Frequency Standards and Metrology (FSM) researchers are involved in exciting, timely projects ranging from fundamental tests of physics to commercial and space applications. Professor Michael Tobar said his group's microwave laboratories received one of the biggest Australian Research Council grants in 2005. "We are now expanding rapidly as well as consolidating our national and international research collaborations," he said. Professor Tobar said scientists could measure time and frequency more precisely than other physical parameters, an important technological asset. "Research in this field can challenge our understanding of the universe by testing theory with the most accurate measurements possible, as well as enable novel technological applications," he said. Uses for atomic clocks include navigation, geodesy, national and international timekeeping and telecommunication. Associate Professor Tobar said the group's commercial and fundamental-related research were complementary, with discoveries in both domains directly benefiting the other.
The group's projects include:
- The European Space Agencies (ESA) Atomic Clock Ensemble in Space (ACES) Mission
Professor Tobar said the ESA had chosen his group as the only Southern Hemisphere User Group for the mission. "ACES is an exciting microgravity physics experiment," he said. "Atomic clocks will be sent to the International Space Station where the perturbation of the Earth's gravitational force is almost totally removed. "Physics experiments will include gravitational frequency shift (Einstein effect), time variation of the fine structure constant and tests of special relativity. "We were chosen because we have precise oscillators and clocks, sufficiently stable for comparison with the worldwide network; and we have expertise in ultra-high accuracy, long-distance time transfer techniques," he said.
- Testing Special Relativity: Einstein is still right
The FSM group tested Albert Einstein's theory of special relativity during the International Year of Physics in 2005, which celebrated the centenary of his discovery. Associate Professor Tobar said the modern version of Michelson-Morley's original experiment tested Lorentz Invariance. "Theories that try and unify all fundamental forces of nature suggest that Lorentz Invariance may be broken due to high-energy processes in the early universe just after the big bang," he said. "The UWA experiment is among the most promising for detecting such violations." The French Society for Microtechnics and Chronometry awarded the group Best Presented Paper at the 2005 European Frequency and Time Forum for the work.
- Poseidon Scientific Instruments Pty Ltd
PSI has been using the group's technology since the early 1990s and the cutting-edge performance of the Poseidon-UWA oscillators has attracted the world's most sophisticated defence contractors. Professor Tobar said signal generators his group created for PSI have been used in defence systems. "Our technology enables systems developers to build radars that can see further, with higher resolution and lower system weight and cost than could be achieved with established technologies," he said. PSI contributes significant resources to the FSM research group.