Einstein@Home
Encyclopedia
Einstein@Home is a volunteer distributed computing
project hosted by the University of Wisconsin–Milwaukee and the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, Hannover, Germany)
. The project is directed by Bruce Allen. Running on the Berkeley Open Infrastructure for Network Computing (BOINC)
software platform, Einstein@Home searches through data from the LIGO
detectors for evidence of continuous gravitational-wave sources, which are expected for instance from rapidly spinning non-axisymmetric neutron stars. Einstein@Home also searches radio telescope data from the Arecibo Observatory
for radio pulsar
s. On August 12, 2010, the first discovery by Einstein@Home of a previously undetected radio pulsar J2007+2722
, found in data from the Arecibo Observatory, was published in Science
. The project has discovered 14 pulsars as of November 2011.
's contribution to the World Year of Physics 2005
. It uses the power of volunteer-driven distributed computing
in solving the computationally intensive problem of analyzing a large volume of data. Such an approach was pioneered by the SETI@home
project, which is designed to look for signs of extraterrestrial life by analyzing radio wave data. Einstein@Home runs through the same software platform as SETI@home, the Berkeley Open Infrastructure for Network Computing (BOINC)
.
, over 300,000 volunteers in 221 countries have participated in the project, making it the third most popular BOINC project. About 66,000 active users contribute about 450 teraFLOPS
of computational power, which would rank Einstein@Home among the top 20 on the TOP500
list of supercomputer
s.
detector instruments. The primary class of target CW sources are rapidly rotating neutron stars (including pulsars) which emit gravitational waves due to a deviation from axissymmetry. Besides validating Einstein's theory of General Relativity, direct detection of gravitational waves will also constitute an important new astronomical tool. As most neutron stars are electromagnetically invisible, gravitational-wave observations might allow to reveal completely new populations of neutron stars. Therefore, a CW detection could potentially be extremely helpful for neutron-star astrophysics and will eventually provide unique insights into the nature of matter at high densities.
Since March 2009, part of the Einstein@Home computing power is used to also analyze data taken by the PALFA Consortium at the Arecibo Observatory
in Puerto Rico
. This search effort is designed to find radio pulsars in tight binary systems.
the quality of the LIGO data has constantly improved from enhanced detector instrument performance, as well as the Einstein@Home search algorithms which have been improved from run to run, achieving an increasing search sensitivity.
Einstein@Home's first analysis used data from the "third science run" (S3) of LIGO. Processing of the S3 data set was conducted between 22 February 2005 and 2 August 2005. This analysis employed 60 segments from the LIGO Hanford 4-km detector totaling ten hours of data each. Each 10-hour segment was analyzed for CW signals by the volunteers computers using a matched-filtering
technique. When all matched-filtering results were returned, the results from different segments were then combined in a "post-processing step" on the Einstein@Home servers via a coincidence scheme to further enhance the search sensitivity.
The results were published on the Einstein@Home webpages.
Work on the S4 data set (LIGO's fourth science run) was started interlaced with the S3 calculations, and had finished in July 2006.
This analysis used 10 segments of 30 hours from the LIGO Hanford 4-km detector and 7 segments of 30 hours from the LIGO Livingston 4-km detector. Besides the S4 data being more sensitive, also a more sensitive coincidence combination scheme was applied in the post-processing. The results of this search have led to the first scientific publication of Einstein@Home in Physical Review D.
Einstein@home has gained considerable attention of the world's distributed computing
community when an optimized application for the S4 data set analysis was developed and released in March 2006 by project volunteer Akos Fekete, a Hungarian programmer. Fekete improved the official S4 application and introduced SSE
, 3DNow!
and SSE3
optimizations into the code improving performance by up to 800%. Fekete was recognized for his efforts and was afterward officially involved with the Einstein@home team in the development of the new S5 application. As of late July 2006 this new official application became widely distributed among the Einstein@home users, creating a large surge in the project's total performance and productivity, best measured by floating point speed (or FLOPS
), which has increased by approximately 50% compared to non-optimized S4 application.
