Tag Archives: Philip Ball

Fish gets invisibility cloak first, cat waits patiently

An invisibility cloak devised by researchers in Singapore and China is receiving a high degree of interest online with a June 14, 2013 news item on Nanowerk, a June 11, 2013 article by Philip Ball for Nature, and a June 13, 2013 article by Sarah Gates for Huffington Post.

The research paper, Natural Light Cloaking for Aquatic and Terrestrial Creatures by Hongsheng Chen, Bin Zheng, Lian Shen, Huaping Wang, Xianmin Zhang, Nikolay Zheludev, Baile Zhang was submitted June 7, 2013 to arXiv.org (arXiv is an e-print service in the fields of physics, mathematics, computer science, quantitative biology, quantitative finance and statistics. Submissions to arXiv must conform to Cornell University academic standards. arXiv is owned and operated by Cornell University, a private not-for-profit educational institution),

A cloak that can hide living creatures from sight is a common feature of mythology but still remains unrealized as a practical device. To preserve the phase of wave, the previous cloaking solution proposed by Pendry \emph{et al.} required transforming electromagnetic space around the hidden object in such a way that the rays bending around it have to travel much faster than those passing it by. The difficult phase preservation requirement is the main obstacle for building a broadband polarization insensitive cloak for large objects. Here, we suggest a simplifying version of Pendry’s cloak by abolishing the requirement for phase preservation as irrelevant for observation in incoherent natural light with human eyes that are phase and polarization insensitive. This allows the cloak design to be made in large scale using commonly available materials and we successfully report cloaking living creatures, a cat and a fish, in front of human eyes.

What they seem to be saying is that it’s possible to create an invisibility cloak perceptible to the human eye that is made of everyday materials.

I’ll show the fish video first. Pay attention as that fish darts behind its invisibility cloak almost as soon as the video starts (from the Nanowerk Youbube channel; June 14, 2013 Nanowerk news item),

Then, there’s the cat (also from the Nanowerk Youtube channel),

The June 11, 2013 article by Philip Ball for Nature describes the device which provides invisibility,

… This latest addition to the science of invisibility cloaks is one of the simplest implementations so far, but there’s no denying its striking impact.

The ‘box of invisibility’ has been designed by a team of researchers at Zhejiang University in Hangzhou, China, led by Hongsheng Chen, and their coworkers. The box is basically a set of prisms made from high-quality optical glass that bend light around any object in the enclosure around which the prisms are arrayed, the researchers describe in a paper posted on the online repository arXiv.

Ball suggests that this latest invisibility cloak is very similar to a Victorian era music hall trick,

As such, the trick is arguably closer to ‘disappearances’ staged in Victorian music hall using arrangements of slanted mirrors than to the modern use of substances called metamaterials to achieve invisibility by guiding light rays in unnatural ways.

As far as I know, the ‘metamaterial’ invisibility cloaks require very sophisticated equipment for their production, are incredibly expensive, and aren’t all that practical.

Gates’s June 13, 2013 article for the Huffington Post provides an overview of some of the recent work on invisibility cloaks and metamaterials, as well as, previous work done by Dr. Hongsheng Chen, an electromagnetics professor at Zhejiang University (China), and Baile Zhang, an assistant physics professor at Singapore’s Nanyang Technological University before they unveiled this latest invisibility cloak.

My most recent posting on the topic was a June 6, 2013 piece on a temporal invisibility cloak.

Art/Sci: Survival of the beautiful

Peafowl flaring its feathers. Credit: Jebulon

Thanks to Wikipedia and Jebulon for this image to illustrate this story about a special event in New York titled, Survival of the Beautiful, Feb. 25, 2012.  (I took my inspiration from the event poster.) From the event’s home page,

Why did the peacock’s tail so trouble Charles Darwin?  Natural selection could not explain it, so he had to contrive a whole new theory of sexual selection, which posited that certain astonishingly beautiful traits became preferred even when not exactly useful, simply because they appealed to the opposite sex, and specifically so in each case.  And yet the parallels in what gets preferred at different levels of life suggest that nature may in fact favor certain kinds of patterns over others.  Visually, the symmetrical; colorwise, the contrasting and gaudy; displaywise, the gallant and extreme.  Soundwise, the strong contrast between low note and high, between fast rhythm and the long clear tone. For that matter, plenty of beauty in nature would seem to arise for reasons other than mere sexual selection: for example, the mysterious inscriptions on the backs of seashells, or the compounding geometric symmetries of microscopic diatoms, or the live patterns pulsating across the bodies of octopus and squid.

