9 December 2010
Here’s today’s stories from the physics congress in Melbourne.
Good Aussie home wanted for gravitational wave detector
The physics of money – testing the stability of the system
Superconductors reveal their secrets
First results from the ATLAS experiment
Sun sneaks up on winter workers
Watching electrons in action
Laser beams on steroids
Light rays treat tumours
US researchers are offering to give Australia a gravitational wave detector provided we can build an appropriate facility to house it, costing a further $140 million.
The sophisticated detector would be part of a global search for gravitational waves which were predicted by Einstein in his General Theory of Relativity, but have not yet been found.
“Later in this decade, a new generation of large ‘gravitational wave observatories’ promises to make the first direct detections of these waves. This will usher in a new way to ‘see’ the universe and a new era in astronomy and astrophysics,” he said.
The proposal will be discussed by Australian physicists at the Congress today.
The $280-million observatory, to be known as LIGO-Australia, would be built at Gingin, 65 km north of Perth, where there is already a small test detector. It would use incredibly precise lasers to measure minute movements of two mirrors several kilometres apart to ‘feel’ the gravitational waves passing.
Every working day some $150 billion flows through Australia’s Interbank system.
Postgraduate student Andrey Sokolov (email@example.com) from the University of Melbourne, and colleagues from Melbourne and Swinburne universities are analysing the flow of that money to study the dynamics of the overnight loan flows and the stability of the network.
The team are developing dynamic models that test whether the daily flow of funds between Australia’s banks is as robust as it seems – and what might cause its collapse.
Following this money trail as it grows and evolves should help financial regulators to protect our banks better.
For further information, contact Dr Andrew Melatos at firstname.lastname@example.org
US researchers are beginning to understand how copper oxides can transmit electricity with no power loss at temperatures not far below -100˚C. Research which gives clues as to just how these superconductors work was presented at the Australian Institute of Physics conference in Melbourne by Michael Norman (email@example.com) from Argonne National Laboratory in Illinois.
Norman said his co-workers had found pockets of electrons hidden within the superconducting materials. Their discovery could help unravel the mechanism of superconductors, he said, and point the way towards materials that work at room temperature and above.
He is convinced such materials exist, Norman said, it is just a question of finding them. “The record for high temperature superconductors has already increased by a factor of eight. To achieve room temperature superconductivity, we only need to improve by another factor of two.”
It took less than 19 days of smashing lead ions together at the Large Hadron Collider in Switzerland for physicists confirm a new state of matter, the Australian Institute of Physics Conference was told in Melbourne. What the ATLAS experiment found was the first direct evidence of the Quark Gluon Plasma- a 200 million degree Celsius soup of subatomic particles.
“It’s the very definition of primordial,” said Dr Martin White, a postdoctoral fellow from the University of Melbourne working on the project
When particles collide at extremely high energies, their constituents spray in all directions creating ‘jets’ of matter, some larger than others. The ATLAS discovery was made when one of two large jets went missing- lost in the plasma in a process called ‘jet quenching’. This direct evidence builds upon the early hints of the Quark Gluon Plasma first found at the RHIC collider in New York.
“It’s like trying to jab a shard of frozen syrup through a mass of boiling syrup. It just doesn’t come out the other side,” said White. This phenomenon was observed in the first few days of atomic collisions at the experiment.
“This is the first direct observation of jet quenching, an exciting discovery for ATLAS in heavy ion physics,” says White.
The danger of sunburn for construction workers is just as high in autumn and winter as in spring and summer, a researcher has told the Australian Institute of Physics conference in Melbourne. Just as skiers need to be careful of UV rays reflected off snow, construction workers run the risk of exposure from light reflected by metals on the building site. And in winter they’re less likely to be wearing sunscreen.
Joanna Turner, a PhD student at the University of Southern Queensland, attached radiation-detection devices to mannequins placed in front of vertical reflecting surfaces. She discovered that those near zinc aluminium, commonly used in construction, experienced between 20 and 50% more UV exposure than those out in the open.
This level of exposure depended on the season. Surprisingly, the solar reflection is less significant in the warmer months. In spring and summer, the angle of the sun to the ground causes more widely-scattered reflection, leading to little difference between open air exposure and that near vertical surfaces. In autumn and winter, however, the reflected UV rays are preferentially concentrated in one direction which boosts exposure levels.
“The message for construction workers is to take care to wear sunscreen all year round. Reflections in the construction environment may allow sunburn to sneak up on them when they least expect it,” said Turner.
An international team of researchers based in Colorado has captured the movements of single electrons in a chemical bond, using ultra -short x-ray pulses. The technique, which allows them to follow the movement of electrons across solar cells and other materials, was presented at the Australian Institute of Physics conference in Melbourne.
While x-rays have a long history of probing the tiniest of structures –the new technique is “like swapping a flashlight for a laser pointer”, says Margaret Murnane (firstname.lastname@example.org), from the University of Colorado talking about the research she has undertaken with her husband Henry Kapteyn.
The x-ray pulses— a billionth of a billionth of a second long—are being used to reveal the flow of energy and electrons in the fastest circuits, and in materials for energy recovery devices. The team are also using their approach to investigate physical phenomena as fundamental as magnetism.
UK physicists have developed new ways of generating industrial lasers powerful enough to slice through steel. The trick is to pass the beam along active optical fibres, David Payne (email@example.com) from the University of Southampton told the Australian Institute of Physics conference in Melbourne.
Fifty years after the first demonstration of a laser, the intense beams that can be generated are so powerful they can be used to cut out car parts and weld them together.
At present, optical fibres are used passively to carry internet and telephone traffic, but Payne and his colleagues have developed fibres spiked with rare earth metals which interact with the lasers to amplify the beam. Future applications for their technology include powerful projectors for next-generation cinema screens and new kinds of wiring for telecommunications.
Recurring prostate cancers can be subdued with a blast of laser light, say Swedish researchers presenting their latest research at the Australian Institute of Physics conference in Melbourne.
Katarina Svanberg (firstname.lastname@example.org) and colleagues at Lund University Hospital use lasers to build 3D maps of the tumours, and then to kill the cancerous cells.
She reported early success in managing what is usually a fatal condition. More work remains to be done, however, before the technique becomes used routinely in hospitals.
Prostate cancer is one of the most common cancers in men—70% are affected by the disease by the age of 70. The current treatment for recurrent prostate cancer involves hormone therapy, which has particularly unpleasant side effects, so new treatments are urgently sought.
As light can only penetrate the skin so far, the researchers deliver their laser therapy by inserting a network of optic fibres into the tumour, ensuring all the cancerous cells are treated. Using this strategy, the limited penetration of light becomes an advantage, as sensitive healthy tissues surrounding the prostate are left unscathed.
Svanberg’s team also recently has shown that a similar set-up can treat skin and oesophagal cancers effectively.
The stories are all being presented this week at the Melbourne Convention Centre at the 19th Australian Institute of Physics Congress incorporating the 35th Australian Conference on Optical Fibre Technology.
Niall Byrne, email@example.com, 0417 131 977;
Tim Thwaites, firstname.lastname@example.org, 0422 817 372.