Tag Archives: University of Vermont

The Storywrangler, tool exploring billions of social media messages, could predict political & financial turmoil

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Being able to analyze Twitter messages (tweets) in real-time is amazing given what I wrote in this January 16, 2013 posting titled: “Researching tweets (the Twitter kind)” about the US Library of Congress and its attempts to access tweets for scholars,”

At least one of the reasons no one has received access to the tweets is that a single search of the archived (2006- 2010) tweets alone would take 24 hours, [emphases mine] …

So, bravo to the researchers at the University of Vermont (UVM). A July 16, 2021 news item on ScienceDaily makes the announcement,

For thousands of years, people looked into the night sky with their naked eyes — and told stories about the few visible stars. Then we invented telescopes. In 1840, the philosopher Thomas Carlyle claimed that “the history of the world is but the biography of great men.” Then we started posting on Twitter.

Now scientists have invented an instrument to peer deeply into the billions and billions of posts made on Twitter since 2008 — and have begun to uncover the vast galaxy of stories that they contain.

Caption: UVM scientists have invented a new tool: the Storywrangler. It visualizes the use of billions of words, hashtags and emoji posted on Twitter. In this example from the tool’s online viewer, three global events from 2020 are highlighted: the death of Iranian general Qasem Soleimani; the beginning of the COVID-19 pandemic; and the Black Lives Matter protests following the murder of George Floyd by Minneapolis police. The new research was published in the journal Science Advances. Credit: UVM

A July 15, 2021 UVM news release (also on EurekAlert but published on July 16, 2021) by Joshua Brown, which originated the news item, provides more detail abut the work,

“We call it the Storywrangler,” says Thayer Alshaabi, a doctoral student at the University of Vermont who co-led the new research. “It’s like a telescope to look — in real time — at all this data that people share on social media. We hope people will use it themselves, in the same way you might look up at the stars and ask your own questions.”

The new tool can give an unprecedented, minute-by-minute view of popularity, from rising political movements to box office flops; from the staggering success of K-pop to signals of emerging new diseases.

The story of the Storywrangler — a curation and analysis of over 150 billion tweets–and some of its key findings were published on July 16 [2021] in the journal Science Advances.

EXPRESSIONS OF THE MANY

The team of eight scientists who invented Storywrangler — from the University of Vermont, Charles River Analytics, and MassMutual Data Science [emphasis mine]– gather about ten percent of all the tweets made every day, around the globe. For each day, they break these tweets into single bits, as well as pairs and triplets, generating frequencies from more than a trillion words, hashtags, handles, symbols and emoji, like “Super Bowl,” “Black Lives Matter,” “gravitational waves,” “#metoo,” “coronavirus,” and “keto diet.”

“This is the first visualization tool that allows you to look at one-, two-, and three-word phrases, across 150 different languages [emphasis mine], from the inception of Twitter to the present,” says Jane Adams, a co-author on the new study who recently finished a three-year position as a data-visualization artist-in-residence at UVM’s Complex Systems Center.

The online tool, powered by UVM’s supercomputer at the Vermont Advanced Computing Core, provides a powerful lens for viewing and analyzing the rise and fall of words, ideas, and stories each day among people around the world. “It’s important because it shows major discourses as they’re happening,” Adams says. “It’s quantifying collective attention.” Though Twitter does not represent the whole of humanity, it is used by a very large and diverse group of people, which means that it “encodes popularity and spreading,” the scientists write, giving a novel view of discourse not just of famous people, like political figures and celebrities, but also the daily “expressions of the many,” the team notes.

In one striking test of the vast dataset on the Storywrangler, the team showed that it could be used to potentially predict political and financial turmoil. They examined the percent change in the use of the words “rebellion” and “crackdown” in various regions of the world. They found that the rise and fall of these terms was significantly associated with change in a well-established index of geopolitical risk for those same places.

WHAT’S HAPPENING?

The global story now being written on social media brings billions of voices — commenting and sharing, complaining and attacking — and, in all cases, recording — about world wars, weird cats, political movements, new music, what’s for dinner, deadly diseases, favorite soccer stars, religious hopes and dirty jokes.

