Particle Decelerator

Largest Radio Telescope Ever Launched into Space is Set to Go

2011-07-17T21:09:00.003+02:00

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.

Source: http://www.asc.rssi.ru/radioastron/

http://www.federalspace.ru/main.php?id=2&nid=17486

http://wvgazette.com/News/201107120808

Dark Energy Lurking in the Cosmic Background?

2011-07-17T12:45:00.003+02:00

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 physicsworld.com. "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."

Source: http://physicsworld.com/cws/article/news/46572

Particle physics wind chime

2011-06-25T14:08:00.002+02:00

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).

Sources: https://news.slac.stanford.edu/features/ear-science-particle-physics-windchime-0

http://www.stanford.edu

A history of the universe in sound

2011-06-25T13:26:00.003+02:00

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.

Source: http://www.ted.com/talks/honor_harger_a_history_of_the_universe_in_sound.html

Uncertainty isn't what it used to be

2011-06-04T12:05:00.002+02:00

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".

Source: http://news.sciencemag.org

&
http://www.sciencemag.org/content/332/6034/1170.abstract

Sail to The Moon

2011-05-15T13:08:00.002+02:00

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: http://www.guardian.co.uk

Source: Titan.pdf

&: SailtoThe Moon

Can bacteria transmit radio waves?

2011-04-25T16:05:00.003+02:00

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.

Source:
http://arxiv.org/abs/1104.3113
http://www.technologyreview.com/blog/arxiv/26670/

Electron beams link Saturn with Enceladus

2011-04-22T17:47:00.002+02:00

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."

Source: http://www.ucl.ac.uk/news/news-articles/1104/11042001

Jodrell Bank selected for Square Kilometre Array

2011-04-04T21:02:00.002+02:00

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.

Sources:
http://www.skatelescope.org
http://www.bbc.co.uk/news/science-environment-12891215

special B mesons found at LHCb

2011-03-28T17:09:00.001+02:00

Interesting news from the LHCb detector today. Physorg.com 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.

Physorg.com 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."

Source: http://www.physorg.com/news/2011-03-physicists-rare-particles-large-hadron.html

Nature Network

2011-03-28T15:56:00.002+02:00

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.

Source: http://blogs.nature.com/blogs/atoz/P

Is the Universe really cloaked in invisible cloth?

2011-03-08T21:59:00.002+01:00

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.

cf: https://www.newsdesk.umd.edu

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."

cf: http://scienceblogs.com/weizmann

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"

cf. http://blogs.discovermagazine.com/cosmicvariance

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."

cf: http://scienceblogs.com/startswithabang

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"

cf: http://blogs.discovermagazine.com/badastronomy

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.

Other sources: http://news.sciencemag.org

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

2011-02-22T00:31:00.003+01:00

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" (http://radioqualia.va.com.au/honor/research.html). But astroseismology is proving to be an equally powerful instrument in helping us appreciate the sonic character of our universe.

Sources:
http://v.gd/kepler
http://is.gd/chaplin

Network of radio astronomy dishes redrawing the map of our galaxy

2011-02-22T00:11:00.002+01:00

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.

Source: http://www.sciencedaily.com

Space-time cloak can edit history

2010-11-17T10:45:00.003+01:00

One of the central planks of science-fiction, the invisibility cloak, has taken one step closer to becoming reality, according to extraordinary new research revealed today in the Journal of Optics. And it isn't just matter it can render invisible, but entire tracts of history.

The "space-time cloak" is a device conceived by Martin McCall, an optical physicist at Imperial College London. It generates a pocket in reality in which actions can be concealed. Unlike "standard" invisibility cloaks, which bend light around an object, a space-time cloak would open up a time gap in the light by controlling its speed through optical fibres, and then seal it again to hide all traces of activity within the gap.

"I realised that it may be possible to use metamaterials to bend light rays in both space and time, not just in space," says Martin McCall, in Nature. "This would add a new dimension to the invisibility cloak - literally."

"You could imagine a burglar using a space-time cloak to create an invisible corridor leading to a safe," says McCall. With the cloak turned on, the burglar could run through this corridor, open the safe, steal the contents, shut the safe and escape, while any security camera trained on the safe would just show a continuous image of a locked door at every point in time, explains McCall. "The dastardly event would have been edited from history," he says.

