Particle Decelerator

Dark matter remains dark - for now

2013-04-18T19:39:00.000+02:00

CDMS detector. Courtesy of Fermilab.

For the past month and a bit, the biggest story in physics has undoubtedly been dark matter.

When Sam Ting, the charismatic Nobel Prize winning director of the AMS project, announced in February that the team who monitor his orbiting Alpha Magnetic Spectrometer, latched to the ISS, would be announcing 'significant results' in the search for dark matter, the whole physics community held its breath. Somewhat skeptically.

The results, when they were announced on 30 March at CERN, seemed to add weight to the measurements made by PAMELA, in 2008, and were certainly of significant interest.

AMS-02 on ISS. Courtesy of CERN

But they perhaps fell short of what many were hoping for. As theoretical physicist, Katie Mack put it on 5 April in Physics Focus - somewhat bluntly, it should be said, "the AMS-02 detector on the International Space Station has not detected dark matter. It hasn't found 'indications' of dark matter, or even 'hints'. It certainly is not providing the 'best evidence yet' of dark matter's existence."

She did, however, acknowledge the important measurements the AMS-02 detector has made:

"What AMS has done is measure, to very high accuracy, the amount of antimatter the galaxy is bombarding us with. [....]. The AMS experiment detects cosmic rays - protons, electrons, and the antimatter counterparts of each, antiprotons and positrons. Before the experiment ran, we had predictions of how the matter/antimatter fraction should vary with the energy of the particles. AMS tells us our predictions were wrong. The antiprotons look about right, but there's a huge excess of high-energy positrons over what astrophysical models predict, and a bump in the electron flux at high energies. All of these results were actually seen by earlier experiments PAMELA and Fermi, but AMS confirms them to higher precision and higher energies. There's more antimatter than we thought; now we have to figure out why."

This is a concise explanation of the so-called 'positron-excess', which is one of the key indicators that dark matter - whatever it is - exists. Mack goes on to explain, that the radio astronomers' favourite phenomenon, pulsars, are thought by many astrophysicists to be the cause of the positron excess.

"Pulsars [...] can use their extreme magnetic fields to accelerate particles and create electron-positron pairs. The fact that pulsars do this is solidly in the realm of known physics, and theoretical models can easily fit the signals seen in the cosmic ray experiments."

This is far from an accepted theory of the origin of dark matter, but it is a fascinating one nonetheless. But where else might we look to find out about the origins of dark matter? The answer is: the mines.

Far beneath the surface of the earth, some of the most significant searches for dark matter have been underway for years. This week, one of the most notable of these, the CDMS experiment (the Cryogenic Dark Matter Search) in the Soudan mine in Minnesota, posted some extremely interesting results. Graduate student, Kevin McCarthy, reported at the American Physical Society meeting in Denver on 13 April that CDMS has found "three promising clues" of dark matter. The their silicon detectors had picked up possible signs of three weakly interacting massive particles (or 'WIMPs', as physicists call them). Their evidence is verifiable to a level of three-sigma.

As Jason Palmer explains, particle physics has an accepted definition for a "discovery": a five-sigma level of certainty. "The number of standard deviations, or sigmas, is a measure of how unlikely it is that an experimental result is simply down to chance, in the absence of a real effect Similarly, tossing a coin and getting a number of heads in a row may just be chance, rather than a sign of a "loaded" coin The "three sigma" level represents about the same likelihood of tossing nine heads in a row. Five sigma, on the other hand, would correspond to tossing more than 21 in a row. With independent confirmation by other experiments, five-sigma findings become accepted discoveries."

So CDMS' three-sigma result falls short of this, but it most certainly counts as a 'tantalising hint'.

As science writer Valerie Jamieson notes, the CDMS dark matter signal fits with recent theories that suggest dark matter is, "not a single entity, but a 'dark sector of particles' that could include dark antimatter".

"This may be the start of a very big deal" observes dark matter theorist Dan Hooper, of Fermilab, who manage CDMS.

So whilst dark matter remains enigmatic, and most certainly dark, for now, there's some hope we may be closing in on its secrets.

Sources:

http://www.aps.org/meetings/april/

http://is.gd/coldwater

http://cdms.berkeley.edu/

Storifying Critical Citizen Science

2013-04-07T19:28:00.001+02:00

MadLab Scientists investigating food products. Image (cc) MadLabUK, 2013.

Alice Bell recently drew my attention to a fascinating piece of writing by the Goldsmiths academic, Dan McQuillan. The piece entitled, What is Critical Citizen Science? (A Dialogue), is a meditation on the emerging field of citizen science. It takes the form of a fictional dialogue between 'nomad', the apotheosis of a free-thinking scientist-cum-hacker, and 'royalist', a caricature of an antediluvian traditionalist academic. Through the voices of these archetypes, McQuillan sets out what he refers to as 'critical citizen science', a bottom-up, participative scientific movement.

The piece is published on Storify, the social media service that lets users create stories using elements from other platforms such as Twitter, YouTube or Instagram. Users build a story from video, images, and quotations from various places, using their own words to formulate a narrative.

Through a combination of well-chosen references, polemics and poetry, a sense of what 'critical citizen science' might be, gradually emerges from McQuillan's text. The dialogic format inevitably calls to mind the conversations between Achilles and the tortoise in Zeno, Carroll, and perhaps most fittingly, Hofstadter's Gödel, Escher, Bach. In McQuillan's work too, the medium of dialogue lends itself well to an inquiry into the complex ethics, aesthetics and politics that 'critical citizen science' might be engaged with.

Intriguingly, over the course of the dialogue, McQuillan correlates emerging community science and technology practices, exemplified by crowdmapping initiatives like Harassmap, hackerspaces such as MadLab, and open hardware projects such as Safecast and Water Hack, with an analysis of radical media art practice of the late 20th century, particularly the Electronic Disturbance Theater.

Ricardo Dominguez, Electronic Disturbance Theater

As someone very much engaged with the wider context of tactical media as a cultural strategy in the 1990s, and now equally fascinated by emerging forms of participatory science, I found McQuillan's juxtaposition of these two discrete areas, deeply compelling.

