Tag Archives: physics

From the quantum to the cosmos; an event at Vancouver’s (Canada) Science World

ARPICO (Society of Italian Researchers & Professionals in Western Canada) sent out an April 9, 2014 announcement,

FROM THE QUANTUM TO THE COSMOS

May 7 [2014] “Unveiling the Universe” lecture registration now open:

Join Science World and TRIUMF on Wednesday, May 7, at Science World at TELUS World of Science in welcoming Professor Edward “Rocky” Kolb, the Arthur Holly Compton Distinguished Service Professor of Astronomy and Astrophysics at the University of Chicago, for his lecture on how the laws of quantum physics at the tiniest distances relate to structures in the universe at the largest scales. He also will highlight recent spectacular results into the nature of the Big Bang from the orbiting Planck satellite and the South Pole-based BICEP2 telescope.

Doors open at 6:15pm and lecture starts at 7pm. It will be followed by an audience Q&A session.

Tickets are free but registration is required. Details on the registration page (link below)
See http://www.eventbrite.ca/o/unveiling-the-universe-lecture-series-2882137721?s=23658359 for more information.

You can go here to the Science World website for more details and another link for tickets,

Join Science World, TRIUMF and guest speaker Dr Rocky Kolb on Wednesday, May 7 [2014], for another free Unveiling the Universe public lecture about the inner space/outer space connection that may hold the key to understanding the nature of dark matter, dark energy and the mysterious seeds of structure that grew to produce everything we see in the cosmos.

I notice Kolb is associated with the Fermi Lab, which coincidentally is where TRIUMF’s former director, Nigel Lockyer is currently located. You can find out more about Kolb on his personal webpage, where I found this description from his repertoire of talks,

Mysteries of the Dark Universe
Ninety-five percent of the universe is missing! Astronomical observations suggest that most of the mass of the universe is in a mysterious form called dark matter and most of the energy in the universe is in an even more mysterious form called dark energy. Unlocking the secrets of dark matter and dark energy will illuminate the nature of space and time and connect the quantum with the cosmos.

Perhaps this along with the next bit gives you a clearer idea of what Kolb will be discussing. He will also be speaking at TRIUMF, Canada’s national laboratory of particle and nuclear physics, from the events page,

Wed ,2014-05-07    14:00    Colloquium    Rocky Kolb, Fermilab     Auditorium    The Decade of the WIMP
Abstract:    The bulk of the matter in the present universe is dark. The most attractive possibility for the nature of the dark matter is a new species of elementary particle known as a WIMP (a Weakly Interacting Massive Particle). After a discussion of how a WIMP might fit into models of particle physics, I will review the current situation with respect to direct detection, indirect detection, and collider production of WIMPs. Rapid advances in the field should enable us to answer by the end of the decade whether our universe is dominated by WIMPs.

You may want to get your tickets soon as other lectures in the Unveiling the Universe series have gone quickly.

Violating the 2nd law of thermodynamics—temporarily—at the nanoscale

For anyone unfamiliar with the laws of thermodynamics or anyone who enjoys some satire with their music, here’s the duo of Flanders & Swann with the ‘First and Second Law’ in a 1964 performance,

According to a March 31, 2014 news item on Nanowerk, it seems, contrary to scientific thought and Flanders & Swann, the 2nd law can be violated, for a time, albeit at the nanoscale,

Objects with sizes in the nanometer range, such as the molecular building blocks of living cells or nanotechnological devices, are continuously exposed to random collisions with surrounding molecules. In such fluctuating environments the fundamental laws of thermodynamics that govern our macroscopic world need to be rewritten. An international team of researchers from Barcelona, Zurich and Vienna found that a nanoparticle trapped with laser light temporarily violates the famous second law of thermodynamics, something that is impossible on human time and length scale.

A March 31, 2014 University of Vienna news release on EurekAlert, which originated the news item, describes the 2nd law and gives details about the research,

Watching a movie played in reverse often makes us laugh because unexpected and mysterious things seem to happen: glass shards lying on the floor slowly start to move towards each other, magically assemble and suddenly an intact glass jumps on the table where it gently gets to a halt. Or snow starts to from a water puddle in the sun, steadily growing until an entire snowman appears as if molded by an invisible hand. When we see such scenes, we immediately realize that according to our everyday experience something is out of the ordinary. Indeed, there are many processes in nature that can never be reversed. The physical law that captures this behavior is the celebrated second law of thermodynamics, which posits that the entropy of a system – a measure for the disorder of a system – never decreases spontaneously, thus favoring disorder (high entropy) over order (low entropy).

However, when we zoom into the microscopic world of atoms and molecules, this law softens up and looses its absolute strictness. Indeed, at the nanoscale the second law can be fleetingly violated. On rare occasions, one may observe events that never happen on the macroscopic scale such as, for example heat transfer from cold to hot which is unheard of in our daily lives. Although on average the second law of thermodynamics remains valid even in nanoscale systems, scientists are intrigued by these rare events and are investigating the meaning of irreversibility at the nanoscale.