Nature go on to explain that the key feature of the proposed space-time cloak is that its refractive index - the optical property that governs the speed of light within a material - is continually changed, pulling light rays apart in time. When the leading edge of a light wave hits the cloak, the material is manipulated to speed up the light, but when the trailing edge hits, the light is slowed down and delayed. "Between these two parts of the light, there will be a temporal void - a space in which there will be no illuminating light for a brief period of time," explains McCall.

McCall hopes that a fibre-optic cloak creating a space-time void around 30 centimetres long, to hide actions taking place over a few nanoseconds, could be built within the next year.

Source: http://www.nature.com

http://iopscience.iop.org

The galaxy is full of fullerenes

2010-11-10T10:18:00.002+01:00

Last week, the Astrophysical Journal Letters published an interesting finding from astronomers working with NASA's Spitzer Space Telescope. It appears that fullerenes (aka buckyballs) are far more widespread in our galaxy than what we thought. The discovery has lead some astronomers to speculate that the spherical carbon molecules may have even seeded life of earth.

Astronomers found fullerenes in staggering quantities throughout the Milky Way, in the space between stars and around dying stars. Fullerenes are molecules consisting of 60 linked carbon atoms. They are also known as buckyballs, so named for their resemblance to the architect Buckminster Fuller's geodesic domes.

As NASA report: "The miniature spheres were first discovered in a lab on Earth 25 years ago, but it wasn't until this past July that Spitzer was able to provide the first confirmed proof of their existence in space. At that time, scientists weren't sure if they had been lucky to find a rare supply, or if perhaps the cosmic balls were all around."

"It turns out that buckyballs are much more common and abundant in the universe than initially thought," said astronomer Letizia Stanghellini of the National Optical Astronomy Observatory in Tucson. "Spitzer had recently found them in one specific location, but now we see them in other environments. This has implications for the chemistry of life. It's possible that buckyballs from outer space provided seeds for life on Earth."

Source:
http://www.spitzer.caltech.edu/news/1212-feature10-18 http://www.jpl.nasa.gov/news/news.cfm?release=2010-351

Radio astronomers find the largest-ever pulsar

2010-10-27T23:23:00.002+02:00

Major news from the National Radio Astronomy Observatory today as reports emerge that radio astronomers have discovered the most massive pulsar yet found. The giant neutron-star is almost twice the mass of the sun, and it's discovery will have strong and wide-ranging impacts across several fields of physics and astrophysics.

Pulsars are spinning neutron-stars. They are the radiophonic clocks of the universe, emitting a steady pulse of radio waves with each rotation, which can be detected here on Earth using radio telescopes like the Green Bank Telescope (GBT). This most recent addition to the pulsar family is known as J1614-2230, and is located about 3,000 light-years away in the direction of the constellation Scorpio. It is nearly 20% more massive than any previously measured star of its class, and is rotating at an incredible speed, completing 317 rotations every second.

Described, rather poetically, by the National Radio Astronomy Observatory as "the superdense corpses of massive stars that have exploded", neutron-stars have long been known to be ideal natural laboratories for studying the most dense and exotic states of matter known to physics. With all their mass packed into a sphere the size of a small city, their protons and electrons are crushed together into neutrons. A thimbleful of neutron-star material would weigh more than 500 million tons.

Discovering a neutron-star as large as J1614-2230 has come as a major surprise to astrophysicists. It's not just it's sheer size that's causing a flurry, it's the implications for our understanding of what pulsars are made of. Most existing computer models can not account for neutron-stars bigger than 1.5 times the mass of the sun without resorting to modelling the star using exotic particles. But initial measurements of J1614-2230 seem to indicate that this giant amongst neutron-stars is made up of just that - neutrons - rather than the exotic matter, such as hyperons, that many theories have predicted. Paul Demorest of the National Radio Astronomy Observatory believes their discovery "weakens the possibility that neutron stars are made from anything other than neutrons".

Source: http://www.nrao.edu/pr/2010/bigns/ http://www.nature.com/nature/journal/v467/n7319/full/nature09466.html

Artists Use Augmented Reality to Hack Public Space

2010-10-23T13:54:00.003+02:00

Augmented reality technology is starting to mature, creating increasing complex and imaginative sedimentary layers onto our lived environment.

