Making the Invisible Visible

It is becoming increasingly evident that computer vision is changing
the way that we are perceiving the world. New research revealed this
week by MIT researchers, shows how computer vision techniques are
enabling us to see the human body in striking new ways. By
amplifying the variations in video footage of human subjects,
imperceptible processes, such as the circulation of blood through
skin, become clearly visible.

This is enabled by new software developed within MIT's Computer
Science and Artificial Intelligence Laboratory by a team comprised of Michael Rubinstein,
Hao-Yu Wu, Eugene Shih, William Freeman, Fredo Durand and John Guttag.

Their software works by magnifying and emphasising colour changes
which occur within video footage. When observing human subjects,
these colour changes correspond to physical processes such as the
beating the of the heart and the inflation of the lungs. But the
software can also be used to analyse other imperceptible phenomena,
such as the movement of a vibrating string.

MIT describe the system as "somewhat akin to the equalizer in a
stereo sound system, which boosts some frequencies and cuts others,
except that the pertinent frequency is the frequency of color changes
in a sequence of video frames, not the frequency of an audio signal."

Researcher, Michael Rubinstein believes the system could be used for "contactless monitoring" of
hospital patients' vital signs. Boosting one set of frequencies would
allow measurement of pulse rates, via subtle changes in skin
coloration; boosting another set of frequencies would allow
monitoring of breathing. The approach could be particularly useful
with infants who are born prematurely or otherwise require early
medical attention. Rubinstein says, "Their bodies are so fragile, you
want to attach as few sensors as possible."

Source: http://web.mit.edu/newsoffice/2012/amplifying-invisible-video-0622.html
http://www.youtube.com/watch?v=Fpv0CWLouzc

Exploiting Quantum Weirdness

After last week's news that physicists in Shanghai have smashed the distance record for teleporting photons, more research emerged this week about science striving to exploit quantum weirdness for
technological purposes.

Guan Ru Feng, again in China, but this time at Tsinghua University in Beijing has become the first scientist to create a simulation of quantum tunnelling, on a quantum computer.

Quantum tunnelling is the quantum-mechanical effect of transitioning through a classically-forbidden energy state. It plays an important role in phenomena such as nuclear fusion in stars. Tunnelling was predicted by Friedrich Hund and others as early as 1927, and has been accepted as a physical phenomenon for over 50 years.

An abstract of Guan Ru Feng's new paper, "Experimental Digital Simulation of Quantum Tunneling in a NMR Quantum Simulator", was published on arXiv on 11 May. The pithy abstract reads:
"It is well-known that quantum computers are superior to classical computers in efficiently simulating quantum systems. Here we report the first experimental simulation of the quantum tunneling through potential barriers, a widespread phenomenon of unique quantum feature [...] The occurrence of quantum tunneling through a barrier is clearly observed through the experimental result. This experiment has clearly demonstrated the viability of quantum simulation [...]"

So why is this significant? Well, quantum computers, as you may expect, are excellent at simulating quantum systems. As MIT's Technology Review explains, they've been used to simulate phenomenon such as quantum phase transitions and the dynamics of entanglement "things that classical computers simply cannot handle." But there is one quantum phenomenon that has never been simulated - tunnelling. This is the ability of quantum particles to cross a barrier without seeming to have passed through it.

The reason for this is the massive complexity of the task. As Technology Review remarks, it requires "numerous quantum logic gates processing dozens of qubits. That's always been beyond the state-of-the-art for quantum computing."

So the fact that Guan Ru Feng's team have now successfully simulated tunnelling suggests a significant advance in quantum computing, which will, no doubt, herald further simulations of much more complex phenomenon than we've seen to date.

Science is continuously and assiduously working towards harnessing quantum weirdness for practical technological applications. And it's interesting that so many of the recent advances in this field are coming from research Universities in China. Watch this space.

Source:
http://arxiv.org/abs/1205.2421
http://www.technologyreview.com/blog/arxiv/27849/

Tesla: the greatest geek who ever lived

The Oatmeal comic has published a lovely homage to science's
favourite forgotten genius, Nikola Tesla:

"On behalf of those who obsess, tinker & fix things that aren't
broken, thank you Nikola Tesla"

Source:
http://theoatmeal.com/comics/tesla

Physicists break distance record for teleportation

A few days ago a new paper published in arXiv indicated an exciting new development within the emerging science of teleportation.

In an advance that has significance for quantum computing and secure wireless communication, physicists at the University of Science and Technology in Shanghai have broken the record for the distance photons have been artificially teleported.  Their research is important, because teleportation is considered to be extremely useful for the future of secure communication across satellite networks.

MIT's Technology Review reports:

"Teleportation is the enabling technology behind quantum cryptography, a way of sending information with close-to-perfect secrecy. Because teleported information does not travel through the intervening space, it cannot be secretly accessed by an eavesdropper."
"Unfortunately, entangled photons are fragile objects. They cannot travel further than a kilometre or so down optical fibres because the photons end up interacting with the glass breaking the entanglement. That severely limits quantum cryptography's usefulness. However, physicists have had more success teleporting photons through the atmosphere."

Scientists at the University of Science and Technology in Shanghai have had considerable success with this technique. In 2010 they teleported photons 16km, and last week, they confirmed they have broken their own distance record by teleporting photons across 97km. Juan Yin, and his colleagues in Shanghai used a 1.3-watt laser to beam photons across the 97 km, and retrieve them at the final location.
Teleportation has moved on considerably in recent years, and is no longer the preserve of science-fiction, but rather an important new technology within communications, computing and cryptography.  Quantum teleportation takes advantage of quantum entanglement for the purposes of moving an object from one place to another without it ever moving in the space between. As Technology Review put it, "the idea is not that the physical object is teleported but the information that describes it."

Juan Yin's team in Shanghai have advanced the science of teleportation by developing a superior aiming technique, which prevents the disintegration of entanglement over short distances.  This has enabled them to increase the distance they can teleport photons from merely a few kilometres, to close to 100 kilometres.  Further improvements will be required in order for the technique to be of widespread use in secure satellite communications, but the rapid advances Juan in's team have made, suggest this is merely a matter of time.

As Juan Yin commented:
"The successful quantum teleportation [...] in combination with our high-frequency and high-accuracy [aiming] technique show the feasibility of satellite-based ultra-long-distance quantum teleportation".

Sources:
http://arxiv.org/abs/1205.2024
http://is.gd/teleportation

Oxygen discovered on Saturn's moon, Dione

Since the space probes, Galileo and Cassini, began sending ever more precise data from the farther reaches of the solar system, the Saturnian moon system has provided astronomers with a more-or-less constant stream of incredible information.

The latest discovery is that Saturn's moon, Dione, has an oxygen atmosphere.

Los Alamos National Laboratory announced this week that their scientists have detected molecular oxygen ions (O2+) in the upper atmosphere of the moon.

A sensor aboard the Cassini spacecraft called the Cassini Plasma Spectrometer (CAPS) detected the oxygen ions in Dione's wake during a flyby of the moon two years ago. Researchers Robert Tokar and Michelle Thomsen noticed the presence of the oxygen ions, and published their results in Geophysical Research Letters.

Robert Tokar notes:
"The concentration of oxygen in Dione's atmosphere is roughly similar to what you would find in Earth's atmosphere at an altitude of about 300 miles. It's not enough to sustain life, but, together with similar observations of other moons around Saturn and Jupiter, these are definitive examples of a process by which a lot of oxygen can be produced in icy celestial bodies that are bombarded by charged particles or photons from the Sun or whatever light source happens to be nearby."

The discovery is already generating interest within the astrobiology community. If oxygen exists on Dione, then why not also on some of the solar system's other moons? If oxygen is present on a moon within our solar system which is known to have sub-surface water - such as the Jovian moon, Europa - that oxygen could combine with carbon in subsurface lakes to form the building blocks of life.

Astronomy journalist, Jason Major notes:

"On Dione the energy source is Saturn's powerful magnetic field. As the moon orbits the giant planet, charged ions in Saturn's magnetosphere slam into the surface of Dione, stripping oxygen from the ice on its surface and crust. This molecular oxygen flows into Dione's exosphere, where it is then steadily blown into space by - once again - Saturn's magnetic field.

[...] Molecular oxygen, if present on other moons as well could potentially bond with carbon in subsurface water to form the building blocks of life. Since there's lots of water ice on moons in the outer solar system, as well as some very powerful magnetic fields emanating from planets like Jupiter and Saturn, there's no reason to think there isn't more oxygen to be found? in our solar system or elsewhere."

Dione was discovered by renown Italian-French astronomer, Giovanni Cassini (who the Cassini spaceprobe is named after) in 1684. It is one of 62 known moons which orbit Saturn, and is is the 15th largest. It is composed primarily of water ice and shared many physical features with it's neighbour, Rhea.

Sources: http://www.lanl.gov & http://www.agu.org/pubs/crossref/2012/2011GL050452.shtml

Fundaments of physics safe - thanks to dodgy cable

The physics world was alive this week with news that last year's celebrated superluminal neutrino results from the OPERA experiment may have been down to the most domestic of causes - dodgy wiring.

