the millions. Had he lived, I'm sure he would have addressed these concerns as part of his vision of "The Beloved Community," which ostensibly included all of humanity.
I would hear my parents cry.
They would still be crying as they tried to get through their daily routine. Getting me ready for kindergarten at Bethlehem Community Center. I had seen my mother cry on occasion - church, funerals - my father's eyes were red and his hands trembled as we drove from our home to school. They were both worried about my older sister - a youth active in the Civil Rights movement. They briefly didn't know here whereabouts. The worry hung over the home like a dark veil. I was too: like every march, every demonstration where it wasn't guaranteed she'd get out of it alive. It was a lot for someone new to the planet sometimes. She turned up, heartbroken. She and my mother hugged each other and cried, inconsolably.
This was a time of emotions - rough, raw and gut-wrenching. I was five years old. I didn't know what to feel until I arrived at Bethlehem.
I remember seeing this the night before from my father's lap:
But I'm not concerned about that now. I just want to do God's will. And He's allowed me to go up to the mountain. And I've looked over. And I've seen the promised land. I may not get there with you. But I want you to know tonight, that we, as a people, will get to the promised land. And I'm happy, tonight. I'm not worried about anything. I'm not fearing any man. Mine eyes have seen the glory of the coming of the Lord.
I didn't quite understand his eloquence. I asked my father. It was April 3, 1968. He honestly didn't know.
These broadcasts were probably what caused the walls of hope to come crashing around my family:
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| Cristiano Nisoli. Credit: Los Alamos National Laboratory |
Topics: Applied Physics, Materials Science, Theoretical Physics, Thermodynamics
Physicists have identified a new state of matter whose structural order operates by rules more aligned with quantum mechanics than standard thermodynamic theory. In a classical material called artificial spin ice, which in certain phases appears disordered, the material is actually ordered, but in a "topological" form.
"Our research shows for the first time that classical systems such as artificial spin ice can be designed to demonstrate topological ordered phases, which previously have been found only in quantum conditions," said Los Alamos National Laboratory physicist Cristiano Nisoli, leader of the theoretical group that collaborated with an experimental group at the University of Illinois at Urbana-Champaign, led by Peter Schiffer (now at Yale University).
Physicists generally classify the phases of matter as ordered, such as crystal, and disordered, such as gases, and they do so on the basis of the symmetry of such order, Nisoli said.
"The demonstration that these topological effects can be designed into an artificial spin ice system opens the door to a wide range of possible new studies," Schiffer said.
Finding order in disorder demonstrates a new state of matter, Los Alamos National Laboratory
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| The Tower of the Moon and the Stars, an observatory built by Queen Sonduk, after she came to power in 632 CE. Credit: GABRIELLA BERNARDI |
Topics: Astronomy, Astrophysics, History, Diversity in Science, Women in Science
Will I ever know the truth about the stars?
I’m too young to engage in theories about our Universe.
I just know that I want to understand more. I want to know all
I can. Why should it be forbidden?
This sentence, found on a votive jar dedicated to her grandmother, had been written by a young girl, a Korean princess of the Silla Dynasty, when she was 15 years old. Her name was Sonduk, but it is also written as Sondok or Seondeok, and she was very interested in astronomy in an era where no education was granted to women. Nevertheless, she became a queen and could pursue her astronomical passion, at least in a certain sense. But let’s go in order.
She was born in 610 CE, and later became the first female monarch of Korea, ruling her country for 14 years. Jinpyeong, her father, was the king of Silla, a kingdom that was born as a city-state in 57 BCE and grew into a kingdom in about 350 CE. The king had no male heirs, so the choice fell on his daughter Sonduk.
This young princess had a brilliant mind, evident from a very young age. At seven, for example, a box of peony seeds arrived at the Court, from China. It had been sent with an accompanying painting that showed what the flowers looked like. Sonduk, looking at the picture, remarked that the flower was pretty, but it was a pity that it did not smell. When asked why, she answered: “If it did, there would be butterflies and bees around the flower in the painting.” Her observation about the peonies’ lack of smell proved correct – one illustration among many of her intelligence.