Humans see such things and find them astonishingly beautiful: are we wrong to experience Nature in such terms?  Far greater than our grandest edifices and epic tales, Nature itself nevertheless seems entirely without purposeful self-consciousness or self-awareness.  Meanwhile, though we ourselves are as nothing compared to it, we still seem possessed of a parallel need to create.  So: can we in fact create our way into better understanding of the role of beauty in the vast natural world?  David Rothenberg recently published a book on these themes, Survival of the Beautiful (Bloomsbury, 2011), and many of the protagonists he encountered on his quest will join him on stage at the Cantor Film Center to debate the question of whether nature’s beauty is actual, imaginary, useful, excessive, or perhaps even entirely beside the point.

What a great event to publicize a book! The schedule reveals some very interesting guests, including Vancouver-based rapper, Baba Brinkman,



10:45 am
DAVID ROTHENBERG and JARON LANIER offer a musical and conceptual introduction.

11:00 am
GAIL PATRICELLI on building a fembot bowerbird to study how male bowerbirds woo females through elaborate dancing and decorating rituals; drawing on her example, RICHARD PRUM explains why everyone misses the point of sexual selection except him.

12:00 pm
OFER TCHERNICHOVSKI responds to Prum’s claim by way of introducing
CHRISTINE ROESKE, a postdoc in his lab, who, veritably haunted
by the beauty of the nightingale’s song, nevertheless tries to subject it to scientific analysis.

12:45 pm
ANNA LINDEMANN, Prum alum turned performance artist, enacts her Theory of Flight.

(1:00 – 1:30 pm:  Break)


2:00 pm
PHILIP BALL shows how chemistry and physics might trump biology in their ability to account for formal natural beauty.  TYLER VOLK deploys his concept of metapatterns to explain how 3 realms and 13 steps (from quarks to culture) make us who we are.

3:00 pm
We know how Science is regularly said to influence Art, but SUZANNE ANKER
explores the flow in the other direction.  DAVID SOLDIER and VITALY KOMAR revisit
their classic elephant art experiment, asking whether we can learn anything about art by
teaching animals to make it.

4:00 pm
Composer DAVID DUNN details his proposal to use music to
save the forests of the American West from destruction by pine bark beetles.
DAVID ABRAM on how synaesthesia (the blending of the senses) might help us
feel our way into the experience of another animal.

(5:00 – 5:30 pm:  Break)


5:30 pm
Digital artist SCOTT SNIBBE recounts how he helped morph
Björk’s love of science into the Biophilia app.

6:15 pm
BABA BRINKMAN, direct from off-Broadway, performs
a special version of The Rap Guide to Evolution.

7:00 pm
JARON LANIER explains why if squid only had childhoods,
they would rule the world.
LAURIE ANDERSON evokes some of her journeys along
the borderlands of nature and culture.

(Times listed above are approximate at best.)

The event is being hosted by the New York Institute for the Humanities and the New Jersey Institute of Technology. The event, which is open and free to the public (due to funding from the Alfred P. Sloan Foundation), will be held at New York University.

Here’s more information about the presenters, from the (sigh) undated news release,

Jaron Lanier is one of the pioneers in virtual reality. His book You Are Not a Gadget is an international bestseller and he was named one of the 100 most influential people in the world by Time Magazine in 2010.

Gail Patricelli is associate professor of evolution and ecology at the University of California Davis.  She specializes in the study of acoustic communication in birds, and is the inventor of the fembot bowerbird.

Richard Prum is professor of evolutionary biology at Yale, and a specialist on the evolution of feathers and the role of beauty in sexual selection.  He received a MacArthur Fellowship in 2009.

Ofer Tchernichovski is associate professor of animal behavior at CUNY, where he studies songbird learning by recording every single sounds baby birds make when learning to sing.

Christina Roeske is postdoctoral associate in biology at the CUNY laboratory for animal behaviour, where she is focusing on the structure of complex birdsongs.

Anna Lindemann is visiting assistant professor of art at Colgate University.  She is a multimedia artist and composer whose works are based on evolutionary/developmental (Evo Devo) biology.

Philip Ball is a science writer and formerly an editor at Nature.  His many books include Natures Patterns: Shape- FlowBranches; The Music Instinct; and Critical Mass.

Tyler Volk is professor of biology and science director of environmental studies at NYU and author of Metapatterns, CO2 Rising, and other books.

Suzanne Anker is chair of the Fine Arts Department at the School of Visual Arts, and the co-author with Dorothy Nelkin of The Molecular Gaze: Art in the Genetic Age.  She recently built a bio-art lab at SVA, just opened for the spring 2012 semester.

David Soldier is a composer who has collaborated with elephants, zebra finches, and, together with Komar and Melamid, written the best and worst songs in the world.  In his other life as David Sulzer he is professor of neuroscience at Columbia.

Vitaly Komar, together with Alex Melamid, is known for trying to paint the best and worst paintings in the world, and for his work with with elephants in Thailand.  He was one of the first Russian-exile artists to receive a grant from the National Endowment for the Arts.

David Dunn is a composer, sound artist, and theorist, who has lately discovered a new way to listen inside of trees that may radically change the way we manage the forest destruction wrought by the pine bark beetle.