“The Storywrangler gives us a data-driven way to index what regular people are talking about in everyday conversations, not just what reporters or authors have chosen; it’s not just the educated or the wealthy or cultural elites,” says applied mathematician Chris Danforth, a professor at the University of Vermont who co-led the creation of the StoryWrangler with his colleague Peter Dodds. Together, they run UVM’s Computational Story Lab.

“This is part of the evolution of science,” says Dodds, an expert on complex systems and professor in UVM’s Department of Computer Science. “This tool can enable new approaches in journalism, powerful ways to look at natural language processing, and the development of computational history.”

How much a few powerful people shape the course of events has been debated for centuries. But, certainly, if we knew what every peasant, soldier, shopkeeper, nurse, and teenager was saying during the French Revolution, we’d have a richly different set of stories about the rise and reign of Napoleon. “Here’s the deep question,” says Dodds, “what happened? Like, what actually happened?”

GLOBAL SENSOR

The UVM team, with support from the National Science Foundation [emphasis mine], is using Twitter to demonstrate how chatter on distributed social media can act as a kind of global sensor system — of what happened, how people reacted, and what might come next. But other social media streams, from Reddit to 4chan to Weibo, could, in theory, also be used to feed Storywrangler or similar devices: tracing the reaction to major news events and natural disasters; following the fame and fate of political leaders and sports stars; and opening a view of casual conversation that can provide insights into dynamics ranging from racism to employment, emerging health threats to new memes.

In the new Science Advances study, the team presents a sample from the Storywrangler’s online viewer, with three global events highlighted: the death of Iranian general Qasem Soleimani; the beginning of the COVID-19 pandemic; and the Black Lives Matter protests following the murder of George Floyd by Minneapolis police. The Storywrangler dataset records a sudden spike of tweets and retweets using the term “Soleimani” on January 3, 2020, when the United States assassinated the general; the strong rise of “coronavirus” and the virus emoji over the spring of 2020 as the disease spread; and a burst of use of the hashtag “#BlackLivesMatter” on and after May 25, 2020, the day George Floyd was murdered.

“There’s a hashtag that’s being invented while I’m talking right now,” says UVM’s Chris Danforth. “We didn’t know to look for that yesterday, but it will show up in the data and become part of the story.”

Here’s a link to and a citation for the paper,

Storywrangler: A massive exploratorium for sociolinguistic, cultural, socioeconomic, and and political timelines using Twitter by Thayer Alshaabi, Jane L. Adams, Michael V. Arnold, Joshua R. Minot, David R. Dewhurst, Andrew J. Reagan, Christopher M. Danforth and Peter Sheridan Dodds. Science Advances 16 Jul 2021: Vol. 7, no. 29, eabe6534DOI: 10.1126/sciadv.abe6534 DOI: 10.1126/sciadv.abe6534

This paper is open access.

A couple of comments

I’m glad to see they are looking at phrases in many different languages. Although I do experience some hesitation when I consider the two companies involved in this research with the University of Vermont.

Charles River Analytics and MassMutual Data Science would not have been my first guess for corporate involvement but on re-examining the subhead and noting this: “potentially predict political and financial turmoil”, they make perfect sense. Charles River Analytics provides “Solutions to serve the warfighter …”, i.e., soldiers/the military, and MassMutual is an insurance company with a dedicated ‘data science space’ (from the MassMutual Explore Careers Data Science webpage),

What are some key projects that the Data Science team works on?

Data science works with stakeholders throughout the enterprise to automate or support decision making when outcomes are unknown. We help determine the prospective clients that MassMutual should market to, the risk associated with life insurance applicants, and which bonds MassMutual should invest in. [emphases mine]

Of course. The military and financial services. Delightfully, this research is at least partially (mostly?) funded on the public dime, the US National Science Foundation.

