Friday, 23 December 2011

Listening to the earth move

Christchurch-based sound engineer Ben Edwards recorded a magnitude 6 earthquake which struck earthquake-plagued Christchurch in New Zealand on 23.12.11.

As Edwards tells it, "whilst recording some drums in an old brick warehouse for the up and coming Eastern album we experienced a large aftershock. (5.8 in magnitude). We sat outside for a while and convinced ourselves it was ok to re enter the old building and continue our project... I was rolling as we were undertaking some line and level checking... this time we got it. 6.0 magnitude in a room full of kegs and bottles."

It's an incredible and sobering listen, and helps you understand what it must be like living in Christchurch - a city that's experienced nearly 10,000 earthqukes since the big one in September 2010.


Thursday, 22 December 2011

The LHC finds its first new particle

After the excitement from last week's press conference from CERN, which revealed that whilst they are getting closer, scientists still haven't found the Higg's boson, I don't think anyone was expecting a boson discovery from the Large Hadron Collider (LHC) after-all. But we've been given an early Christmas present: the LHC has found it's first particle - Chi_b(nP).

Chi_b(nP) was found by physicists working with the ATLAS detector, who published their findings on arXiv yesterday. It is the first clear evidence for a new particle since the LHC opened in 2009.

Chi_b(nP) is made of a beauty quark and it's antiquark bound together. They are bonded by the so-called strong nuclear force which also causes the atomic nucleus to stick together. Chi_b(nP) is a heavier version of a particle that was first observed around 25 years ago. Like the elusive Higgs, it is a boson, meaning it is a particle that carries force.

"It's interesting for what it tells us about the forces that hold the quark and the anti-quark together - the strong nuclear force. And that's the same force that holds, for instance, the atomic nucleus together with its protons and the neutrons."
Prof Roger Jones from the ATLAS Collaboration, quoted on BBC News.


The 3D printer as teleporter

If you only read one article on 3D printing this year, it should be Anil Dash's fascinating analysis of this important emerging technology. Set out as a set of observations and pearls of wisdom aimed at people experimenting with the technology, the article acts as a sort of wishlist for where Dash hopes the 3D fabrication and printing world is headed. Contained within the list is this nugget:

"These devices are not '3D fax machines'. What you've actually made, when you have an internet-connected device that can both send and receive 3D-printed objects, is a teleporter."
Provocative and exciting stuff. Read the article now.


Tuesday, 13 December 2011

Science has nothing to fear from uncertainty

Ahead of today's press conference from CERN, which provides an update of the search for the Higg's boson, LHC physicist, Jon Butterworth, published a thoughtful piece in the Guardian, which reflected on this and the recent neutrino results from OPERA. In relation to the Higgs, he noted;

"Thanks to this machine, we will know quite soon which option – Higgs boson, or not – is realised in nature. If you are curious about the universe we live in, the prospect is pretty tasty either way. The Higgs boson is a long-searched-for prediction of the "standard model" of particle physics. Should it exist, it is responsible for the mass of the fundamental particles we are all made of, such as electrons and quarks. Its discovery would be a stunning vindication that our aesthetics and mathematics are genuinely connected with how the universe really operates. If it doesn't exist, then in a sense it's back to the drawing board: it would mean our understanding of nature has failed at the energies accessible at the LHC. We would have to learn some new tricks."

The quote that really caught my eye though was Butterworth's elaboration of the title of this post:

"It is worth being wrong in public sometimes. We should all know that science is a betting system, not a belief system. Near-certainty arises from a morass of uncertainty, it does not drop from heaven gift-wrapped. "

And now back to holding our breath ahead of the CERN press seminar ....


Wednesday, 7 December 2011

Has the LHC found the Higgs?

The science blogosphere has been alive with rumours for the past few days suggesting that the large Hadron Collider may have found strong evidence for the Higgs boson. Staff have been notified that a press conference is being held on 13 December, with updates being given from the research groups associated with the two main detectors at the LHC - ATLAS and the CMS.

The rumours are centred on evidence of the Higgs being located at low mass ranges - around 125-126 GeV.