Last September the OPERA research group at the Gran Sasso underground lab in central Italy shocked the physics world by reporting they had recorded neutrinos travelling faster than the speed of light. Neutrinos released from the LHC particle accelerator near Geneva appeared to have travelled the 730km to the Italian lab at speeds exceeding the speed of light. It was a finding that would have turned all of modern physics on it's proverbial head, as it contradicts Einstein's special theory of relativity. The physics community responded with overwhelming skepticism, but as yet had not been able to find the error in their research.
Until this week.

CERN have now released a statement to confirm that a flaw in the OPERA experiment that could explain its puzzling neutrino discovery. It could be down to a faulty optical fibre. The collaboration is now investigating this, and another possible source of error, and it plans to carry out new experimental runs in May.

The statement reads:

"The OPERA collaboration has informed its funding agencies and host laboratories that it has identified two possible effects that could have an influence on its neutrino timing measurement. These both require further tests with a short pulsed beam. If confirmed, one would increase the size of the measured effect, the other would diminish it. The first possible effect concerns an oscillator used to provide the time stamps for GPS synchronizations. It could have led to an overestimate of the neutrino's time of flight. The second concerns the optical fibre connector that brings the external GPS signal to the OPERA master clock, which may not have been functioning correctly when the measurements were taken. If this is the case, it could have led to an underestimate of the time of flight of the neutrinos. The potential extent of these two effects is being studied by the OPERA collaboration. New measurements with short pulsed beams are scheduled for May."

Source: http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html

Holy yoctometers! A new scale-model of the universe

This simply extraordinary online project created by a ninth-grade pupil called Cary Huang is a scale model of the universe from it's smallest particle scales to it's largest cosmic scales.

As Physics Buzz reports:

"The model serves as both a virtual microscope and telescope, allowing viewers to see the relative sizes of the smallest quarks, the largest galaxy clusters, and everything in between. There are hundreds of objects to scroll through, and each one has its own quirky description."

The level of detail in the project is breathtaking. It's a remarkably instructive visualisation and a very beautiful tool. That it was made by a school student is quite astonishing.

Source: http://htwins.net/scale2/

Time Crystals

Are crystals possible in time, as well as in space?

Undoubtedly the most outlandish, and beautiful story in this week's science press was the pre-publication of two new papers by MIT's Nobel Prize–winning physicist, Frank Wilczek, which suggests that they are.

Wilczek postulates that if crystals exist in spatial dimensions, then they should exist in the dimension of time too. A time crystal is the temporal equivalent of an everyday crystal, in which atoms occupy positions that repeat periodically in space.

The new research stems from Wilczek's analysis of one of the most important tenets of modern physics - "symmetry breaking". Wilczek, and theoretical particle physicist, Al Shapere, conclude that time symmetry seems just as breakable as spatial symmetry at low energies. Their pithy abstract, published on arXiv earlier this week says:

"We consider the possibility that classical dynamical systems display motion in their lowest energy state, forming a time analogue of crystalline spatial order."

A further abstract postulating the existence of "quantum time crystals" states: "Difficulties around the idea of spontaneous breaking of time translation symmetry in a closed quantum mechanical system are identified, and then overcome in a simple model. The possibility of ordering in imaginary time is also discussed."

Science writers have been quick to interpret the significance of this work, with one helpful article by Alexandra Witze in Science News explaining how Wilczek dreamed up time crystals after teaching a class about classifying crystals in three dimensions. He wondered why that structure couldn’t extend to the fourth dimension - time.

She writes:
"To visualize a time crystal, think of Earth looping back to its same location in space every 365¼ days; the planet repeats itself periodically as it moves through time. But a true time crystal is made not of a planet but of an object in its lowest energy state, like an electron stripped of all possible energy. This object could endlessly loop in time, just as electrons in a superconductor could theoretically flow through space for all eternity."

Wilczek has described how the concept of time crystals reminds him of the excitement he felt when he helped describe a new class of fundamental particles, called anyons, in the 1982.

“I had very much the same kind of feeling as I’m having here,” he says, “that I had a found a new logical possibility for how matter might behave that opened up a new world with many possible directions.”

He went on to note: “I don’t know if this will be of lasting value at all,”

I couldn't help being reminded of Heinrich Hertz's quote when he produced radio waves in the laboratory for the first time: "It's of no use whatsoever...this is just an experiment that proves Maestro Maxwell was right" - Hertz (1887)

It remains to be seen if Wilczek and Shapere's outlandish theory proves to have the profound impact on physics that Hertz's work has had. It will be interesting to see what research follows this publication, and whether or not this idea can be experimentally tested. As physicist Ben Still noted in his talk on Wednesday 15 February, ""Until theorists can come up with ways we can test their theories, they are just dealing with works of fiction."