David Abram, cultural ecologist and philosopher, is the award-winning author of Becoming Animal and The Spell of the Sensuous. Described as as “daring” and “truly original” by Science, his work has helped catalyze the burgeoning field of ecopsychology.

Scott Snibbe is a media artist and researcher into interactivity.  His works are in the permanent collection of the Whitney and MOMA, and he has collaborated with James Cameron and Björk.

Baba Brinkman is a Canadian rap artist, writer, actor, and tree planter. He is best known for his award-winning shows The Rap Canterbury Tales and The Rap Guide to Evolution, which interpret the works of Chaucer and Darwin for a modern audience.

Laurie Anderson is one of the most celebrated performance artists in the world.  She is the inventor of the tape-bow violin and sometimes alters her voice to a low baritone to perform as Fenway Bergamot.  She was awarded the Gish Prize in 2007, and is a Fellow of the New York Institute for the Humanities at NYU.

David Rothenberg is the author of Survival of the Beautiful, Thousand Mile Song, Why Birds Sing, and a recording artist with ECM Records.  He is professor of philosophy and music at the New Jersey Institute of Technology, and a Fellow of the New York Institute for the Humanities at NYU.

Between this and the events at the New York Academy of Sciences, it all makes me wish I lived in New York.

Entangling diamonds

Usually when you hear about entanglement, they’re talking about quantum particles or kittens. On Dec. 2, 2011, Science magazine published a paper by scientists who had entangled diamonds (that can be touched and held in human hands). From the Dec. 1, 2011 CBC (Canadian Broadcasting Corporation) news article by Emily Chung,

Quantum physics is known for bizarre phenomena that are very different from the behaviour we are familiar with through our interaction with objects on the human scale, which follow the laws of classical physics. For example, quantum “entanglement” connects two objects so that no matter how far away they are from one another, each object is affected by what happens to the other.

Now, scientists from the U.K., Canada and Singapore have managed to demonstrate entanglement in ordinary diamonds under conditions found in any ordinary room or laboratory.

Philip Ball in his Dec. 1, 2011 article for Nature magazine describes precisely what entanglement means when applied to the diamond crystals that were entangled,

A pair of diamond crystals has been linked by quantum entanglement. This means that a vibration in the crystals could not be meaningfully assigned to one or other of them: both crystals were simultaneously vibrating and not vibrating.

Quantum entanglement — interdependence of quantum states between particles not in physical contact — has been well established between quantum particles such as atoms at ultra-cold temperatures. But like most quantum effects, it doesn’t tend to survive either at room temperature or in objects large enough to see with the naked eye.

Entanglement, until now, has been demonstrated at very small scales due to an issue with coherence and under extreme conditions. Entangled objects are coherent with each other but other objects such as atoms can cause the entangled objects to lose their coherence and their entangled state. In order to entangle the diamonds, the scientists had to find a way of dealing with the loss of coherence as the objects are scaled up and they were able to achieve this at room temperature. From the Emily Chung article,

Walmsley [Ian Walmsley, professor of experimental physics at the University of Oxford] said it’s easier to maintain coherence in smaller objects because they can be isolated practically from disturbances. Things are trickier in larger systems that contain lots of interacting, moving parts.

Two things helped the researchers get around this in their experiment, Sussman [Ben Sussman, a quantum physicist at the National Research Council of Canada and adjunct professor at the University of Ottawa] said:

  • The hardness of the diamonds meant it was more resistant to disturbances that could destroy the coherence.
  • The extreme speed of the experiment — the researchers used laser pulses just 60 femtoseconds long, about 6/100,000ths of a nanosecond (a nanosecond is a billionth of a second) — meant there was no time for disturbances to destroy the quantum effects.

Laser pulses were used to put the two diamonds into a state where they were entangled with one another through a shared vibration known as a phonon. By measuring particles of light called photons subsequently scattered from the diamonds, the researchers confirmed that the states of the two diamonds were linked with each other — evidence that they were entangled.

If you are interested in the team’s research and can get past Science magazine’s paywall, here’s the citation,

“Entangling Macroscopic Diamonds at Room Temperature,” by K.C. Lee; M.R. Sprague; J. Nunn; N.K. Langford; X.-M. Jin; T. Champion; P. Michelberger; K.F. Reim; D. England; D. Jaksch; I.A. Walmsley at University of Oxford in Oxford, UK; B.J. Sussman at National Research Council of Canada in Ottawa, ON, Canada; X.-M. Jin; D. Jaksch at National University of Singapore in Singapore. Science 2 December 2011: Vol. 334 no. 6060 pp. 1253-1256 DOI: 10.1126/science.1211914

All of the media reports I’ve seen to date focus on the UK and Canadian researchers and I cannot find anything about the contribution of the researcher based in Singapore.

I do wish I could read more languages as I’d be more likely to find information about work which is not necessarily going to be covered in English language media.