Recently, a team of physicists of the University of Vienna, the Institute of Photonic Sciences in Barcelona and the Swiss Federal Institute of Technology in Zürich succeeded in accurately predicting the likelihood of events transiently violating the second law of thermodynamics. They immediately put the mathematical fluctuation theorem they derived to the test using a tiny glass sphere with a diameter of less than 100 nm levitated in a trap of laser light. Their experimental set-up allowed the research team to capture the nano-sphere and hold it in place, and, furthermore, to measure its position in all three spatial directions with exquisite precision. In the trap, the nano-sphere rattles around due to collisions with surrounding gas molecules. By a clever manipulation of the laser trap the scientists cooled the nano-sphere below the temperature of the surrounding gas and, thereby, put it into a non-equilibrium state. They then turned off the cooling and watched the particle relaxing to the higher temperature through energy transfer from the gas molecules. The researchers observed that the tiny glass sphere sometimes, although rarely, does not behave as one would expect according to the second law: the nano-sphere effectively releases heat to the hotter surroundings rather than absorbing the heat. The theory derived by the researchers to analyze the experiment confirms the emerging picture on the limitations of the second law on the nanoscale.

Given the theoretical descriptions of the applications mentioned in the news release, it sounds like at least one of them might be a ‘quantum computing project’,

The experimental and theoretical framework presented by the international research team in the renowned scientific journal Nature Nanotechnology has a wide range of applications. Objects with sizes in the nanometer range, such as the molecular building blocks of living cells or nanotechnological devices, are continuously exposed to a random buffeting due to the thermal motion of the molecules around them. As miniaturization proceeds to smaller and smaller scales nanomachines will experience increasingly random conditions. Further studies will be carried out to illuminate the fundamental physics of nanoscale systems out of equilibrium. The planned research will be fundamental to help us understand how nanomachines perform under these fluctuating conditions.

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

Dynamic Relaxation of a Levitated Nanoparticle from a Non-Equilibrium Steady State by Jan Gieseler, Romain Quidant, Christoph Dellago, and Lukas Novotny. Nature Nanotechnology AOP, February 28, 2014. DOI: 10.1038/NNANO.2014.40

The paper is behind a paywall but a free preview is available via ReadCube access.

Richard Van Duyne solves mystery of Renoir’s red with surface-enhanced Raman spectroscopy (SERS) and Canadian scientists uncover forgeries

The only things these two items have in common is that they are concerned with visual art. and with solving mysteries The first item concerns research by Richard Van Duyne into the nature of the red paint used in one of Renoir’s paintings. A February 14, 2014 news item on Azonano describes some of the art conservation work that Van Duyne’s (nanoish) technology has made possible along with details about this most recent work,

Scientists are using powerful analytical and imaging tools to study artworks from all ages, delving deep below the surface to reveal the process and materials used by some of the world’s greatest artists.

Northwestern University chemist Richard P. Van Duyne, in collaboration with conservation scientists at the Art Institute of Chicago, has been using a scientific method he discovered nearly four decades ago to investigate masterpieces by Pierre-Auguste Renoir, Winslow Homer and Mary Cassatt.

Van Duyne recently identified the chemical components of paint, now partially faded, used by Renoir in his oil painting “Madame Léon Clapisson.” Van Duyne discovered the artist used carmine lake, a brilliant but light-sensitive red pigment, on this colorful canvas. The scientific investigation is the cornerstone of a new exhibition at the Art Institute of Chicago.

The Art Institute of Chicago’s exhibition is called, Renoir’s True Colors: Science Solves a Mystery. being held from Feb. 12, 2014 – April 27, 2014. Here is an image of the Renoir painting in question and an image featuring the equipment being used,

Renoir-Madame-Leon-Clapisson.Art Institute of Chicago.

Renoir-Madame-Leon-Clapisson.Art Institute of Chicago.

Renoir and surface-enhanced Raman spectroscopy (SERS). Art Institute of Chicago

Renoir and surface-enhanced Raman spectroscopy (SERS). Art Institute of Chicago

The Feb. 13, 2014 Northwestern University news release (also on EurekAlert) by Megan Fellman, which originated the news item, gives a brief description of Van Duyne’s technique and its impact on conservation at the Art Institute of Chicago (Note: A link has been removed),

To see what the naked eye cannot see, Van Duyne used surface-enhanced Raman spectroscopy (SERS) to uncover details of Renoir’s paint. SERS, discovered by Van Duyne in 1977, is widely recognized as the most sensitive form of spectroscopy capable of identifying molecules.

Van Duyne and his colleagues’ detective work informed the production of a new digital visualization of the painting’s original colors by the Art Institute’s conservation department. The re-colorized reproduction and the original painting (presented in a case that offers 360-degree views) can be viewed side by side at the exhibition “Renoir’s True Colors: Science Solves a Mystery” through April 27 [2014] at the Art Institute.

I first wrote about Van Duyne’s technique in my wiki, The NanoTech Mysteries. From the Scientists get artful page (Note: A footnote was removed),

Richard Van Duyne, then a chemist at Northwestern University, developed the technique in 1977. Van Duyne’s technology, based on Raman spectroscopy which has been around since the 1920s, is called surface-enhanced Raman spectroscopy’ or SERS “[and] uses laser light and nanoparticles of precious metals to interact with molecules to show the chemical make-up of a particular dye.”

