MilkyWay@Home
Encyclopedia
MilkyWay@home is a volunteer 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...

 project in astrophysics
Astrophysics
Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...

 running on the Berkeley Open Infrastructure for Network Computing
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,...

 (BOINC) platform. Using spare computing power from over 38,000 computers run by over 27,000 active volunteers as of November 2011, the MilkyWay@home project aims to generate accurate three-dimensional dynamic models of stellar streams in the immediate vicinity of our Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...

 galaxy. With 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...

 and Einstein@home
Einstein@Home
Einstein@Home is a volunteer distributed computing project hosted by the University of Wisconsin–Milwaukee and the Max Planck Institute for Gravitational Physics . The project is directed by Bruce Allen...

, it is the third computing project of this type that has the investigation of phenomena in interstellar space as its primary purpose. Its secondary objective is to develop and optimize algorithms for distributed computing.

Purpose and design

MilkyWay@home is a collaboration between the Rensselaer Polytechnic Institute
Rensselaer Polytechnic Institute
Stephen Van Rensselaer established the Rensselaer School on November 5, 1824 with a letter to the Rev. Dr. Samuel Blatchford, in which van Rensselaer asked Blatchford to serve as the first president. Within the letter he set down several orders of business. He appointed Amos Eaton as the school's...

's departments of Computer Science
Computer science
Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

 and Physics, Applied Physics and Astronomy and is supported by the U.S. National Science Foundation
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...

. It is operated by a team that includes astrophysicist Heidi Jo Newberg
Heidi Jo Newberg
Heidi Jo Newberg is an American astrophysicist known for her work in understanding the structure of our Milky Way galaxy...

 and computer scientists Malik Magdon-Ismail, Boleslaw Szymanski
Boleslaw Szymanski
Boleslaw Karl Szymanski is a Professor at the Department of Computer Science and the Founding Head of the Center for Pervasive Computing and Networking, Rensselaer Polytechnic Institute. He's known for multiple contributions into computer science, including Szymanski's Algorithm.-Current Work:Dr...

 and Carlos A. Varela.

By mid-2009 the project's main astrophysical interest is in the Sagittarius stream, a stellar stream emanating from the Sagittarius Dwarf Elliptical Galaxy
Sagittarius Dwarf Elliptical Galaxy
The Sagittarius Dwarf Elliptical Galaxy is an elliptical loop-shaped satellite galaxy of the Milky Way Galaxy. It consists of four globular clusters, the main cluster being discovered in 1994...

 which partially penetrates the space occupied by the Milky Way and is believed to be in an unstable orbit around it, probably after a close encounter or collision with the Milky Way which subjected it to strong galactic tide
Galactic tide
A galactic tide is a tidal force experienced by objects subject to the gravitational field of a galaxy such as the Milky Way. Particular areas of interest concerning galactic tides include galactic collisions, the disruption of dwarf or satellite galaxies, and the Milky Way's tidal effect on the...

 forces. Mapping such interstellar streams and their dynamics with high accuracy is expected to provide crucial clues for understanding the structure, formation, evolution, and gravitational potential distribution of the Milky Way and similar galaxies. It could also provide insight on the dark matter
Dark matter
In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...

 issue. As the project evolves it might turn its attention to other starstreams.

Using data from the Sloan Digital Sky Survey
Sloan Digital Sky Survey
The Sloan Digital Sky Survey or SDSS is a major multi-filter imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project was named after the Alfred P...

, MilkyWay@home divides starfields into wedges of about 2.5 deg. width and applies self-optimizing probabilistic separation techniques (i.e., evolutionary algorithms) to extract the optimized tidal streams. The program then attempts to create a new, uniformly dense wedge of stars from the input wedge by removing streams of data. Each stream removed is characterized by 6 parameters: percent of stars in the stream; the angular position in the stripe; the three spatial components (two angles, plus radial distance from Earth) defining the removed cylinder; and a measure of width. For each search, the server application keeps track of a population of individual stars, each of which is attached to a possible model of the Milky Way.