Building a wrench 1.7 nanometres wide

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A blue wrench (of molecules) to adjust a green bolt (a pillarene ring) that binds a yellow chemical “guest.” It’s a new tool — just 1.7 nanometers wide — that could help scientists catalyze and create a host of useful new materials. Image courtesy of Severin Schneebeli

A blue wrench (of molecules) to adjust a green bolt (a pillarene ring) that binds a yellow chemical “guest.” It’s a new tool — just 1.7 nanometers wide — that could help scientists catalyze and create a host of useful new materials.
Image courtesy of Severin Schneebeli

So, if you can imagine 1.7 nanometers, that’s what the wrench would look like without all the colour effects. A Sept. 25, 2015 news item on Nanotechnology Now describes the scientific breakthrough,

University of Vermont chemist Severin Schneebeli has invented a new way to use chirality to make a wrench. A nanoscale wrench. His team’s discovery allows them to precisely control nanoscale shapes and holds promise as a highly accurate and fast method of creating customized molecules.

This use of “chirality-assisted synthesis” is a fundamentally new approach to control the shape of large molecules–one of the foundational needs for making a new generation of complex synthetic materials, including polymers and medicines.

A Sept. 24, 2015 University of Vermont news release (also on EurekAlert) by Joshua E. Brown, which originated the news item, expands on the theme,

Experimenting with anthracene, a substance found in coal, Schneebeli and his team assembled C-shaped strips of molecules that, because of their chirality, are able to join each other in only one direction. “They’re like Legos,” Schneebeli explains. These molecular strips form a rigid structure that’s able to hold rings of other chemicals “in a manner similar to how a five-sided bolt head fits into a pentagonal wrench,” the team writes.

The C-shaped strips can join to each other, with two bonds, in only one geometric orientation. So, unlike many chemical structures–which have the same general formula but are flexible and can twist and rotate into many different possible shapes–“this has only one shape,” Schneebeli says. “It’s like a real wrench,” he says–with an opening a hundred-thousand-times smaller than the width of human hair: 1.7 nanometers.

“It completely keeps its shape,” he explains, even in various solvents and at many different temperatures, “which makes it pre-organized to bind to other molecules in one specific way,” he says.

This wrench, the new study shows, can reliably bind to a family of well-known large molecules called “pillarene macrocycles.” These rings of pillarene have, themselves, often been used as the “host,” in chemistry-speak, to surround and modify other “guest” chemicals in their middle–and they have many possible applications from controlled drug delivery to organic light-emitting substances.

“By embracing pillarenes,” the Vermont team writes, “the C-shaped strips are able to regulate the interactions of pillarene hosts with conventional guests.” In other words, the chemists can use their new wrench to remotely adjust the chemical environment inside the pillarene in the same way a mechanic can turn an exterior bolt to adjust the performance inside an engine.

The new wrench can make binding to the inside of the pillarene rings “about one hundred times stronger,” than it would be without the wrench, Schneebeli says.

MAKING MODELS

Also, “because this kind of molecule is rigid, we can model it in the computer and project how it looks before we synthesize it in the lab,” says UVM theoretical chemist Jianing Li, Schneebeli’s collaborator on the research and a co-author on the new study. Which is exactly what she did, creating detailed simulations of how the wrench would work, using computer processors in the Vermont Advanced Computing Core.

“This is a revolutionary idea,” Li said, “We have 100% control of the shape, which gives great atomic economy–and lets us know what will happen before we start synthesizing in the lab.”

In the lab, post-doctoral researcher and lead author Xiaoxi Liu, undergraduate Zackariah Weinert, and other team members were guided by the computer simulations to test the actual chemistry. Using a mass spectrometer and an NMR spectrometer in the UVM chemistry department, the team was able to confirm Schneebeli’s idea.

CREATIVE SIMPLICITY

Sir Fraser Stoddart, a world-leading chemist at Northwestern University, described the new study as, “Brilliant and elegant! Creative and simple.” And, indeed, it’s the simplicity of the approach that makes it powerful, Schneebeli says. “It’s all based on geometry that controls the symmetry of the molecules. This is the only shape it can take–which makes it very useful.”

