Tag Archives: classical physics

Emergence in Toronto and Ottawa and brains in Vancouver (Canada): three April 2018 events

April 2018 is shaping up to be quite the month where art/sci events are concerned. I just published a March 27, 2018 posting titled ‘Curiosity collides with the quantum and with the Science Writers and Communicators of Canada in Vancouver (Canada)‘ and I’ve now received news about more happenings in Toronto and Ottawa.  Plus, there’s a science-themed meeting organized by ARPICO (Society of Italian Researchers &; Professionals in Western Canada) featuring brains and brain imaging in Vancouver.

Toronto’s and Ottawa’s Emergence

There’s an art/sci exhibit opening, from a March 27, 2018 Art/Sci Salon announcement (received via email),

You are invited!

FaceBook event:

The Oakwood Village Library and Arts Centre event:

341 Oakwood Avenue, Toronto, ON  M6E 2W1

I check the library webpage listed in the above and found this artist’s statement,

Artist / Scientist Statement [Stephen Morris]

I am interested in self-organized, emergent patterns and textures. I make images of patterns both from the natural world and of experiments in my laboratory in the Department of Physics at the University of Toronto. Patterns naturally attract casual attention but are also the subject of serious scientific research. Some things just evolve all by themselves into strikingly regular shapes and textures. Why? These shapes emerge spontaneously from a dynamic process of growing, folding, cracking, wrinkling, branching, flowing and other kinds of morphological development. My photos are informed by the scientific aesthetic of nonlinear physics, and celebrate the subtle interplay of order and complexity in emergent patterns. They are a kind of “Scientific Folk Art” of the science of Emergence.

While the official opening is April 5, 2018, the event itself runs from April 1 – 30, 2018.

Next, there’s another March 27, 2018 announcement (received via email) from the Art/Sci Salon but this one concerns a series of talks about ’emergence’, Note: Some of the event information was a little difficult to decipher so I’ve added a note to the relevant section).

What is Emergent Form?

Nature teems with self-organized forms that seem to spring spontaneously from the smooth background of things, by mechanisms that are not always apparent. Think of rippled sand on a beach or regular stripes in the clouds.  Plants, insects and animals exhibit spirals and spots and stripes in an exuberant riot of colours.  Fluid flows in amazingly regular swirls and eddies.  The emergence of form is ubiquitous, and presents a challenge and an inspiration to both artists and scientists. In mathematics, patterns appear as solutions of the nonlinear partial differential equations in the continuum limit of classical physics, chemistry and biology. In the arts and humanities, “emergent form” addresses the entangled ways in which humans, plants animals, microorganisms inevitably co-exist in the universe; the way that human intervention and natural transformation can generate new landscapes and new forms of life.

With Emergent Form, we want to question the idea of a fixed world.

For us, Emergent Form is not just a series of natural and human phenomena too complicated to understand, measure or predict, but also a concept to help us identify ways in which we can come to term with, and embrace their complexity as a source of inspiration.

Join us in Toronto and Ottawa for a series of interdisciplinary discussions, performances and exhibitions on Emergent Form on Apr 10, 11, 12 (Toronto) and Apr. 14 [2018] (Ottawa).

This series is the result of a collaboration among several parties. Each event of the series is different and has its dedicated RSVP 

Tue. Apr 10 The Fields Institute, 222 College Street

Emergent form: an interdisciplinary concept 6:00-8:00 pm Pier Luigi Capucci, Accademia di Belle Arti Urbino. Founder and director, Noemalab*, Charles Sowers, Independent artist and exhibit designer, the Exploratorium, Stephen Morris, Professor of of Physics University of Toronto, Ron Wild, smART Maps

CLICK HERE FOR MORE AND TO RSVP

Wed. Apr 11 The Fields Institute6:00-8:00 pm

Anatomy of an Interconnected SystemA Performative Lecture with Margherita Pevere, Aalto University, Helsinki

