A new class of super-accurate atomic clocks may detect miniscule changes in the laws of physics and shed light on how and why life exists in the universe, Sydney physicists have found.
Andrew Ong and his collaborators at the University of New South Wales discovered that the clocks could detect potential changes in a fundamental constant that governs the interaction between electrically charged objects.
“A changing fine-structure constant could explain why the conditions of our universe are so finely-tuned for all life to exist,” says Andrew, who did the research as part of his PhD.
“The value of the certain physical constants have to fall within a narrow range in order for carbon to be produced in stars. Without this mechanism, there would be no building blocks for all carbon-based life on our planet,” he says.
Atomic clocks, which measure time via the frequency of atomic transitions, are about 100 times more accurate than existing clocks. They are used in GPS satellites and the definition of the standard second.
The researchers hope to measure the frequency change over a few years so they can collect enough data to reach a conclusion about whether the fundamental constants vary and the rate at which they might vary.
“If we could show that the physical laws are always changing, then we can say that life exists simply in the region of the universe where the conditions are just right,” Andrew says.
NSW State Finalist: Andrew Ong, University of New South Wales
Soccer ball-like molecules may help improve the performance of plastic solar cells, which could be used as the next-generation energy source, a Melbourne physicist says.
Yaou Smets, a PhD student at La Trobe University, and his colleagues from Australian Synchrotron and University of Kaiserslautern, Germany, used a small amount of fluorinated C60-buckyballs to understand the physics that governs the photovoltaic cell efficiency. This study was recently published in the journal Organic Electronics.
“One of the major drawbacks of the conventional silicon solar cell technology is that highly efficient cells are very expensive to produce. Therefore, as a cost-effective alternative, plastic solar cells have attracted extensive attention among scientists as a promising candidate to become the next generation photovoltaic devices,” says Yaou.
Scientists around the world are trying to find ways in which the electronic properties of the solar cells can be controlled and the cell efficiency increased. One of the key technologies is called doping, where dopants are introduced to the materials. Semiconducting or even insulating materials can be transformed into efficient conductors, which carry electrical current and enhance the cell efficiency.
“The molecule C60F48 is proven be the most effective dopant in its class, as only a very small amount of it is needed to initiate a considerable amount of free charge carriers in the semiconducting layers,” Yaou says.
Victoria State Finalist: Yaou Smets, La Trobe University