The rumours have become so strong that John Ellis, Clerk Maxwell Professor of Theoretical Physics at King's College London, was quoted today on the BBC, saying that he's expecting to see "the first glimpse of the Higgs next week:

"I think we are going to get the first glimpse. The LHC experiments have already looked high and low for this missing piece. It could be that it weighs several hundred times the proton mass, but that seems very unlikely, then there's a whole intermediate range where we know it cannot be, then there's the low mass range where we actually expect it might be. There seem to be some hints emerging there... and that's what we're going to learn on Tuesday".

Ian Sample provided a useful update of the various positions and murmurings here.


Friday, 18 November 2011

Is the wavefunction physically real?

Fundamental physics is having a big week! This week Eugenie Reich at Nature reported on a paper that's sending shockwaves through the quantum physics world. Physicists including by Matthew Pusey at Imperial College London, are daring to imagine that the staple of quantum theory - the wavefunction - might be a little bit more real that physicists had previous believed.

As Reich outlines:
"At the heart of the weirdness for which the field of quantum mechanics is famous is the wavefunction, a powerful but mysterious entity that is used to determine the probabilities that quantum particles will have certain properties. [....] Whereas many physicists have generally interpreted the wavefunction as a statistical tool that reflects our ignorance of the particles being measured, [Pusey & co] argue that, instead, it is physically real."

“I don't like to sound hyperbolic, but I think the word 'seismic' is likely to apply to this paper,” says Antony Valentini, a theoretical physicist specializing in quantum foundations at Clemson University in South Carolina.

Source: &

Thursday, 10 November 2011

20Hz by Semiconductor

One of the works commissioned for the Invisible Fields: Geographies of Radio Waves exhibition in Barcelona was 20 Hz, an amazing new piece by Brighton-based artists and filmmakers, Semiconductor.

Semiconductor were commissioned to make a piece which showed us the relationship between radio waves and sound. The resulting work - 20 Hz - is an astonishing 5 minute video which uses data collected by the CARISMA radio array. CARISMA (Canadian Array for Realtime Investigations of Magnetic Activity) is is an array of magnetometers which study the Earth’s magnetosphere. 20 Hz is an interpretation of a magnetic storm occurring in the Earth’s upper atmosphere. The CARISMA data – captured at the frequency of 20 Hertz – is interpreted as audio, allowing us to hear the “tweets” and “rumbles” caused by the interaction of solar wind with the Earth’s magnetosphere. The visual element of the film is generated directly by the sound. Tangible and sculptural forms emerge suggestive of scientific visualisations. As different frequencies interact both visually and aurally, complex patterns emerge to create interference phenomena that probe the limits of our perception.

You can watch it at the artists’ website here.

Invisible Fields: Geographies of Radio Waves is a show that explores how our understanding of our world and our cosmos has been transformed by the study of radio waves. It is showing at Arts Santa Mònica in Barcelona, from 14 October 2011 - 4 March 2012.


Tuesday, 25 October 2011

Invisible Fields: Geographies of Radio Waves

Wireless in the World by Timo Arnall, showing at Invisible Fields.

Last week a new exhibition exploring the radio spectrum - the invisible environment that underpins contemporary technology - opened at Arts Santa Mònica in Barcelona. Mixing science, politics, architecture, design and art, Invisible Fields sets out the spectrum as a physical space, invisible but present, a terrain that can be studied, mapped, surveyed and explored.

It is co-curated by Spanish researcher and curator, José Luis de Vicente and Particle Decelerator's Honor Harger, and is a co-production of Arts Santa Mònica and Lighthouse in the UK (where Honor works).

The exhibition illustrates how artists, designers and activists have worked in tandem with scientists and researchers to illuminate some of most important characteristics of this intangible ecology. It includes well-known artists such as Rafael Lozano-Hemmer, Trevor Paglen, Semiconductor, and Joyce Hinterding, as well as designers including Timo Arnall (of super-design form, BERG) and Anthony DeVincenzi (of the MIT Media Lab), and interventions from astrophysicists, engineers and hackers.

Invisible Fields shows how radio space is an environment made of signals and waves from nature, and from us. Its topography is formed of waves of different scales, from tiny emissions given off by domestic objects to vast emissions made by distant astronomical phenomena. It's made up of signals that are very familiar, such as television and radio, to the esoteric and enigmatic signals. It is an ecology that has public spaces - wireless internet and amateur radio - and secret spaces - coded military transmissions and clandestine signals.