The first Einstein@Home analysis of early LIGO S5 data set, where the instruments reached their design sensitivity for the first time, began on 15 June 2006. This search used 22 segments of 30 hours from the LIGO Hanford 4-km detector and 6 segments of 30 hours from the LIGO Livingston 4-km detector. This analysis run (code name "S5R1") employed the search methodology on Einstein@Home was very similar to the previous S4 analysis. However, the search results were still more sensitive due to using more data which also had improved quality compared to S4. Over large parts of the searched parameter space these results (which also appeared in Physical Review D
) are the most sensitive ones published to date.
The second Einstein@Home search of LIGO S5 data (code name "S5R3") has constituted once more a major improvement in terms of search sensitivity. In contrast to the previous searches, here the matched-filtering results from 84 data segments of 25 hours each, from both 4-km LIGO Hanford and Livingston instruments, were already combined on the volunteers' computers via a Hough transform
technique. The results of this search are currently undergoing further examination.
On May 7, 2010, a new Einstein@Home search (code name "S5GC1") has been launched which uses a significantly improved search method. This search analyses 205 data segments of 25 hours each, from both 4-km LIGO Hanford and Livingston instruments, using a technique which exploits global parameter-space correlations to efficiently combine the matched-filtering results from the different segments.
in Puerto Rico
.
On November 26, 2009, CUDA
-optimized application for Arecibo Binary Pulsar Search was announced, on official Einstein@home webpages. This application uses both a regular CPU plus NVIDIA
GPU to perform the analysis faster (in some cases up to 50% faster).
In its analysis of radio data from the Arecibo Observatory, Einstein@Home has re-detected 134 different known radio pulsars that include 8 milli-second pulsars.
On August 12, 2010, the Einstein@Home project announced their discovery of a new disrupted binary pulsar, PSR J2007+2722
; it may be the fastest-spinning such pulsar discovered to date. The computers of Einstein@Home volunteers Chris and Helen Colvin and Daniel Gebhardt observed PSR 2007+2722 with the highest statistical significance.
On March 1, 2011, the Einstein@Home project announced their second discovery: binary pulsar PSR J1952+2630. The computers of Einstein@Home volunteers from Russia and UK observed PSR J1952+2630 with the highest statistical significance.
As of November 2011, the Einstein@Home project has discovered a total of 14 pulsars: ten using Parkes Multibeam Survey data and four using Arecibo radio data.
Distributed computing
Distributed computing is a field of computer science that studies distributed systems. A distributed system consists of multiple autonomous computers that communicate through a computer network. The computers interact with each other in order to achieve a common goal...
project hosted by the University of Wisconsin–Milwaukee and the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, Hannover, Germany)
Max Planck Institute for Gravitational Physics
The Max Planck Institute for Gravitational Physics is a Max Planck Institute whose research is aimed at investigating Einstein’s theory of relativity and beyond: Mathematics, quantum gravity, astrophysical relativity, and gravitational wave astronomy...
. The project is directed by Bruce Allen. Running on the Berkeley Open Infrastructure for Network Computing (BOINC)
Berkeley Open Infrastructure for Network Computing
The Berkeley Open Infrastructure for Network Computing is an open source middleware system for volunteer and grid computing. It was originally developed to support the SETI@home project before it became useful as a platform for other distributed applications in areas as diverse as mathematics,...
software platform, Einstein@Home searches through data from the LIGO
LIGO
LIGO, which stands for the Laser Interferometer Gravitational-Wave Observatory, is a large-scale physics experiment aiming to directly detect gravitational waves. Cofounded in 1992 by Kip Thorne and Ronald Drever of Caltech and Rainer Weiss of MIT, LIGO is a joint project between scientists at MIT,...
