Featured Research

from universities, journals, and other organizations

Gravitational waves that are 'sounds of the universe'

Date:
October 3, 2011
Source:
The Hebrew University of Jerusalem
Summary:
Einstein wrote about them, and we're still looking for them -- gravitational waves, which are small ripples in the fabric of space-time, that many consider to be the sounds of our universe. Just as sound complements vision in our daily life, gravitational waves will complement our view of the universe taken by standard telescopes.

This is a simulation of matter ejected from a star merger.
Credit: Stephan Rosswog

Einstein wrote about them, and we're still looking for them -- gravitational waves, which are small ripples in the fabric of space-time, that many consider to be the sounds of our universe. Just as sound complements vision in our daily life, gravitational waves will complement our view of the universe taken by standard telescopes.

Albert Einstein predicted gravitational waves in 1918. Today, almost 100 years later, advanced gravitational wave detectors are being constructed in the US, Europe, Japan and Australia to search for them.

While any motion produces gravitational waves, a signal loud enough to be detected requires the motion of huge masses at extreme velocities. The prime candidate sources are mergers of two neutron stars: two bodies, each with a mass comparable to the mass of our sun, spiraling around each other and merging at a velocity close to the speed of light.

Such events are rare, and take place once per hundreds of thousands of years per galaxy. Hence, to detect a signal within our lifetime the detectors must be sensitive enough to detect signals out to distances of a billion light years away from Earth. This poses an immense technological challenge. At such distances, the gravitational waves signal would sound like a faint knock on our door when a TV set is turned on and a phone rings at the same time.

Competing noise sources are numerous, ranging from seismic noise produce by tiny quakes or even a distant ocean wave. How can we know that we have detected a gravitational wave from space rather than a falling tree or a rambling truck?

Therefore, astronomers have been looking for years for a potential electromagnetic light signal that would accompany or follow the gravitational waves. This signal would allow us to "look through the peephole" after hearing the faint knock on the door, and verify that indeed "someone" is there. In their new article just published in Nature, Prof. Tsvi Piran, Schwarzmann University Professor at the Hebrew University of Jerusalem, and Dr. Ehud Nakar from Tel Aviv University describe having found just that.

They noticed that surrounding interstellar material would slow debris ejected at velocities close to the speed of light during the merger of two neutron stars. Heat generated during this process would be radiated away as radio waves. The resulting strong radio flare would last a few months and would be detectable with current radio telescopes from a billion light years away.

Search after such a radio signal would certainly take place following a future detection, or even a tentative detection of gravitational waves. However, even before the advanced gravitational wave detectors become operational, as expected in 2015, radio astronomers are geared to looking for these unique flares.

Nakar and Piran point out in their article that an unidentified radio transient observed in 1987 by Bower et al. has all the characteristics of such a radio flare and may in fact have been the first direct detection of a neutron star binary merger in this way.

Dr. Nakar's research was supported by an International Reintegration Grant from the European Union and a grant from the Israeli Science Foundation and an Alon Fellowship. Prof. Piran's research was supported by an Advanced European Research Council grant and by the High Energy Astrophysics Center of the Israeli Science Foundation.


Story Source:

The above story is based on materials provided by The Hebrew University of Jerusalem. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ehud Nakar, Tsvi Piran. Detectable radio flares following gravitational waves from mergers of binary neutron stars. Nature, 2011; DOI: 10.1038/nature10365

Cite This Page:

The Hebrew University of Jerusalem. "Gravitational waves that are 'sounds of the universe'." ScienceDaily. ScienceDaily, 3 October 2011. <www.sciencedaily.com/releases/2011/10/111003094408.htm>.
The Hebrew University of Jerusalem. (2011, October 3). Gravitational waves that are 'sounds of the universe'. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2011/10/111003094408.htm
The Hebrew University of Jerusalem. "Gravitational waves that are 'sounds of the universe'." ScienceDaily. www.sciencedaily.com/releases/2011/10/111003094408.htm (accessed July 24, 2014).

Share This




More Matter & Energy News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com
Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Car Market on the Rebound?

Europe's Car Market on the Rebound?

Reuters - Business Video Online (July 23, 2014) Daimler kicks off a round of second-quarter earnings results from Europe's top carmakers with a healthy set of numbers - prompting hopes that stronger sales in Europe will counter weakness in emerging markets. Hayley Platt reports. Video provided by Reuters
Powered by NewsLook.com
9/11 Commission Members Warn of Terror "fatigue" Among American Public

9/11 Commission Members Warn of Terror "fatigue" Among American Public

Reuters - US Online Video (July 22, 2014) Ten years after releasing its initial report, members of the 9/11 Commission warn of the "waning sense of urgency" in combating terrorists attacks. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins