Researchers are applying big data analysis techniques used in astronomy to better understand diseases of the eye and brain.
The team, led by ophthalmologist Dr Peter van Wijngaarden (CERA) and astrophysicist Associate Professor Christopher Fluke (Centre for Astrophysics and Supercomputing at Swinburne University and OzGrav), will be working together to apply the same big data analysis used by astronomers in their study of the universe, to the field of ophthalmology.
The collaboration will be formalised thanks to a generous donation from Australian entrepreneur Dr Steven Frisken, CEO of ophthalmic tech company Cylite, who was one of four people jointly awarded the Prime Minister’s Prize for Innovation last night in Canberra.
Daniel Brown from OzGrav’s team at the University of Adelaide travelled to MIT for the A+ Balanced Homodyne Workshop, 11-12 Oct, 2018. Overall this was a productive meeting which favourably demonstrated how the research being undertaken here in the Adelaide node of OzGrav is pushing the future detectors forward.
Recently the next iteration of the LIGO experiment was announced, named A+. This upgrade takes us from Advanced LIGO and further improves the sensitivity. One of the more involved upgrades is to change the gravitational wave readout scheme, from what is currently used and is called “DC Readout” to “Balanced Homodyne Readout” (BHD). Both of these techniques are employed to provide a strong optical field, called a local oscillator, at the output port, which beats with the optical fields generated by a gravitational wave and allows us to measure them on a photodiode.
For A+ the plan is pick off a small amount of light from the power recycling cavity through one of its mirrors. We then have to shape and align this light correctly and combine it with the signal coming out of the detector. This beam shaping and designing of optical control systems is some of the core OzGrav research Daniel is undertaking at the University of Adelaide.
The outcome of this meeting was that much work still needs to be done. The output part of LIGO is having a complete redesign. New suspension stages must be designed to accommodate the adaptive optic elements being developed at Adelaide. There is also scope for our new beam shape sensing technique to also be employed for controlling these adaptive elements. Next a control system must be designed and modelled for all this, which is being simulated in my modelling software Finesse. In the coming months we aim to write several design documents outlining all the new elements for the BHD system of A+.
- Daniel Brown, Postdoctoral Researcher at University of Adelaide
From March to June 2018 Sebastian (postdoc), Alexei (PhD student), and Daniel (postdoc) from the OzGrav team at the University of Adelaide travelled to the USA to attend the LIGO-Virgo Collaboration (LVC) meeting along with further trips to LIGO Hanford and the California Institute of Technology (Caltech).
One of Daniel’s main research topics is the creation of numerical simulation software, called
Finesse, which is used for understanding the complex optical interferometers that are at the core of gravitational wave detectors; we use this for design and commissioning work.
Sebastian's main research focus is 2µm fiber laser development which is one of the core research topics for OzGrav instrumentation. His research is in the development of lasers for the third generation of gravitational wave detectors. Sebastian spent time during the LVC engaging with research groups focussed on the current and future laser systems. Following the LVC he travelled south to Pasadena to visit the Caltech arm of LIGO Lab. This gave him an opportunity to examine the material and detector technologies being developed for the future detectors. While there he helped design the optical layout for the signal recycling heater and characterise the CO2 laser.
After this Sebastian joined Alexei and Daniel in Hanford and participated in the mode matching of the 70W upgrade to the prestabilised laser and helped with the implementation of the CO2 laser heater.
Arriving at the LIGO site at first is nothing short of daunting. Usually we work on small table-top optics experiments. The physical size of the LIGO experiment always blows me away, from the size of the vacuum chambers to the arms that shoot out into the desert.
The team at LIGO was amazing; their patience in teaching us how it all works and trust in us to let us work on the experiment really made the trip.
During our time there we all worked on several parts. First, we helped design and construct the new prototype adaptive optic system. This system uses a CO2 laser to heat the signal
recycling mirror to induce a small lens on its surface. This then shapes the beam exiting
the interferometer and will be used to better shape it for extracting the signal. This involved a lot of plumbing work (getting covered in aged coolant left in old pipes...) and aligning the CO2 laser into the vacuum chamber to correctly deform the mirror.
Alexei also looked into how we can better interpret cavity mode scans to infer the correct way to shape the laser beam. From this we found that we can actually extract more information than we expected previously, such as the astigmatism of the beam. Using this knowledge he wrote a new commissioning tool for analysing the output mode cleaner scans in a more automated and easier to use fashion.