The first contact with astronomy and the study of the stars occurred through her tutor, the Chinese ambassador Lin Fang, who was also an astronomer. At the age of 15 she was introduced to Confucianism, which soon became an obstacle to her thirst for knowledge. The Confucian model, indeed, placed women in a subordinate position within the family, which meant that education in general, let alone astronomy, was not considered suitable. Sonduk, however, used to make observations every night and was mostly self-taught. A clash of wills was inevitable.
The unforgotten sisters: Sonduk, the astronomer queen, Gabriella Bernardi, Cosmos Magazine
In the first of a three-part series, Italian science writer Gabriella Bernardi profiles a seventh century Korean astronomy pioneer.
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| The image on the right shows the galaxy, full of "globular clusters." The image on the left shows the measurement the researchers used to track the speed of one such object. Credit: Gemini Observatory / NSF / AURA / W.M. Keck Observatory / Jen Miller / Joy Pollard |
Topics: Astronomy, Astrophysics, Cosmology, Dark Matter, Theoretical Physics
Note: I almost didn't blog about this, because the original links at Live Science and Cosmos Magazine lead to "page not found" errors. I was able to find the article on Nature's direct website and provide it here. It's strange both sites had the same bogus links.
Here's a problem: The universe acts like it's a lot more massive than it looks.
Take galaxies, those giant, spinning masses of stars. The laws of motion and gravity tell us how fast these objects should turn given their bulk. But observations through telescopes show them spinning way faster than we'd expect, as if they were actually much more massive than the stars we can see indicate.
Astrophysicists have come up with two main solutions to this problem. Either there's a lot of mass out there in the universe that we can't detect directly, mass scientists call dark matter, or there's no dark matter out there, but there is something missing from our laws of gravity and motion. Researchers call the second proposed solution modified Newtonian dynamics (MOND), which suggests that if the laws are properly tweaked, the universe would make sense without dark matter.
A new paper, published today (March 28) in the journal Nature, provides compelling evidence that there really is dark matter out there and that modifying the laws of physics wouldn't by itself solve the universe's weight problem.
In that study, the researchers found an object that could exist in a universe that has dark matter, but that would be nearly unimaginable in a MOND universe: a totally normal galaxy, one that seems to operate without any dark matter-type forces. [1]
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In a study published in the journal Nature, scientists have found a galaxy that appears to contain no dark matter — the unknown material thought to be common in the universe because of its gravitational effect on normal matter.
It was a startling discovery, because galaxies similar to our own Milky Way generally appear to contain 30 times more of the mysterious substance than normal matter, while smaller galaxies can contain up to 400 times as much.
The dark-matter-free galaxy, called NGC 1052-DF2, lies 65 million light years away in the constellation Cetus. It initially caught the attention of astronomers because, while it’s about the size of the Milky Way, it contains only 0.5% as many stars.
“That makes it very diffuse,” says the study’s lead author, Pieter van Dokkum of Yale University, in Connecticut, US. “You can look straight through it. You can see galaxies behind it.”
It was discovered by a special, low-tech telescope in New Mexico called the Dragonfly Telephoto Array, which consists of a bundle of 400-millimetre camera lenses of the same type used by sports photographers, and can scan the sky for large, dim objects. So far, it’s found 23 of them, but NGC 1052-DF2 (the DF is for “Dragonfly”) stood out because it wasn’t just a big, diffuse blob. [2]
1. Astrophysicists Claim They Found a 'Galaxy Without Dark Matter', Rafi Letzter, Live Science
2. Found: a galaxy devoid of dark matter, Richard A Lovett, Cosmos Magazine
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| "The new battery design protects the lithium metal anode with a coating of lithium carbonate. That allows lithium ions from the anode to enter the electrolyte while keeping unwanted compounds from reaching the anode. It’s easy to create this protective layer, too. The researchers just had to run a few charge-discharge cycles with a pure carbon dioxide atmosphere, and a crystal mesh of lithium carbonate accumulated." Extreme Tech |
Topics: Alternative Energy, Green Energy, Green Tech, Solar Power
The lithium-ion battery has transformed the portable electronics industry and is making inroads into energy storage on the electric grid and electrically powered transportation. Today, research laboratories around the world are seeking to develop beyond-lithium-ion batteries that are even more powerful, cheaper, safer and longer lived.
