Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Superstrings could add gravitational cacophony to universe's chorus

10.01.2007
Albert Einstein theorized long ago that moving matter would warp the fabric of four-dimensional space-time, sending out ripples of gravity called gravitational waves.

No one has observed such a phenomenon so far, but University of Washington researchers believe it is possible to detect such waves coming from strange wispy structures called cosmic superstrings.

Many physicists consider a complex and sometimes-controversial premise called string theory to be a leading candidate to unify their understanding of the four basic forces of nature – gravity, electromagnetic, weak and strong. String theory is sometimes criticized for being untestable or even unscientific, but some versions now predict an exotic behavior with observable effects: the formation of cosmic superstrings, narrow tubes of energy left from the beginning of the universe that have been stretched to enormous lengths by the expansion of the universe, said UW cosmologist Craig Hogan.

If the theories are correct, there are countless cosmic superstrings stretched like a galactic-sized rubber band. They resemble ultra-thin tubes with some of the vacuum of the early universe preserved inside, Hogan said. The strings can form into loops that "flop around" and emit gravitational waves as they decay and eventually disappear.

"They're so light that they can't have any effect on cosmic structure, but they create this bath of gravitational waves just by decaying," he said.

Theory holds that every time something moves it emits a gravitational wave. Colliding black holes send out more waves than anything else, typically a million times more power than is produced by all the galaxies in the universe. While some gravitational waves could occur at frequencies high enough that a human theoretically could hear them, many more of the sources have very low frequencies, 10 to 20 octaves below the range of human hearing, Hogan said.

"Big masses tend to take a long time to move about, so there are more sources at lower frequencies," he said. "Sensing these vibrations would add the soundtrack to the beautiful imagery of astronomy that we are used to seeing. All this time, we have been watching a silent movie."

A proposed orbiting observatory called the Laser Interferometer Space Antenna, being developed by the National Aeronautics and Space Administration, could provide the first measurements of very low frequency gravitational waves, perhaps the first such measurements at any frequency, Hogan said. In addition to the expected wave sources, such as binary stars and black holes, these signals also might include the first direct evidence of cosmic superstrings.

"If we see some of this background, we will have real physical evidence that these strings exist," he said.

Calculations for gravitational waves generated by cosmic strings, as well as the larger rationale for the space antenna mission, are being presented today at the American Astronomical Society national meeting in Seattle in a poster by Hogan and Matt DePies, a UW physics doctoral student and visiting physics lecturer.

An Earth-based project called the Laser Interferometer Gravitational-Wave Observatory also is attempting to observe gravitational waves, but it is searching in higher frequencies where Hogan believes waves from superstrings would be much harder to detect. That's because the background noise would make it difficult to identify the waves emitted by strings.

"The strings, if they exist, are part of that noise, but we want to listen in at lower frequencies and try to detect them," he said.

Vince Stricherz | EurekAlert!
Further information:
http://www.washington.edu

More articles from Physics and Astronomy:

nachricht Riddle of matter remains unsolved: Proton and antiproton share fundamental properties
19.10.2017 | Johannes Gutenberg-Universität Mainz

nachricht Space radiation won't stop NASA's human exploration
18.10.2017 | NASA/Johnson Space Center

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

New procedure enables cultivation of human brain sections in the petri dish

19.10.2017 | Life Sciences

The “everywhere” protein: honour for the unravellor of its biology

19.10.2017 | Life Sciences

Rapid environmental change makes species more vulnerable to extinction

19.10.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>