CLICK HERE FOR MORE AND TO RSVP

Thu. Apr 12 (Note: I believe that from 5 – 6 pm, you’re invited to see Pevere’s exhibit and then proceed to Luella Massey Studio Theatre for performances)

5:00 pm  Cabinets in the Koffler Student Centre [I believe this is at the University of Toronto] Anatomy of an Interconnected System An exhibition by Margherita Pevere

6:00 pm Luella Massey Studio Theatre, 4 Glen Morris Ave., Toronto biopoetriX – conFiGURing AI

6:00-8:00 pm Performance: 

6:00pm Performance “Corpus Nil. A Ritual of Birth for a Modified Body” conceived and performed by Marco Donnarumma

6.30pm LAB dance: Blitz media posters on labs in the arts, sciences and engineering

7.10pm Panel: Performing AI, hybrid media and humans in/as technologyMarco Donnarumma, Doug van Nort (Dispersion Lab, York U.), Jane Tingley (Stratford User Research & Gameful Experiences Lab –SURGE-, U of Waterloo), Angela Schoellig (Dynamic Systems Lab, U of T)

Panel animators: Antje Budde (Digital Dramaturgy Lab) and Roberta Buiani (ArtSci Salon)

8.15pm Reception at the Italian Cultural Institute, 496 Huron St, Toronto

CLICK HERE FOR MORE AND TO RSVP

Ottawa. Sat. Apr. 14 National Arts Centre, 1 Elgin Street11:00 am-1:00 pm

Emergent Form and complex phenomenaA creative panel discussion and surprise demonstrationsWith Pier Luigi Capucci, Margherita Pevere, Marco Donnarumma, Stephen Morris

CLICK HERE FOR MORE AND TO RSVP

This event would not be possible without the support of The Fields Institute for Research in Mathematical Science, The Italian Embassy, the Centre for Drama, Theatre and Performance Studies at the University of Toronto, the Digital Dramaturgy Lab, and the Istituto Italiano di Cultura. Many thanks to our community partner BYOR (Bring your own Robot)

I wonder if some of the funding from Italy is in support of Italian Research in World Day. This is the inaugural year for the event, which will be held annually on April 15.

Vancouver’s brains

The Society of Italian Researchers and Professionals in Western Canada (ARPICO) is hosting an event in Vancouver (from a March 22, 2018 ARICO announcement received via email),

Our second speaking event of the year, in collaboration with the Consulate General of Italy in Vancouver, has been scheduled for Wednesday, April 11th, 2018 at the Roundhouse Community Centre. Professor Vesna Sossi’s talk will be examining how positron emission tomography (PET) imaging has contributed to better understanding of the brain function and disease with particular focus on Parkinson’s disease. You can read a summary of Prof. Sossi’s lecture as well as her short professional biography at the bottom of this message.

This event is organized in collaboration with the Consulate General of Italy in Vancouver to celebrate the newly instituted Italian Research in the World Day, as part of the Piano Straordinario “Vivere all’Italiana” – Giornata della ricerca Italiana nel mondo. You can read more on our website event page.

We look forward to seeing everyone there.

Please register for the event by visiting the EventBrite link or RSVPing to info@arpico.ca.

The evening agenda is as follows:

  • 6:45 pm – Doors Open
  • 7:00 pm – Lecture by Prof. Vesna Sossi
  • ~8:00 pm – Q & A Period
  • Mingling & Refreshments until about 9:30 pm

If you have not yet RSVP’d, please do so on our EventBrite page.

Further details are also available at arpico.ca, our facebook page, and Eventbrite.


Imaging: A Window into the Brain

Brain illness, comprising neurological disorders, mental illness and addiction, is considered the major health challenge in the 21st century with a socio-economic cost greater than cancer and cardiovascular disease combined. There are at least three unique challenges hampering brain disease management: relative inaccessibility, disease onset often preceding the onset of clinical symptoms by many years and overlap between clinical and pathological symptoms that makes accurate disease identification often difficult. This talk will give examples of how positron emission tomography (PET) imaging has contributed to better understanding of the brain function and disease with particular focus on Parkinson’s disease. Emphasis will be placed on the interplay between scientific discoveries and instrumentation and data analysis development as exemplified by the current understanding of the brain function as comprised by interactions between connectivity networks and neurochemistry and advancement in multi-modal imaging such as simultaneous PET and magnetic resonance imaging (MRI).