Here's a short extract, where we listen in on nomad and royalist, discussing new sites of scientific learning:

nomad: there is already an emerging set of learning spaces for critical citizen science; hackerspaces, makerspaces and fablabs...

royalist: what nonsense. these aren't labs, they're garages; and it's not science, merely an obsessive meddling with hardware.

nomad: popularly known as hacking. i refer you to early hacktivists the Electronic Disturbance Theater and their 'science of the oppressed" - "...alternative social forms of life and art that fall between the known and unknown, between fiction and the real, between clean science and dirty science - each a part of a long history of an epistemology of social production which privileges the standpoint of the proletariat, the multitude, the open hacks of the DIY moments, and of autonomous investigators who stage test zones of cognitive styles... concrete practices as speculation and speculation as concrete practices - at the speed of dreams."

This is not a manifesto for 'critical citizen science' (or perhaps just as accurately, 'tactical citizen science'?). It's more of a persuasive suggestion. But one can't help but recall another grass-roots movement which argues for a similarly critically engaged approach to science and technology. In October 2011, Julian Oliver, Gordan Savicic and Danja Vasiliev published the Critical Engineering Manifesto. It begins by stating:

"The Critical Engineer considers Engineering to be the most transformative language of our time, shaping the way we move, communicate and think. It is the work of the Critical Engineer to study and exploit this language, exposing its influence."

As co-author, Oliver noted in an interview in 2012, "as thinkers with technical abilities in several areas, we want to take on our built and increasingly automated environment by the terms in which it's given, opening it up for post-utilitarian conversation, for play and interrogation. If there's ever a time to be doing that, it's now, especially with opaque and hidden infrastructure in the telecommunications space deeply impacting diplomatic relations and civil liberties world wide."

The manifesto provides an analytical framework for artistic practice which exposes the technological and scientific systems which unpin much of society. By making these infrastructures and systems visible, the 'critical engineer' reveals the political and power structures at play, instigates critical discussion, and questions who has agency within these systems.

Transparency Grenade (2011) by Julian Oliver

Projects such as Oliver's Transparency Grenade (2011) and Oliver and Vasiliev's Newstweek (2011) are designed as both functional tools, which both reveal and disrupt the invisible information and communication networks that surround us, and conversation-starters about our unquestioning reliance on technological systems we often don't understand. Their intention is to expose the deep reach that science and technology have in our lives, and to try and encourage more active forms of intervention and agency. As Oliver (2012) has noted, we all "think through tools both before and while we use them and the more we depend upon a tool the more we are changed by it."

McQuillan's speculations on critical citizen science seem to originate from a similar desire to question the power structures and politics of scientific practice. He insinuates an anxiety about popular citizen-science efforts such as Galaxy Zoo and LHC@Home, which harness the labour of users, without deeply engaging them in the scientific process. To frame that concern, he cites Tiziana Terranova's critique of user-generated content outlined in her text, Free Labor: Producing Culture for the Digital Economy (2000).

His text also conveys an unease with the exponential hype surrounding 'big data' and 'open data':

royalist: [...] The networks you rely on for your delocalised tinkering have already given birth to a new science; and it's name is Data Science; and its Data shall be Big.

nomad: [...] As our data is always ambiguous, we shall Glitch; becoming the discontinuities and unexpected artefacts in the big data you crave.

Later, McQuillan points to the value of critical citizen scientists in bearing witness to events which governments and bureaucracies would prefer citizens not to see, let alone intervene into:

nomad: [....] Why not look to the example of white coated citizens weapons inspectors for responsible empiricism. In a horsemeat crisis, the critical citizen scientist packs their DIY bio and flashmobs the nearest Lidl. This isn't an idle fantasy; only recently, Madlab testers set up shop as the Deptford Market DNA FoodLab.

Elsewhere the piece, McQuillan muses whether 'critical citizen science' could be the site at which the Internet of Things becomes the "Parliament of Things" as described by Bruno Latour in his 1991 book, We Have Never Been Modern. By this, Latour was referring to a kind of symmetry between people and what he calls "non-human entities" (or "things"). He argues that our society is comprised of people assembled around "things". Latour dismantles the barrier between culture and nature, between subject and object, proposing more subtle relations between humans and "things", in which the latter are granted the same amount of agency as we are. McQuillan spiritedly picks this up, in the voice of nomad, contending:

"Through citizen science, the Parliament of Things will become the Occupy of Objects."

Whilst I was originally drawn to the subject of the piece - its evocation of radical tactical art media practices, entwined with new community science efforts, and echoing (perhaps inadvertently) the philosophy of the critical engineering movement - the methodology of the story construction is also worthy of note. When I first read the piece and started thinking about it, I opined to the science policy researcher, Justin Pickard, that such evocative material deserved to be written up in a more formal manner. He responded by saying:

"This *is* it written up properly. Storify-native STS. Look how reliant it is on the video clips, images, and hyperlinks."

So, tools like Storify enable writers and makers to build layered, interwoven narratives around science and technology research and ideas. These tools provide us with a different vector to be able to express heterogeneous, emerging and often conflicting ideas. As such, they have the potential to develop into an intriguing and valuable alternative platforms for science communication, and the analysis of scientific research.

Source:

http://storify.com/danmcquillan/what-is-critical-citizen-science-a-dialogue/

Neutrinos back in the spotlight

2013-04-07T18:55:00.001+02:00

It's been a big couple of weeks for neutrinos. First, the OPERA experiment in Italy revealed that they had detected the transformation of a muon neutrino to a tau neutrino for only the third time in their history. Soon after, Fermilab's NOvA neutrino detector in the States published their first three-dimensional images of the elusive particles (pictured above). All this followed hard on the heels of one of the most discussed and celebrated science results of the year so far - the new Planck measurement of the cosmic microwave background - which has interesting implications for neutrino physics.

Neutrinos are among the more mysterious and slippery inhabitants of the fundamental particle zoo. They can be created by certain types of radioactive decay, or nuclear reactions like those that take place in stars, or when cosmic rays hit atoms. They have barely any mass and therefore rarely interact with other types of matter. This makes them fiendishly difficult to observe. But they are a fascinating area of study for physicists. Many of the neutrinos around today are thought to have originated in the Big Bang, so understanding their properties will give us important new insights into what the universe was like 13.7 billion years ago, and how it operates on a fundamental level now.