But when ideas like this emerge, one can't help celebrating the existence of theorists.

Source: http://arxiv.org/abs/1202.2537 & http://arxiv.org/abs/1202.2539

& http://www.sciencenews.org

Chasing Ghosts - those elusive neutrinos

T2K (Tokai to Kamioka) Experiment, Japan. Image courtesy of http://t2k-experiment.org/

Particle Decelerator attended a fascinating talk on 15 February by Ben Still, a particle physicist working on the Tokai to Kamioka (T2K) neutrino experiment in Japan, alongside another 500 scientists and engineers.
Held in Lewes in Sussex, Still's talk, entitled "Chasing Ghosts and the Creation of the Universe" attempted to shine a light on the current state of play in neutrino research.

As the abstract noted:
Neutrinos are all around us in every nook and cranny. Trillions upon trillions inside and out of every planet, star, galaxy and the space in between. Billions pass through you every single second, night and day. But despite the phenomenal numbers it was not until 1953 that conclusive evidence of the existence of the neutrino, the most abundant thing in nature, was discovered. Since then scientists have devoted their lives to chasing these ghosts of nature. Despite its meagre size the tiny neutrino has had a profound effect upon our Universe and may hold the answer to one of the greatest questions of all time: the creation of the universe.

Still began by giving an introductory background to the history of this field of science, noting the key contributions by Wolfgang Pauli, Enrico Fermi, Clyde Cowan and Frederick Reines.He then analysed the famous faster-than-light neutrino results, which the OPERA experiment yielded in 2011. He concluded by providing insight into why this field of study is beginning to yield results that may help us answer fundamental questions such as where all the matter in the universe came from. Preliminary results from T2K in 2011 are discussed in further detail here.

"We are going to work as hard as we can to confirm or refute it"
Ben Still on T2K's commitment to cross-check OPERA's neutrino result.

During his talk, Still confirmed that checking the OPERA results is a key priority for both T2K in Japan, and their sister experiment MINOS in the States. T2K was taken offline due to the logistical impact of the earthquake in Japan in 2011, and the subsequent Fukushima disaster, and is only just now coming back online. Upgrades of both MIINOS and T2K are underway, and it is expected that MINOS will start yielding research that may refute or confirm the OPERA result within a year, with things taking a bit longer at T2K - perhaps up to 2 - 3 years.

In many ways, the Q&A was the most fascinating part of the evening, with Still clearly identifying himself as an experimentalist first. He spoke articulately and passionately about the importance of evidence based science, declaring,"we should be lead by experiment, not theory."

"Until theorists can come up with ways we can test their theories, they are just dealing with works of fiction."

Whilst clearly respectful of the elegance of mathematics and theory, Still advocated an experiment-lead approach to science, stating that experiments such as the LHC were correcting a "bias toward theory that has defined physics since the 1970s".

He quipped, "mathematicians and theorists are going to love super-luminal neutrinos, because they enable them write grant applications that will allow them to indulge in the realm of fiction".

Deliberately provocative stuff, and a fantastically stimulating insight into the current lay of the land in neutrino research.

Intuition and Ingenuity - Art and Alan Turing

At Lighthouse in Brighton science and art collide in a show which explores the enduring influence of of computer science pioneer, Alan Turing.

Curated by British-based artists, Sue Gollifer, Nick Lambert and Anna Dumitriu, Intuition and Ingenuity is a group exhibition, staged as part of Brighton Science Festival, that illustates the impact of Alan Turing on contemporary art. The exhibition includes computer art pioneers Roman Verostko, William Latham, Ernest Edmonds, and Paul Brown, as well as contemporary media artists, boredomresearch (their work is pictured), Greg Garvey, Patrick Tresset, Anna Dumitriu and Alex May.

The exhibition marks the 100th anniversary of Alan Turing, and it’s part of a year of programmes which celebrate Turing's centenary.

Whilst he may be best known the person who cracked the German Enigma codes during World War II, thus significantly altering the course of the war, Turing also undoubtedly paved the way for the digital world that we live in today. He gave us algorithms and computation, created the foundations of computer science and artificial intelligence, and pioneered new thinking in the field of morphogenesis. So influential is his work, that it's almost impossible to imagine the modern world, now so thoroughly replete with computational technology, without him.It's great to see his legacy honoured by artists and curators.

Intuition and Ingenuity is showing at Lighthouse in Brighton 17 - 26 February, and will then tour to venues in London, Sheffield, Birngham and beyond.