Next, the team aims to modify the C-shaped pieces–which are tied together with two bonds formed between two nitrogens and bromines–to create other shapes. “We’re making a special kind of spiral which is going to be flexible like a real spring,” Schneebeli explains, but will hold its shape even under great stress.

“This helical shape could be super-strong and flexible. It could create new materials, perhaps for safer helmets or materials for space,” Schneebeli says. “In the big picture, this work points us toward synthetic materials with properties that, today, no material has.”

Here’s a link to and a citation for the paper,

Regulating Molecular Recognition with C-Shaped Strips Attained by Chirality-Assisted Synthesis by Dr. Xiaoxi Liu, Zackariah. Weinert, Mona Sharafi, Dr. Chenyi Liao, Prof. Jianing Li, and Prof. Severin T. Schneebeli. Angewandte Chemie DOI: 10.1002/anie.201506793 Article first published online: 9 SEP 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

University of Vermont and the ‘excitons’ of an electron superhighway

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This story starts off with one of the current crazes, folding and bendable electronics, before heading off onto the ‘electron highway’. From a Sept. 14, 2015 news item on ScienceDaily (Note: Links have been removed),

TV screens that roll up. Roofing tiles that double as solar panels. Sun-powered cell phone chargers woven into the fabric of backpacks. A new generation of organic semiconductors may allow these kinds of flexible electronics to be manufactured at low cost, says University of Vermont physicist and materials scientist Madalina Furis.

But the basic science of how to get electrons to move quickly and easily in these organic materials remains murky.

To help, Furis and a team of UVM materials scientists have invented a new way to create what they are calling “an electron superhighway” in one of these materials — a low-cost blue dye called phthalocyanine — that promises to allow electrons to flow faster and farther in organic semiconductors.

A Sept. 14, 2015 University of Vermont news release (also on EurekAlert) by Joshua E. Brown, which originated the news item, describes the problem the researches were trying to solve and the solution they found,

Hills and potholes

Many of these types of flexible electronic devices will rely on thin films of organic materials that catch sunlight and convert the light into electric current using excited states in the material called “excitons.” Roughly speaking, an exciton is a displaced electron bound together with the hole it left behind. Increasing the distance these excitons can diffuse — before they reach a juncture where they’re broken apart to produce electrical current — is essential to improving the efficiency of organic semiconductors.

Using a new imaging technique, the UVM team was able to observe nanoscale defects and boundaries in the crystal grains in the thin films of phthalocyanine — roadblocks in the electron highway. “We have discovered that we have hills that electrons have to go over and potholes that they need to avoid,” Furis explains.

To find these defects, the UVM team — with support from the National Science Foundation — built a scanning laser microscope, “as big as a table” Furis says. The instrument combines a specialized form of linearly polarized light and photoluminescence to optically probe the molecular structure of the phthalocyanine crystals.

“Marrying these two techniques together is new; it’s never been reported anywhere,” says Lane Manning ’08 a doctoral student in Furis’ lab and co-author on the new study.

The new technique allows the scientists a deeper understanding of how the arrangement of molecules and the boundaries in the crystals influence the movement of excitons. It’s these boundaries that form a “barrier for exciton diffusion,” the team writes.

And then, with this enhanced view, “this energy barrier can be entirely eliminated,” the team writes. The trick: very carefully controlling how the thin films are deposited. Using a novel “pen-writing” technique with a hollow capillary, the team worked in the lab of UVM physics and materials science professor Randy Headrick to successfully form films with jumbo-sized crystal grains and “small angle boundaries.” Think of these as easy-on ramps onto a highway — instead of an awkward stop sign at the top of a hill — that allow excitons to move far and fast.

Better solar cells

Though the Nature Communications study focused on just one organic material, phthalocyanine, the new research provides a powerful way to explore many other types of organic materials, too — with particular promise for improved solar cells. A recent U.S. Department of Energy report identified one of the fundamental bottlenecks to improved solar power technologies as “determining the mechanisms by which the absorbed energy (exciton) migrates through the system prior to splitting into charges that are converted to electricity.”