Neutrinos come in three different types, called "flavours": electron, muon and tau. Forty years ago physicists posited that these particles may occasionally be able to change from flavour to flavour - for instance starting out as a muon neutrino and ending up as a tau neutrino. This transformation could explain one of the great puzzles of neutrino physics. Theoretical models imply there should be far more neutrinos raining down on the Earth from nuclear reactions in the Sun, than there actually are. So the mystery of the 'missing neutrinos' has been bothering physicists for over a generation. If it could be proven that the missing particles are actually neutrinos which have changed flavour as they move through space, then this mystery could be solved.

The OPERA experiment in Gran Sasso, Italy was set up specifically for this purpose. It is designed to detect and analyse exactly these kinds of transformations. But spotting them is no easy matter. On 26 March 2013, OPERA announced that it had observed this exceptionally rare act of 'shape-shifting' for just the third time. A muon-type neutrino produced at CERN in Geneva arrived at the Gran Sasso laboratory as a tau neutrino. This has only been observed only twice before, once in 2010 and again last year.

OPERA works by studying beams of neutrinos produced at CERN in Switzerland, which travel 732km to the underground laboratory at the Gran Sasso facility, where they can be studied by physicists working on the OPERA detector. As Kathryn Jepsen, writing in Symmetry, puts it, "the OPERA experiment is a fast-moving, long-distance game of catch, with CERN laboratory at the border of France and Switzerland pitching a concentrated beam of neutrinos toward the 1250-ton OPERA detector. The neutrino is a difficult ball to snag; it interacts so rarely with matter that it can zip unflinchingly through an entire planet."

The neutrinos which leave CERN are muon neutrinos. OPERA is configured to detect tau neutrinos. If it spots one, it can deduce that a 'change of flavour' has occurred en-route. Detecting such a flavour oscillation, as the team did this March, is significant. Not only is it, "an important confirmation of the two previous observations", as the the head of OPERA's international research team, Giovanni De Lellis, has said; it also provides more evidence that flavour oscillation may indeed be the reason why the flux of neutrinos from the Sun and Earth's atmosphere is so much smaller than what theorists predict it should be.

Over on the other side of the Atlantic, Fermilab are in the process of establishing the NOvA experiment as the most powerful neutrino detector in the States. They recently took a significant step towards this goal, by releasing their first three-dimensional images of particles analysed in the under-construction detector.

NOvA detector in construction - near Ash River, USA, photographed in 2012. Image courtesy NOvA collaboration.

NOvA is a collaboration of 180 scientists, technicians and students from 20 universities and laboratories in the U.S and another 14 institutions around the world. Later this year, the NOvA detector at Ash River, near the Canadian border will start receiving beams of neutrinos sent from Fermilab, the US equivalent of CERN, which is based near Chicago. The beams of neutrinos will travel 500km from Fermilab to NOvA. As they say, "when a neutrino interacts with the detector, the particles it produces leave trails of light in their wake. The detector records these streams of light, enabling physicists to identify the original neutrino and measure the amount of energy it had."

Using the first completed section of the NOvA detector, physicists have begun collecting data from cosmic rays - the particles produced by a constant stream of atomic nuclei falling on the Earth's atmosphere from space. The 3D particle images they have produced as a result of this work are helping the physicists fine-tune the instrument. When cosmic rays pass through the NOvA detector, they leave straight tracks and well-understood energy signatures. As Mat Muether, a Fermilab researcher, notes, "they are great for calibration. Everybody loves cosmic rays for this reason. They are simple and abundant and a perfect tool for tuning up a new detector."

Fermilab state, "the detector at its current size catches more than 1000 cosmic rays per second. Naturally occurring neutrinos from cosmic rays, supernovae and the sun stream through the detector at the same time. But the flood of more visible cosmic-ray data makes it difficult to pick them out. Once the upgraded Fermilab neutrino beam starts, the NOvA detector will take data every 1.3 seconds to synchronize with the Fermilab accelerator. Inside this short time window, the burst of neutrinos from Fermilab will be much easier to spot."

And this is important. As Gary Feldman of Harvard University says, "the more we know about neutrinos, the more we know about the early universe and about how our world works at its most basic level".

The most headline-stealing physics result of the year so far has given us breathtaking new insights into the early universe and our world at it's most basic level. On the 21 March 2013, scientists working with the Planck Space Telescope unveiled the most detailed map ever created of the cosmic microwave background (CMB) - the leftover radiation from the Big Bang. Whilst the Planck measurement of the CMB hasn't given us that many clues as to what the fundamental properties of neutrinos are, it may have helped us learn what they are not. In recent times, physicists have begun to speculate that there may be a fourth type of neutrino flavour - the sterile neutrino, so called because it is not effected by the weak nuclear force, and therefore interacts even less with other particles than it's shy and retiring, tau, muon and electron neutrino cousins. But as John Matson writing in Scientific American has noted, Planck's findings suggest that physicists hoping for experimental proof of the sterile neutrino are going to have to look harder or rethink altogether.

All and all, these are fascinating times for neutrino physics, and we shouldn't be surprised if these ghostly little particles take their share of the limelight in the coming year.

Sources:

http://www.fnal.gov/

http://www.infn.it/news/newsen.php?id=663

http://www.symmetrymagazine.org/

D mesons flipping

2013-02-28T13:30:00.001+01:00

The magnet at the LHCb detector

A result today from the LHCb had me humming:
"On the 18th day of shut-down, my true love sent to me: D mesons flipping".

To put this in English, the Large Hadron Collider's LHCb detector has published highly significant results indicating that they have detected particles called D mesons, oscillating from matter into antimatter. The results come 18 days after the LHC shut down for maintenance.

Their paper, pre-published on arXiv, outlines how the D mesons, the last of the four types of mesons to be 'observed' undergoing this oscillation, were detected to a five-sigma level of certainty.

As science writer Jason Palmer puts it:
"In the complicated zoo of subatomic physics, particles routinely decay into other particles, or spontaneously change from a matter type to their antimatter counterparts. This "oscillation" forms an important part of the theory that attempts to tame the zoo - the Standard Model. Mesons are part of a large family of particles made up of the fundamental particles known as quarks. The protons and neutrons at the centres of the atoms of matter we know well are each made up of three such quarks.
Mesons, on the other hand, are made of just two - specifically one quark and one antimatter quark. Theory holds that four members of the meson family can undergo the matter-antimatter oscillation - the matter and antimatter quarks both flip to their opposites."