As reported in the journal Nature, a team of scientists from the University of Illinois at Chicago and the U.S. Department of Energy’s (DOE) Argonne National Laboratory has produced a new design for a beyond-lithium-ion battery cell that operates by running on air (hence, referred to as “lithium-air”) over many charge and discharge cycles. Larry Curtiss, co-principal investigator and Argonne Distinguished Fellow, observed that the team’s article was appealing to Nature because “others have tried to build lithium-air battery cells that run on air, but they failed because of little cycle life.”
“This first demonstration of a true lithium-air battery is an important step toward what we call ‘beyond-lithium-ion’ batteries.” — Amin Salehi-Khojin, assistant professor, University of Illinois at Chicago.
The problem with past technology has been that battery cells tested in the lab required a separate supply of pure oxygen (hence, referred to as lithium-oxygen batteries). As a consequence, a tank of oxygen gas would have to be part of the battery system, making it prohibitive for use in electric vehicles due to space requirements. A lithium-air battery that uses air from outside eliminates this problem.
The key features of the team’s newly developed battery cell are a new protective coating for the lithium metal anode, which prevents the anode from reacting with oxygen and hence deteriorating, and a novel electrolyte mixture that allows the cell to operate in an air atmosphere. In tests under an air environment, this cell maintained high performance during 700 cycles, far surpassing previous technology. According to Amin Salehi-Khojin, co-principal investigator and assistant professor at the University of Illinois at Chicago, “The energy storage capacity was about three times that of a lithium-ion battery, and five times should be easily possible with continued research. This first demonstration of a true lithium-air battery is an important step toward what we call beyond-lithium-ion batteries.”
Out Of thin air, Joe Harmon, Argonne National Laboratory
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| Tiangong-1 altitude decay forecast as of March 22, 2018. |
Topics: ESA, NASA, Space Exploration
China's first space station may fall to the ground as soon as one week from now, and certainly within two, orbital debris experts with the European Space Agency (ESA) say. Scientists, however, still cannot predict with any confidence where pieces of the 10.4-meter long Tiangong-1 station, which is traveling at 17,000 km/h, will land.
The latest estimate from the ESA indicates the station will enter Earth's atmosphere between March 30 and April 3, at which time most of the station will burn up. However, the station is large enough—it weighed 8.5 tons when fully fueled but has since used much of that propellant—that some pieces will very likely reach the planet's surface.
Beyond the fact that the station will reach a final impact point somewhere between 42.8 degrees north and 42.8 degrees south in latitude and probably near the northern or southern extremity of those boundaries due to Tiangong-1's orbital inclination, it is not possible to say where on Earth the debris will land. However, the likelihood of it affecting humans is quite low. Scientists estimate the "personal probability of being hit by a piece of debris from the Tiangong-1" is about 10 million times smaller than the annual chance of being hit by lightning.
A Fiery End - Chinese space station will fall to Earth within two weeks
Eric Berger, Ars Technica
#P4TC: Tiangong, Tentatively... April 30, 2011
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| Image Source: Link below |
Topics: Atomic Physics, Quantum Computer, Quantum Mechanics, Nanotechnology
Researchers at Griffith University working with Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) have unveiled a stunningly accurate technique for scientific measurements which uses a single atom as the sensor, with sensitivity down to 100 zeptoNewtons.
(Zepto = 10-21, or 0.000000000000000000001.)
Using highly miniaturised segmented-style Fresnel lenses - the same design used in lighthouses for more than a century - which enable exceptionally high-quality images of a single atom, the scientists have been able to detect position displacements with nanometre precision in three dimensions.
"Our atom is missing one electron, so it's very sensitive to electrical fields. By measuring the displacement, we've built a very sensitive tool for measuring electrical forces." Dr Erik Streed, of the Centre for Quantum Dynamics, explained.
"100 zeptoNewtons is a very small force. That's about the same as the force of gravity between a person in Brisbane and a person in Canberra. It can be used to investigate what's occurring on surfaces, which will help miniaturise ion trap type quantum computers and other quantum devices.
Scientists unveil high-sensitivity 3-D technique using single-atom measurements, Griffith University