The new UVM study — led by two of Furis’ students, Zhenwen Pan G’12, and Naveen Rawat G’15 — opens a window to view how increasing “long-range order” in the organic semiconductor films is a key mechanism that allows excitons to migrate farther. “The molecules are stacked like dishes in a dish rack,” Furis explains, “these stacked molecules — this dish rack — is the electron superhighway.”

Though excitons are neutrally charged — and can’t be pushed by voltage like the electrons flowing in a light bulb — they can, in a sense, bounce from one of these tightly stacked molecules to the next. This allows organic thin films to carry energy along this molecular highway with relative ease, though no net electrical charge is transported.

“One of today’s big challenges is how to make better photovoltaics and solar technologies,” says Furis, who directs UVM’s program in materials science, “and to do that we need a deeper understanding of exciton diffusion. That’s what this research is about.”

Here’s a link to and a citation for the paper,

Polarization-resolved spectroscopy imaging of grain boundaries and optical excitations in crystalline organic thin films by Z. Pan, N. Rawat, I. Cour, L. Manning, R. L. Headrick, & M. Furis. Nature Communications 6, Article number: 8201 doi:10.1038/ncomms9201 Published 14 September 2015

This is an open access article.

McGill University researchers put the squeeze Tomonaga-Luttinger theory in quantum mechanics

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McGill University (Montréal, Québec, Canada) researchers testing the Tomonaga-Luttinger theory had international help according to a May 15, 2015 news item on ScienceDaily,

We all know intuitively that normal liquids flow more quickly as the channel containing them tightens. Think of a river flowing through narrow rapids.

But what if a pipe were so amazingly tiny that only a few atoms of superfluid helium could squeeze through its opening at once? According to a longstanding quantum-mechanics model, the superfluid helium would behave differently from a normal liquid: far from speeding up, it would actually slow down.

For more than 70 years, scientists have been studying the flow of helium through ever smaller pipes. But only recently has nanotechnology made it possible to reach the scale required to test the theoretical model, known as the Tomonaga-Luttinger theory (after the scientists who developed it).

Now, a team of McGill University researchers, with collaborators at the University of Vermont and at Leipzig University in Germany, has succeeded in conducting experiments with the smallest channel yet – less than 30 atoms wide. In results published online today in Science Advances, the researchers report that the flow of superfluid helium through this miniature faucet does, indeed, appear to slow down.

A May 15, 2015 University of McGill news release (also on EurekAlert), which originated the news item, expands on the theme and notes this is one step on the road to proving the theory,

“Our results suggest that a quantum faucet does show a fundamentally different behaviour,” says McGill physics professor Guillaume Gervais, who led the project. “We don’t have the smoking gun yet. But we think this a great step toward proving experimentally the Tomonaga-Luttinger theory in a real liquid.”

The zone where physics changes

Insights from the research could someday contribute to novel technologies, such as nano-sensors with applications in GPS systems. But for now, Gervais says, the results are significant simply because “we’re pushing the limit of understanding things on the nanoscale. We’re approaching the grey zone where all physics changes.”

Prof. Adrian Del Maestro from the University of Vermont has been employing high-performance computer simulations to understand just how small the faucet has to be before this new physics emerges. “The ability to study a quantum liquid at such diminutive length scales in the laboratory is extremely exciting as it allows us to extend our fundamental understanding of how atoms cooperate to form the superfluid state of matter,” he says. “The superfluid slowdown we observe signals that this cooperation is starting to break down as the width of the pipe narrows to the nanoscale” and edges closer to the exotic one-dimensional limit envisioned in the Tomonaga-Luttinger theory.

Building what is probably the world’s smallest faucet has been no simple task. Gervais hatched the idea during a five-minute conversation over coffee with a world-leading theoretical physicist. That was eight years ago. But getting the nano-plumbing to work took “at least 100 trials – maybe 200,” says Gervais, who is a fellow of the Canadian Institute for Advanced Research.