The LHCb, which has had a series of stunning results with B mesons, had observed two types of B mesons and a K meson oscillating between matter and antimatter before. But with this new paper, the team provide evidence that the last of the four types of particles, D mesons, has now been detected undertaking the same type of oscillation.

As Chris Parkes, LHC researcher from University of Manchester said:
"This is a nice moment, it's a sort of completeness.”

It is striking to note that the abstract on arXiv lists 60 authors, with another 550 not cited, due to lack of space. This really underscores the collaborative nature of physics at the Large Hadron Collider.

The results are significant because the LHCb is investigating the unsolved question of why there is more matter than antimatter in the Universe. According to the Standard Model, particles of matter and antimatter come in pairs, and matter and antimatter should obey the same laws. Therefore, we ought to expect an equal amount of both. So the question, "where's all the antimatter?" has had physicists scratching their heads for some time. The team at the LHCb, are undertaking some of the most significant and fundamental work to try and answer this question.

LHCb's result comes through two and half weeks after the LHC was shut-down for a lengthy period of maintenance. But it emphasises just how much science will be carrying on whilst the main detectors are serviced and upgraded. The data collected by researchers during the first phase of collisions will be pored over for years to come, and we should expect more fascinating results like these, in the coming months.

Source: http://arxiv.org/abs/1211.1230
http://www.bbc.co.uk/news/science-environment-21594357

Ensonifying space

2013-02-25T11:36:00.000+01:00

It is very heartening and interesting to read so many fascinating articles, emerging from my Tuning into the Universe piece for Huffington Post this weekend.

Scientists and journalists from Huffington Post community have published a range of pieces on everything from data sonification, to astereoseismology, to the reminiscences of a former astronaut. Together these articles greatly expand the field of general knowledge around the physics of radio astronomy, and our capacity to sensorially experience it.

One of the pieces draws on an interview with radio astronomer, and the co-founder of the SETI Institute, Jill Tarter. Amplifying the central message of Tuning into the Universe, Tarter notes that:

"when SETI listens to the cosmos, the institute is actually receiving electromagnetic radiation. And then, just the way your radio does, that energy can be used to make audible sound."

The pieces published in response to the article extend, expand and ensonify this notion. Some of my favourites include:

The Sound of the Deep Sea of Space by radio astronomer, Dr. Tyler Nordgren equates the universe with a vast ocean, echoing Carl Sagan's famous analogy from his series, Cosmos. He poetically maps out the methods of astronomical observation available to modern astronomers, beyond the detection of visible light. He notes: "as a young radio astronomer I learned early on that every time human beings have explored the world with new senses we have discovered new and amazing phenomena".

Voices Carry by Anna Leahy and Douglas Dechow explores the sonic signature of our own planet:

"The sound of the Earth's inherent dynamics -- the movement of atmosphere and oceans -- produces a steady drone as well. Lightning produces crackling, which scientists call sferics."

Voyager Golden Record

The article includes a memorable passage about the Voyager Golden Record, which contains 'greetings in 56 languages, natural sounds like thunder and crickets chirping, and music from around the world', encoded in audio and now travelling towards the outer reaches of our solar system on board Voyager.

In An Audible Tour of the Solar System? Sign Me Up!, astronomer and planetary scientist, Jim Bell analyses our celestial neighbourhood, exploring the potential for acoustic sound on each of our nearest planets. The Perfect Quiet of Space by legendary astronaut, Jerry L. Ross, is the extraordinary account of his nine spacewalks, undertaken during his seven missions into space.

Jerry L. Ross n one of his nine spacewalks.

He writes eloquently about the silence which astronauts experience, when outside the International Space Station:

"Without the sophisticated listening devices scientists use on earth to hear the whispers of the universe, to an astronaut space is infinite quiet, a place where we bring the only sounds that break the silence."

Sound: The Music of the Universe by Mark Ballora and George Smoot III is an excellent overview of the practice of data sonification, which takes in in the brilliant work of the xSonify team, who are making sonification applications for blind scientists. The article also refers to the emerging science of astereoseismology and exoseismology, which I talked about last Friday in my Sonic Acts talk.

They clearly explain why data sonification methods can be useful:

"Symbolic renderings create other perspectives. Literal renderings are not always compatible with the capabilities of our auditory system. When data points are treated as audio samples and played back at audio rates (typically at 44100 values/second) quick changes are lost to us, as we can't hear fluctuations discretely at the millisecond level. If, instead, we treat the data points symbolically, for example as pitches, we are better able to "magnify" what we are listening to."

In Understanding the Sound of Space, Ayodele Faiyetole notes that sound is under used in science. He draws on an interview with cosmologist, Yuko Takahashi, who believes there's a great value in presenting scientific results in a totally different dimensions, such as sound:

"Maps of CMB anisotropy can be converted to sound as a telescope sweeps across the sky to give the audience a better appreciation of the fluctuations."

As Ballora and Smoot put it, "if the universe is, at some level, music, then it seems only natural that we should study it with musical tools of thinking."

Source: http://www.huffingtonpost.com/tedweekends/

Tuning into the sound of the universe with radio

2013-02-23T09:49:00.000+01:00

This weekend, Huffington Post have published my piece, Tuning the Universe, which contextualses my TED talk, which they are featuring as part of TED Weekends.

The piece provides some background into the audified radio waves which I played during my talk. Here's the gist of the article:

"We have been surrounded by stunning portrayals of our own solar system and beyond for generations, in books, on film and on television. But in popular culture, we have no sense of what space sounds like. And indeed, most people associate space with silence.
There are, of course, perfectly valid scientific reasons for assuming so. Space is a vacuum. Sounds cannot propagate in a vacuum. But through the intervention of radio, it is possible for us to listen to the Sun's fizzling solar flares, the roaring waves and spitting fire of Jupiter's stormy interactions with its moon Io, pulsars' metronomic beats, or the eerie melodic shimmer of a whistler in the magnetosphere."

My talk, and my work in this area, emerges from the science of radio astronomy.