This next item is about forgery detection. A March 5, 2014 news release on EurekAlert describes the latest developments,

Gallery owners, private collectors, conservators, museums and art dealers face many problems in protecting and evaluating their collections such as determining origin, authenticity and discovery of forgery, as well as conservation issues. Today these problems are more accurately addressed through the application of modern, non-destructive, “hi-tech” techniques.

Dmitry Gavrilov, a PhD student in the Department of Physics at the University of Windsor (Windsor, Canada), along with Dr. Roman Gr. Maev, the Department of Physics Professor at the University of Windsor (Windsor, Canada) and Professor Dr. Darryl Almond of the University of Bath (Bath, UK) have been busy applying modern techniques to this age-old field. Infrared imaging, thermography, spectroscopy, UV fluorescence analysis, and acoustic microscopy are among the innovative approaches they are using to conduct pre-restoration analysis of works of art. Some fascinating results from their applications are published today in the Canadian Journal of Physics.

Since the early 1900s, using infrared imaging in various wave bands, scientists have been able to see what parts of artworks have been retouched or altered and sometimes even reveal the artist’s original sketches beneath layers of the paint. Thermography is a relatively new approach in art analysis that allows for deep subsurface investigation to find defects and past reparations. To a conservator these new methods are key in saving priceless works from further damage.

Gavrilov explains, “We applied new approaches in processing thermographic data, materials spectra data, and also the technique referred to as craquelure pattern analysis. The latter is based on advanced morphological processing of images of surface cracks. These cracks, caused by a number of factors such as structure of canvas, paints and binders used, can uncover important clues on the origins of a painting.”

“Air-coupled acoustic imaging and acoustic microscopy are other innovative approaches which have been developed and introduced into art analysis by our team under supervision of Dr. Roman Gr. Maev. The technique has proven to be extremely sensitive to small layer detachments and allows for the detection of early stages of degradation. It is based on the same principles as medical and industrial ultrasound, namely, the sending a sound wave to the sample and receiving it back. ”

Spectroscopy is a technique that has been useful in the fight against art fraud. It can determine chemical composition of pigments and binders, which is essential information in the hands of an art specialist in revealing fakes. As described in the paper, “…according to the FBI, the value of art fraud, forgery and theft is up to $6 billion per year, which makes it the third most lucrative crime in the world after drug trafficking and the illegal weapons trade.”

One might wonder how these modern applications can be safe for delicate works of art when even flash photography is banned in art galleries. The authors discuss this and other safety concerns, describing both historic and modern-day implications of flash bulbs and exhibit illumination and scientific methods. As the paper concludes, the authors suggest that we can expect that the number of “hi-tech” techniques will only increase. In the future, art experts will likely have a variety of tools to help them solve many of the mysteries hiding beneath the layers.

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

A review of imaging methods in analysis of works of art: Thermographic imaging method in art analysis by D. Gavrilov, R.Gr. Maev, and D.P. Almond. Canadian Journal of Physics, 10.1139/cjp-2013-0128

This paper is open access.

ARPICO offers scholarship for Canadian grad. students and young postdocs at Italy’s School on Neutron Scattering (SoNS)

ARPICO (Society of Italian Researchers and Professionals in Western Canada) is offering a scholarship (deadline Mar. 31, 2014) for Canadian students according to its Feb. 14, 2014 announcement,

ARPICO is pleased to announce the 2014 ARPICO Scholarship to attend the 12th School on Neutron Scattering Francesco Paolo Ricci:

http://www.sonsfpricci.org/
Erice (Italy) from 30 April to 9 May 2014

ARPICO invites graduate students and post-doctoral researchers
at Canadian Universities and Laboratories to apply.

How to apply:

* Graduate students and post-doctoral researchers at Canadian
Universities/Laboratories are eligible
* Please, send a cover letter and your CV to [email protected] (.pdf format)

Deadline for application: March 31st, 2014

Scholarship covers for return-airfare from home institution to Italy,
school registration fee, lodging, and meals. The winner will be notified
by email by April 3rd, 2014.

For more information, please contact us at [email protected]

For anyone curious about Erice’s location in Italy, that would be the west coast of Sicily,

Erice (Vagabonda, May 2008) [downloaded from http://www.tripadvisor.ca/Tourism-g194757-Erice_Province_of_Trapani_Sicily-Vacations.html#17970260]

Erice (Vagabonda, May 2008) [downloaded from http://www.tripadvisor.ca/Tourism-g194757-Erice_Province_of_Trapani_Sicily-Vacations.html#17970260]

Good luck!

Sculplexity: 3D printing explains theoretical physics

An example of sculplexity (3D printed data visualization of concepts in theoretical physics),

3D Printed Forest Fire Model. Caption: Researchers have successfully demonstrated how complex theoretical physics can be transformed into a physical object using a 3D printer. Credit: Imperial College London/EPL

3D Printed Forest Fire Model. Caption: Researchers have successfully demonstrated how complex theoretical physics can be transformed into a physical object using a 3D printer. Credit: Imperial College London/EPL

A Dec. 9, 2013  Institute of Physics (IOP) news release (also on EurekAlert, dated Dec. 8, 2013) tells the story behind sculplexity,

In a new study published today, 9 December [2013], in the journal EPL, the researchers have successfully demonstrated how complex theoretical physics can be transformed into a physical object using a 3D printer.