This kind of interdisciplinary exploration of a topic such as the radio spectrum, is rarely undertaken by cultural institutions. With the exception of visionary galleries such as The Science Gallery in Dublin, few arts organisations are open to the idea of exhibitions which blend artistic practice, social-cultural analysis, and science communication. This makes the Laboratory space of Arts Santa Mònica, directed by Josep Perelló, very special, and well worth keeping an eye on.

A catalogue is being produced featuring guest essays by guest essays by Douglas Kahn, Adam Greenfield, Martin Howse. The catalogue, pub;lished by ACTAR, is released in three editions - English, Spanish and Catalan.
There's an online preview of the catalogue here.

Invisible Fields is showing at Arts Santa Mònica in Barcelona, from 14 October 2011 - 4 March 2012.


Sunday, 17 July 2011

Largest Radio Telescope Ever Launched into Space is Set to Go


Exciting news in the world of radio astronomy this week, as several sources confirm that the long awaited Russian space telescope, RadioAstron, is due to launch on 18 July from Kazakhstan's Baikonur cosmodrome.

RadioAstron (pictured at Baikonur) will orbit the earth, and using interferometry, will become the the largest radio telescope ever built, with an observing area almost 30 times the Earth's diameter.

"There has never been a radio telescope that has been sent so far from the Earth," commented Yuri Kovalev, of Lebedev Physical Institute's Astro Space Center in Moscow, Russia, the managers of the project.

When it reaches an orbit that will extend almost as far as the moon, it will begin coordinating observations with telescopes on the ground, including the 100 metre radio telescopes in Green Bank, West Virginia, and Effelsberg, Germany, and the world's largest dish, the 305 metre Arecibo telescope in Puerto Rico.

The technique of interferometry is commonly used in radio astronomy. It involves linking telescopes from across the world in simultaneous observations of a single astronomical target. It is the basis for the Square Kilometre Array (SKA), which is being hailed - alongside the LHC - as one of the great science endeavours of the early 21st Century. Particle Decelerator reported on the SKA in April.

RadioAstron's principle science objective is to study the super massive black hole at the centre of Messier 87, a nearby galaxy. It will also be observing pulsars - spinning neutron stars - attempting to help astronomers understand how dust and gas is distributed around stars. But perhaps the most fascinating phenomena that RadioAstron will examine is natural masers. In electronics, a maser - "microwave amplification by stimulated emission of radiation" - is a device that amplifies electromagnetic waves. But masers occur in nature as well. Natural masers are found in outer space when water or other substances are excited by radiation from a star or by the energy of a collision.

As Rachel Courtland explains in New Scientist, RadioAstron "will also be able to register the radio waves emitted by water masers, clouds of water molecules that emit microwave radiation, in the discs of galaxies. This motion can be used to study the rotation rate of the galaxies and measure their distance from Earth. When combined with observations of how fast the galaxies are moving, astronomers can use the galaxy distances to calculate the present-day expansion rate of space and the effect of dark energy."

Conceived in Soviet times, RadioAstron has been delayed multiple times over the past two decades, so it's launch is being met with excitement and relief within the international radio astronomy community. The rocket carrying RadioAstron is due for launch from Baikonur at 0231 GMT on 18 July 2011.


Dark Energy Lurking in the Cosmic Background?

Two new papers published in the Physical Review Letters appear to provide new evidence for the existence of dark energy – the mysterious substance that appears to be accelerating the expansion of the universe. A team of astronomers at the University of California, Berkeley have found what they refer to as "direct evidence" for dark energy within the cosmic microwave background (CMB).

Science writer, Colin Stuart explains:

"The CMB is the faint afterglow of the universe's birth in the Big Bang. Around 400,000 years after its creation, the universe had cooled sufficiently to allow electrons to bind to atomic nuclei. This "recombination" set the CMB radiation free from the dense fog of plasma that was containing it. Space telescopes such as WMAP and Planck have charted the CMB and found its presence in all parts of the sky, with a temperature of 2.7K. However, measurements also show tiny fluctuations in this temperature on the scale of one part in a million. These fluctuations follow a Gaussian distribution."

Sudeep Das and his colleagues at the University of California, Berkeley, used the Atacama Cosmology Telescope in Chile to uncover fluctuations in the CMB that deviate from this Gaussian distribution. "On average, a CMB photon will have encountered around 50 large-scale structures before it reaches our telescope," Das told Physics World.