detectors for evidence of continuous gravitational-wave sources, which are expected for instance from rapidly spinning non-axisymmetric neutron stars. Einstein@Home also searches radio telescope data from the Arecibo Observatory
Arecibo Observatory
The Arecibo Observatory is a radio telescope near the city of Arecibo in Puerto Rico. It is operated by SRI International under cooperative agreement with the National Science Foundation...
for radio pulsar
Pulsar
A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name...
s. On August 12, 2010, the first discovery by Einstein@Home of a previously undetected radio pulsar J2007+2722
PSR J2007+2722
PSR J2007+2722 is a 40.8-hertz isolated pulsar in the Vulpecula constellation, 5.3 kpc distant in the plane of the Galaxy, and is most likely a Disrupted Recycled Pulsar ....
, found in data from the Arecibo Observatory, was published in Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....
. The project has discovered 14 pulsars as of November 2011.
Introduction
The project was officially launched on 19 February 2005 as part of American Physical SocietyAmerican Physical Society
The American Physical Society is the world's second largest organization of physicists, behind the Deutsche Physikalische Gesellschaft. The Society publishes more than a dozen scientific journals, including the world renowned Physical Review and Physical Review Letters, and organizes more than 20...
's contribution to the World Year of Physics 2005
World Year of Physics 2005
The year 2005 has been named the World Year of Physics in recognition of the 100th anniversary of Albert Einstein's "Miracle Year," in which he published four landmark papers, and the subsequent advances in the field of physics.-History:...
. It uses the power of volunteer-driven distributed computing
Distributed computing
Distributed computing is a field of computer science that studies distributed systems. A distributed system consists of multiple autonomous computers that communicate through a computer network. The computers interact with each other in order to achieve a common goal...
in solving the computationally intensive problem of analyzing a large volume of data. Such an approach was pioneered by the SETI@home
SETI@home
SETI@home is an Internet-based public volunteer computing project employing the BOINC software platform, hosted by the Space Sciences Laboratory, at the University of California, Berkeley, in the United States. SETI is an acronym for the Search for Extra-Terrestrial Intelligence...
project, which is designed to look for signs of extraterrestrial life by analyzing radio wave data. Einstein@Home runs through the same software platform as SETI@home, the Berkeley Open Infrastructure for Network Computing (BOINC)
Berkeley Open Infrastructure for Network Computing
The Berkeley Open Infrastructure for Network Computing is an open source middleware system for volunteer and grid computing. It was originally developed to support the SETI@home project before it became useful as a platform for other distributed applications in areas as diverse as mathematics,...
.
, over 300,000 volunteers in 221 countries have participated in the project, making it the third most popular BOINC project. About 66,000 active users contribute about 450 teraFLOPS
FLOPS
In computing, FLOPS is a measure of a computer's performance, especially in fields of scientific calculations that make heavy use of floating-point calculations, similar to the older, simpler, instructions per second...
of computational power, which would rank Einstein@Home among the top 20 on the TOP500
TOP500
The TOP500 project ranks and details the 500 most powerful known computer systems in the world. The project was started in 1993 and publishes an updated list of the supercomputers twice a year...
list of supercomputer
Supercomputer
A supercomputer is a computer at the frontline of current processing capacity, particularly speed of calculation.Supercomputers are used for highly calculation-intensive tasks such as problems including quantum physics, weather forecasting, climate research, molecular modeling A supercomputer is a...
s.
Scientific objectives
The Einstein@Home project has been created to perform all-sky searches for previously unknown continuous gravitational-wave (CW) sources using data from the LIGOLIGO
LIGO, which stands for the Laser Interferometer Gravitational-Wave Observatory, is a large-scale physics experiment aiming to directly detect gravitational waves. Cofounded in 1992 by Kip Thorne and Ronald Drever of Caltech and Rainer Weiss of MIT, LIGO is a joint project between scientists at MIT,...
detector instruments. The primary class of target CW sources are rapidly rotating neutron stars (including pulsars) which emit gravitational waves due to a deviation from axissymmetry. Besides validating Einstein's theory of General Relativity, direct detection of gravitational waves will also constitute an important new astronomical tool. As most neutron stars are electromagnetically invisible, gravitational-wave observations might allow to reveal completely new populations of neutron stars. Therefore, a CW detection could potentially be extremely helpful for neutron-star astrophysics and will eventually provide unique insights into the nature of matter at high densities.
