Nav: Home

New era of astronomy as gravitational wave hunt begins

May 20, 2015

Australian scientists are in the hunt for the last missing piece of Einstein's General Theory of Relativity, gravitational waves, as the Advanced LIGO Project in the United States comes on line.

LIGO (the Laser Interferometer Gravitational-wave Observatories) aims to find gravitational waves, ripples in the fabric of space and time caused by the most violent events in the universe such as supernovae or collisions between black holes.

"We'll find things we can't imagine - gravitational waves are a completely different messenger from light," said Professor David McClelland from The Australian National University (ANU), who leads the Australian LIGO team.

"It's like the moment when Galileo first turned a telescope towards the skies and started a new epoch of astronomy. Here we shall begin a whole new and fundamentally different way of observing the Universe."

Australia is a partner in Advanced LIGO with research groups from ANU and the University of Adelaide, supported by the Australian Research Council, directly contributing to its construction and commissioning.

LIGO will ultimately be joined by detectors in Europe, Japan and India seeking evidence for gravitational waves, in the form of movements a fraction of the radius of a proton.

"Advanced LIGO is easily the most sensitive detector ever created, at the limits of the Heisenberg Uncertainty Principle," said Professor Jesper Munch, leader of the University of Adelaide research group.

In his 1915 General Theory of Relativity, Einstein proposed that large masses such as stars cause curvature in space and time, which leads to gravity and also bends light.

A number of observations in the past 100 years have confirmed other consequences of Einstein's theory, but only in regions of weak gravity, said LIGO team member Professor Daniel Shaddock, from ANU Research School of Physics and Engineering (RSPE).

"Gravitational waves are produced when massive objects accelerate or collide," he said.

"Finding gravitational waves would test our theories in a completely different scenario, where huge gravitational forces are at play. It is the ultimate test for General Relativity."

Gravitational waves have been proven to exist indirectly through the decay of the orbit of two neutron stars rotating around each other. However, Professor McClelland says direct detection of them is within our grasp.

"By the end of the year there's a chance that the 100-year search will be over," he said.

"Or, if we don't see something in the next 12 to 24 months then we may have found either a problem with Einstein's General Relativity or some new insight about the Universe," he said.

LIGO is an identical pair of laboratories in opposite corners of the United States. Each laboratory consists of two four-kilometre-long vacuum-pipes at right angles to each other, with mirrors suspended at either end. A laser beam is sent back and forth between the mirrors to form an interferometer.

They were built by Caltech and MIT in the 1990s. However, they have only now the sensitivity levels required to detect gravitational waves with a tenfold improvement following a complete redesign and replacement of the detectors.

A gravitational wave passing through the interferometer should momentarily move the mirrors at a frequency of about a kilohertz somewhere in the region of 10-19 of a meter (one ten-thousandth of the radius of a proton), which will be picked up by the laser system.

The team at ANU have developed a system which locks the laser beam to the 40 kilogram mirrors to ensure that infinitesimal movements caused by a passing gravitational wave are identified, while other small movements are nullified.

The University of Adelaide group has developed a system to correct for any deformation of the mirrors due to heat, a crucial factor with the stored laser power of the system approaching half a megawatt.

"The technology required pushes the limit of all the components, including low noise detectors, high power lasers, quantum effects and technology such as optical polishing, coatings and vacuum systems," said Professor Munch.

"It is a crowning achievement in optical sensing as the world celebrates the International Year of Light in 2015."

Australian National University

Related Gravitational Waves Articles:

Are dense star clusters the origin of the gravitational waves discovered by LIGO?
Much to their surprise, scientists are finding dozens of black holes deep within densely packed collections of stars called globular clusters.
Gravitational waves detected a third time
On Jan. 4, 2017, an international team of scientists (including representatives from the University of Maryland) observed gravitational waves -- ripples in the fabric of spacetime -- for the third time.
LIGO detects gravitational waves for third time
The Laser Interferometer Gravitational-wave Observatory (LIGO) has made a third detection of gravitational waves, ripples in space and time, demonstrating that a new window in astronomy has been firmly opened.
Third gravitational wave detection offers new insight into black holes
An international team of researchers has made a third detection of gravitational waves, ripples in space and time, in a discovery that provides new insights into the mysterious nature of black holes and, potentially, dark matter.
Monash researchers uncover new gravitational wave characteristics
Monash researchers have identified a new concept -- 'orphan memory' -- which changes the current thinking around gravitational waves.
Gravitational wave kicks monster black hole out of galactic core
Astronomers have uncovered a supermassive black hole that has been propelled out of the center of a distant galaxy by what could be the awesome power of gravitational waves.
'Gravitational noise' interferes with determining the coordinates of distant sources
A group of Russian astrophysicists from the Astro Space Center (ASC) of P.N.
LIGO veteran to give talk about gravitational waves
Caltech's Stan Whitcomb, who has been involved with nearly every aspect of the development and ultimate success of the Laser Interferometer Gravitational-wave Observatory (LIGO), will give a talk about the project's historic detection of gravitational waves on Feb.
Increasing the sensitivity of next-generation gravitational wave detectors
Nearly one year ago today, the LIGO Collaboration announced the detection of gravitational waves, once again confirming Einstein's theory of General Relativity.
Gravitational biology
Akira Kudo at Tokyo Institute of Technology(Tokyo Tech) and colleagues report in Scientific Reports, December 2016, that live-imaging and transcriptome analysis of medaka fish transgenic lines lead to immediate alteration of cells responsible for bone structure formation.

Related Gravitational Waves Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Climate Crisis
There's no greater threat to humanity than climate change. What can we do to stop the worst consequences? This hour, TED speakers explore how we can save our planet and whether we can do it in time. Guests include climate activist Greta Thunberg, chemical engineer Jennifer Wilcox, research scientist Sean Davis, food innovator Bruce Friedrich, and psychologist Per Espen Stoknes.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...