In just eight hours and at the cost of around 15 euros, they were able to use a commercially available 3D printer to create their own 8 cm3 object based on a mathematical model that described how forest fires can be started and how they eventually spread over time.

The researchers have labelled the approach “Sculplexity”—standing for sculptures of complexity—and believe it could also be used to produce works of art based on science, or transform the way that ideas and concepts are presented and discussed within the scientific community.

Co-author of the study Dr Tim Evans, a theoretical physicist at Imperial, said: “The work was inspired by a visit to the Victoria and Albert Museum in London where I came across the first ever 3D printed object the museum had acquired.

“The object was a table inspired by the tree-like structures found in nature, which is an example of a branching process that is commonly encountered in complex systems in theoretical physics. This led me to think, what other processes familiar to physics could be turned into a 3D printed object?”

The news release goes on to explain a little about complex systems and discusses the ’3D Printed Forest Fire Model’ illustrated in the above,

Complex systems are made up of many parts that interact on many time and length scales and which show coherent behaviour and certain patterns on a large scale. A living organism is the best example of a complex system, whereby the individual parts—in this case the molecular processes in the cell — interact with each other and contribute to much larger processes on a macroscopic scale.

The interactions at play in many complex systems can be mapped out onto a two-dimensional grid which is divided into identical squares, or “cells”. Each of the cells can exist in a certain state and evolve over time, which is governed by a certain set of rules.

In their study, the researchers used a forest fire as an example, in which each cell represented a tree which could either be alive, dead or burning. The exact state that each cell occupied over time depended on a set of rules, which took into account the cell’s proximity to other cells that may be burning or if it was struck by lightning.

“The basic idea is simple,” continued Dr Evans. “A 3D printer builds up its object in layers. So the height of the object can be thought of as time. Suppose you have a mathematical model which defines a flat, two-dimensional picture that evolves in time — typically this will be a grid with some squares full and some empty.

“The mathematical model will define at each point in time what the printer should print at one height. The next step in the model will then define what to print on top of the first layer, and so forth. The result is a 3D object which shows how the mathematical model has evolved over time.”

The resulting model the researchers created was not without glitches; however, Dr Evans believes the experience has allowed them to identify the obstacles, formulate solutions and inspire the physics community to “get creative”.

“In our own group at Imperial we are trying to explain heartbeat anomalies by looking at simple models for the behaviour of individual cells in heart muscle — it’s possible that this could be visualised using 3D printing. Most models that represent the spread of disease could also be visualised.

“There may be many other examples and we just hope our rather literal translation from theoretical model to 3D printer output stimulates others to get creative,” Dr Evans concluded.

This is a very interesting approach to data visualization. The researchers’ paper is well illustrated and includes an image of object (“a table inspired by the tree-like structures found in nature, which is an example of a branching process that is commonly encountered in complex systems”) which inspired to Dr. Evans’ project,

Sculplexity: Sculptures of Complexity using 3D printing by D. S. Reiss, J. J. Price and T. S. Evans.  EPL (Europhysics Letters) Volume 104 Number 4, EPL 104 48001 doi:10.1209/0295-5075/104/48001

At the time of this writing (Dec. 11, 2013), this paper is open access.

Putting a new spin on it: Whirling Dervishes and physics and ballet dancers and neuroscience

Many years ago I was dragged to a movie about J. Krishnamurti (a philosopher and spiritual teacher; there’s more in this Wikipedia essay) which, for some reason, featured Whirling Dervishes amongst many other topics. Watching those dervishes was hypnotic and I now find out it was also an experience in physics, according to a Nov. 26, 2013 news item on ScienceDaily,

A force that intricately links the rotation of the Earth with the direction of weather patterns in the atmosphere has been shown to play a crucial role in the creation of the hypnotic patterns created by the skirts of the Whirling Dervishes.

This is according to an international group of researchers who have demonstrated how the Coriolis force is essential for creating the archetypal, and sometimes counterintuitive, patterns that form on the surface of the Whirling Dervishes skirts by creating a set of very simple equations which govern how fixed or free-flowing cone-shaped structures behave when rotating.

The Nov. 26, 2013 Institute of Physics (IOP) news release on EurekAlert (also on the IOP website but dated Nov. 27, 2013), which originated the news item, gives an explanation of Whirling Dervishes and describes the research further,

The Whirling Dervishes, who have become a popular tourist attraction in Turkey, are a religious movement who commemorate the 13th-century Persian poet, Rumi, by spinning on the spot and creating mesmerising patterns with their long skirts. A YouTube video of the Whirling Dervishes in action can be viewed here: https://www.youtube.com/watch?v=L_Cf-ZxDfZA.

Co-author of the study James Hanna, from Virginia Polytechnic Institute and State University, said: “The dancers don’t do much but spin around at a fixed speed, but their skirts show these very striking, long-lived patterns with sharp cusp-like features which seem rather counterintuitive.”

Hanna, along with Jemal Guven at the Universidad Nacional Autónoma de México and Martin Michael Müller at Université de Lorraine, found that it was the presence of a Coriolis force that was essential in the formation of the different patterns.