We can see this in the emergence of urban augmented reality projects, which explore what Bruce Sterling refers to as "atemporality" - where the past, present and the future collide in a collaged moment.
Among the leading applications in this field are the likes of The Museum of London's "Streetmuseum" app and Sarah & Arthur Cox's "A Time Traveller's Guide".

Alongside these attempts to overlay the present with the past, is a trend amongst artists to augment - or improve - our cities' often overly commercial facades. One such example is the art project, "The Artvertiser", created by Berlin-based New Zealander, Julian Oliver. It imagines a near-future where advertising in public space can be replaced by art. It consists of custom-made handheld binocular devices and specially designed software. The Artvertiser considers Potsdamer Platz in Berlin, Puerta del Sol in Madrid, Times Square in New York, and other sites dense with advertisements, as potential exhibition space. The Artvertiser software recognises individual advertisements, each of which become a virtual 'canvas' displaying artworks when viewed through the Artvertiser binoculars. The Artvertiser allows artists to create a new visual layer onto the topology of the city, which can only be seen when viewed through a device which cogently blends the aesthetics of the past, with a futuristic functionality.

A number of other artists are also using augmented reality to allow the public to subvert or remove the logos and adverts that are all around us. The New Scientist recently reported on the work of US artists Mark Skwarek and Jeff Crouse, alongside Julian Oliver's work. The article notes:

"New York artist Jeff Crouse has designed a program called Unlogo, which detects corporate logos in a video stream, then replaces them [...] Mark Skwarek, is using AR to make a political point about the Gulf of Mexico oil spill. The Leak in your Home Town is a smartphone app that overlays an animation of a leaking oil pipe over BP logos in gas stations or on billboards. [He] describes it as a kind of benign graffiti."

"Technology-inspired artists have designed ways for you to mask or perhaps even delete company logos in your field of view as you wander around a city or shopping centre."

Sources:
http://theartvertiser.com
http://www.newscientist.com

http://www.atimetravellersguide.com/

Listen to the Deep Ocean - live!

2010-10-11T09:27:00.002+02:00

Last year, we reported on research published in Nature that showed how marine biologists were working hand-in-hand with physicists to use bio-acoustics technology for the dual purpose of monitoring marine live, and searching for neutrinos.

The recently launched Listening to the Deep Ocean Environment (LIDO) website takes this collaborative approach one step further. Michel André, a bioacoustician at the Technical University of Catalonia in Barcelona, Spain, and his colleagues, have spent the past 10 years placing hydrophones on the seabed, on existing research platforms that monitor earthquakes, tsunamis and detect neutrino particles from space.

They are studying sub-sea noise so that researchers can better understand the effects of human activity on whales and dolphins. But what's really extraordinary about their work is that they're allowing us to tune in. The LIDO website has links to live audio feeds from eleven hydrophones located in European waters, and North American waters.

André, quoted in the New Scientist, notes: "the system is powered from the shore, and streams audio data to a server where the signals are analysed and published directly on the internet."

With more hydrophones in the network the new system could reveal the effects of noise pollution on whales. Hydrophones can pick up sounds from baleen whales hundreds of kilometres away, so installations in different places could be used to triangulate an animal's position and track its course. It should therefore be possible to determine if animals change course in response to bursts of noise, or alter their preferred routes because of new sources of noise like shipping routes or harbours.

"It's the first time we have been able to monitor acoustic events on a large temporal and spatial scale," André says

An algorithm developed by André's laboratory filters the different frequencies in the signal to identify specific sounds, including the songs of 26 species of whales and dolphins, and noise from human activities such as shipping, wind farms, oil and gas drilling, and seismic testing.

Roger Gentry, an adviser for the E&P Sound and Marine Life Joint Industry Programme, comments that, "[Michel] André deserves a lot of credit for thinking in broad terms and using modern technology to make the oceans and marine mammals more familiar and accessible to us all."

André is a previous Rolex award-winner, acknowledged for his work designing a system to protect whales from collisions with ships: http://rolexawards.com/en/the-laureates/michelandre-biography.jsp

Sources:

http://listentothedeep.net
http://www.newscientist.com

A drop in the ocean - the Census of Marine Life reveals we've only just begun

2010-10-06T11:14:00.002+02:00

This week in London, the Census of Marine Life reported on their ten-year quest to count and document life in the world's oceans.