A beam of electrons as drill bit

Using a beam of electrons as a kind of drill bit, the team made holes as small as seven nanometers wide in a piece of silicon nitride, a tough material used in applications such as automotive diesel engines and high-performance ball bearings. By cooling the apparatus to very low temperatures, placing superfluid helium on one side of the pore and applying a vacuum to the other, the researchers were able to observe the flow of the superfluid through the channel. Varying the size of the channel, they found that the maximum speed of the flow slowed as the radius of the pore decreased.

The experiments take advantage of a unique characteristic of superfluids. Unlike ordinary liquids – water or maple syrup, for example – superfluids can flow without any viscosity. As a result, they can course through extremely narrow channels; and once in motion, they don’t need any pressure to keep going. Helium is the only element in nature known to become a superfluid; it does so when cooled to an extremely low temperature.

An inadvertent breakthrough

For years, however, the researchers were frustrated by a technical glitch: the tiny pore in the silicon nitride material kept getting clogged by contaminants. Then one day, while Gervais was away at a conference abroad, a new student in his lab inadvertently deviated from the team’s operating procedure and left a valve open in the apparatus. “It turned out that this open valve kept the hole open,” Gervais says. “It was the key to getting the experiment to work. Scientific breakthroughs don’t always happen by design!”

Prof. Bernd Rosenow, a quantum physicist at Leipzig University’s Institute for Theoretical Physics, also contributed to the study.

Here’s a link to and a citation for the paper,

Critical flow and dissipation in a quasi–one-dimensional superfluid by Pierre-François Duc, Michel Savard, Matei Petrescu, Bernd Rosenow, Adrian Del Maestro, Guillaume Gervais. Science Advances 15 May 2015: Vol. 1 no. 4 e1400222 DOI: 10.1126/sciadv.1400222

This is an open access paper.

December 2014 issue of the Nano Bite (from the Nanoscale Informal Science Education Network) features last day (Dec. 1, 2014) to apply for NanoDays 2015 physical kit and a bit about a medieval cleric who* ‘unwove’ light

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Depending on your timezone, there are still a few hours left to submit an online application for a NanoDays 2015 physical kit. From a Sept. 15, 2014 posting by Catherine McCarthy for NISENet (Nanoscale Informal Science Education Network),

Apply now for a NanoDays 2015 physical kit!
NanoDays 2015 will be held from March 28 through April 5, 2015. NanoDays is a week of community-based educational outreach events to raise public awareness of nanoscale science, technology and engineering throughout the United States. NanoDays kits are currently in production and will be ready for distribution in early 2015. We invite you to fill out an online application for a physical kit containing all of the materials and resources you need to start planning your community events; applications are due December 1, 2014.

 

We’re in Year 10 of funding for NISE Net, what’s going to happen to NanoDays?

This is the final NanoDays physical kit that will be funded through the current NISE Net award. Beyond 2015, we encourage you to continue to host NanoDays and strengthen local partnerships by using this kit (and any previous kits you have). We’ve set dates for the next five years to promote national participation in NanoDays in the years to come.

Future NanoDays will be held:

  • 2016: March 26-April 3
  • 2017: March 25-April 2
  • 2018: March 31-April 8
  • 2019: March 30-April 7
  • 2020: March 28-April 5

The NISE Network leadership is seeking opportunities to continue NanoDays after 2015, so stay tuned for further information!

Who can participate in NanoDays?
NanoDays kits are intended for use in public events; most host organizations are informal science education institutions and public outreach programs of nanoscience research centers. We invite you and your organization to participate in NanoDays 2015, whether or not you have previous experience with nano-related public outreach activities.

For anyone unfamiliar with the NanoDays programs, the post goes on to provide more details.

Here’s more about the upcoming International Year of Light (IYL)  mentioned in my Nov. 7, 2014 post,

→ What’s Nano about Light?
The United Nations has declared that 2015 is the International Year of Light (IYL) and light-based technologies. This global initiative helps to highlight for the public the importance of light and optical technologies in ones’ everyday life and it’s role in the development of society and the future. Endorsed by the International Council of Science, the International Year of Light 2015 has more than 100 partners from more than 85 countries!