"The gravitational influence of these structures, which are dominated by massive clumps of dark matter, will each deflect the path of the photon," he adds. This process, called "lensing", eventually adds up to a total deflection of around 3 arc minutes – one-20th of a degree.

Stuart elaborates further:

"In the second paper Das, along with Blake Sherwin of Princeton University and Joanna Dunkley of Oxford University, looks at how lensing could reveal dark energy. Dark energy acts to counter the emergence of structures within the universe. A universe with no dark energy would have a lot of structure. As a result, the CMB photons would undergo greater lensing and the fluctuations would deviate more from the original Gaussian distribution. However, the opposite was found to be true. "We see too little lensing to account for a universe with no dark energy," Sherwin told "In fact, the amount of lensing we see is consistent with the amount of dark energy we would expect to see from other measurements."

This is the first time dark energy has been inferred from measurements of the CMB alone.

The fact that this is direct evidence, rather than relying on a second measurement, excites Stephen Boughn, a cosmologist at Haverford College in the US. "We currently only have two pieces of direct evidence for dark energy. Any additional evidence that indicates its existence is very important," he says. "We want a patchwork of evidence, from many different places, just to make sure the whole picture hangs together. This work helps with that."


Saturday, 25 June 2011

Particle physics wind chime


Continuing our theme of sonification, particle physicist Matt Bellis is one of a group of scientists who have created a novel way of transforming particle detectors into musical instruments. The Particle Physics Windchime is a computer application that takes particle physics data, such as particle type, momentum, distance from a fixed point, and other datasets, and turns it into sound. First conceived at the Science Hack Day in San Francisco in 2010 by Bellis and fellow scientist, David Harris, the Windchime is currently sonifying data from BABAR, a high energy physics experiment located at SLAC National Accelerator Laboratory in California.

In creating their instrument, Bellis and his collaborators were inspired by the way that wind chimes work. Their chime is played by the particles passing through it, just like wind through a wind chime. "Think of it," Bellis said in a recent interview with SLAC, "the wind itself makes no sound. You hear the wind if it rustles the leaves in a tree. The motion of the wind itself doesn't necessarily make a sound. The wind has to interact with something to make noise." In the same way, "When you have these particles that pass through the detector, they send it ringing, resonating."

Bellis emphasises that sonifying data in this way can help lead to important new scientific insights: "I wanted to create the Particle Physics Windchime partly because I wanted to see if there's something new we can learn from the data. Is there something I can hear in the data that I can't see or that a computer can't pick up? Will it add to an intuitive understanding of the data?"

The Particle Physics Windchime is by no means the only project that sonifies particle physics data in order to understand it in new ways. The LHC Sound Project has been converting data from the ATLAS experiment at CERN for the last two years.

Run by Lily Asquith, Richard Dobson, Archer Endrich and Alabama 3 percussionist, Sir Eddie Real, the project is helping scientists see data from the LHC in different ways. The scientists and composers have notes in several interviews how musical the data appears to be:

"We can hear clear structures in the sound, almost as if they had been composed. They seem to tell a little story all to themselves. They're so dynamic and shifting all the time, it does sound like a lot of the music that you hear in contemporary composition," Richard Dobson (in an interview with the BBC, June 2010).



A history of the universe in sound


Our Particle Decelerator correspondent gives a TED talk on the story of the history of the universe by listening. It's punctuated by three anecdotes which show how accidental encounters with strange noises, taught us some of the most important things we know about space ...

Whilst the talk refers to "sounds from space", it is important to emphasise that stars and planets are not directly audible. Sound waves can not propagate in the vacuum of space. However, it is possible for radio waves emitted from celestial bodies to be heard by using radio technology.

The talk recalls the early history of the science of radio astronomy. Before astronomy was computerised, radio astronomers would monitor radio telescopes by listening. In our solar system, the Sun is the strongest source of radio waves, so it's the most powerful transmitter in our radio sky. Jupiter also sends us strong, and beautifully varied, radio signals. And radio astronomers also detect radio waves from far-flung celestial bodies in the distant universe, and simple audification techniques allow us to hear these signals.


Saturday, 4 June 2011

Uncertainty isn't what it used to be


One of the central planks of quantum mechanics was this week called into question in a new take on the classic two-slit experiment.