The discoveries made over the past decade have inspired, surprised and delighted all of us who have been following the work of this epic project, which has dramatically expanded our understanding of the underwater realm. But the Census team ended their work on a humble note, stressing that despite ten years of work, and the coordinated global effort of over 2,700 scientists from more than 600 institutions, who examined every oceanic body on the planet, during 9,000 days at sea on more than 540 expeditions, they have barely scratched the surface of the diversity and strangeness of life in the sea.

"There's a lot of ocean left to explore", says environmental scientist and Census cofounder, Jesse Ausubel.

Dr. Ian Poiner, chair of the Census Steering Committee, underscored the importance of this vast body of research by noting:

"All surface life depends on life inside and beneath the oceans. Sea life provides half of our oxygen and a lot of our food and regulates climate. We are all citizens of the sea. And while much remains unknown, including at least 750,000 undiscovered species and their roles, we are better acquainted now with our fellow travelers and their vast habitat on this globe."

Science News gets to grips with the scale of the work still to do, by observing that according to the Census summary, the tally of 16,764 marine fish species formally named as of early 2010 probably falls short by an estimated 5,000 species. And fish aren't the half of it. They're perhaps 12 percent of the total of marine species, according to the census estimates. Fishes trail after crustaceans and mollusks in number of species, and researchers report evidence of major undercounts in the numbers of recorded species for these other groups too. Overall at least 750,000 marine species, not including microbes, still await discovery, the census teams predict. In the seas, the mysteries easily outnumber known species, now estimated at 250,000.

Deep waters below 200 meters are so under-explored that their life forms constitute "biodiversity's big wet secret," says the census's chief scientist, Ron O'Dor of Dalhousie University in Halifax, Canada. Fewer than 10 percent of records of marine life come from the zone of abyssal plains between 4,000 and 5,000 meters deep, yet that zone accounts for half the oceans' area.

Sources: http://www.sciencedaily.com/releases/2010/10/101004101319.htm
http://www.sciencenews.org/view/generic/id/64013/description/Massive_count_a_...

Information Physics - The New Frontier?

2010-10-04T11:05:00.002+02:00

As classical reductionist physics collides with the quantum brick wall, an information systems model of our universe seems to be emerging. A recent abstract published on arXiv by Professor Kevin Knuth, from the Information Physics Laboratory at the University at Albany in Albany in New York, articulates ways that "Information Physics" may be a new technique to derive new physical laws.

In this seemingly controversial abstract, Knuth writes:

"At this point in time, two major areas of physics, statistical mechanics and quantum mechanics, rest on the foundations of probability and entropy. The last century saw several significant fundamental advances in our understanding of the process of inference, which make it clear that these are inferential theories. That is, rather than being a description of the behavior of the universe, these theories describe how observers can make optimal predictions about the universe. In such a picture, information plays a critical role. What is more is that little clues, such as the fact that black holes have entropy, continue to suggest that information is fundamental to physics in general.

In the last decade, our fundamental understanding of probability theory has led to a Bayesian revolution. ...I will introduce [a] new way of thinking by demonstrating how one can quantify partially-ordered sets and, in the process, derive physical laws. The implication is that physical law does not reflect the order in the universe, instead it is derived from the order imposed by our description of the universe. Information physics, which is based on understanding the ways in which we both quantify and process information about the world around us, is a fundamentally new approach to science."

Source: http://arxiv.org/abs/1009.5161

Science & science fiction: two worlds meet

2010-10-02T14:20:00.002+02:00

"This is the future really ... The 21st century is going to be full of developments like this."
Bruce Sterling, interviewed by Euronews in September 2010.

Euronews have just released a short documentary exploring the intersection between science and science fiction. It is online in various languages, here:

http://www.euronews.net/2010/09/30/science-and-science-fiction-two-worlds-meet/

The documentary takes Europe's Museum of Science Fiction (Maison d'Ailleurs: http://www.ailleurs.ch) as a case study, focusing on their collaborations with science institutions such as the European Space Agency, and their recent exhibition of robotic art by Ken Rinaldo.
It analyses how engineers and scientists have taken inspiration for important research and inventions from imaginative stories and artistic work created throughout the 19th and 20th century. The documentary reveals that much of what used to be considered science fiction - from the imagined worlds of Jules Vernes and Arthur C Clarke, to futuristic machines and journeys into space - is now reality.

The documentary features interviews with writers, Alastair Reynolds and Bruce Sterling, artist, Ken Rinaldo and the director of the museum, Patrick Gyger.