RT16 at the Ventspils International Radio Astronomy Centre. Latvia

Whilst optical astronomers use telescopes to look at the visible light emitted by stars, radio astronomers use radio telescopes, or antennae, to detect radio waves. By combining radio astronomy with radio and sound engineering, we can hear as well as see the stars, and thus greatly expand our sensory perception of our cosmos.

It is important to remember that stars and planets are not directly audible. The recordings I played in my talk are radio waves which have been converted into sound waves using radio receives and amplifiers. This is a process I refer to as audification. Huffington Post have also published two companion pieces which respond to the talk, the first of which emphasises this point. Celestial Sound Effects by Seth Shostak notes correctly that, "they're electromagnetic noise, converted by electronic devices ... into signals that - when played through a loudspeaker - become the atmospheric pressure waves we call sound."

The second piece is What Is the Color of the Universe? by Mario Livio, which uses Karl Glazebrook and Ivan Baldry survey of more than 200,000 galaxies (the 2dF Galaxy Redshift Survey) as a basis for examining the colour of the universe.

Thanks to Huffington Post and Janet Lee at TED for publishing the piece.

And here's the talk in full:

Source: http://www.huffingtonpost.com/honor-harger/tuning-into-the-universe_b_2737168.html

New Zealand recognised as major contributor to radio astronomy history

2013-02-05T09:47:00.000+01:00

John Bolton (left) and New Zealander Gordan Stanley (centre), pictured with Jow Pawsey

New Zealand has claimed its place in radio astronomy history. As reported here a year ago, New Zealand has significant scientific heritage in the field of radio astronomy, and has begun to explore and celebrate this history.

Last week, some of the biggest names in the field gathered for an international conference which marked New Zealand's role in helping to kick-start radio astronomy research in the 1940s. Attended by the doyenne of the field, Jocelyn Bell Burnell, and researchers and historians from New Zealand, Australia and the UK, the conference explored the work of John Bolton and New Zealander, Gordon Stanley, who detected radio waves from outside the solar system in August 1948 from sites in Pakiri and Piha in the North Island of New Zealand.

Elizabeth Alexander

The conference also commemorated the pioneering work of Elizabeth Alexander, often referred to as the first female radio astronomer, who helped helped establish some of the early foundations of solar radio astronomy in 1946. Alexander studied sources of interference effecting radar stations in New Zealand established during World War II. During March-April 1945, solar radio emission was detected at 200 MHz by operators of a Royal New Zealand Air Force radar unit located on Norfolk Island.

The emissions became known as the "Norfolk Island effect". Alexander, then based at the Department of Scientific and Industrial Research in Wellington, heading up the Operational Research Section of the Radio Development Laboratory, carried out the most significant early work on the effect throughout 1945. In 1946. she published a paper in the journal, Radio & Electronics describing the emissions, and in doing so, furthered the fledgling field of radio astronomy.

Wayne Orchiston, writing in "The New Astronomy", has noted that Alexander's research also led to further solar radio astronomy projects in New Zealand in the immediate post-war year, and in part was responsible for the launch of the radio astronomy program at the CSIRO, in Australia."

Radar Station (Whangaroa) - one of five involved in New Zealand's investigation of solar radio emission. Image courtesy of Wayne Orchiston.

Astronomer Miller Goss, from the National Astronomy Observatory in New Mexico, puts it:

"Bolton and Stanley's discovery revolutionised twentieth century astronomy."

Following their pioneering discoveries, Bolton went on to become a major figure in Australian radio astronomy, helping found the famous Parkes radio telescope, becoming director of the Australian National Radio Astronomy Observatory and winning the the inaugural Jansky Prize in 1966 (so named after the father of radio astronomy, Karl Jansky).

Sergei Gulyaev

The conference was organised by the extraordinary Sergei Gulyaev, who has revitalised radio astronomy in New Zealand, spearheading the nation's participation in the SKA, amongst many other efforts.

Source: http://www.stuff.co.nz/auckland/local-news/rodney-times/8250497/Stars-align-for-conference

Can particle physics transform our online experience?

2013-01-20T17:36:00.000+01:00

One of the more intriguing papers we've happened upon early this year is some research from the University of Fribourg which suggests that particle physics can improve the technology behind recommendation systems.

Recommendation systems are software which websites such as Amazon and Facebook use to tailor information for users. When Amazon, somewhat eerily, suggests that you check out a book by a writer you've been just been thinking about, that's a recommendation system, or "engine", in action. Recommendation engines are at the heart of online business, as the good ones are known to generate profits. Improving them is a key goal for retailers and software companies alike.

But what on earth does particle physics have to do with software like that? Well, a group of researchers at the at the University of Fribourg in Switzerland believe that the physics which governs the behaviour of photons and electrons may also be used to optimise recommendation engines.

Stanislao Gualdi, Matus Medo, and Yi-Cheng Zhang this month published an abstract on arXiv entitled, "Crowd Avoidance and Diversity in Socio-Economic Systems and Recommendation". The paper's key insight is that the problem with recommendation engines is that they can lead to 'overcrowding' around a specific product or service, which can be detrimental to the experience users have with it. Surges in demand can be sometimes advantageous, but if the value of a resource diminishes as more people use it, then this creates a problem. A good example would be a service like Netflix recommending the same movie to too many of its users, thereby creating long waiting times for everyone. Another good example, would be a travel website recommending a beach or a picnic spot because it is quiet. As Technology Review noted "this can end up destroying the peace that gives it value. Similarly, restaurant recommendations can lead to overcrowding or difficulty getting a table which again makes the dining experience unpleasant."

These examples show how over-stimulated demand can reduce the value of a resource. Gualdi, Medo and Zhang set about to tackle this issue. They applied the logic employed in particle physics, where particles tend to occupy the most energetically favourable states. Technology Review explain:
"If the particles are bosons, such as photons, there is no limit to the number that can occupy a given state. But if they are fermions, like electrons, their physical properties dictate that no two can occupy the same state. Clearly the resulting distribution of these different types of particles is entirely different.The analogy here is with goods that any number of people can share or that only one person can have."

The latter case - products or experiences that are best experienced by small groups, or even individuals - provides a dilemma for recommendation engines. In order for these things to retain their value, they need to remain available only to limited umbers of people. Gualdi, Medo and Zhang insist that the principle of 'crowd avoidance' needs to be employed to avoid oversubscription, crowding and disappointment.