Vesna Sossi is a Professor in the University of British Columbia (UBC) Physics and Astronomy Department and at the UBC Djavad Mowafaghian Center for Brain Health. She directs the UBC Positron Emission Tomography (PET) imaging centre, which is known for its use of imaging as applied to neurodegeneration with emphasis on Parkinson’s disease. Her main areas of interest comprise development of imaging methods to enhance the investigation of neurochemical mechanisms that lead to an increased risk of Parkinson’s disease (PD) and mechanisms that contribute to treatment-related complications. She uses PET imaging to explore how alterations of the different neurotransmitter systems contribute to different trajectories of disease progression. Her other areas of interest are PET image analysis, instrumentation and multi-modal, multi-parameter data analysis. She published more than 180 peer review papers, is funded by several granting agencies, including the Michael J Fox Foundation, and sits on several national and international review panels.


WHEN: Wednesday, April 11th, 2018 at 7:00pm (doors open at 6:45pm)
WHERE: Roundhouse Community Centre, Room B – 181 Roundhouse Mews, Vancouver, BC, V6Z 2W3
RSVP: Please RSVP at EventBrite (https://imaging-a-window-into-the-brain.eventbrite.ca) or email info@arpico.ca


Tickets are Needed

  • Tickets are FREE, but all individuals are requested to obtain “free-admission” tickets on EventBrite site due to limited seating at the venue. Organizers need accurate registration numbers to manage wait lists and prepare name tags.
  • All ARPICO events are 100% staffed by volunteer organizers and helpers, however, room rental, stationery, and guest refreshments are costs incurred and underwritten by members of ARPICO. Therefore to be fair, all audience participants are asked to donate to the best of their ability at the door or via EventBrite to “help” defray costs of the event.

You can find directions for the Roundhouse Community Centre here

I have one idle question. What’s going to happen these groups if Canadians change their use of  Facebook or abandon the platform as they are threatening to do in the face of Cambridge Analytica’s use of their data? A March 25, 2018 article on huffingtonpost.ca outlines the latest about Canadians’ reaction to the Cambridge Analytical news according to an Angus Reid poll,

A survey by Angus Reid Institute suggests 73 per cent of Canadian Facebook users say they will make changes, while 27 per cent say it will be “business as usual.”

Nearly a quarter (23 per cent) said they would use Facebook less in the future, and 41 per cent of users said they would check and/or change their privacy settings.

The survey also found that one in 10 say they plan to abandon the platform, at least temporarily.

Facebook has been under fire for its ability to protect user privacy after Cambridge Analytica was accused of lifting the Facebook profiles of more than 50 million users without their permission.

There you have it.

*Well, a bit more information about one of the “Emergent’ speakers was received in an April 4, 2018 ArtSci Salon email announcement,

Do make sure to check out Pier Luigi Capucci’s EU-based (but with international breadth) Noemalab platform. https://noemalab.eu/ since the mid-nineties, this platform has been an important node of information for New Media Art and the relation between the arts and science.

noemalab’s blog regularly hosts reviews of events and conferences occurring around the world, including  the Subtle Technologies Festival between 2007 and 2014. you can search its archives here http://blogs.noemalab.eu/

Capucci has been writing several reflections on emergent forms of Life and theorized what he called the “third life”. See a recent essay https://noemalab.eu/memo/events/evolutionary-creativity-the-inner-life-and-meaning-of-art/ here is a picture which I would love him to explain during Emergent Form. Intrigued? come listen to him!

Keeping up with science is impossible: ruminations on a nanotechnology talk

I think it’s time to give this suggestion again. Always hold a little doubt about the science information you read and hear. Everybody makes mistakes.