We also helped in mode matching the squeezer beam to the interferometer and develop better Finesse models of the output path. Before we left we then also helped test the new Hartmann sensor system for sensing the deformations in the end test mass mirrors, something that previously had not worked optimally.
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The neutron star merger, known as GW170817, occurred 130 million light-years from Earth and sent a burst of both gravitational and electromagnetic waves rippling through space that reached the Earth one year ago.
In the aftermath of the violent collision, GW170817 was observed worldwide by telescopes across the electromagnetic spectrum. By tracking changes in the optical, radio, and X-ray emission of the afterglow, scientists including Swinburne's Dr Adam Deller, from OzGrav, were able to study how the material flung out during the merger interacted with its surroundings.
Read more here.
OzGrav is delighted to be involved in a new art-science planetarium show that will have its world premier at the Melbourne International Arts Festival from October 6-13, 2018.
Particle/Wave sees poets, musicians, sound and video artists joining forces with renowned scientists to interpret the theories of gravitational waves, which Stephen Hawking has called “a completely new way of looking at the universe.”
Particle/Wave is directed by Alicia Sometimes, and includes narration by OzGravers Kendall Ackley, Lilli Sun, and Alan Duffy, along with video contributions from our own Mark Myers and Carl Knox.
OzGrav Associate Investigator Dr Adam Deller has helped test Einstein’s theory of general relativity and shown it still can’t be proven wrong, using the complicated orbital dance of three compact stars. Einstein’s strong equivalence principle says all objects should fall the same way in a gravitational field, regardless of their composition or how dense they are.
After five years of intensive observation of a triple stellar system, the international team of nine astronomers was able to conclude that the theory of general relativity is still relevant, as seen in the research paper published in the prestigious international science journal, Nature.
“This particular system consists of one ultra-dense neutron star and two less-dense white dwarf stars, which makes these stars the dream team for testing relativity,” Dr Deller says.
Read the press release here.
A new technique developed to detect the faint background hum of gravitational waves in the Universe is making headlines! Eric Thrane and Rory Smith from OzGrav's Monash Node have made the remarkable prediction that their new technique - combined with the grunt of a supercomputer like Swinburne's OzSTAR - could give them the exquisite level of sensitivity needed to measure the subtle background noise caused by black holes and neutron stars colliding throughout the universe.
Their result is described in The Age and ABC news, and on TV on the 7:30 Report.
On 16 March 2018, OzGrav Deputy Director Prof David McClelland (ANU) received the International Organisation for Quantum Communication, Measurement and Computing Award for Outstanding Achievements in Quantum Experimentation. In bestowing McClelland with this award, the organisation cited his “pioneering experimental work and leadership in the development of squeezed vacuum light sources in the audio-band and its successful application to the gravitational wave detector interferometers GEO and LIGO.” The award was shared in equal parts with OzGrav Partner Investigator Prof Nergis Mavalvala (MIT) and Prof Roman Schnabel (Hamburg).
Advances in this technology are sure to lead to even more discoveries. Says Prof McClelland, "manipulating the quantum world to enhance the sensitivity of world’s biggest laser interferometers will enable the deepest searches yet for new gravitational wave sources".
“It is gratifying to see Professor McClelland's pioneering work in quantum squeezing acknowledged with this prize. His group's work will enable us all to see further into the Universe and accelerate the advancement of the new field of gravitational wave astrophysics", says OzGrav Director Prof Matthew Bailes.
Image: Prof McClelland receiving his award from Prof Joerg Schmiedmayer, Chair of the International Organisation for Quantum Communication, Measurement and Computation.
OzGrav Deputy Director David McClelland was awarded the Walter Boas Medal by the Australian Institute of Physics for his contributions to “one of the greatest achievements in the history of physics”, the direct observation of gravitational waves. "For his role in bringing about the epochal breakthrough, and securing Australia’s place in the international collaboration that made it possible, Professor David McClelland of the Australian National University has been awarded the 2017 Walter Boas Medal by the Australian Institute of Physics."
In addition to his role in OzGrav, he is Professor of Physics, Department of Quantum Science and Director of the ANU Centre for Gravitational Physics. He is also the Chief Investigator for Australia's Partnership in Advanced LIGO. The Walter Boas Medal is awarded yearly by the AIP for excellence in research.