The Coriolis effect accounts for the deflection of objects on a rotating surface and is most commonly encountered when looking at the Earth’s rotations and its effect on the atmosphere around it. The rotation of the Earth creates the Coriolis force which causes winds to be deflected clockwise in the Northern Hemisphere and anti-clockwise in the Southern Hemisphere – it is this effect which is responsible for the rotation of cyclones.

“Because the sheet is conically symmetric, material can flow along its surface without stretching or deforming. You can think of the rotating Earth, for example, with the air of the atmosphere free to flow around it.

“The flow of a sheet of material is much more restrictive than the flow of the atmosphere, but nonetheless it results in Coriolis forces. What we found was that this flow, and the associated Coriolis forces, plays a crucial role in forming the dervish-like patterns,” Hanna continued.

By providing a basic mathematical description of the spinning skirts of the Dervishes, the researchers hope their future research will discern how different patterns are selected, how stable these patterns are and if gravity or any other effects make a qualitative difference.

The news release notes,

The equations, which have been published today, 27 November,[2013], in the Institute of Physics and German Physical Society’s New Journal of Physics, were able to reproduce the sharp peaks and gentle troughs that appear along the flowing surface of the Dervishes’ skirts and showed a significant resemblance to real-life images.

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

Whirling skirts and rotating cones by Jemal Guven, J A Hanna, and Martin Michael Müller. New Journal of Physics Volume 15 November 2013 doi:10.1088/1367-2630/15/11/113055  Published 26 November 2013

© IOP Publishing and Deutsche Physikalische Gesellschaft

This paper is open access.

While the Whirling Dervishes and the fabric in their clothing provide insights into aspects of physics, ballet dancers are providing valuable information to neuroscientists and geriatric specialists with pirouettes, according to a Sept. 26, 2013 news item on ScienceDaily,

Scientists have discovered differences in the brain structure of ballet dancers that may help them avoid feeling dizzy when they perform pirouettes.

The research suggests that years of training can enable dancers to suppress signals from the balance organs in the inner ear.

The findings, published in the journal Cerebral Cortex, could help to improve treatment for patients with chronic dizziness. Around one in four people experience this condition at some time in their lives.

The Imperial College of London (ICL) Sept. 26, 2013 news release on EurekAlert (also on the ICL website but dated Sept. 27, 2013), which originated the news item, describes dizziness, this research, and ballet dancers’ unique brains in more detail,

Normally, the feeling of dizziness stems from the vestibular organs in the inner ear. These fluid-filled chambers sense rotation of the head through tiny hairs that sense the fluid moving. After turning around rapidly, the fluid continues to move, which can make you feel like you’re still spinning.

Ballet dancers can perform multiple pirouettes with little or no feeling of dizziness. The findings show that this feat isn’t just down to spotting, a technique dancers use that involves rapidly moving the head to fix their gaze on the same spot as much as possible.

Researchers at Imperial College London recruited 29 female ballet dancers and, as a comparison group, 20 female rowers whose age and fitness levels matched the dancers’.

The volunteers were spun around in a chair in a dark room. They were asked to turn a handle in time with how quickly they felt like they were still spinning after they had stopped. The researchers also measured eye reflexes triggered by input from the vestibular organs. Later, they examined the participants’ brain structure with MRI scans.

In dancers, both the eye reflexes and their perception of spinning lasted a shorter time than in the rowers.

Dr Barry Seemungal, from the Department of Medicine at Imperial, said: “Dizziness, which is the feeling that we are moving when in fact we are still, is a common problem. I see a lot of patients who have suffered from dizziness for a long time. Ballet dancers seem to be able to train themselves not to get dizzy, so we wondered whether we could use the same principles to help our patients.”

The brain scans revealed differences between the groups in two parts of the brain: an area in the cerebellum where sensory input from the vestibular organs is processed and in the cerebral cortex, which is responsible for the perception of dizziness.

The area in the cerebellum was smaller in dancers. Dr Seemungal thinks this is because dancers would be better off not using their vestibular systems, relying instead on highly co-ordinated pre-programmed movements.

“It’s not useful for a ballet dancer to feel dizzy or off balance. Their brains adapt over years of training to suppress that input. Consequently, the signal going to the brain areas responsible for perception of dizziness in the cerebral cortex is reduced, making dancers resistant to feeling dizzy. If we can target that same brain area or monitor it in patients with chronic dizziness, we can begin to understand how to treat them better.”

Another finding in the study may be important for how chronic dizzy patients are tested in the clinic. In the control group, the perception of spinning closely matched the eye reflexes triggered by vestibular signals, but in dancers, the two were uncoupled.

“This shows that the sensation of spinning is separate from the reflexes that make your eyes move back and forth,” Dr Seemungal said. “In many clinics, it’s common to only measure the reflexes, meaning that when these tests come back normal the patient is told that there is nothing wrong. But that’s only half the story. You need to look at tests that assess both reflex and sensation.”

For the curious, here’s a link to and a citation for the paper,

The Neuroanatomical Correlates of Training-Related Perceptuo-Reflex Uncoupling in Dancers by Yuliya Nigmatullina, Peter J. Hellyer, Parashkev Nachev, David J. Sharp, and Barry M. Seemungal. Cereb. Cortex (2013) doi: 10.1093/cercor/bht266 First published online: September 26, 2013

Delightfully, this article too is open access.

