Tag Archives: particles

Quantum Rhapsodies

Leave a reply
“Quantum Rhapsodies” combines a narrative script, video images and live music by the Jupiter String Quartet to explore the world of quantum physics. The performance will premiere April 10 [2019] at the Beckman Institute for Advanced Science and Technology. Courtesy Beckman Institute for Advanced Science and Technology

Here’s more about Quantum Rhapsodies, a free public art/science music performance at the University of Illinois on April 10, 2019, from an April 5, 2019 University of Illinois news release (also here) by Jodi Heckel,

A new performance that explores the world of quantum physics will feature the music of the Jupiter String Quartet, a fire juggler and a fantastical “Alice in Quantumland” scene.

“Quantum Rhapsodies,” the vision of physics professor Smitha Vishveshwara, looks at the foundational developments in quantum physics, the role it plays in our world and in technology such as the MRI, and the quantum mysteries that remain unanswered.

“The quantum world is a world that inspires awe, but it’s also who we are and what we are made of,” said Vishveshwara, who wrote the piece and guided the visuals.

The performance will premiere April 10 [2019] as part of the 30th anniversary celebration of the Beckman Institute for Advanced Science and Technology. The event begins with a 5 p.m. reception, followed by the performance at 6 p.m. and a meet-and-greet with the show’s creators at 7 p.m. The performance will be in the atrium of the Beckman Institute, 405 N. Mathews Ave., Urbana, [emphases mine] and it is free and open to the public. While the available seating is filling up, the atrium space will allow for an immersive experience in spite of potentially restricted viewing.

The production is a sister piece to “Quantum Voyages,” a performance created in 2018 by Vishveshwara and theatre professor Latrelle Bright to illustrate the basic concepts of quantum physics. It was performed at a quantum physics conference celebrating Nobel Prize-winning physicist Anthony Leggett’s 80th birthday in 2018.

While “Quantum Voyages” was a live theater piece, “Quantum Rhapsodies” combines narration by Bright, video images and live music from the Jupiter String Quartet. It ponders the wonder of the cosmos, the nature of light and matter, and the revolutionary ideas of quantum physics. A central part of the narrative involves the theory of Nobel Prize-winning French physicist Louis de Broglie that matter, like light, can behave as a wave.

The visuals – a blend of still images, video and animation – were created by a team consisting of the Beckman Visualization Laboratory; Steven Drake, a video producer at Beckman; filmmaker Nic Morse of Protagonist Pizza Productions; and members of a class Vishveshwara teaches, Where the Arts Meet Physics.

The biggest challenge in illustrating the ideas in the script was conveying the scope of the piece, from the galactic scale of the cosmos to the subatomic scale of the quantum world, Drake said. The concepts of quantum physics “are not something you can see. It’s theoretical or so small you can’t put it under a microscope or go out into the real world and film it,” he said.

Much of the work involved finding images, both scientific and artistic, that would help illustrate the concepts of the piece and complement the poetic language that Vishveshwara used, as well as the music.

Students and teaching assistant Danielle Markovich from Vishveshwara’s class contributed scientific images and original paintings. Drake used satellite images from the Hubble Space Telescope and other satellites, as well as animation created by the National Center for Supercomputing Applications in its work with NASA, for portions of the script talking about the cosmos. The Visualization Laboratory provided novel scientific visualizations.

“What we’re good at doing and have done for years is taking research content and theories and visualizing that information. We do that for a very wide variety of research and data. We’re good at coming up with images that represent these invisible worlds, like quantum physics,” said Travis Ross, the director of the lab.

Some ideas required conceptual images, such as footage by Morse of a fire juggler at Allerton Park to represent light and of hands moving to depict the rotational behavior of water-based hydrogen within a person in an MRI machine.

Motion was incorporated into a painting of a lake to show water rippling and light flickering across it to illustrate light waves. In the “Alice in Quantumland” sequence, a Mad Hatter’s tea party filmed at the Illini Union was blended with cartoonlike animated elements into the fantasy sequence by Jose Vazquez, an illustrator and concept artist who works in the Visualization Lab.

“Our main objective is making sure we’re representing it in a believable way that’s also fun and engaging,” Ross said. “We’ve never done anything quite like this. It’s pretty unique.”

