Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A new window on the universe

20.11.2007
UWM physicists involved in international project to scour space for gravitational waves

Using new tools to look at the universe, says Patrick Brady, often has led to discoveries that change the course of science. History is full of examples.

“Galileo was the first person to use the telescope to view the cosmos,” says Brady, a UWM professor of physics. “His observations with the new technology led to the discovery of moons orbiting Jupiter and lent support to the heliocentric model of the solar system.”

Just such an opportunity exists today with a unique observatory that is scanning the skies, searching for one of Einstein’s greatest predictions – gravitational waves.

Gravitational waves are produced when massive objects in space move violently. The waves carry the imprint of the events that cause them. Scientists already have indirect evidence that gravitational waves exist, but have not directly detected them.

UWM researchers, backed by considerable funding from the National Science Foundation, are taking a leadership role in the quest.

It is an epic undertaking involving about 500 scientists worldwide, including Brady and other members of UWM’s Center for Cosmology and Gravitation: associate professors Alan Wiseman and Jolien Creighton, and assistant professor Xavier Siemens.

Two UWM adjunct physicists, who work at the Max Planck Institute in Germany, also are involved – former UWM professor Bruce Allen and scientist Maria Alessandra Papa.

“It’s an unimaginable opportunity to be on the forefront of scientific discovery,” says Creighton.

The Laser Interferometer Gravitational-wave Observatory, or LIGO, consists of detectors at two U.S. sites managed by the California Institute of Technology (Caltech) and Massachusetts Institute of Technology (MIT).

UWM’s physicists are analyzing the data generated by the LIGO facilities.

The project is supported with a sizable investment of grant money from both federal and UWM sources.

Last year, UWM’s LIGO group brought in $3 million in grant funding. Since 1999, UWM has received more than $9 million for the project, with much of it going toward a supercomputer called Nemo that operates unobtrusively on the second floor of the Physics Building.

Stretching and squeezing

The LIGO observatories use lasers to accurately monitor the distance between a central station and mirrors suspended three miles away along perpendicular arms. When a gravitational wave, a traveling ripple in space-time, passes by, the mirror in one arm will move closer to the central station, while the other mirror will move away.

The change in distance caused by stretching and squeezing is what LIGO is designed to measure, says Wiseman.

Those changes will be inconceivably tiny. LIGO can record distortions at a scale so small, it is comparable in distance to a thousandth of the size of an atomic nucleus.

LIGO records a series of numbers – lots of them – and feeds them to several supercomputer clusters around the country, including UWM’s Nemo cluster.

Think of a modern hard disk on a desktop computer, which stores about 100 gigabytes. LIGO fills up about 10 of those at Nemo in a single day, says Brady.

The computer’s job is to sort out the numerical patterns representing gravitational waves buried in ambient noise produced by lots of other vibrations – from internal vibrations of the equipment itself, to magnetic fluctuations from lightning storms, to seismic vibrations from trains rolling along the tracks a few miles from the observatory, or from earthquakes on the other side of the world.

“There are thousands or even millions of different signals that could be emitted from space,” says Wiseman. “So you have to take each segment of data individually. That turns out to be a formidable computational problem.”

Nemo performs many billions of calculations per second in its search for these signals.

Space sounds

The strings of numbers from LIGO are like tracks on a compact disk, says Brady. That means, once detected, gravitational-wave signals can be converted into sound.

In fact, scientists have already simulated, based on mathematical predictions, what certain events in space will sound like.

When two black holes are merging, for example, you might expect to hear a “chirp” that represents the spiraling together of the black holes just before they collide. “The spiral can go on for tens of thousands of years,” says Brady. “The sound is the identifying signal of the last few seconds of the process!”

Those analyzing the data from space could actually listen to the data. Instead, scientists look for the signals using computers like Nemo.

To augment the computing capacity, UWM is hosting a way for anyone with a computer and a high-speed Internet connection to join the astrophysical treasure hunt. Called “Einstein@Home, the program borrows computer power available when participants are not using it, and pool those resources to aid in filtering the massive amounts of data from LIGO.

Possible secrets

Scientists concede that the current LIGO facilities will need to be improved to increase the chances of detecting gravitational waves. More NSF funding to do that is requested in the 2009 U.S. budget currently winding its way through the approval process.

For now, the best hope is to detect events relatively close to Earth.

So what is the likelihood of success"

“The events we are looking for may only happen once every million years in our galaxy,” says Wiseman, “but if your instrument is sensitive enough to see such events in, say, one million galaxies, then the probability of detecting something is much larger.”

Gravitational waves may hold secrets to the nature of black holes, the unknown properties of nuclear material, and maybe even how the universe began.

“We’ve only been able to find out about the universe since it became cool,” says Siemens. “But with gravitational waves, we’ll see the universe when it was much younger – and hotter.”

But then again, scientists don’t really know.

“I think we’re in for a surprise,” says Siemens. “We have all these ideas about what we think we will find, but it could be something completely different.”

Patrick Brady | EurekAlert!
Further information:
http://www.uwm.edu

More articles from Physics and Astronomy:

nachricht Study offers new theoretical approach to describing non-equilibrium phase transitions
27.04.2017 | DOE/Argonne National Laboratory

nachricht SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>