Reifying quantum mechanics

Berkeley (2011) by Alejandro Guijarro

The interface between the outer reaches of theoretical physics and conceptual art is becoming ever closer, it seems.  This year the the work of Austrian physicist, Anton Zeilinger was shown alongside works by major conceptual artist, Lawrence Weiner, and contemporary artists, such as Thomas Bayrle, at Documenta - the contemporary artworld's premier shop window.

Quantum Now by Anton Zeilinger (2012) at dOCUMENTA 13

And this month, a new exhibition has opened at the Wilmotte art gallery in London, which exhibits the working surfaces of some of the world's leading quantum mechanics labs.

Momentum by Spanish artist Alejandro Guijarro, brings together a collection of large-format photographs of chalkboards taken at the quantum mechanics departments of Oxford and Cambridge universities in the UK, Berkeley and SLAC (the National Accelerator Laboratory) in the States, CERN in Switzerland, and the Instituto de Física Corpuscular in Spain. 

The blackboard has long been the iconic visual symbol of the physics lab, an ever-shifting collaborative canvas, exhibiting the abstract mental processes of those working there.  Seemingly impenetrable to the lay-eye, they possess an enigmatic aesthetic quality.

As Megan Garber notes in The Atlantic, "in an age of dry-erase whiteboards and write-on wall paint - an age that has produced surfaces and markers that allow writings to be undone with the ruthless efficiency of a single swipe - blackboards have taken on the wistfulness of the outmoded technology. And the semi-erased chalkboard, in particular - its darkness swirled with the detritus of unknown decisions and revisions - compounds the nostalgia. Its spectral insights mingle in the bright dust of calcium carbonate."

The exhibition displays the images of blackboards life-size, allowing us to scrutinise the equations and begin to appreciate them, not only for their symbolic value, but their line and form.  Guijarro notes, "the images in this series do not purport to be documents holding an objective truth. They function purely as suggestions. They are fragmented pieces of ideas, thoughts or explanations from which arises a level of randomness. They are an attempt to portray the space of a flat surface and of a given frame. They are arbitrary moments in the restless life of an object in constant motion."

The curatorial text of the exhibition also emphasises the art historical lineage of Guijarro's photographs:

"The colourful equations remind us of Basquiat's formulaic language and the white chalk evokes Cy Twombly's later canvases. Each line and smudge has its own history and meaning, produced by a scientist unaware of their artistic merit."

Untitled (2011) by Alejandro Guijarro

At a time where developments such as the LHC at CERN have brought both experimental and theoretical physics to the wider attention of the public, one is tempted to wonder if these exhibitions are an attempt by the artworld to aestheticise, or even reify, the seemingly abstract field of quantum mechanics.

Momentum is on show at the Wilmotte gallery until the 9th November 2012.

Sources:

http://www.alejandroguijarro.com/ongoing/blackboards/

http://www.tristanhoare.co.uk/exhibitions_Alejandro_Guijarro.htm

Archaeologists of the Sky

This week I have been spending a lot of time thinking about the artwork of Trevor Paglen, which is currently featuring in an exhibition I co-curated at Lighthouse in Brighton, UK called Geographies of Seeing. Paglen describes his practice as "experimental geography". He is interested in illuminating the "black world" of clandestine military operations carried out in orbit and here on earth.

They Watch the Moon, 2010, C-print © Trevor Paglen

To do so, one writer has noted, "Paglen looks upwards to the night sky, one of the oldest laboratories of rational thought".

This quote prompted Mark Simpkins to note that, "astronomy is archaeology of the sky", something that resonated strongly with me. It prompted me to check in on the progress of the 21st century's grandest sky archaeology project - the Square Kilometre Array, or SKA.

As we reported in April last year, the SKA will be the world's largest and most sensitive radio telescope.  Rather than being a huge single radio dish, it will be made up of thousands of smaller ones, which are distributed across vast geographical areas.

In May this year it was announced that the SKA would be jointly hosted in Southern Africa and Australia and New Zealand, a decision that prompted some controversy, as the two geographical areas had been in direct competition to host the array.  But controversies aside, this month, the SKA took a major step forward with the launch of Australia's ASKAP - or Australian Square Kilometre Array Pathfinder.

Australian Square Kilometre Array Pathfinder (ASKAP). Image courtesy of CSIRO.

ASKAP is located in remote Western Australia, and is operated by the Murchison Radio Astronomy Observatory. It is made up of 36 identical antennas, each 12 metres in diameter, working together as a single instrument, using the technique of interferometry.  As well as being a significant radio telescope in its own right, ASKAP is an important testbed for the SKA .

A new receiver technology called a "phased array feed" means ASKAP will be able scan the sky much more rapidly than existing radio telescopes, prompting claims it is the fastest radio telescope in the world today.

The sky archaeologists at ASKAP are focusing on some of the major fundamental issues within cosmology and astronomy.  ASKAP is expected to make advances in understanding galaxy formation, dark energy the evolution of the Universe. Some of the initial research will include a census of all galaxies within two billion light years. This may shed light on how our own galaxy, the Milky Way, was formed.

Brian Boyle, the director of ASKAP for CSIRO, Australia's national scientific research organisation, explained why radio astronomy is such a powerful tool in the arsenal of modern science:

"Radio waves tell us unique things about the cosmos, about the gas from which stars were formed, and about exotic objects, pulsars and quasars, that really push the boundaries of our knowledge of the physical laws in the universe".

Writer, Rebekah Kebede notes that ASKAP is located in remote Murchison, "an area of 50,000 square kms, or the size of Costa Rica, with barely 120 people."

The location is ideal for radio astronomy because it is "radio quiet" - it lacks man-made radio signals that interfere with antennas designed to detect celestial signals.  The area is the home of the Yamatji Marlpa people, who are the traditional owners of the land on which the observatory is cited.

ASKAP opened on 5 October 2012. Australia will build another 60 antennas for the SKA, which begins construction in 2016.

Huffington Post writer, Alex Cherney has put together a stunning time-lapse video showing ASKAP in motion. The two night-sky images of ASKAP used in this post are from him.

Sources:
http://phys.org/news/2012-10-askap-dish-australian-telescope-array.html
http://www.universetoday.com/97688/36-dish-australian-telescope-array-opens-for-business/
http://www.cosmosmagazine.com/news/6044/worlds-fastest-radio-telescope-starts-australian-outback

Sea Above, Sky Below

Sea above, sky below.  The phrase is seemingly a contradiction and a mental paradox.  Yet recent research into cosmology, astronomy and oceanography suggests that this riddle is perhaps not as irreconcilable as what it may first appear. Recalling Milton's evocation of the empty heavens as a kind of ocean, the inversion of sea and sky is taking place all around us, in physics and in oceanography.

The most important advances in scientific thought about the origins and structure of the universe now suggest that our world may be just one amongst many, floating in a cosmological sea. The space probe Cassini has revealed that even in the heavens above, oceans may in fact, be commonplace.  Radio astronomers describe the noise storms of Jupiter and its moon Io as sounding like ocean waves breaking up on the beach. And here on the firmament we are increasingly turning to the oceans in order to better understand the skies.

ALMA (the Atacama Large Millimetre/submillimetre Array)

After recently watching the documentary, Seeing Stars, which analyses the new generation of telescopes that enable scientists and engineers to do 'extreme astronomy', I was prompted to revisit some of the unusual techniques which are currently being used to probe the edges of our universe, which I first starting looking into a few years ago.
The documentary, by the way, is well worth watching:

The infant branch of astronomy, known as "neutrino astronomy" is motivated by the possibility of observing phenomena, such as cosmic neutrinos, that are inaccessible to optical telescopes.  Cosmic neutrinos, which are believed to be produced by cosmic rays, are very difficult to detect. By building arrays deep under water, astronomers can make sure that most of the particles they detect are actually produced by cosmic sources. These detectors look down through the Earth to see the universe, using the whole planet as a shield to absorb the riffraff of particles from the atmosphere.

One of the leading voices within oceanic neutrino science is Dr Paschal Coyle (pictured), who is based in Marseille in France.  His 2007 Journal of Physics paper, Neutrinos Out of the (Deep) Blue remains a valuable reference in surveying the various approaches to underwater neutrino observation.

He is a key researcher with the ANTARES observatory, which is situated under the Mediterranean Sea, 42km off the coast of Toulon. His team set out to monitor their below-sea telescope in the brilliantly named research vessel, Pourquoi Pas?.

ANTARES research vessel, Pourquois Pas?

ANTARES stands for "Astronomy with a Neutrino Telescope and Abyss environmental RESeach project", a rather clunkily assembled acronym, but one that figuratively at least, situates one of our most charismatic stars - Antares - deep under the sea.

The ANTARES detector comprises a total of 900 optical modules distributed over 12 flexible lines, each comprising 25 storeys.  They are anchored at the bottom of the sea at a depth of about 2.5 km, approximately 70 meters apart from each other.

Design visualisation of the ANTARES underwater detector modules

ANTARES is designed to detect neutrinos from space, coming from the direction of the Southern Hemisphere of Earth.  As neutrinos have no mass and no charge, they fly through matter as if it wasn't there, and are therefore fiendishly difficult to detect.  If a cosmic neutrino collided with Earth in the Southern Hemisphere, say for example in Australia, it would fly through the Earth and exit through the Mediterranean sea off southern France on it's way back out to space. ANTARES is constructed with the specific intention of detecting those elusive neutrinos on their ghostly and perpetual journey.  Occasionally, on its journey, a muon neutrino will interact with the water in the Mediterranean. When this happens, it will produce a high energy muon.

 

ANTARES works by detecting Cherenkov radiation (pictured) emitted as the muon passes through the water.  So ANTARES is a highly sensitive optical instrument designed to detect the uncanny blue glow of Cherenkov radiation caused by one of the rarest phenomena in existence.

Over the past four years, Paschal Coyle and his team, have made many expeditions to the underwater detector hunting for neutrinos.  Whilst they have detected many neutrinos - consistent with what might be found in the Earth's atmosphere at any one time - they haven't found a single cosmic neutrino.

To put it more formally, as the team did in their May 2012 abstract, "no significant neutrino signal in excess of that expected from atmospheric background has been found".  The team submitted a further paper to the Astrophysical Journal in July, and in it they emphasised, "no statistically significant signal has been found and upper limits on the neutrino flux have been obtained."

Despite this, the search goes on, and ANTARES has more than one function. As well as looking for particles of cosmic origin, and thus being an important part of the astrophysics community, ANTARES is also at the forefront of particle physics research, taking part in the search for dark matter. It complements the dark matter searches performed by experiments such as Fermilab's CDMS, and at CERN's dark matter work at the LHC.

ANTARES instrument panel aboard Pourquois Pas?

ANTARES' contribution to the field is to attempt to detect a hypothetical phenomena known as "neutralino annihilation", which is thought to take place in the Sun, or the centre of our galaxy.  The theoretical particle, the neutralino, is considered a good candidate for the substance of the universe's cold dark matter. To confirm its existence, neutrino telescopes, such as ANTARES, look for evidence of the annihilation of neutralinos in regions of high dark matter density such as the centres of stars or galaxies.  If ANTARES was able to detect this speculative phenomena, it would be a major breakthrough in our understanding of the universe.

A new generation of telescopes are analysing our skies in ever more novel ways: from vast radio arrays in arid desert mountains, to telescopes strapped to aircraft soaring into the stratosphere, to futuristic Air Fluorescence telescopes looking for high-energy cosmic rays. At the forefront of these techniques are telescopes built underwater, searching our skies from the depths of our oceans.

As it looks through the earth to detect neutrinos from space, ANTARES is peering at the sky below, from the sea above.

Dedication:

Sea Above, Sky Below is the title of a song by Dirty Three, which appears on the 1995 album, Ocean Songs. This post is dedicated to Peter Kirk.



Sources:
http://antares.in2p3.fr/Overview/index.html
http://www.iop.org/
http://arxiv.org/abs/1207.3105

Physics on the edge of the possible

Solar flare, as depicted in Black Rain by Semiconductor

A fascinating post in Henning Dekant's excellent Wavewatching blog this week, adds some depth to August's stories suggesting scientists had found a way to predict solar storms.

Jere Jenkins and Ephraim Fischbach of Purdue University published a paper in Astroparticle Physics which showed evidence that the rate of the breakdown of radioactive materials changes in advance of solar flares. They believe this fluctuation should be able to be used to create an early-warning system for potentially destructive solar storms.

The astrophysics community met this with surprise, skepticism and even alarm in some quarters, as whilst an early-warning system for solar flares is something of a holy grail within space engineering, Jenkins and Fischbach did appear to be challenging our fundamental understanding of radioactive decay.

Their latest work builds on earlier research, including a paper four years ago, which presented surprising evidence of a correlation between nuclear decay rates and Earth-Sun distance.

So why is all of this weird? Radioactive elements are unstable and break down over time. As they do this they release energy in the form of radiation. As Dekant notes,"radioactive decay is supposed to be the ultimate random process, immutably governed by an element's half life and nothing else. There is no way to determine when a single radioactive atom will decay, nor any way to speed-up or slow down the process." He emphasises this is considered to be an "iron clad certainty".

Therefore the absolute last thing you'd be expecting reputable scientists to report is results which show "a discernible pattern in the decay rate of a radioactive element" or "any correlation with outside events". That's precisely what Jenkins and Fischbach have presented in their latest paper. Beyond the practical implications for an early-warning system for solar storms, this has far-reaching implications for our understanding of radiation in general.

Jenkins' research was inspired by what Jonathan Ball describes as a chance event. Jenkins "was watching television coverage of astronauts spacewalking at the International Space Station. A solar flare erupted and was thought to pose a risk to the astronauts. On checking equipment in his laboratory, he was surprised to discover that the rate of radioactive decay changed before the solar flare."

This lead to Jenkins, and colleagues, developing a hypothesis that radioactive decay rates are influenced by solar activity, possibly streams of subatomic particles called solar neutrinos. This influence can wax and wane due to seasonal changes in the Earth's distance from the sun and also during solar flares. The latest paper in Astroparticle Physics provides the evidence for this hypothesis, and as Dekant notes, "the evidence for the reality of this effect is surprisingly good, and that is rather shocking".

Shocking, because:
"It does not fit into any established theory at this time."

Sources:
http://wavewatching.net/
Astroparticle Physics
http://www.astronomynow.com/news/n1208/15solarflares/

Thanks to Dan Hon for directing me to this.

LHC as Cathedral

Much has been written about the cathedral-like qualities of the LHC detectors, CMS and ATLAS.
A new set of images published on the blog, Does It Float beautifully communicates the site's visual grandeur.

All Images © CERN.

Source: Does It Float 

Listening to the Aurora

 

For centuries, folklore has reported that people have been able to hear, as well as see, the Northern Lights, or the aurora borealis. For the first time, researchers in Finland have been able to provide
evidence of what these historical listeners may have been detecting.

The "auroral sounds" are formed about 70 meters above the ground level, according to a team from Aalto University in Finland. They report that "researchers located the sound sources by installing three separate microphones in an observation site where the auroral sounds were recorded. They then compared sounds captured by the microphones and determined the location of the sound source. The aurora borealis was seen at the observation site. The simultaneous measurements of the geomagnetic disturbances, made by the Finnish Meteorological Institute, showed a typical pattern of the northern lights episodes."

Science Daily noted that: "Details about how the auroral sounds are created are still a mystery. The sounds do not occur regularly when the northern lights are seen. The recorded, unamplified sounds can be similar to crackles or muffled bangs which last for only a short period of time. Other people who have heard the auroral sounds have described them as distant noise and sputter. Because of these different descriptions, researchers suspect that there are several mechanisms behind the formation of these auroral sounds. These sounds are so soft that one has to listen very carefully to hear them and to distinguish them from the ambient noise."

Professor Unto Laine from Aalto University commented, "our research proved that, during the occurrence of the northern lights, people can hear natural auroral sounds related to what they see. In the past, researchers thought that the aurora borealis was too far away for people to hear the sounds it made. This is true. However, our research proves that the source of the sounds that are associated with the aurora borealis we see is likely caused by the same energetic particles from the sun that create the northern lights far away in the sky. These particles or the geomagnetic disturbance produced by them seem to create sound much closer to the ground."

