Thursday, 28 February 2013

D mesons flipping

The magnet at the LHCb detector

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

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

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

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

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

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

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

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

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


Monday, 25 February 2013

Ensonifying space

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

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

One of the pieces draws on an interview with radio astronomer, and the co-founder of the SETI Institute, Jill Tarter. Amplifying the central message of  Tuning into the Universe, Tarter notes that:
"when SETI listens to the cosmos, the institute is actually receiving electromagnetic radiation. And then, just the way your radio does, that energy can be used to make audible sound."

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

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

Voices Carry by Anna Leahy and Douglas Dechow explores the sonic signature of our own planet:
"The sound of the Earth's inherent dynamics -- the movement of atmosphere and oceans -- produces a steady drone as well. Lightning produces crackling, which scientists call sferics."

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

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

Jerry L. Ross n one of his nine spacewalks.

He writes eloquently about the silence which astronauts experience, when outside the International Space Station:
"Without the sophisticated listening devices scientists use on earth to hear the whispers of the universe, to an astronaut space is infinite quiet, a place where we bring the only sounds that break the silence."

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

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

In Understanding the Sound of Space, Ayodele Faiyetole notes that sound is under used in science.  He draws on an interview with cosmologist, Yuko Takahashi, who believes there's a great value in presenting scientific results in a totally different dimensions, such as sound:
"Maps of CMB anisotropy can be converted to sound as a telescope sweeps across the sky to give the audience a better appreciation of the fluctuations."

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

Saturday, 23 February 2013

Tuning into the sound of the universe with radio

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

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

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

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

RT16 at the Ventspils International Radio Astronomy Centre. Latvia
Whilst optical astronomers use telescopes to look at the visible light emitted by stars, radio astronomers use radio telescopes, or antennae, to detect radio waves. By combining radio astronomy with radio and sound engineering, we can hear as well as see the stars, and thus greatly expand our sensory perception of our cosmos.

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

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

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

And here's the talk in full:

Tuesday, 5 February 2013

New Zealand recognised as major contributor to radio astronomy history

John Bolton (left) and New Zealander Gordan Stanley (centre), pictured with Jow Pawsey
New Zealand has claimed its place in radio astronomy history. As reported here a year ago, New Zealand has significant scientific heritage in the field of radio astronomy, and has begun to explore and celebrate this history.

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

Elizabeth Alexander
The conference also commemorated the pioneering work of Elizabeth Alexander, often referred to as the first female radio astronomer, who helped helped establish some of the early foundations of solar radio astronomy in 1946. Alexander studied sources of interference effecting radar stations in New Zealand established during World War II.  During March-April 1945, solar radio emission was detected at 200 MHz by operators of a Royal New Zealand Air Force radar unit located on Norfolk Island.
The emissions became known as the "Norfolk Island effect". Alexander, then based at the Department of Scientific and Industrial Research in Wellington, heading up the Operational Research Section of the Radio Development Laboratory, carried out the most significant early work on the effect throughout 1945. In 1946. she published a paper in the journal, Radio & Electronics describing the emissions, and in doing so, furthered the fledgling field of radio astronomy.

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

Radar Station (Whangaroa) - one of five involved in New Zealand's investigation of solar radio emission. Image courtesy of Wayne Orchiston.
Astronomer Miller Goss, from the National Astronomy Observatory in New Mexico, puts it:
"Bolton and Stanley's discovery revolutionised twentieth century astronomy."

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

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