Are you looking for ways to get involved?

There’s this tidbit about a special event featuring the University of Vermont physics department, light, and a local watershed (from the newsletter),

A Bi-Polar Affair Captivates Visitors with EnLIGHTening Nanoscale Science

By Luke Donforth, The University of Vermont

The University of Vermont (UVM) Physics Department and ECHO Lake Aquarium and Science Center have a long collaborative relationship, through which the NISE Network has provided an excellent framework to help strengthen and deepen. Although an institution of formal learning, UVM values and contributes to informal education in the surrounding community.

Recently, the UVM Physics Department and ECHO received a NISE Net mini-grant to develop a daylong event outside the purview of NanoDays. ECHO focuses on the Lake Champlain watershed, and the Physics Department wanted to show how basic science is a useful tool for investigating, understanding, and caring for the lake and world around us. Light, and specifically polarization, gave us a unifying theme to bring a number of activities and concepts to ECHO. Visible light, something most museum visitors have experience with, has wavelengths in the hundreds of nanometers. This provides a comfortable entry point to familiarize visitors with “nano,” and from there we can highlight how interacting with light at the length scale of its wavelength allows us to investigate both light and the world around us.

….

Polarization, the orientation of components of light, provides a tool with uses ranging from telling the time of day to monitoring invasive species in Lake Champlain. As an example of the later, Professor J. Ellen Marsden (an ichthyologist with UVM’s Rubenstein School of Environment and Natural Resources and long-time ECHO collaborator) supplied samples of larval zebra mussels from Lake Champlain. Zebra mussels, an invasive species actively monitored in the lake, are more easily distinguished and detected earlier with the thoughtful application polarized light.

We’re going to be hearing a lot more about light as we gear up for 2015. Meanwhile, you can read the entire December 2014 issue of the Nano Bite here.

In keeping with my previous comment, there’s this bit about a medieval cleric who helped us to understand light and optics. From a Nov. 27, 2014 posting by Michael Brooks, on the Guardian science blog, concerning his recent participation in a Festival of Humanities event held at the medieval Durham Cathedral,

Robert Grosseteste was a medieval pioneer of science. And, despite having died in 1253, the good bishop is up for an award on Thursday night [Nov. 27, 2014]. The shortlist for the Times Higher Education’s 2014 Research Project of the Year includes the researchers from Durham University who laid on last week’s activities in the cathedral’s Chapter House and Deanery, and they openly describe Grosseteste as one of their collaborators.

They made this clear in a paper they published in the prestigious journal Nature Physics in July. The scientists are re-examining Grosseteste’s work, and finding he made contributions to the field of optics that have yet to be assimilated into the canon of science. So they’ve come on board to help complete the record.

Grosseteste’s insight into the physics of rainbows has, for instance, enabled the researchers in the Ordered Universe collaboration to create a new co-ordinate system for colour. Anyone who has tried to calibrate a computer monitor knows that we now talk in terms of hue (a particular ratio of red, green and blue), saturation and brightness. Examination of Grosseteste’s writings has inspired an equally valid rainbow-based colour system.

It is based on the angle through which sunlight is scattered by the water drops, the “purity” of the medium – related to the size of the water drops – and the distance of the sun above the horizon. Grosseteste’s three-dimensional scheme outlines what Durham physicist Tom McLeish calls “the space of all possible rainbows”.

Here’s an image of a rainbow over Durham Cathedral,

Rainbow over Durham Cathedral by StephieBee [downloaded from https://www.flickr.com/photos/visitengland/galleries/72157625178514241/]


Rainbow over Durham Cathedral
by StephieBee [downloaded from https://www.flickr.com/photos/visitengland/galleries/72157625178514241/]

Here’s where you can find more of StephieBee‘s work.

