Friday, 24 February 2012

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."


Tuesday, 21 February 2012

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.


Friday, 17 February 2012

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: &

Thursday, 16 February 2012

Chasing Ghosts - those elusive neutrinos

T2K (Tokai to Kamioka) Experiment, Japan. Image courtesy of

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.

Tuesday, 14 February 2012

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.