Since March 2009, part of the Einstein@Home computing power is used to also analyze data taken by the PALFA Consortium at the Arecibo Observatory
Arecibo Observatory
The Arecibo Observatory is a radio telescope near the city of Arecibo in Puerto Rico. It is operated by SRI International under cooperative agreement with the National Science Foundation...
in Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
. This search effort is designed to find radio pulsars in tight binary systems.
Gravitational-wave data analysis and results
Einstein@Home has carried out a number of analysis runs using data from the LIGO instruments. Since its first search run in 2005,the quality of the LIGO data has constantly improved from enhanced detector instrument performance, as well as the Einstein@Home search algorithms which have been improved from run to run, achieving an increasing search sensitivity.
Einstein@Home's first analysis used data from the "third science run" (S3) of LIGO. Processing of the S3 data set was conducted between 22 February 2005 and 2 August 2005. This analysis employed 60 segments from the LIGO Hanford 4-km detector totaling ten hours of data each. Each 10-hour segment was analyzed for CW signals by the volunteers computers using a matched-filtering
Matched filter
In telecommunications, a matched filter is obtained by correlating a known signal, or template, with an unknown signal to detect the presence of the template in the unknown signal. This is equivalent to convolving the unknown signal with a conjugated time-reversed version of the template...
technique. When all matched-filtering results were returned, the results from different segments were then combined in a "post-processing step" on the Einstein@Home servers via a coincidence scheme to further enhance the search sensitivity.
The results were published on the Einstein@Home webpages.
Work on the S4 data set (LIGO's fourth science run) was started interlaced with the S3 calculations, and had finished in July 2006.
This analysis used 10 segments of 30 hours from the LIGO Hanford 4-km detector and 7 segments of 30 hours from the LIGO Livingston 4-km detector. Besides the S4 data being more sensitive, also a more sensitive coincidence combination scheme was applied in the post-processing. The results of this search have led to the first scientific publication of Einstein@Home in Physical Review D.
Einstein@home has gained considerable attention of the world's distributed computing
Distributed computing
Distributed computing is a field of computer science that studies distributed systems. A distributed system consists of multiple autonomous computers that communicate through a computer network. The computers interact with each other in order to achieve a common goal...
community when an optimized application for the S4 data set analysis was developed and released in March 2006 by project volunteer Akos Fekete, a Hungarian programmer. Fekete improved the official S4 application and introduced SSE
Streaming SIMD Extensions
In computing, Streaming SIMD Extensions is a SIMD instruction set extension to the x86 architecture, designed by Intel and introduced in 1999 in their Pentium III series processors as a reply to AMD's 3DNow! . SSE contains 70 new instructions, most of which work on single precision floating point...
, 3DNow!
3DNow!
3DNow! is an extension to the x86 instruction set developed by Advanced Micro Devices . It adds single instruction multiple data instructions to the base x86 instruction set, enabling it to perform simple vector processing, which improves the performance of many graphic-intensive applications...
and SSE3
SSE3
SSE3, Streaming SIMD Extensions 3, also known by its Intel code name Prescott New Instructions , is the third iteration of the SSE instruction set for the IA-32 architecture. Intel introduced SSE3 in early 2004 with the Prescott revision of their Pentium 4 CPU...
optimizations into the code improving performance by up to 800%. Fekete was recognized for his efforts and was afterward officially involved with the Einstein@home team in the development of the new S5 application. As of late July 2006 this new official application became widely distributed among the Einstein@home users, creating a large surge in the project's total performance and productivity, best measured by floating point speed (or FLOPS
FLOPS
In computing, FLOPS is a measure of a computer's performance, especially in fields of scientific calculations that make heavy use of floating-point calculations, similar to the older, simpler, instructions per second...