Source: http://www.aalto.fi/en/current//news/view/2012-07-09/
Listen: http://www.youtube.com

Science History is Made

This is the moment history was made.

In an emotional seminar on 4 July between 0900 - 1100 CEST, CERN scientists presented overwhelming evidence for a new particle, consistent with descriptions of the Higgs boson.

Joe Incandela first revealed that CMS have significant evidence of a new boson at 125.3 GeV. Huge applause greeted his news that CMS rate the significance of the results 4.9 sigma. Fabiola Gianotti, head of ATLAS followed, noting with her customary humour and humility, "it's not easy to speak second as all the clever things have been said".
After a lengthy recap on their work from 2011, Gianotti revealed, "you see the excellent consistency everywhere, except one big spike here ....".

The room erupted in spontaneous applause as Gianotti showed that ATLAS have evidence of a new boson at 126.5 GeV with a significance of 5 sigma.

These levels of certainty are worthy of a discovery, prompting CERN director, Rolf Dieter Heuer to comment, "as a layman, I can say, I think we have it".

The particle has been the subject of a 45-year hunt to explain how matter attains its mass.

Both CMS and ATLAS have been quick to caution that more data is needed before they can confirm that their boson discovery is indeed the Higgs mechanism described by theorists. As Rolf Dieter Heuer stressed in the press conference afterward, "we can say we've found a Higgs boson; not the Higgs boson". But it is absolutely evident that whatever has been discovered is what the LHC was designed to detect. The data analysed by both ATLAS and the CMS in the forthcoming months will provide further detail about the precise nature of the new boson.  As Gianotti said, "we are entering the era of Higgs measurements".

Theorist Ignatios Antoniadis commented on the implications of the announcement for theoretical descriptions of the Universe.  "Because of its low mass, such a Higgs boson would allow us to rule out theories known as “technicolor” and some of the theoretical models used in supersymmetry. However, other supersymmetric scenarios could still apply, as well as extra-dimensional theories."

Image by Samuel Richards.

Source: http://webcast.web.cern.ch/webcast/play_press.html

CERN have found the Higgs boson

ATLAS and CMS have found a particle consistent with the descriptions of the Higgs boson! They revealed their results this morning at a dramatic seminar at CERN.

The results from both Joe Incandela from CMS and Fabiola Gianotti of ATLAS were complementary, showing a 4.9 - 5.0 sigma result of a boson a 125-126 GeV.

"You see the excellent consistency everywhere, except one big spike here ...." Fabiola Gianotti, head of ATLAS revealed at the seminar, sparking a huge round of applause from the physicists attending the seminar. "We are now entering the era of Higgs measurements" she added.

Rolf Dieter Heuer, director of CERN said, "As a layman, I think I can say, I think we have it. We have a discovery. We have a particle consistent with the Higgs boson".

Peter Higgs, one of the theorists who described the Higgs mechanism in the 1960s who were present at the seminar, commented, "I think it's incredible it happened in my lifetime".

The Higgs seminar

As we speak ATLAS and CMS are presenting their latest efforts in the search for the Higgs boson at a seminar at CERN near Geneva, which is being simulcast to the ICHEP physics conference in Melbourne. Our friend, Samuel Richards is at ICHEP in Melbourne at to document the seminar for us.
Here's a shot of an earlier briefing. Stay tuned for more ...

Source: https://indico.cern.ch/conferenceDisplay.py?confId=197461

We'll be at the Higgs seminar in Melbourne

On 4 July at 0900 CEST, one of the most hotly anticipated science seminars in a decade will be held, announcing new results from the CMS and ATLAS experiments at the LHC, which are both searching for the Higgs boson.

The seminar will be held live from CERN in Geneva and simulcast to the Conference on High Energy Physics (ICHEP) in Melbourne.
And we'll be there.

Our friend, Samuel Richards, a filmmaker from New Zealand will be on hand in Melbourne at ICHEP to document the seminar, and we'll be posting his thoughts and photographs here.

For background reading on why all this matters, take a look at these excellent primers from ATLAS physicist, Jon Butterworth and theoretical physicist, Sean Carroll.

Image © Samuel Richards