Project details and statistics

MilkyWay@home has been active since 2007, and optimized client applications for 32-bit
32-bit
The range of integer values that can be stored in 32 bits is 0 through 4,294,967,295. Hence, a processor with 32-bit memory addresses can directly access 4 GB of byte-addressable memory....

 and 64-bit
64-bit
64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s...

 operating systems became available in 2008. Its screensaver capability is limited to a revolving display of users' BOINC statistics, with no graphical component.

The workunits that are sent out to clients used to require only 2–4 hours of computation on modern CPUs, however they were scheduled for completion with a short deadline (typically, 3 days). By early 2010 the project routinely sent much larger units that take 15–20 hours of computation time on the average processor core, and are valid for about a week from download. This makes the project less suitable for computers that are not in operation for periods of several days, or for user accounts that do not allow BOINC to compute in the background.

The project's data throughput progress has been very dynamic recently. In mid-June 2009, the project had about 24,000 registered users and about 1,100 participating teams in 149 countries, and was operating at 31.7 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...

. , these figures were at 44,900 users and 1,590 teams in 170 countries, but average computing power had jumped to 1,382 TFlops, which would rank MilkyWay@home second among 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. MilkyWay@home is currently the 2nd largest distributed computing project behind Folding@Home
Folding@home
Folding@home is a distributed computing project designed to use spare processing power on personal computers to perform simulations of disease-relevant protein folding and other molecular dynamics, and to improve on the methods of doing so...

 which crossed 5,000 TFlops in 2009.

That data throughput massively outpaced new user acquisition is mostly due to the deployment of client software that uses commonly available medium and high performance graphics processing units (GPUs) for numerical operations in Windows and Linux environments. MilkyWay@home 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...

 code for a broad range of 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...

 GPUs was first released on the project's code release directory on June 11, 2009 following experimental releases in the MilkyWay@home(GPU) fork of the project. An application for ATI Technologies
ATI Technologies
ATI Technologies Inc. was a semiconductor technology corporation based in Markham, Ontario, Canada, that specialized in the development of graphics processing units and chipsets. Founded in 1985 as Array Technologies Inc., the company was listed publicly in 1993 and was acquired by Advanced Micro...

 GPUs is also available and currently outperforming the CUDA application. For example, a task that requires 10 minutes using an AMD
Ati
As a word, Ati may refer to:* Ati, a town in Chad* Ati, a Negrito ethnic group in the Philippines* Ati-Atihan Festival, an annual celebration held in the Philippines* Ati, a queen of the fabled Land of Punt in Africa...

 HD3850
Radeon R600
The graphics processing unit codenamed the Radeon R600 is the foundation of the Radeon HD 2000/3000 series and the FireGL 2007 series video cards developed by ATI Technologies...

 GPU or 5 minutes using an AMD
Ati
As a word, Ati may refer to:* Ati, a town in Chad* Ati, a Negrito ethnic group in the Philippines* Ati-Atihan Festival, an annual celebration held in the Philippines* Ati, a queen of the fabled Land of Punt in Africa...

 HD4850
Radeon R700
The Radeon R700 is the engineering codename for a graphics processing unit series developed by Advanced Micro Devices under the ATI brand name. The foundation chip, codenamed RV770, was announced and demonstrated on June 16, 2008 as part of the FireStream 9250 and Cinema 2.0 initiative launch media...

 GPU, requires 6 hours using one core of an AMD Phenom II
Phenom II
Phenom II is a family of AMD's multi-core 45 nm processors using the AMD K10 microarchitecture, succeeding the original Phenom. Advanced Micro Devices released the Socket AM2+ version of Phenom II in December 2008, while Socket AM3 versions with DDR3 support, along with an initial batch of...

 processor at 2.8 GHz.

Scientific results

Large parts of the MilkyWay@home project build on the thesis of Nathan Cole which has been published in the highly reputed Astrophysical Journal
Astrophysical Journal
The Astrophysical Journal is a peer-reviewed scientific journal covering astronomy and astrophysics. It was founded in 1895 by the American astronomers George Ellery Hale and James Edward Keeler. It publishes three 500-page issues per month....

. Other results have been presented at several astrophysical and computing congresses.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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