), which has increased by approximately 50% compared to non-optimized S4 application.
The first Einstein@Home analysis of early LIGO S5 data set, where the instruments reached their design sensitivity for the first time, began on 15 June 2006. This search used 22 segments of 30 hours from the LIGO Hanford 4-km detector and 6 segments of 30 hours from the LIGO Livingston 4-km detector. This analysis run (code name "S5R1") employed the search methodology on Einstein@Home was very similar to the previous S4 analysis. However, the search results were still more sensitive due to using more data which also had improved quality compared to S4. Over large parts of the searched parameter space these results (which also appeared in Physical Review D
Physical Review
Physical Review is an American scientific journal founded in 1893 by Edward Nichols. It publishes original research and scientific and literature reviews on all aspects of physics. It is published by the American Physical Society. The journal is in its third series, and is split in several...
) are the most sensitive ones published to date.
The second Einstein@Home search of LIGO S5 data (code name "S5R3") has constituted once more a major improvement in terms of search sensitivity. In contrast to the previous searches, here the matched-filtering results from 84 data segments of 25 hours each, from both 4-km LIGO Hanford and Livingston instruments, were already combined on the volunteers' computers via a Hough transform
Hough transform
The Hough transform is a feature extraction technique used in image analysis, computer vision, and digital image processing. The purpose of the technique is to find imperfect instances of objects within a certain class of shapes by a voting procedure...
technique. The results of this search are currently undergoing further examination.
On May 7, 2010, a new Einstein@Home search (code name "S5GC1") has been launched which uses a significantly improved search method. This search analyses 205 data segments of 25 hours each, from both 4-km LIGO Hanford and Livingston instruments, using a technique which exploits global parameter-space correlations to efficiently combine the matched-filtering results from the different segments.
Radio data analysis and results
On March 24, 2009, it was announced that the Einstein@Home project is beginning to analyze data taken by the PALFA Consortium at the Arecibo ObservatoryArecibo Observatory
The Arecibo Observatory is a radio telescope near the city of Arecibo in Puerto Rico. It is operated by SRI International under cooperative agreement with the National Science Foundation...
in Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
.
On November 26, 2009, CUDA
CUDA
CUDA or Compute Unified Device Architecture is a parallel computing architecture developed by Nvidia. CUDA is the computing engine in Nvidia graphics processing units that is accessible to software developers through variants of industry standard programming languages...
-optimized application for Arecibo Binary Pulsar Search was announced, on official Einstein@home webpages. This application uses both a regular CPU plus NVIDIA
NVIDIA
Nvidia is an American global technology company based in Santa Clara, California. Nvidia is best known for its graphics processors . Nvidia and chief rival AMD Graphics Techonologies have dominated the high performance GPU market, pushing other manufacturers to smaller, niche roles...
GPU to perform the analysis faster (in some cases up to 50% faster).
In its analysis of radio data from the Arecibo Observatory, Einstein@Home has re-detected 134 different known radio pulsars that include 8 milli-second pulsars.
On August 12, 2010, the Einstein@Home project announced their discovery of a new disrupted binary pulsar, PSR J2007+2722
PSR J2007+2722
PSR J2007+2722 is a 40.8-hertz isolated pulsar in the Vulpecula constellation, 5.3 kpc distant in the plane of the Galaxy, and is most likely a Disrupted Recycled Pulsar ....
; it may be the fastest-spinning such pulsar discovered to date. The computers of Einstein@Home volunteers Chris and Helen Colvin and Daniel Gebhardt observed PSR 2007+2722 with the highest statistical significance.
On March 1, 2011, the Einstein@Home project announced their second discovery: binary pulsar PSR J1952+2630. The computers of Einstein@Home volunteers from Russia and UK observed PSR J1952+2630 with the highest statistical significance.
As of November 2011, the Einstein@Home project has discovered a total of 14 pulsars: ten using Parkes Multibeam Survey data and four using Arecibo radio data.