They provide evidence in their paper that building crowd avoidance into the recommendation process can increase the accuracy of the recommendation, and therefore the potential profitability of the recommendation engine. As they put it:
"We use real data to show that contrary to expectations, the introduction of these constraints enhances recommendation accuracy and diversity even in systems where overcrowding is not detrimental. The observed accuracy improvements are explained in terms of removing potential bias of the recommendation method."

It's a fascinating and quirky approach, and if they are right, and their technique is employed by the software developers who design and build our online world, it might just transform what is recommended to us, and when, and how we experience it.

Source: http://arxiv.org/abs/1301.1887

It's full of stars

2013-01-20T15:44:00.001+01:00

This week the noted photographer and optics engineer, Stéphane Guisard posted a stunning mosaic image of the Milky Way captured at ESO's Paranal Observatory in Chile.

The mosaic is constructed from 52 fields, shot over 29 nights, and consists of 1200 separate photos and 1 billion pixels. The image transports us to the centre of the Milky Way, giving us a scalable and zoomable encounter with literally millions of stars.

As Guisard notes, "it shows the region spanning from Sagittarius (with the Milky Way center and M8/M20 area on the left) to Scorpius (with colorful Antares and Rho Ophiuchus region on the right) and Cat Paw nebula (red nebula at the bottom)."

This is the galaxy in extreme fidelity. Enjoy getting lost in the detail.

Source: http://sguisard.astrosurf.com/Pagim/GC.html

Did Einstein discover dark energy?

2012-12-02T18:19:00.001+01:00

One of the more interesting things that popped up on arXiv this week was the quirkily titled abstract, How Einstein Discovered Dark Energy, submitted by Alex Harvey, Visiting Scholar at New York University on 22 November.

It bears repeating in its entirety:

"In 1917 Einstein published his Cosmological Considerations Concerning the General Theory of Relativity. In it was the first use of the cosmological constant. Shortly thereafter Schrodinger presented a note providing a solution to these same equations with the cosmological constant term transposed to the right hand side thus making it part of the stress-energy tensor. Einstein commented that if Schrodinger had something more than a mere mathematical convenience in mind he should describe its properties. Then Einstein detailed what some of these properties might be. In so doing, he gave the first description of Dark Energy. We present a translation of Schrodinger's paper and Einstein's response."
The full paper and references are downloadable here.

It will be interesting to hear what the responses are to this.

Source: http://arxiv.org/abs/1211.6338

The rise of the algorithms

2012-11-27T11:51:00.001+01:00

The Knife - a financial trading algorithm

This week Tarleton Gillespie was the latest critical commentator to analyse the role that algorithms play in contemporary life. His detailed insightful and urgent essay, The Relevance of Algorithms was published on the Culture Digitally blog this week, ahead of it's forthcoming publication in the MIT book, "Media Technologies".

Picking up where Kevin Slavin's excoriating Lift talk, "Those algorithms that govern our lives" (later reprised for TED) left off, Gillespie conducts a thorough investigation into how algorithms provide the basis for a great deal of our individual and societal choices. That we understand their impact on our daily lives so poorly is cause for great concern, Gillespie argues. He notes a particular anxiety with the way that algorithms are starting to influence how we find and interpret information, and points to the obvious impact this will have on politics:

"Algorithms not only help us find information, they provide a means to know what there is to know and how to know it, to participate in social and political discourse."

This has strong and relevant echoes back to the set of concerns raised by both designers and artists working with technology, as alluded to in a previous post. Artists Julian Oliver, Danja Vasiliev and Gordan Savicic have developed a discourse they refer to as "critical engineering", which aims to expose the systems, mechanisms, languages and logics which make up our engineered world. This is urgent, political work, they argue, as the encroachment of engineering into our lives, is matched only by its increasing invisibility. If we lose our ability to perceive this technological infrastructure, we lose agency.

As Oliver wrote recently:
"As thinkers with technical abilities in several areas, we want to take on our built and increasingly automated environment [...] If there's ever a time to be doing that, it's now, especially with opaque and hidden infrastructure in the telecommunications space deeply impacting diplomatic relations and civil liberties world wide. [...] Our inability to describe and understand technological infrastructure reduces our critical reach, leaving us both disempowered and, quite often, vulnerable." - Julian Oliver (September 2012)

These thoughts are echoed almost precisely by designer, writer and publisher, James Bridle (who's work in this area was referenced here recently), who notes:
"By legibility I mean our own ability to read these systems, how much they can affect the way we see and act in the world, and the differing positions of power we have in the world based on how legible those systems are. [...] Programmers have a huge amount of agency in the world, because they can deconstruct, reverse engineer and write and construct and create these systems. People who can't, don't, and they have less power in the world because of it." - James Bridle (September 2012). He later wrote:
"Those who cannot perceive the network cannot act effectively within it, and are powerless. The job, then, is to make such things visible."

Gillespie's essay operates very much within this spirit, insisting on the need to be able to perceive and understand the way that algorithms are becoming part of our lived environment. He writes:
"What we need is an interrogation of algorithms as a key feature of our information ecosystem, and of the cultural forms emerging in their shadows, with a close attention to where and in what ways the introduction of algorithms into human knowledge practices may have political ramifications."

His essay then seeks to do just that, providing an excellent map for this emerging terrain. His perspective is not technological, but rather sociological, an analysis which he insists "must not conceive of algorithms as abstract, technical achievements, but must unpack the warm human and institutional choices that lie behind these cold mechanisms."

His essay is a vital insight into these choices. Resonating with the worlds of both Oliver and Bridle, he concludes:
"In many ways, algorithms remain outside our grasp, and they are designed to be. This is not to say that we should not aspire to illuminate their workings and impact. We should. But we may also need to prepare ourselves for more and more encounters with the unexpected and ineffable associations they will sometimes draw for us, the fundamental uncertainty about who we are speaking to or hearing, and the palpable but opaque undercurrents that move quietly beneath knowledge when it is managed by algorithms.