One of the central notions in quantum mechanics is that light and matter can behave as both particle and wave. The principle of "complementarity" has always been understood to prevent the observation of both behaviours simultaneously. However, new research published in Science on 2 June, suggests that physicists at the University of Toronto and Griffith University in Brisbane have for the first time observed both behaviours at the same time.

In Thomas Young's 19th century "two-slit experiment", light is passed through two tiny holes and is then viewed on a screen. The two beams interfere with each other, forming a diffraction pattern, as if the light were made of waves. If one of the slits is blocked, the light can be seen as a single beam on the screen, as if light were made of particles. The two-slit experiment shows that, depending on how it's measured, a photon will act like either a particle or a wave, but never both.

Aephraim Steinberg of the University of Toronto and Sacha Kocsis of Griffith recreated this experiment, easily observing the interference pattern indicative of the wave nature of light. But significantly, they were also able measure the path of the particles of light.

Science reporter, Adrian Cho elaborates on the importance of their new research:
"For decades, [the] experiment has served as physicists' canonical example of the uncertainty principle: the law of nature that says you can't know both where a subatomic particle is and how fast it is moving, and thus can't trace its trajectory. But now physicists have tweaked that classic experiment to show that they can follow the average path taken by many particles."

Steinberg and his team allowed photons to pass through a calcite crystal which gave each photon a small deviation in its path. By measuring the light patterns on a camera, the team was able to deduce what paths the photons had taken. They clearly saw the interference pattern which infers the wave nature of light, but surprisingly they also could see from which slits the photons had come from, a telltale sign of the particle nature of light.

Marlan Scully, a quantum physicist at Texas University, commented:

"It's a beautiful series of measurements by an excellent group, the likes of which I've not seen before.",

"This paper is probably the first that has really put this weak measurement idea into a real experimental realisation." He said that the work would - inevitably - raise philosophical issues as well. "The exact way to think about what they're doing will be researched for some time, and the weak measurement concept itself will be a matter of controversy"

Professor Steinberg commented, "I feel like we're starting to pull back a veil on what nature really is".



Sunday, 15 May 2011

Sail to The Moon

In one of the more poetic and outlandish stories this week, The Observer report that engineers are planning to build the first extraterrestrial boat.

They want to launch the craft towards Titan - Saturn's largest moon - and parachute it on to the Ligeia Mare, a sea of methane and ethane on its surface.

Robin McKie, Science Editor of The Observer writes, "the robot ship would sail around this extraterrestrial sea for several months, exploring its coastline and measuring the winds and waves that sweep its surface."

Professor John Zarnecki, of the Open University is one of the scientists working on the project. "Waves on Titan's seas will be far larger, but much slower, than on earthly oceans, according to our calculations. That suggests Titan is the best spot in the solar system for surfing."

The mission to Titan - the only moon in the solar system with a thick atmosphere, of nitrogen and methane - would be the first exploration of a sea beyond Earth and could provide evidence about the possible existence of complex organic chemicals, the precursors of life.

It is part of the proposed Titan Mare Explorer, or TiME project.

If TiME is selected from a shortlist of three possible missions being considered for funding by NASA, McKie explains that "the TiME probe will be fired at Titan on a billion-mile journey across the solar system. Once it enters the moon's thick atmosphere the craft would parachute down towards the surface and then drop into the 300-mile-wide Ligeia Mare. It would then spend several months afloat on an oily sea taking measurements of waves, chemicals and other variables."

It follows on from the research undertaken by Cassini-Huygens. In 2005, the space-probe, Cassini deployed Huygens on the surface of Titan. Many of the instruments for that craft were built by Zarnecki and his Open University team, and that experience will put them in good stead for the TiME mission, should it go ahead.

Full story:

Source: Titan.pdf

&: SailtoThe Moon

Monday, 25 April 2011

Can bacteria transmit radio waves?


This week arXiv published a controversial abstract positing possible evidence for electromagnetic emissions from bacterial organisms.

Whilst seemingly outlandish, this isn't a new area research. Bacterial radio waves were theorised in 2009 by French virologist Luc Montagnier, who won the Nobel Prize for medicine in 2008 for the discovery of HIV.

Montagnier's highly controversial theory suggests that solutions containing the DNA of pathogenic bacteria and viruses, including HIV, could emit low frequency radio waves that induced surrounding water molecules to become arranged into nanostructures. These water molecules, he posited, could also emit radio waves. His research is summarised in this presentation paper.