In addition to performing the score, members of the Jupiter String Quartet were the musical directors, creating the musical narrative to mesh with the script. The music includes contemplative compositions by Beethoven to evoke the cosmos and playful modern compositions that summon images of the movements of particles and waves.

“I was working with such talented people and creative minds, and we had fun and came up with these seemingly absurd ideas. But then again, it’s like that with the quantum world as well,” Vishveshwara said.

“My hope is not necessarily for people to understand everything, but to infuse curiosity and to feel the grandness and the beauty that is part of who we are and the cosmos that we live in,” she said..

Here’s a preview of this free public performance,

How to look at SciArt (also known as, art/science depending on your religion)

There’s an intriguing April 8, 2019 post on the Science Borealis blog by Katrina Vera Wong and Raymond Nakamura titled: How to look at (and appreciate) SciArt,

….

The recent #SciArt #TwitterStorm, in which participants tweeted their own sciart and retweeted that of others, illustrated the diversity of approaches to melding art and science. With all this work out there, what can we do, as advocates of art and science, to better appreciate sciart? We’d like to foster interest in, and engagement with, sciart so that its value goes beyond how much it costs or how many likes it gets.

An article by Kit Messham-Muir based on the work of art historian Erwin Panofsky outlines a three-step strategy for looking at art: Look. See. Think. Looking is observing what the elements are. Seeing draws meaning from it. Thinking links personal experience and accessible information to the piece at hand.

Looking and seeing is also part of the Visual Thinking Strategies (VTS) method originally developed for looking at art and subsequently applied to science and other subjects as a social, object-oriented learning process. It begins by asking, “What is going on here?”, followed by “What do you see that makes you think that?” This allows learners of different backgrounds to participate and encourages the pursuit of evidence to back up opinions.

Let’s see how these approaches might work on your own or in conversation. Take, for example, the following work by natural history illustrator Julius Csotonyi:

…

I hope some of our Vancouver-based (Canada) art critics get a look at some of this material. I read a review a few years ago and the critic seemed intimidated by the idea of looking at work that explicitly integrated and reflected on science. Since that time (Note: there aren’t that many art reviewers here), I have not seen another attempt by an art critic.

Tractor beams for humans?

Leave a reply

I got excited for a moment before realizing that, if tractor beams for humans result from this work, it will be many years in the future. Still, one can dream, eh? Here’s more about the current state of tractor beams (the acoustic kind) from a January 21, 2018 news item on ScienceDaily,

Acoustic tractor beams use the power of sound to hold particles in mid-air, and unlike magnetic levitation, they can grab most solids or liquids. For the first time University of Bristol engineers have shown it is possible to stably trap objects larger than the wavelength of sound in an acoustic tractor beam. This discovery opens the door to the manipulation of drug capsules or micro-surgical implements within the body. Container-less transportation of delicate larger samples is now also a possibility and could lead to levitating humans.

A January 22, 2018 University of Bristol press release (also on EurekAlert but dated January 21, 2018), which originated the news item, expands on the theme,

Researchers previously thought that acoustic tractor beams were fundamentally limited to levitating small objects as all the previous attempts to trap particles larger than the wavelength had been unstable, with objects spinning uncontrollably. This is because rotating sound field transfers some of its spinning motion to the objects causing them to orbit faster and faster until they are ejected.

The new approach, published in Physical Review Letters today [Monday 22 January]{2018}], uses rapidly fluctuating acoustic vortices, which are similar to tornadoes of sound, made of a twister-like structure with loud sound surrounding a silent core.

The Bristol researchers discovered that the rate of rotation can be finely controlled by rapidly changing the twisting direction of the vortices, this stabilises the tractor beam. They were then able to increase the size of the silent core allowing it to hold larger objects. Working with ultrasonic waves at a pitch of 40kHz, a similar pitch to that which only bats can hear, the researchers held a two-centimetre polystyrene sphere in the tractor beam. This sphere measures over two acoustic wavelengths in size and is the largest yet trapped in a tractor beam. The research suggests that, in the future much larger objects could be levitated in this way.

Dr Asier Marzo, lead author on the paper from Bristol’s Department of Mechanical Engineering, said: “Acoustic researchers had been frustrated by the size limit for years, so its satisfying to find a way to overcome it. I think it opens the door to many new applications.”