Here’s an example of what can happen. George Tulevski who gave a talk about nanotechnology in Nov. 2016 for TED@IBM is an accomplished scientist who appears to have made an error during his TED talk. From Tulevski’s The Next Step in Nanotechnology talk transcript page,

When I was a graduate student, it was one of the most exciting times to be working in nanotechnology. There were scientific breakthroughs happening all the time. The conferences were buzzing, there was tons of money pouring in from funding agencies. And the reason is when objects get really small, they’re governed by a different set of physics that govern ordinary objects, like the ones we interact with. We call this physics quantum mechanics. [emphases mine] And what it tells you is that you can precisely tune their behavior just by making seemingly small changes to them, like adding or removing a handful of atoms, or twisting the material. It’s like this ultimate toolkit. You really felt empowered; you felt like you could make anything.

In September 2016, scientists at Cambridge University (UK) announced they had concrete proof that the physics governing materials at the nanoscale is unique, i.e., it does not follow the rules of either classical or quantum physics. From my Oct. 27, 2016 posting,

A Sept. 29, 2016 University of Cambridge press release, which originated the news item, hones in on the peculiarities of the nanoscale,

In the middle, on the order of around 10–100,000 molecules, something different is going on. Because it’s such a tiny scale, the particles have a really big surface-area-to-volume ratio. This means the energetics of what goes on at the surface become very important, much as they do on the atomic scale, where quantum mechanics is often applied.

Classical thermodynamics breaks down. But because there are so many particles, and there are many interactions between them, the quantum model doesn’t quite work either.

It is very, very easy to miss new developments no matter how tirelessly you scan for information.

Tulevski is a good, interesting, and informed speaker but I do have one other hesitation regarding his talk. He seems to think that over the last 15 years there should have been more practical applications arising from the field of nanotechnology. There are two aspects here. First, he seems to be dating the ‘nanotechnology’ effort from the beginning of the US National Nanotechnology Initiative and there are many scientists who would object to that as the starting point. Second, 15 or even 30 or more years is a brief period of time especially when you are investigating that which hasn’t been investigated before. For example, you might want to check out the book, “Leviathan and the Air-Pump: Hobbes, Boyle, and the Experimental Life” (published 1985) is a book by Steven Shapin and Simon Schaffer (Wikipedia entry for the book). The amount of time (years) spent on how to make just the glue which held the various experimental apparatuses together was a revelation to me. Of  course, it makes perfect sense that if you’re trying something new, you’re going to have figure out everything.

By the way, I include my blog as one of the sources of information that can be faulty despite efforts to make corrections and to keep up with the latest. Even the scientists at Cambridge University can run into some problems as I noted in my Jan. 28, 2016 posting.

Getting back to Tulevsk, herei’s a link to his lively, informative talk :
https://www.ted.com/talks/george_tulevski_the_next_step_in_nanotechnology#t-562570

ETA Jan. 24, 2017: For some insight into how uncertain, tortuous, and expensive commercializing technology can be read Dexter Johnson’s Jan. 23, 2017 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website). Here’s an excerpt (Note: Links have been removed),

The brief description of this odyssey includes US $78 million in financing over 15 years and $50 million in revenues over that period through licensing of its technology and patents. That revenue includes a back-against-the-wall sell-off of a key business unit to Lockheed Martin in 2008.  Another key moment occured back in 2012 when Belgian-based nanoelectronics powerhouse Imec took on the job of further developing Nantero’s carbon-nanotube-based memory back in 2012. Despite the money and support from major electronics players, the big commercial breakout of their NRAM technology seemed ever less likely to happen with the passage of time.

Connecting chaos and entanglement

Researchers seem to have stumbled across a link between classical and quantum physics. A July 12, 2016 University of California at Santa Barbara (UCSB) news release (also on EurekAlert) by Sonia Fernandez provides a description of both classical and quantum physics, as well as, the research that connects the two,

Using a small quantum system consisting of three superconducting qubits, researchers at UC Santa Barbara and Google have uncovered a link between aspects of classical and quantum physics thought to be unrelated: classical chaos and quantum entanglement. Their findings suggest that it would be possible to use controllable quantum systems to investigate certain fundamental aspects of nature.