Sources:
http://culturedigitally.org/2012/11/the-relevance-of-algorithms/
http://www.tarletongillespie.org/

Your move, theorists

2012-11-18T13:44:00.000+01:00

B-mesons' decay products

Physicists rather enjoy the friendly rivalry between theorists and experimentalists, and this week has been a fascinating week for both. Results presented at the Hadron Collider Physics symposium in Kyoto this week have proved a triumph for experimentalists working with the most powerful tool at their disposal - the LHC. But theorists have been left scratching their heads, as one of the most prominent theories of "new physics" took a major hit. Since the search for physics beyond the Standard Model is a leading priority in particle physics, this is highly significant for everyone.

Unsurprisingly, the hot topic of discussion at the Hadron Collider Physics symposium was the LHC's incendiary boson results from earlier this year.

Both the teams from the CMS detector and the ATLAS detector presented new analyses of the observations which led them to announce the discovery of a Higgs-like boson in July. What's striking about the new data is that is backs up initial suspicions that the boson discovered at the LHC appears to be behaving precisely as the Standard Model predicted it would. As Tommaso Dorigo noted in Quantum Diaries, the new measurements, "confirm the standard model interpretation of the new found object." Philip Gibbs at viXra provides some further technical analysis of the results here.

The LHCb Experiment. Photo courtesy of CERN.

But perhaps more sensational was the new results presented by their colleagues over at the LHCb Experiment. Johannes Albrecht reported that the LHCb team have observed one of the rarest particle decay events in physics, a Bs meson decaying into 2 muons. These events are so rare that the Standard Model predicts they should only occur about once in 300 million collisions.

That LHCb has observed one of these events at all is a stunning achievement for the experimentalists working on the detector. But the fact that their results suggest the the Bs meson decay is every bit as rare as the Standard Model predicted it should be, is a serious blow for one of the leading theories of new physics - supersymmetry.

The theory of supersymmetry, often referred to by its shortened nickname, SUSY, states that every fundamental matter particle should have a more massive, or 'super' force carrier particle, and every force carrier should have a 'super' matter particle. These particles are often referred to as 'sparticles' (supersymmetric particles). Supersymmetry. has been championed by theorists such as Savas Dimopoulos and Gordon Kane, who memorably described the theory as a "wonderful, beautiful and unique" solution for the problems in our understanding of the subatomic world.

However, the LHCb results have cast serious doubt on the viability of supersymmetry as a theory. Supersymmetry predicts that if superparticles exist the Bs meson decay to a pair of muons should occur far more often than one in 300 million. The work the LHCb team were doing has long been considered the most important experimental test for supersymmetry. Whilst the LHCb results, which prove the rarity of the decay, don't rule supersymmetry out all together, the parameters for superparticles have narrowed dramatically, making the theory a much less likely explanation for the mysteries in our subatomic world, than many had hoped.

Why is this significant? Well, all physicists know that the Standard Model, despite its elegance, does not function as a complete explanation for the forces which govern our universe. It provides little explanation for gravity, and it noticeably fails to explain either dark energy or dark matter. Given that it is believed that dark matter may constitute up to 84% of all matter in the universe, and dark energy up to 73% of all the known energy in the universe, a theory which explains neither is clearly inadequate.

The science community at large had been hoping that the experiments running at the LHC would start to uncover evidence for "new physics" beyond the Standard Model, which would begin to explain these puzzling features of the universe. But so far, not only have the main results not done so, they've simply provided ever-strengthening evidence for the veracity of the Standard Model.

As Marc-Olivier Bettler from LHCb noted this week, "if new physics is present then it is hiding very well behind the Standard Model".

A typical candidate event for the Higgs boson measured in the CMS electromagnetic calorimeter. Image courtesy of CERN

The fact that CMS and ATLAS this week seemed to be describing a Higgs boson which looks awfully like the one predicted by the Standard Model, is compounding theoretical concern. Expressing this eloquently this week, Guido Altarelli from CERN stated that a Standard Model Higgs was, "a toy model to make the theory match the data, a crutch to allow the Standard Model to walk a bit further until something better comes along."

As Matthew Chalmers noted in an article which starkly set out the challenges the experimental results are raising, a Higgs boson at 125 GeV (the measurements both CMS and ATLAS have provided further evidence for this week) not only has a mass "vastly less than it should be, it is also about as small as it can possibly be without dragging the universe into another catastrophic transition. If it were just a few GeV lighter, the strength of the Higgs interactions would change in such a way that the lowest energy state of the vacuum would dip below zero. The universe could then at some surprise moment "tunnel" into this bizarre state, again instantly changing the entire configuration of the particles and forces and obliterating structures such as atoms."
He dramatically intoned, "as things stand, the universe is seemingly teetering on the cusp of eternal stability and total ruin."

All of this is to say that whilst results presented by ATLAS, CMS, and the LHCb are bringing relief in some quarters, as they certainly prove how exceptional the LHC is as a tool of discovery, they are causing some deep unease amongst theorists.

These are exciting times.

As particle physicist Ben Still observed earlier this year, "until theorists can come up with ways we can test their theories, they are just dealing with works of fiction."

So after some cracking moves this week in which the experimentalists have put pay to some of the most treasured literary works of physics theory, the ball is now back in the court of the theorists. They need to dream up new theories which help make sense of these results, and suggest new routes forward.

Sources:
http://www.nature.com/
http://www.quantumdiaries.org/

http://profmattstrassler.com/

A drones-eye-view: revealing the killing fields

2012-11-10T16:49:00.000+01:00

Jaar, Yemen, October 18 2012 / 7-9 killed. Image from Dronestagram by James Bridle

The unmanned aerial vehicle (UAV), or drone, has become one of the most potent weapons of contemporary warfare. Remotely controlled by operators thousands of miles away from the theatre of war, drones carry out aerial attacks which leave hundreds of people dead. The increasing amount of 'collateral damage' from US drone strikes on the Pakistan-Afghanistan border recently lead prominent politician, Imran Khan, to lead a high-profile protest against their use.

Drone Vision by Trevor Paglen

Artists have been actively documenting the impact of the use of drones in warfare for some years now. Trevor Paglen's Drone Vision, recently on show at Lighthouse in Brighton, provides us with a chilling "drones-eye-view" of a landscape, enabling us to see what drone-operators see.