Dr Mihai Caleap, Senior Research Associate, who developed the simulations, explained: “In the future, with more acoustic power it will be possible to hold even larger objects. This was only thought to be possible using lower pitches making the experiment audible and dangerous for humans.”

Bruce Drinkwater, Professor of Ultrasonics from the Department of Mechanical Engineering, who supervised the work, added: “Acoustic tractor beams have huge potential in many applications. I’m particularly excited by the idea of contactless production lines where delicate objects are assembled without touching them.”

The researchers have included a video representing their work,

I always liked the tractor beams on Star Trek as they seemed very useful. For those who can dream in more technical language, here’s a link to and a citation for the paper,

Acoustic Virtual Vortices with Tunable Orbital Angular Momentum for Trapping of Mie Particles by Asier Marzo, Mihai Caleap, and Bruce W. Drinkwater. Phys. Rev. Lett. Vol. 120, Iss. 4 — 26 January 2018 DOI:https://doi.org/10.1103/PhysRevLett.120.044301 Published 22 January 2018

This paper is open access.

An atom without properties?

Leave a reply

There’s rather intriguing Swiss research into atoms and so-called Bell Correlations according to an April 21, 2016 news item on ScienceDaily,

The microscopic world is governed by the rules of quantum mechanics, where the properties of a particle can be completely undetermined and yet strongly correlated with those of other particles. Physicists from the University of Basel have observed these so-called Bell correlations for the first time between hundreds of atoms. Their findings are published in the scientific journal Science.

Everyday objects possess properties independently of each other and regardless of whether we observe them or not. Einstein famously asked whether the moon still exists if no one is there to look at it; we answer with a resounding yes. This apparent certainty does not exist in the realm of small particles. The location, speed or magnetic moment of an atom can be entirely indeterminate and yet still depend greatly on the measurements of other distant atoms.

An April 21, 2016 University of Basel (Switzerland) press release (also on EurekAlert), which originated the news item, provides further explanation,

With the (false) assumption that atoms possess their properties independently of measurements and independently of each other, a so-called Bell inequality can be derived. If it is violated by the results of an experiment, it follows that the properties of the atoms must be interdependent. This is described as Bell correlations between atoms, which also imply that each atom takes on its properties only at the moment of the measurement. Before the measurement, these properties are not only unknown – they do not even exist.

A team of researchers led by professors Nicolas Sangouard and Philipp Treutlein from the University of Basel, along with colleagues from Singapore, have now observed these Bell correlations for the first time in a relatively large system, specifically among 480 atoms in a Bose-Einstein condensate. Earlier experiments showed Bell correlations with a maximum of four light particles or 14 atoms. The results mean that these peculiar quantum effects may also play a role in larger systems.

Large number of interacting particles

In order to observe Bell correlations in systems consisting of many particles, the researchers first had to develop a new method that does not require measuring each particle individually – which would require a level of control beyond what is currently possible. The team succeeded in this task with the help of a Bell inequality that was only recently discovered. The Basel researchers tested their method in the lab with small clouds of ultracold atoms cooled with laser light down to a few billionths of a degree above absolute zero. The atoms in the cloud constantly collide, causing their magnetic moments to become slowly entangled. When this entanglement reaches a certain magnitude, Bell correlations can be detected. Author Roman Schmied explains: “One would expect that random collisions simply cause disorder. Instead, the quantum-mechanical properties become entangled so strongly that they violate classical statistics.”

More specifically, each atom is first brought into a quantum superposition of two states. After the atoms have become entangled through collisions, researchers count how many of the atoms are actually in each of the two states. This division varies randomly between trials. If these variations fall below a certain threshold, it appears as if the atoms have ‘agreed’ on their measurement results; this agreement describes precisely the Bell correlations.

New scientific territory

The work presented, which was funded by the National Centre of Competence in Research Quantum Science and Technology (NCCR QSIT), may open up new possibilities in quantum technology; for example, for generating random numbers or for quantum-secure data transmission. New prospects in basic research open up as well: “Bell correlations in many-particle systems are a largely unexplored field with many open questions – we are entering uncharted territory with our experiments,” says Philipp Treutlein.