“It’s kind of surprising because chaos is this totally classical concept — there’s no idea of chaos in a quantum system,” Charles Neill, a researcher in the UCSB Department of Physics and lead author of a paper that appears in Nature Physics. “Similarly, there’s no concept of entanglement within classical systems. And yet it turns out that chaos and entanglement are really very strongly and clearly related.”

Initiated in the 15th century, classical physics generally examines and describes systems larger than atoms and molecules. It consists of hundreds of years’ worth of study including Newton’s laws of motion, electrodynamics, relativity, thermodynamics as well as chaos theory — the field that studies the behavior of highly sensitive and unpredictable systems. One classic example of chaos theory is the weather, in which a relatively small change in one part of the system is enough to foil predictions — and vacation plans — anywhere on the globe.

At smaller size and length scales in nature, however, such as those involving atoms and photons and their behaviors, classical physics falls short. In the early 20th century quantum physics emerged, with its seemingly counterintuitive and sometimes controversial science, including the notions of superposition (the theory that a particle can be located in several places at once) and entanglement (particles that are deeply linked behave as such despite physical distance from one another).

And so began the continuing search for connections between the two fields.

All systems are fundamentally quantum systems, according [to] Neill, but the means of describing in a quantum sense the chaotic behavior of, say, air molecules in an evacuated room, remains limited.

Imagine taking a balloon full of air molecules, somehow tagging them so you could see them and then releasing them into a room with no air molecules, noted co-author and UCSB/Google researcher Pedram Roushan. One possible outcome is that the air molecules remain clumped together in a little cloud following the same trajectory around the room. And yet, he continued, as we can probably intuit, the molecules will more likely take off in a variety of velocities and directions, bouncing off walls and interacting with each other, resting after the room is sufficiently saturated with them.

“The underlying physics is chaos, essentially,” he said. The molecules coming to rest — at least on the macroscopic level — is the result of thermalization, or of reaching equilibrium after they have achieved uniform saturation within the system. But in the infinitesimal world of quantum physics, there is still little to describe that behavior. The mathematics of quantum mechanics, Roushan said, do not allow for the chaos described by Newtonian laws of motion.

To investigate, the researchers devised an experiment using three quantum bits, the basic computational units of the quantum computer. Unlike classical computer bits, which utilize a binary system of two possible states (e.g., zero/one), a qubit can also use a superposition of both states (zero and one) as a single state. Additionally, multiple qubits can entangle, or link so closely that their measurements will automatically correlate. By manipulating these qubits with electronic pulses, Neill caused them to interact, rotate and evolve in the quantum analog of a highly sensitive classical system.

The result is a map of entanglement entropy of a qubit that, over time, comes to strongly resemble that of classical dynamics — the regions of entanglement in the quantum map resemble the regions of chaos on the classical map. The islands of low entanglement in the quantum map are located in the places of low chaos on the classical map.

“There’s a very clear connection between entanglement and chaos in these two pictures,” said Neill. “And, it turns out that thermalization is the thing that connects chaos and entanglement. It turns out that they are actually the driving forces behind thermalization.

“What we realize is that in almost any quantum system, including on quantum computers, if you just let it evolve and you start to study what happens as a function of time, it’s going to thermalize,” added Neill, referring to the quantum-level equilibration. “And this really ties together the intuition between classical thermalization and chaos and how it occurs in quantum systems that entangle.”

The study’s findings have fundamental implications for quantum computing. At the level of three qubits, the computation is relatively simple, said Roushan, but as researchers push to build increasingly sophisticated and powerful quantum computers that incorporate more qubits to study highly complex problems that are beyond the ability of classical computing — such as those in the realms of machine learning, artificial intelligence, fluid dynamics or chemistry — a quantum processor optimized for such calculations will be a very powerful tool.

