A distributed system consists of a collection of singled-out computers that have been connected through a network and distribution middleware, which enables these computers to organize their activities and share the resources of the system, so that the users of the distributed system perceive them as a single, integrated computing facility ("Distributed Systems Principles."). An application of distributed systems is two pulsars on Einstein@Home project.
Einstein@Home is a distributed computing project that runs on volunteers' computers and searches for gravitational waves in LIGO data and binary pulsars in Arecibo PALFA data. "J2007+27 is an isolated pulsar with a period of 24.49 ms. Einstein@Home's unusually large duty cycle and the presence of emission almost throughout the rotation period suggests that its magnetic and spin axes are nearly aligned. Limits on the period derivative, magnetic field, and age indicate that this is the fastest-spinning disrupted recycled pulsar known to date. J1952+26 has a period of 20.73 ms and is in a 7-hour binary. Assuming a pulsar mass of 1.4 Msun, the system's mass function indicates that the minimum companion mass is 0.95 Msun. The companion is likely a neutron star or a massive white dwarf, which makes the system an excellent candidate for Shapiro delay measurement and therefore an accurate estimate of the pulsar and companion masses" ("Two Pulsar Discoveries from ... Project").
"Einstein@Home searches data from the US Laser Interferometer Gravitational wave Observatory (LIGO) and the British/German GEO-600 gravitational wave observatory for signals coming from very dense, rapidly rotating compact quark and neutron stars. Einstein's theory predicts that if these compact stars are not perfectly spherical, they should continuously emit gravitational waves. LIGO and GEO-600 are now sufficiently sensitive that they might detect these signals if the stars are close enough to earth. Finding such signals in gravitational wave data requires an enormous amount of computing power. Estimates indicate that searching gravitational data with the maximum possible sensitivity would require many times the computing capacity of even the most powerful supercomputer." In essence, the Scientific Collaboration researchers from the Albert Einstein Institute, UWM, and the LIGO Laboratory allow private or home computer users to analyze the data. The Einstein@Home software program is available for PCs running Windows, Linux, and Mac operating systems" ("Project 'Einstein@Home'...Waves").
The private computers are essentially used to process the LIGO and GEO 600 data. The computer users can easily download the specified software onto their computers that receives data from a central server. The private computers usually process the data when they are not being used for other things, such as the surfing the internet or word processing. The computers then send the processed data back to the server, so it can get more data to analyze. Being an efficient distributed system, Einstein@Home doesn't affect how computers perform and you can stop the process at anytime ("Einstein@Home.").
"Two Pulsar Discoveries from the Einstein@Home Distributed Computing Project."
Two Pulsar Discoveries from the Einstein@Home Distributed Computing Project. N.p., n.d. Web.
Sept. 2012. http://adsabs.harvard.edu/abs/2011AAS...21723405D.
"Project 'Einstein@Home' Goes Live: Distributed Computing Project To Search For Gravitational Waves."
ScienceDaily. ScienceDaily, 03 Mar. 2005. Web.
Sept. 2012. http://www.sciencedaily.com/releases/2005/02/050223145425.htm.
"Einstein@Home." Einstein@Home. N.p., n.d. Web.
Sept. 2012. http://www.physicscentral.org/experiment/einsteinathome/index.cfm.
Distributed Systems Principles." N.p., n.d. Web.
Sept. 2012. http://www0.cs.ucl.ac.uk/staff/ucacwxe/lectures/ds98-99/dsee3.pdf.