But as Physics arXiv Blog at Technology Review points out, there are few more divisive figures than Montagnier, and his claims are flatly rejected by most mainstream biologists. PZ Myers memorably condemned the research as, "an awful paper that I would have shredded in a sea of red ink if it had come to me".

So what's new about the current arXiv report, and who would stick their neck out and be associated with furthering a theory that was met with such universal bile? Allan Windom is a theorist at Northeastern University in Boston who specialises in quantum field theory at the interface between high energy theory and condensed matter theory. Along with J. Swain, Y. Srivastava, and S. Sivasubramanian, he believes he may have solved one of the most controversial problems with Montagnier's theory, ie, there is no known mechanism by which bacteria can generate radio waves.

arXiv summarise their abstract (linked to below), as follows:

"Many types of bacterial DNA take the form of circular loops. So they've modelled the behaviour of free electrons moving around such a small loop, pointing out that, as quantum objects, the electrons can take certain energy levels. [They] calculate that the transition frequencies between these energy levels correspond to radio signals broadcast at 0.5, 1 and 1.5 kilohertz. And they point out that exactly this kind of signal has been measured in E Coli bacteria. [...] It is well known that bacterial and other types of cells use electromagnetic waves at higher frequencies to communicate as well as to send and store energy. If cells can also generate radio waves, there's no reason to think they wouldn't exploit this avenue too."

This is undoubtedly going to create a stir in the biological physics community, so stay tuned for more.


Friday, 22 April 2011

Electron beams link Saturn with Enceladus


More exceptionally exciting new research results from NASA's highly productive Cassini mission are being published in Nature this week.

A team of researchers, lead by University College London (UCL), have revealed that Enceladus, one of Saturn's diminutive moons, is linked to Saturn by powerful electrical currents - beams of electrons that flow back and forth between the planet and moon. The UCL announcement elucidates further:

"Since Cassini's arrival at Saturn in 2004 it has passed 500km-wide Enceladus 14 times, gradually discovering more of its secrets on each visit. Research has found that jets of gas and icy grains emanate from the south pole of Enceladus, which become electrically charged and form an ionosphere. The motion of Enceladus and its ionosphere through the magnetic bubble that surrounds Saturn acts like a dynamo, setting up the newly-discovered current system."

Scientists already knew that the giant planet Jupiter is linked to three of its moons by charged current systems set up by the satellites orbiting inside its giant magnetic bubble, the magnetosphere, and that these current systems form glowing spots in the planet's upper atmosphere. The latest discovery at Enceladus shows that similar processes take place at the Saturnian system too.

The detection of the beams was made by the Cassini Plasma Spectrometer's electron spectrometer, the design and building of which was led at UCL's Mullard Space Science Laboratory. UCL co-authors of the Nature paper, Dr Geraint Jones and Professor Andrew Coates, are delighted with this new finding.

Dr Jones said: "Onboard Cassini, only Cassini Plasma Spectrometer's electron spectrometer has the capability of directly detecting the electron beams at the energies they're seen; this finding marks a great leap forward in our understanding of what exactly is going on at mysterious Enceladus."

Professor Coates, added: "This now looks like a universal process - Jupiter's moon Io is the most volcanic object in the solar system, and produces a bright spot in Jupiter's aurora. Now, we see the same thing at Saturn - the variable and majestic water-rich Enceladus plumes, probably driven by cryovolcanism, cause electron beams which create a significant spot in Saturn's aurora too."


Monday, 4 April 2011

Jodrell Bank selected for Square Kilometre Array


Major news from the world of radio astronomy this week, as Jodrell Bank was chosen as the headquarters for the planning and construction of the long-awaited Square Kilometre Array radio telescope.

Set to be one of the great scientific endeavours of the 21st Century, the Square Kilometre Array (SKA) will be the world's largest and most sensitive radio telescope. Jodrell Bank beat off fierce competition from sites in Holland and Germany to be selected as the project headquarters. The SKA itself will be located in either Australia and New Zealand or Southern Africa.

The SKA will investigate fundamental unanswered questions about our Universe, including how the first stars and galaxies formed after the Big Bang, how galaxies have evolved since then, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth.