“It means we can study things that are completely impossible to study right now, once we get to bigger systems,” said Neill.

Experimental link between quantum entanglement (left) and classical chaos (right) found using a small quantum computer. Photo Credit: Courtesy Image (Courtesy: UCSB)

Experimental link between quantum entanglement (left) and classical chaos (right) found using a small quantum computer. Photo Credit: Courtesy Image (Courtesy: UCSB)

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

Ergodic dynamics and thermalization in an isolated quantum system by C. Neill, P. Roushan, M. Fang, Y. Chen, M. Kolodrubetz, Z. Chen, A. Megrant, R. Barends, B. Campbell, B. Chiaro, A. Dunsworth, E. Jeffrey, J. Kelly, J. Mutus, P. J. J. O’Malley, C. Quintana, D. Sank, A. Vainsencher, J. Wenner, T. C. White, A. Polkovnikov, & J. M. Martinis. Nature Physics (2016)  doi:10.1038/nphys3830 Published online 11 July 2016

This paper is behind a paywall.

Complex networks to provide ‘grand unified theory’

Trying to mesh classical physics and quantum physics together in one theory which accounts for behaviour on the macro and quantum scales has occupied scientists for decades and it seems that mathematicians have discovered a clue so solving the mystery. A Sept. 13, 2015 news item on Nanotechnology Now describes the findings,

Mathematicians investigating one of science’s great questions — how to unite the physics of the very big with that of the very small — have discovered that when the understanding of complex networks such as the brain or the Internet is applied to geometry the results match up with quantum behavior.

A Sept. 9, 2015 Queen Mary University of London press release, which originated the news item, describes the collaboration between Queen Mary and Karlsruhe Institute of Technology mathematicians,

The findings, published today (Thursday) in Scientific Reports, by researchers from Queen Mary University of London and Karlsruhe Institute of Technology, could explain one of the great problems in modern physics.

Currently ideas of gravity, developed by Einstein and Newton, explain how physics operates on a very large scale, but do not work at the sub-atomic level. Conversely, quantum mechanics works on the very small scale but does not explain the interactions of larger objects like stars. Scientists are looking for a so called ‘grand unified theory’ that joins the two, known as quantum gravity.

Several models have been proposed for how different quantum spaces are linked but most assume that the links between quantum spaces are fairly uniform, with little deviation from the average number of links between each space. The new model, which applies ideas from the theory of complex networks, has found that some quantum spaces might actually include hubs, i.e. nodes with significantly more links than others, like a particularly popular Facebook user.

Calculations run with this model show that these spaces are described by well-known quantum Fermi-Dirac, and Bose-Einstein statistics, used in quantum mechanics, indicating that they could be useful to physicists working on quantum gravity.

Dr Ginestra Bianconi, from Queen Mary University of London, and lead author of the paper, said:

“We hope that by applying our understanding of complex networks to one of the fundamental questions in physics we might be able to help explain how discrete quantum spaces emerge.

“What we can see is that space-time at the quantum-scale might be networked in a very similar way to things we are starting to understand very well like biological networks in cells, our brains and online social networks.”

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

Complex Quantum Network Manifolds in Dimension d > 2 are Scale-Free by Ginestra Bianconi & Christoph Rahmede. Scientific Reports 5, Article number: 13979 (2015) doi:10.1038/srep13979 Published online: 10 September 2015

This is an open access paper.

Quantum and classical physics may be closer than we thought

It seems that a key theory about the boundary between the quantum world and our own macro world has been disproved and I think the July 21, 2015 news item on Nanotechnology Now says it better,

Quantum theory is one of the great achievements of 20th century science, yet physicists have struggled to find a clear boundary between our everyday world and what Albert Einstein called the “spooky” features of the quantum world, including cats that could be both alive and dead, and photons that can communicate with each other across space instantaneously.