I love these kinds of stories where two very different branches of science find information of interest in something as ordinary as spinning around.

Courtesy: Imperial College of London (downloaded from: http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_26-9-2013-17-43-4]

Courtesy: Imperial College of London (downloaded from: http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_26-9-2013-17-43-4]

Here are some Whirling Dervishes,

Istanbul - Monestir Mevlevi - Dervixos dansaires Credit: Josep Renalias [downloaded from: http://en.wikipedia.org/wiki/File:Istanbul_-_Monestir_Mevlevi_-_Dervixos_dansaires.JPG]

Istanbul – Monestir Mevlevi – Dervixos dansaires Credit: Josep Renalias [downloaded from: http://en.wikipedia.org/wiki/File:Istanbul_-_Monestir_Mevlevi_-_Dervixos_dansaires.JPG]

ETA Nov. 28, 2013: I was most diverted by the Nov. 27, 2013 Virginia Tech news release (also on EurekAlert) which describes how two physicists and an engineer came to study Whirling Dervishes,

James Hanna likes to have fun with his engineering views of physics.

So when he and his colleague Jemal Guven visited their friend Martin Michael Müller in France on a rainy, dreary day, the three intellects decided to stay in. Guven, absent-mindedly switching between channels on the television, stumbled upon a documentary on whirling dervishes, best described as a Sufi religious order, who commemorate the teachings of 13th century Persian mystic and poet Rumi through spinning at a fixed speed in their floor length skirts.

“Their skirts showed these very striking, long-lived patterns,” Hanna, the engineer, recalled.

The film caused physicists Guven and Müller to think about structures with conical symmetry, or those shapes that can be defined as a series of straight lines emanating from a single point. By contrast, Hanna, the engineer with a physicist’s background, thought about rotating flexible structures, namely strings or sheets.

Physicists go beyond semantics by taking tourist walks in complex networks to discover word meanings in context

It was a bit shocking to find out that physicists have made a breakthrough in semantics, a field of interest I associate with writers and linguistics experts, but there it was in a July 3, 2013 news item on the Springer (publisher) Select website,

Two Brazilian physicists have now devised a method to automatically elucidate the meaning of words with several senses, based solely on their patterns of connectivity with nearby words in a given sentence – and not on semantics. Thiago Silva and Diego Amancio from the University of São Paulo, Brazil, reveal, in a paper about to be published in EPJ B [European Physical Journal B]. how they modelled classics texts as complex networks in order to derive their meaning. This type of model plays a key role in several natural processing language tasks such as machine translation, information retrieval, content analysis and text processing.

Here more about the words the physicists used in their ‘tourist walk’ and the text they tested (from the news item),

In this study, the authors chose a set of ten so-called polysemous words—words with multiple meanings—such as bear, jam, just, rock or present. They then verified their patterns of connectivity with nearby words in the text of literary classics such as Jane Austen’s Pride and Prejudice. Specifically, they established a model that consisted of a set of nodes representing words connected by their “edges,” if they are adjacent in a text.The authors then compared the results of their disambiguation exercise with the traditional semantic-based approach. They observed significant accuracy rates in identifying the suitable meanings when using both techniques. The approach described in this study, based on a so-called deterministic tourist walk characterisation, can therefore be considered a complementary methodology for distinguishing between word senses.

Not have coming across the ‘tourist walk’ before, I went looking for a definition, which I found in a 2002 paper (Deterministic walks in random networks: an application to thesaurus graphs by O. Kinouchi, A. S. Martinez, G. F. Lima,  G. M. Lourenço, and S. Risau-Gusman),

In a landscape composed of N randomly distributed sites in Euclidean space, a walker (“tourist”) goes to the nearest one that has not been visited in the last τ steps. This procedure leads to trajectories composed of a transient part and a final cyclic attractor of period p. The tourist walk presents a simple scaling with respect to τ and can be performed in a wide range of networks that can be viewed as ordinal neighborhood graphs. As an example, we show that graphs defined by thesaurus dictionaries share some of the statistical properties of low dimensional (d= 2) Euclidean graphs and are easily distinguished from random link networks which correspond to the d→ ∞ limit. This approach furnishes complementary information to the usual clustering coefficient and mean minimum separation length.

This gives me only the vaguest sense of what they mean by tourist walk but it does give some idea of how these physicists approached a problem that is linguistic and semantic in nature.

Silva’s and Amancio’s paper in the European Physical Journal B is behind a paywall but there’s an earlier version of it freely available on arXiv.org,

Discriminating word senses with tourist walks in complex networks by Thiago C. Silva, Diego R. Amancio. (Submitted on 17 Jun 2013)  DOI:  10.1140/epjb/e2013-40025-4 Cite as:  arXiv:1306.3920 [cs.CL] or (or arXiv:1306.3920v1 [cs.CL] for this version)

I gather this work was done in English. I wonder why there’s no mention of the research being performed on texts in other languages either for this study or future studies. As you can see, the researchers concentrated on 19th century and early 20th century writers in the UK, from page 2 of the PDF available from arXiv.org,

Table 2.
List of books (and their respective authors) employed in the experiments aiming at discriminating the meaning of ambiguous words. The year of publication is speci ed after the title of the book.