Sadly, GrosseTeste did not win top prize but I’m sure if he were still around, he’d say something like, “It was an honour to be nominated and I thank God.” As for the Festival of Humanities (Being Human), there’s more here about its 2014 inaugural year.

*Changed ‘on’ to ‘who’ in headline on Dec. 2, 2014.

When your kinks and your defects are your strength: the truth about copper’s coherent twin boundaries

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There’s perfection and then there’s imperfection in this story about the nanoscale. From the May 19, 2013 news release on EurekAlert,

One of the basic principles of nanotechnology is that when you make things extremely small—one nanometer is about five atoms wide, 100,000 times smaller than the diameter of a human hair—they are going to become more perfect.

“Perfect in the sense that their arrangement of atoms in the real world will become more like an idealized model,” says University of Vermont engineer Frederic Sansoz, “with smaller crystals—in for example, gold or copper—it’s easier to have fewer defects in them.”

And eliminating the defects at the interface separating two crystals, or grains, has been shown by nanotechnology experts to be a powerful strategy for making materials stronger, more easily molded, and less electrically resistant—or a host of other qualities sought by designers and manufacturers.

Scientists thought they’d found perfection in 2004 (from the news release),

Since 2004, when a seminal paper came out in Science, materials scientists have been excited about one special of arrangement of atoms in metals and other materials called a “coherent twin boundary” or CTB.

Based on theory and experiment, these coherent twin boundaries are often described as “perfect,” appearing like a perfectly flat, one-atom-thick plane in computer models and electron microscope images.

Over the last decade, a body of literature has shown these coherent twin boundaries—found at the nanoscale within the crystalline structure of common metals like gold, silver and copper—are highly effective at making materials much stronger while maintaining their ability to undergo permanent change in shape without breaking and still allowing easy transmission of electrons—an important fact for computer manufacturing and other electronics applications.

It turns out that not all coherent twin boundaries are ‘perfect’ (from the news release),

A team of scientists, including Sansoz, a professor in UVM’s College of Engineering and Mathematical Sciences, and colleagues from the Lawrence Livermore National Laboratory and elsewhere, write in the May 19 edition of Nature Materials that coherent twin boundaries found in copper “are inherently defective.”

With a high-resolution electron microscope, using a more powerful technique than has ever been used to examine these boundaries, they found tiny kink-like steps and curvatures in what had previously been observed as perfect.

Even more surprising, these kinks and other defects appear to be the cause of the coherent twin boundary’s strength and other desirable qualities.

“Everything we have learned on these materials in the past 10 years will have to be revisited with this new information,” Sansoz says

The work was performed at the Lawrence Livermore National Laboratory (from the news release),

The experiment, led by Morris Wang at the Lawrence Livermore Lab, applied a newly developed mapping technique to study the crystal orientation of CTBs in so-called nanotwinned copper and “boom—it revealed these defects,” says Sansoz.

This real-world discovery conformed to earlier intriguing theoretical findings that Sansoz had been making with “atomistic simulations” on a computer. The lab results sent Sansoz back to his computer models where he introduced the newly discovered “kink” defects into his calculations. Using UVM’s Vermont Advanced Computing Center, he theoretically confirmed that the kink defects observed by the Livermore team lead to “rather rich deformation processes at the atomic scale,” he says, that do not exist with perfect twin boundaries.

With the computer model, “we found a series of completely new mechanisms,” he says, for explaining why coherent twin boundaries simultaneously add strength and yet also allow stretching (what scientists call “tensile ductility”)— properties that are usually mutually exclusive in conventional materials.

It seems to me that scientists keep discovering that it’s the imperfections and defects which give rise to strength and, often, beauty. I hope this time they remember what they’ve discovered.

For those who need to know more, here’s a citation for and link to the paper,

Defective twin boundaries in nanotwinned metals by Y. Morris Wang, Frederic Sansoz, Thomas LaGrange, Ryan T. Ott, Jaime Marian, Troy W. Barbee Jr, & Alex V. Hamza. Nature Materials (2013) doi:10.1038/nmat3646 Published online 19 May 2013

This paper is behind a paywall.