For the past 60 years, the best guide to that boundary has been a theorem called Bell’s Inequality, but now a new paper shows that Bell’s Inequality is not the guidepost it was believed to be, which means that as the world of quantum computing brings quantum strangeness closer to our daily lives, we understand the frontiers of that world less well than scientists have thought.

In the new paper, published in the July 20 [2015] edition of Optica, University of Rochester [New York state, US] researchers show that a classical beam of light that would be expected to obey Bell’s Inequality can fail this test in the lab, if the beam is properly prepared to have a particular feature: entanglement.

A July 21, 2015 University of Rochester news release, which originated the news item, reveals more about the boundary and the research,

Not only does Bell’s test not serve to define the boundary, the new findings don’t push the boundary deeper into the quantum realm but do just the opposite. They show that some features of the real world must share a key ingredient of the quantum domain. This key ingredient is called entanglement, exactly the feature of quantum physics that Einstein labeled as spooky. According to Joseph Eberly, professor of physics and one of the paper’s authors, it now appears that Bell’s test only distinguishes those systems that are entangled from those that are not. It does not distinguish whether they are “classical” or quantum. In the forthcoming paper the Rochester researchers explain how entanglement can be found in something as ordinary as a beam of light.

Eberly explained that “it takes two to tangle.” For example, think about two hands clapping regularly. What you can be sure of is that when the right hand is moving to the right, the left hand is moving to the left, and vice versa. But if you were asked to guess without listening or looking whether at some moment the right hand was moving to the right, or maybe to the left, you wouldn’t know. But you would still know that whatever the right hand was doing at that time, the left hand would be doing the opposite. The ability to know for sure about a common property without knowing anything for sure about an individual property is the essence of perfect entanglement.

Eberly added that many think of entanglement as a quantum feature because “Schrodinger coined the term ‘entanglement’ to refer to his famous cat scenario.” But their experiment shows that some features of the “real” world must share a key ingredient of Schrodinger’s Cat domain: entanglement.

The existence of classical entanglement was pointed out in 1980, but Eberly explained that it didn’t seem a very interesting concept, so it wasn’t fully explored. As opposed to quantum entanglement, classical entanglement happens within one system. The effect is all local: there is no action at a distance, none of the “spookiness.”

With this result, Eberly and his colleagues have shown experimentally “that the border is not where it’s usually thought to be, and moreover that Bell’s Inequalities should no longer be used to define the boundary.”

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

Shifting the quantum-classical boundary: theory and experiment for statistically classical optical fields by Xiao-Feng Qian, Bethany Little, John C. Howell, and J. H. Eberly. Optica Vol. 2, Issue 7, pp. 611-615 (2015) •doi: 10.1364/OPTICA.2.000611

This paper is open access.

Can the future influence the past? The answer is: mostly yes

The principles of quantum mechanics mystify me which, as it turns out, is the perfect place to start with the work featured in a Feb. 9, 2015 news item on ScienceDaily,

We’re so used to murder mysteries that we don’t even notice how mystery authors play with time. Typically the murder occurs well before the midpoint of the book, but there is an information blackout at that point and the reader learns what happened then only on the last page.

If the last page were ripped out of the book, physicist Kater Murch, PhD, said, would the reader be better off guessing what happened by reading only up to the fatal incident or by reading the entire book?

The answer, so obvious in the case of the murder mystery, is less so in world of quantum mechanics, where indeterminacy is fundamental rather than contrived for our reading pleasure.

A Feb. 13, 2015 Washington University at St. Louis (WUSTL) news release by Diana Lutz, which originated the news item, describes the research,

Even if you know everything quantum mechanics can tell you about a quantum particle, said Murch, an assistant professor of physics in Arts & Sciences at Washington University in St. Louis, you cannot predict with certainty the outcome of a simple experiment to measure its state. All quantum mechanics can offer are statistical probabilities for the possible results.

The orthodox view is that this indeterminacy is not a defect of the theory, but rather a fact of nature. The particle’s state is not merely unknown, but truly undefined before it is measured. The act of measurement itself that forces the particle to collapse to a definite state.