Title Author
Pride and Prejudice (1813) J. Austen
American Notes (1842) C. Dickens
Coral Reefs (1842) C. Darwin
A Tale of Two Cities (1859) C. Dickens
The Moonstone (1868) W. Collins
Expression of Emotions (1872) C. Darwin
A Pair of Blue Eyes (1873) T. Hardy
Jude the Obscure (1895) T. Hardy
Dracula’s Guest (1897) B. Stoker
Uncle Bernac (1897) A. C. Doyle
The Tragedy of the Korosko (1898) A. C. Doyle
The Return of Sherlock Holmes (1903) A. C. Doyle
Tales of St. Austin’s (1903) P. G. Wodehouse
The Chronicles of Clovis (1911) H. H. Munro
A Changed Man (1913) T. Hardy
Beasts and Super Beasts (1914) H. H. Munro
The Wisdom of Father Brown (1914) G. K. Chesterton
My Man Jeeves (1919) P. G. Wodehouse

Three Canadian subatomic physics powerhouses invite graduate students to apply for summer 2013 TRISEP in Vancouver (Canada)

It’s not the first time I’ve been puzzled by a TRIUMF (Canada’s National Particle and Nuclear Physics Laboratory) news release but now I have to break my silence: please, please hire me or someone else or anyone else to help you write these things. Putting the reason (or call to action) for the news release in its last line at the very end is not good practice.

Particle physics graduate students from anywhere in the world are invited to apply for an opportunity to attend the Tri-Institute Summer School on Elementary Particles (TRISEP) sponsored by Canada’s big three subatomic physics research institutions, TRIUMF, Perimeter Institute (PI), and SNOLAB.

From TRIUMF’s Apr. 12, 2013 news release,

… master the pioneering topics of collider physics, neutrino physics, dark matter, Monte-Carlo simulation, and physics beyond the Standard Model.

The new international summer school is convened by Canada’s three subatomic physics powerhouses: TRIUMF in experimental particle physics, Perimeter Institute in theoretical physics, and SNOLAB in deep underground physics. Taken together, these three institutions not only give Canada a competitive advantage on the world stage, but they also give international students an opportunity to learn about and then pursue the hottest science topics with
some of the leaders.

One of the incentives for attending, according to the news release, is this,

A recent independent analysis by the Council of Canadian Academies showed that Canada is one of the world’s top six national performers in terms of physics and astronomy (driven by particle and nuclear physics) as measured by bibliometric analysis and surveys of international scientists.

I’m not quite as impressed by that assessment as the folks at the ‘big three’ since there are problems with bibliometric analysis in general which I noted in part of two of my commentary on the report (The State of Science and Technology in Canada, 2012 report—examined (part 2: the rest of the report).

I find this bit from the TRISEP home page (Note: Some links have been removed) a little more exciting,

TRISEP will feature lectures by leading experts in the field of particle physics and is designed to be very interactive with ample time for questions, discussions and interaction with the speakers. Students will also have the opportunity to present a poster describing their research topic. The summer school can also be taken for graduate course credit, more details are available here

The key note speaker will be Hitoshi Murayama, UC Berkeley/Kavli IPMU

Lecturers at the summer school include:
Richard Baartman, TRIUMF
André de Gouvêa, NorthWestern University
Ashutosh Kotwal, Duke University
Heather Logan, Carleton University
Tsuyoshi Nakaya, Kyoto University
Scott Oser, University of British Columbia
Torbjörn Sjöstrand, Lund University
Tim Tait, University of California, Irvine
Viktor Zacek, Université de Montréal

The deadline for applications as listed on the TRISEP home is Friday, June 1, 2013, which is a little confusing since June 1, 2013 is on a Saturday. Presumably you should have your application submitted by Friday, May 31, 2013.

Get on the waiting list for Professor Gino Segrè’s talk on Galileo & the Higgs Boson on November 20, 2012 in Vancouver

Sadly, I didn’t get the notice until late Friday, Nov. 3, 2012 but on a happier note it looks like Vancouver is really embracing physics. Professor Gino Segrè will be discussing the history of physics and more in a talk titled, Physics From Galileo to the Higgs Boson, which, as of today, is waiting list only.

The talk will take place on Tuesday, Nov. 20, 2012 from 6:30 to 8 pm at Vancouver’s TELUS World of Science. From the ARPICO (Society of Italian Researchers and Professionals in Western Canada) announcement,

Physics From Galileo to the Higgs Boson
Unveiling the Universe Lecture Series
Tuesday, 20 November 2012 from 6:30 PM to 8:00 PM (PST)
Telus World of Science
1455 Quebec Street 
Vancouver, British Columbia V6A 3Z7

This event is co-sponsored by TRIUMF, the Embassy of Italy in Ottawa,
Science World, CMC Engineering Group and the Consulate General Of Italy
at Vancouver.

I gather Segrè has a very personal take on some of the history,

Gino Segrè is a physics professor emeritus at the University of
Pennsylvania and the author of three popular science books, including
“Faust in Copenhagen”. He was the winner of the American Institute of
Physics Award for Best Science Writing. His lecture, entitled “Physics
in Florence from Galileo to the Higgs Boson”, will chart the history of
physics as it grew from the influence of Galileo, his disciples, and the
spirit of exploration in 17th century Florence, to the present day, with
the most recent dramatic example being the discovery of the Higgs boson.
Gino Segrè is also the nephew of 1959 Nobel Laureate Emilio Segrè, and
will be introduced by Ms. Olivia Fermi, granddaughter of 1938 Nobel
Laureate Enrico Fermi. [emphasis mine]

You can arrange to get on the waiting list here and, as encouragement to get on the list, here’s what the event organizers have posted,

Event is sold out at present but more seating likely will become available. Those on the waitlist will be notified automatically if new seating has been added.

Good luck!

Space-time crystals and everlasting clocks

Apparently, a space-time crystal could be useful for such things as studying the many-body problem in physics.  Since I hadn’t realized the many-body problem existed and have no idea how this might affect me or anyone else, I will have to take the utility of a space-time crystal on trust.As for the possibility of an everlasting clock, how will I ever know the truth since I’m not everlasting?

The Sept. 24, 2012 news item on Nanowerk about a new development makes the space-time crystal sound quite fascinating,

Imagine a clock that will keep perfect time forever, even after the heat-death of the universe. This is the “wow” factor behind a device known as a “space-time crystal,” a four-dimensional crystal that has periodic structure in time as well as space. However, there are also practical and important scientific reasons for constructing a space-time crystal. With such a 4D crystal, scientists would have a new and more effective means by which to study how complex physical properties and behaviors emerge from the collective interactions of large numbers of individual particles, the so-called many-body problem of physics. A space-time crystal could also be used to study phenomena in the quantum world, such as entanglement, in which an action on one particle impacts another particle even if the two particles are separated by vast distances. [emphasis mine]

While I’m most interested in the possibility of studying entanglement, it seems to me the scientists are guessing since the verb ‘could’ is being used where they used ‘would’ previously for studying the many body problem.

The Sept. 24, 2012 news release by Lynn Yarris for the Lawrence Berkeley National Laboratory  (Berkeley Lab), which originated the news item, provides detail on the latest space-time crystal development,

A space-time crystal, however, has only existed as a concept in the minds of theoretical scientists with no serious idea as to how to actually build one – until now. An international team of scientists led by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has proposed the experimental design of a space-time crystal based on an electric-field ion trap and the Coulomb repulsion of particles that carry the same electrical charge.

“The electric field of the ion trap holds charged particles in place and Coulomb repulsion causes them to spontaneously form a spatial ring crystal,” says Xiang Zhang, a faculty scientist  with Berkeley Lab’s Materials Sciences Division who led this research. “Under the application of a weak static magnetic field, this ring-shaped ion crystal will begin a rotation that will never stop. The persistent rotation of trapped ions produces temporal order, leading to the formation of a space-time crystal at the lowest quantum energy state.”

Because the space-time crystal is already at its lowest quantum energy state, its temporal order – or timekeeping – will theoretically persist even after the rest of our universe reaches entropy, thermodynamic equilibrium or “heat-death.”

This new development builds on some work done earlier this year at the Massachusetts Institute of Technology (MIT), from the Yarris news release,

The concept of a crystal that has discrete order in time was proposed earlier this year by Frank Wilczek, the Nobel-prize winning physicist at the Massachusetts Institute of Technology. While Wilczek mathematically proved that a time crystal can exist, how to physically realize such a time crystal was unclear. Zhang and his group, who have been working on issues with temporal order in a different system since September 2011, have come up with an experimental design to build a crystal that is discrete both in space and time – a space-time crystal.

Traditional crystals are 3D solid structures made up of atoms or molecules bonded together in an orderly and repeating pattern. Common examples are ice, salt and snowflakes. Crystallization takes place when heat is removed from a molecular system until it reaches its lower energy state. At a certain point of lower energy, continuous spatial symmetry breaks down and the crystal assumes discrete symmetry, meaning that instead of the structure being the same in all directions, it is the same in only a few directions.

“Great progress has been made over the last few decades in exploring the exciting physics of low-dimensional crystalline materials such as two-dimensional graphene, one-dimensional nanotubes, and zero-dimensional buckyballs,” says Tongcang Li, lead author of the PRL paper and a post-doc in Zhang’s research group. “The idea of creating a crystal with dimensions higher than that of conventional 3D crystals is an important conceptual breakthrough in physics and it is very exciting for us to be the first to devise a way to realize a space-time crystal.”

Just as a 3D crystal is configured at the lowest quantum energy state when continuous spatial symmetry is broken into discrete symmetry, so too is symmetry breaking expected to configure the temporal component of the space-time crystal. Under the scheme devised by Zhang and Li and their colleagues, a spatial ring of trapped ions in persistent rotation will periodically reproduce itself in time, forming a temporal analog of an ordinary spatial crystal. With a periodic structure in both space and time, the result is a space-time crystal.

Here’s an image created by team at the Berkeley Lab to represent their work on the space-time crystal,

Imagine a clock that will keep perfect time forever or a device that opens new dimensions into quantum phenomena such as emergence and entanglement. (courtesy of Xiang Zhang group[?] at Berkeley Lab)

For anyone who’s interested in this work, I suggest reading either the news item on Nanowerk or the Berkeley Lab news release in full. I will leave you with Natalie Cole and Everlasting Love,