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

Bell correlations in a Bose-Einstein condensate by Roman Schmied, Jean-Daniel Bancal, Baptiste Allard, Matteo Fadel, Valerio Scarani, Philipp Treutlein, Nicolas Sangouard. Science  22 Apr 2016: Vol. 352, Issue 6284, pp. 441-444 DOI: 10.1126/science.aad8665

This paper is behind a paywall.

Capturing the particle and the wave: photographing light

Leave a reply

On returning to school to get a bachelor’s degree, I registered in a communications course and my first paper was about science, light, and communication. The particle/wave situation still fascinates me (and I imagine many others).

A March 2, 2015 news item on phys.org describes the first successful photography of light as both particle and wave,

Light behaves both as a particle and as a wave. Since the days of Einstein, scientists have been trying to directly observe both of these aspects of light at the same time. Now, scientists at EPFL [École polytechnique fédérale de Lausanne in Switzerland] have succeeded in capturing the first-ever snapshot of this dual behavior.

Quantum mechanics tells us that light can behave simultaneously as a particle or a wave. However, there has never been an experiment able to capture both natures of light at the same time; the closest we have come is seeing either wave or particle, but always at different times. Taking a radically different experimental approach, EPFL scientists have now been able to take the first ever snapshot of light behaving both as a wave and as a particle. The breakthrough work is published in Nature Communications.

A March 2, 2015 EPFL press release (also on EurekAlert), which originated the news item, describes the science and the research,

When UV light hits a metal surface, it causes an emission of electrons. Albert Einstein explained this “photoelectric” effect by proposing that light – thought to only be a wave – is also a stream of particles. Even though a variety of experiments have successfully observed both the particle- and wave-like behaviors of light, they have never been able to observe both at the same time.

A research team led by Fabrizio Carbone at EPFL has now carried out an experiment with a clever twist: using electrons to image light. The researchers have captured, for the first time ever, a single snapshot of light behaving simultaneously as both a wave and a stream of particles particle.

The experiment is set up like this: A pulse of laser light is fired at a tiny metallic nanowire. The laser adds energy to the charged particles in the nanowire, causing them to vibrate. Light travels along this tiny wire in two possible directions, like cars on a highway. When waves traveling in opposite directions meet each other they form a new wave that looks like it is standing in place. Here, this standing wave becomes the source of light for the experiment, radiating around the nanowire.

This is where the experiment’s trick comes in: The scientists shot a stream of electrons close to the nanowire, using them to image the standing wave of light. As the electrons interacted with the confined light on the nanowire, they either sped up or slowed down. Using the ultrafast microscope to image the position where this change in speed occurred, Carbone’s team could now visualize the standing wave, which acts as a fingerprint of the wave-nature of light.

While this phenomenon shows the wave-like nature of light, it simultaneously demonstrated its particle aspect as well. As the electrons pass close to the standing wave of light, they “hit” the light’s particles, the photons. As mentioned above, this affects their speed, making them move faster or slower. This change in speed appears as an exchange of energy “packets” (quanta) between electrons and photons. The very occurrence of these energy packets shows that the light on the nanowire behaves as a particle.

“This experiment demonstrates that, for the first time ever, we can film quantum mechanics – and its paradoxical nature – directly,” says Fabrizio Carbone. In addition, the importance of this pioneering work can extend beyond fundamental science and to future technologies. As Carbone explains: “Being able to image and control quantum phenomena at the nanometer scale like this opens up a new route towards quantum computing.”

This work represents a collaboration between the Laboratory for Ultrafast Microscopy and Electron Scattering of EPFL, the Department of Physics of Trinity College (US) and the Physical and Life Sciences Directorate of the Lawrence Livermore National Laboratory. The imaging was carried out EPFL’s ultrafast energy-filtered transmission electron microscope – one of the two in the world.

For anyone who prefers videos, the EPFL researchers have  prepared a brief description (loaded with some amusing images) of their work,


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

Simultaneous observation of the quantization and the interference pattern of a plasmonic near-field by L Piazza, T.T.A. Lummen, E Quiñonez, Y Murooka, B.W. Reed, B Barwick & F Carbone. Nature Communications 6, Article number: 6407 doi:10.1038/ncomms7407 Published 02 March 2015

This is an open access paper.