Jocelyn Bell Burnell, the eminent radio astronomer who discovered pulsars at Jodrell Bank in 1967 had this to say:
"The power of this new telescope project is going to surpass anything we've seen before, enabling us to see many more radio-emitting stars and galaxies and pulling the curtains wide open on parts of the great beyond that radio astronomers like me have only ever dreamt of exploring."

Steve Rawlings of Oxford University hopes it might explain dark energy:
"The Square Kilometre Array is a time machine. As you look out to greater distances you're seeing the universe as it was when it was younger, and so you can map out the expansion of the universe. Dark energy seems to accelerate that expansion and so we will be able to map out dark energy and perhaps discover what it is."

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. A large array is needed because the wavelength of radio waves is far greater than that of visible light. "In order to get the same level of detail as a good optical telescope you'd need something 100km across. Clearly you can't build a single telescope a 100km across, but what you can do is build a network of telescopes and link those telescopes together." Simon Garrington, of Jodrell Bank explains.

Set to cost an estimated 1.5 billion Euros, this huge endeavour involves more than 70 institutes in 20 countries. The total collecting area will be approximately one square kilometre giving 50 times the sensitivity of the best current-day telescopes.


Monday, 28 March 2011

special B mesons found at LHCb


Interesting news from the LHCb detector today. are carrying a story about group of scientists led by Syracuse University physicist, Sheldon Stone, who have apparently become the first to observe the decays of a rare particle - a special type of B meson - thought to be present right after the Big Bang. write:
"B mesons are a rare and special subgroup of mesons composed of a quark and anti-quark. While B mesons were common after the Big Bang, they are not believed to occur in nature today and can only be created and observed under experimental conditions in the LHC or other high-energy colliders.

Sheldon Stone comments: "We know when the universe formed from the Big Bang, it had just as much matter as antimatter. But we live in a world predominantly made of matter, therefore, there had to be differences in the decaying of both matter and antimatter in order to end up with a surplus of matter."

Because these particles don't play by the same rules of physics as most other matter, scientists believe B mesons may have played an important role in the rise of matter over antimatter. The particles may also provide clues about the nature of the forces that led to this lack of symmetry in the universe.

Sheldon Stone, notes on Physorg, "we want to figure out the nature of the forces that influence the decay of these particles. These forces exist, but we just don't know what they are. It could help explain why antimatter decays differently than matter."


Nature Network


Particle Decelerator has joined the Nature blogosphere.

As well as being a portal to the blogs written by Nature editors and journalists, Nature Blogs aggregates posts from science blogs. We're in the P section.


Tuesday, 8 March 2011

Is the Universe really cloaked in invisible cloth?


This week the science blogs have been alive with conflicting views about dark matter.

Dark matter is the invisible stuff that is supposed to make up around 20% of the Universe. But not everyone is willing to buy the idea that the Universe is cloaked in "invisible cloth." Proponents of an alternative, older theory, modified Newtonian dynamics (MOND), insist theories of dark matter, may simply have no clothes.

The latest MOND vs Dark Matter discussions have been promoted by the publication of a highly controversial paper by University of Maryland astronomer, Stacy McGaugh in the Physical Review Letters, which suggests that for galaxies, MOND fits the facts more reliably than theories of dark matter.

The Weizmann Wave - the blog of the Weizmann Institute, who came up with MOND in 1983 - immediately picked up on this: They wrote:

"Dark matter [...] was thought up to explain a puzzling observation. The amount of mass we can see through our telescopes is not enough to keep galaxies from spinning apart. The existence of great quantities of hidden mass would provide the gravitational pull needed to form those galaxies and enable them to rotate in the way that they do.
[But] an alternate theory, first put forward by Weizmann Institute astrophysicist Prof. Moti Milgrom in 1983, doesn't require dark matter to explain the phenomenon. Instead, it posits that gravity works differently on the intergalactic scale. With a good tweak to Newton's formula, the observed Universe falls into place. This is not the violation of a basic law of physics that it might appear: Milgrom points out that gravity works fine in our every-day world, but the formula breaks down at extremes - at the speed of light or in the sub-atomic world of quantum mechanics, for example. So super-galactic scales could be another case in which the rules of gravity simply don't apply quite as Newton wrote them.
While most are still waiting for the hunt for the mysterious dark matter to yield results, a growing minority of physicists are starting to admit that MOND (modified Newtonian dynamics) could provide a better explanation."