Five Thousand Feet is the Best by Omer Fast

The utterly compelling and disturbing film installation, Five Thousand Feet is the Best by Israeli artist Omer Fast tells the story of a former Predator drone operator, recalling his experience of using drones to fire at civilians and militia in Afghanistan and Pakistan. At one stage of the film, he describes the use of what marines refer to as "the light of god", the laser targeting marker, which is used to direct hellfire missiles to their intended target.

"We call it in, and we're given all the clearances that are necessary, all the approvals and everything else, and then we do something called the Light of God - the Marines like to call it the Light of God. It's a laser targeting marker. We just send out a beam of laser and when the troops put on their night vision goggles they'll just see this light that looks like it's coming from heaven. Right on the spot, coming out of nowhere, from the sky. It's quite beautiful." (quoted from Five Thousand Feet is the Best).

The Light of God by James Bridle

Writer, publisher, web developer and artist, James Bridle responded to this by creating his own work, The Light of God.

Sharing Paglen and Fast's concern with the use of drones in warfare, Bridle has crated a series of projects which attempt to reveal their presence in the landscape. His Drone Shadow interventions are one-to-one representations of the MQ-1 Predator Unmanned Aerial Vehicle (UAV) drawn to scale within urban landscapes. The first was drawn in London this February (in collaboration with Einar Sneve Martinussen), and the second in Turkey this October as part of the Istanbul Design Biennial.

Drone Shadow 002 by James Bridle

Like Paglen and Fast, Bridle's work stems from a deep concern with increasingly invisible and seamless military technologies that are creating the context for "secret, unaccountable, endless wars".

Bridle writes, "the drone also, for me, stands in part for the network itself: an invisible, inherently connected technology allowing sight and action at a distance. Us and the digital, acting together, a medium and an exchange. But the non-human components of the network are not moral actors, and the same technology that permits civilian technological wonder, the wide-eyed futurism of the New Aesthetic and the unevenly-distributed joy of living now, also produces obscurantist "security" culture, ubiquitous surveillance, and robotic killing machines. [....] We all live under the shadow of the drone, although most of us are lucky enough not to live under its direct fire. But the attitude they represent - of technology used for obscuration and violence; of the obfuscation of morality and culpability; of the illusion of omniscience and omnipotence; of the lesser value of other peoples lives; of, frankly, endless war - should concern us all."

His latest work, released yesterday, is Dronestagram. Bridle has been collecting images of the locations of drone strikes, and sharing these photographs on the photo-sharing site Instagram. His intention is to make these locations more visible, bringing them closer to us, and in the process perhaps making the reality of the daily occurrence of deadly drone strikes more tangible.

He utilises public records from the Bureau of Investigative Journalism who document strikes as they happen in Pakistan, Yemen or Somalia. After confirming the location of a strike, he then uses Google Maps to create a satellite image of the targeted location. The image, accompanied by a description of the site, and the death-toll, if known, is uploaded to Instagram.

Wadi Abu Jabara, Yemen, 28 October 2012. 3 killed. Image from Dronestagram by James Bridle

The images of deserted, barren landscapes and abandoned buildings have a sobering potency juxtaposed with with the banal pictures of pets and parties that populate Instagram. But it is what we don't see that gives these images such an emotional power. The mortality.

Bridle writes, "drones are just the latest in a long line of military technologies augmenting the process of death-dealing, but they are among the most efficient, the most distancing, the most invisible. These qualities allow them to do what they do unseen [...]. Whether you think these killings are immoral or not, most of them are by any international standard illegal."

The work of artists such as Trevor Paglen, Omer Fast, and James Bridle exists within a long tradition of artists bearing witness to events that our governments and military would prefer we didn't see.

But Bridle's work is also part of an ongoing collective effort from both artists and engineers to reveal the technological infrastructures that enable events like drone-strikes to occur. As technology becomes more ubiquitous, and our relationship with our devices becomes ever more seamless, our technical infrastructure is becoming ever more invisible. When our environment becomes opaque or invisible, it becomes difficult to interpret it, and act within it. As artist and critical engineer, Julian Oliver recently noted, "our inability to describe and understand technological infrastructure reduces our critical reach, leaving us both disempowered and, quite often, vulnerable."

Or as Bridle puts it, "those who cannot perceive the network cannot act effectively within it, and are powerless. The job, then, is to make such things visible."

Sources:

http://vimeo.com/47723379

http://vimeo.com/34050994

http://booktwo.org/notebook/drone-shadows/

http://booktwo.org/notebook/dronestagram-drones-eye-view/

http://rhizome.org/editorial/2012/sep/5/artist-profile-julian-oliver/

Reifying quantum mechanics

2012-10-28T12:33:00.000+01:00

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

2012-10-14T15:06:00.000+02:00

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.

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

2012-10-07T15:04:00.000+02:00

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

2012-09-02T12:46:00.001+02:00

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

2012-07-12T10:11:00.001+02:00

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.

Listening to the Aurora

2012-07-09T23:55:00.001+02:00

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

2012-07-04T12:06:00.001+02:00

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

2012-07-04T10:59:00.000+02:00

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

2012-07-04T09:49:00.000+02:00

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

2012-07-03T09:30:00.000+02:00

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

Has the Higgs been Found at CERN?

2012-07-02T21:40:00.001+02:00

Nature are this evening sensationally reporting that CERN may well have discovered the Higgs boson.

Both ATLAS and CMS are presenting their latest research at a seminar in Melbourne on 4 July and the blogosphere has been alive with speculation about what they'll be unveiling.

But today, Nature have run an exclusive story confirming that a discovery has been made:

"Without a doubt, we have a discovery", says one member of the team working on the ATLAS experiment."It is pure elation!"

Nature are coy about the precise details of the discovery, cautioning that it is not yet known if the new particle behaves the same way as the Higgs mechanism is described in the Standard Model of physics.

But it is believed that both the ATLAS and CMS experiments are each seeing signals between 4.5 and 5 sigma in the 125 GeV range, where they first reported seeing signs of the Higgs last December.

Crucially, CERN have confirmed that four of the theorists who conceived the Higgs mechanism in the 1960s - including Peter Higgs - will be present at Wednesday's seminar.
It is hard to believe that all would have flown in to attend, if significant news wasn't being announced.

Source:
http://www.nature.com/news/physicists-find-new-particle-but-is-it-the-higgs-1.10932

Making the Invisible Visible

2012-06-23T13:06:00.000+02:00

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