It’s as if what we did today, changed what we did yesterday. And as this analogy suggests, the experimental results have spooky implications for  time and causality—at least in microscopic world to which quantum mechanics applies.

Until recently physicists could explore the quantum mechanical properties of single particles only through thought experiments, because any attempt to observe them directly caused them to shed their mysterious quantum properties.

But in the 1980s and 1990s physicists invented devices that allowed them to measure these fragile quantum systems so gently that they don’t immediately collapse to a definite state.

The device Murch uses to explore quantum space is a simple superconducting circuit that enters quantum space when it is cooled to near absolute zero. Murch’s team uses the bottom two energy levels of this qubit, the ground state and an excited state, as their model quantum system. Between these two states, there are an infinite number of quantum states that are superpositions, or combinations, of the ground and excited states.

The quantum state of the circuit is detected by putting it inside a microwave box. A few microwave photons are sent into the box, where their quantum fields interact with the superconducting circuit. So when the photons exit the box they bear information about the quantum system.

Crucially, these “weak,” off-resonance measurements do not disturb the qubit, unlike “strong” measurements with photons that are resonant with the energy difference between the two states, which knock the circuit into one or the other state.

In Physical Review Letters, Murch describes a quantum guessing game played with the qubit.

“We start each run by putting the qubit in a superposition of the two states,” he said. “Then we do a strong measurement but hide the result, continuing to follow the system with weak measurements.”

They then try to guess the hidden result, which is their version of the missing page of the murder mystery.

“Calculating forward, using the Born equation that expresses the probability of finding the system in a particular state, your odds of guessing right are only 50-50,” Murch said. “But you can also calculate backward using something called an effect matrix. Just take all the equations and flip them around. They still work and you can just run the trajectory backward.

“So there’s a backward-going trajectory and a forward-going trajectory and if we look at them both together and weight the information in both equally, we get something we call a hindsight prediction, or “retrodiction.”

The shattering thing about the retrodiction is that it is 90 percent accurate. When the physicists check it against the stored measurement of the system’s earlier state it is right nine times out of 10.

Going from a 50% accuracy rate to 90% is quite amazing and according to the news release, this has many implications,

The quantum guessing game suggests ways to make both quantum computing and the quantum control of open systems, such as chemical reactions, more robust. But it also has implications for much deeper problems in physics.

For one thing, it suggests that in the quantum world time runs both backward and forward whereas in the classical world it only runs forward.

“I always thought the measurement would resolve the time symmetry in quantum mechanics,” Murch said. “If we measure a particle in a superposition of states and it collapses into one of two states, well, that sounds like a process that goes forward in time.”

But in the quantum guessing experiment, time symmetry has returned. The improved odds imply the measured quantum state somehow incorporates information from the future as well as the past. And that implies that time, notoriously an arrow in the classical world, is a double-headed arrow in the quantum world.

“It’s not clear why in the real world, the world made up of many particles, time only goes forward and entropy always increases,” Murch said. “But many people are working on that problem and I expect it will be solved in a few years,” he said.

In a world where time is symmetric, however, is there such a thing as cause and effect? To find out, Murch proposes to run a qubit experiment that would set up feedback loops (which are chains of cause and effect) and try to run them both forward and backward.

“It takes 20 or 30 minutes to run one of these experiments,” Murch said, “several weeks to process it, and a year to scratch our heads to see if we’re crazy or not.”

“At the end of the day,” he said, “I take solace in the fact that we have a real experiment and real data that we plot on real curves.”

Here are links to and citations for the Physical Review paper and an earlier version of the paper,

 Prediction and retrodiction for a continuously monitored superconducting qubit by D. Tan, S. Weber, I. Siddiqi, K. Mølmer, K. W. Murch. arXiv.org > quant-ph > arXiv:1409.0510 (Submitted on 1 Sep 2014 (v1), last revised 10 Nov 2014 (this version, v2))

I last mentioned Kater Murch and his work in a July 31, 2014 post titled: Paths of desire: quantum style.