Source: http://www.euronews.net

The Micronium - The World's Smallest Musical Instrument

2010-09-30T10:05:00.002+02:00

Musician Tony Conrad is quoted as saying, "modern physics had been generated as a branch of music" (http://bit.ly/fBUSe). New research carried out by the University of Twente seems to bear this out, with engineers and physicists creating the world's smallest musical instrument.

The micronium is the first musical instrument with dimensions measured in mere micrometres that produces audible tones. It has strings a fraction of the thickness of a human hair, with microscopic weights to pluck them: A composition has been specially written for the instrument by Arvid Jense, who is studying MediaMusic at the conservatorium in Enschede.

Science Daily notes that earlier musical instruments with these minimal dimensions only produced tones that are inaudible to humans. But thanks to ingenious construction techniques, students from the MESA+ Institute for Nanotechnology of the University of Twente in The Netherlands have succeeded in producing scales that are audible when amplified. To do so, they made use of the possibilities offered by micromechanics: the construction of moving structures with dimensions measured in micrometres. These miniscule devices can be built thanks to the ultra-clean conditions in a 'clean room', and the advanced etching techniques that are possible there.

The micronium played a leading role at the opening of a two-day scientific conference on micromechanics at Atak (http://www.atak.nl) in Enschede in September, where Arvid Jense's composition,'Impromptu No. 1 for Micronium', was premiered.

The tiny musical instrument is made up of springs that are only a tenth of the thickness of a human hair, and vary in length from a half to a whole millimetre. A mass of a few dozen micrograms is hung from these springs. The mass is set in motion by so-called 'comb drives': miniature combs that fit together precisely and shift in relation to each other, so 'plucking' the springs and creating sounds. The mass vibrates with a maximum deflection of just a few micrometres. This minimal movement can be accurately measured, and produces a tone. Each tone has its own mass spring system, and six tones fit on a microchip. By combining a number of chips, a wider range of tones can be achieved.

"The tuning process turned out to be the greatest challenge," says Johan Engelen, who devised and led the project.

Source: http://www.sciencedaily.com/releases/2010/09/100928083836.htm

New Zealand physicists make a major breakthrough

2010-09-27T12:45:00.001+02:00

Exciting news from Dunedin today, as several news agencies report that University of Otago scientists have made a "major physics breakthrough". The Dunedin-based scientists are the first in the world to consistently isolate and capture a single atom, and the first to take its photograph. The atom is Rubidium 85.

Their discovery has defied accepted science and might help turn the building blocks of life into ultrafast quantum-logic computers, which are still being developed. Mikkel Andersen, Tzahi Grunzweig, Andrew Hilliard and Matt McGovern started work on the project three years ago. They captured their first atom on January 26, but took another four days to accept what had happened.

In their step towards creating what they call a "kind of atomic romance", a team used laser cooling technology to slow a group of atoms, before a laser beam, or "optical tweezers", isolated and held one atom. "What we have done moves the frontier of what scientists can do and gives us deterministic control of the smallest building blocks in our world." Dr Mikkel Andersen said.

"Our method provides a way to deliver those atoms needed to build this type of computer, and it is now possible to get a set of ten atoms held or trapped at the one time [...] You need a set of 30 atoms if you want to build a quantum computer that is capable of performing certain tasks better than existing computers, so this is a big step towards successfully doing that."

Sources: http://www.stuff.co.nz/science/4170693/Kiwi-scientists-make-atomic-breakthrough & http://is.gd/fvptS

Cassini dives inside Saturn's radio aurora

2010-09-26T16:24:00.002+02:00

NASA have produced stunning new images and video of Saturn's shimmering aurora. The images are helping scientists understand what drives some of the solar system's most impressive light shows.

Auroras happen when charged particles are funneled along converging magnetic field lines and into the upper atmosphere of a planet's poles. On Earth, aurora are caused mainly by the solar wind. But on Saturn a complex mixture of other geomagnetic phenomena appear to be involved. For instance, auroras can be caused by electromagnetic waves generated when the Saturn's moons move through the plasma that fills it's magnetosphere.

"Saturn's aurora are very complex and we are only just beginning to understand all the factors involved," said Dr Tom Stallard, from the University of Leicester, who presented some preliminary findings from the images at the European Planetary Science Congress in Rome.

Source: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20100923b/