Monday, 25 April 2011

Can bacteria transmit radio waves?

E_coli

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/

Friday, 22 April 2011

Electron beams link Saturn with Enceladus

Ucl_encel_beam_release_cropped

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

Monday, 4 April 2011

Jodrell Bank selected for Square Kilometre Array

Jodrell_bank_night_203x152

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

Monday, 28 March 2011

special B mesons found at LHCb

Lhcb_detector

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

Nature

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

Tuesday, 8 March 2011

Is the Universe really cloaked in invisible cloth?

Darkmatter

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" (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

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

Wednesday, 17 November 2010

Space-time cloak can edit history

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

Wednesday, 10 November 2010

The galaxy is full of fullerenes

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