This view is deeply controversial. Many senior researchers were quick to criticise the media feeding frenzy which surrounded the publication of McGaugh's paper:

In an article on Cosmic Variance blog, Sean Carroll noted:

"McGaugh's new paper doesn't give any evidence at all against dark matter. What it does is to claim that an alternative theory - MOND, which replaces dark matter with a modification of Newtonian dynamics - provides a good fit to a certain class of gas-rich galaxies. That's an interesting result! Just not the result the headlines would have you believe"

In an illuminating post on Starts With a Bang, Ethan Siegel went one step further, concluding emphatically:

"MOND was designed to work for rotating galaxies. The problem is it doesn't do anything else. And its adherents never point to anything other than rotating galaxies to support it. [...] If you want to be taken seriously as a theory, you need to do more than just the one thing you were designed to do. [...] this isn't to say that MOND isn't an interesting idea, or that the people working on it are frauds. But what's being reported is grossly misleading at best, and blatantly dishonest at worst. General Relativity could still need fixing, and there could be something else going on with gravity beyond dark matter. But we still need dark matter -- or something heretofore indistinguishable from it -- to explain all our large-scale observations."

Phil Plait's analysis on the topic on his well known Bad Astronomy blog is pretty much summed up in the title - "Dark matter is alive and well, thankyouverymuch"

But this isn't a debate which is likely to go away any time soon, so keep an eye on Science blogs for the latest ripostes in the battle of theories.

Tuesday, 22 February 2011

An exquisite new instrument for listening to the Music of the Spheres

This week, the remarkable Kepler spacecraft has been in the news for the fascinating new research it is generating in detecting the size and age of stars. Kepler is using a technique that scientists dub "asteroseismology" to measure minuscule variations in a star's brightness that occur as sound-waves bounce within it.

Dr Bill Chaplin, Reader in Solar and Stellar Physics, from the University of Birmingham's School of Physics and Astronomy, spoke at the American Association for the Advancement of Science conference on Saturday 19 February 2011, giving an overview of results on the study of solar-type stars using the science of asteroseismology.

Asteroseismology is the observation of the natural resonances, or pulsations, of stars. Using the data from these oscillations, collected by the NASA Kepler spacecraft, it is possible to measure the ages and sizes of stars, and to map out their interiors with hitherto unknown precision. The Kepler Mission is primarily used to look for extrasolar planets - planets that are outside our solar system orbiting other stars, but this new finding is one of the most significant pieces of research is has yielded in recent times.

Chaplin told the conference that asteroseismology was, in essence, listening to the "music of the stars" - a somewhat poetically apt reference, given that the Kepler craft is named after the 17th century German mathematician and astronomer, Johannes Kepler who reinvigorated Pythagorus notion of the"music of the spheres".

For some time, I have been researching how radio astronomy, when used as an instrument of audification, can enable us to move closer to the "music of the spheres" ( But astroseismology is proving to be an equally powerful instrument in helping us appreciate the sonic character of our universe.


Network of radio astronomy dishes redrawing the map of our galaxy

It's been a big week for astronomy, with important new data revealing the scale of both stars and planets.

Science Daily reports on how the continent-wide Very Long Baseline Array (VLBA) - an international network of radio astronomy facilities - is redrawing the map of our home galaxy and is poised to yield tantalizing new information about extrasolar planets. Their work also has important implications for numerous areas of astrophysics, including determining the nature of dark energy, which constitutes 70 percent of the Universe.

"Solving the Dark Energy problem requires advancing the precision of cosmic distance measurements, and we are working to refine our observations and extend our methods to more galaxies," said James Braatz, of the National Radio Astronomy Observatory (NRAO).

The project uses the VLBA along with NRAO's Green Bank radio astronomy telescope in West Virginia, the largest fully-steerable dish antenna in the world. The VLBA, dedicated in 1993, uses ten, 25-meter-diameter dish antennas distributed from Hawaii to St. Croix in the Caribbean. All ten antennas work together as a single telescope with the greatest resolving power available to astronomy. Together, these telescopes can detect the faint radio emission from the stars to track their motion over time. This unique capability has produced landmark contributions to numerous scientific fields, ranging from Earth tectonics, climate research, and spacecraft navigation to cosmology.