The emperor has no clothes on, but they sure are having fun.=0A= =0A= Largest-ever cosmological simulation to shed new light on dark matter=0A= 6 million NASA cpu hours to simulate evolution of an E9 light year=0A= sided cube of the universe using the "Lambda Cold Dark Matter" model=0A= (http://en.wikipedia.org/wiki/Lambda-CDM_model)=0A= =0A= http://www.gizmag.com/bolshoi-cosmological-simulation-dark-matter/20028/= =0A= =0A= Article has pictures and nicer formatting=0A= =0A= **** NB ****=0A= =0A= 6 of the resulting research papers are available here - free=0A= full versions.=0A= =0A= http://hipacc.ucsc.edu/Bolshoi/Papers.html=0A= =0A= These will probably turn into for $ versions after publication.=0A= =0A= =0A= =0A= Russell McMahon=0A= =0A= NASA Pleiades supercomputer=0A= http://www.nasa.gov/home/hqnews/2011/jun/HQ-11-194_Supercomputer_Ranks.html= =0A= =0A= The team=0A= http://hipacc.ucsc.edu/Bolshoi/Collaborators.html=0A= =0A= =0A= =0A= =0A= =0A= =0A= _____________________________.=0A= =0A= =0A= Largest-ever cosmological simulation to shed new light on dark matter=0A= By=A0Jan Belezina=0A= 00:17 October 4, 2011=0A= =0A= The Bolshoi* is a cosmological simulation of unprecedented scale and=0A= unparalleled accuracy. Crunching tons of observational input data=0A= necessary to build this enormous model took Pleiades, a supercomputer=0A= based at NASA Ames Research Center, a whooping 6 million CPU hours.=0A= The results - all 90 terabytes of them - allow us to glimpse the=0A= evolution of a representative section of our universe at 180 different=0A= time steps, from the Big Bang to the present day. Now this wealth of=0A= data is going to be made publicly available to scientists, arming them=0A= with tools that should make cracking the mysteries of dark matter,=0A= dark energy and galaxy formation much more feasible.=0A= =0A= Of course, even the=A0mighty Pleiades=A0would not be able to handle an=0A= endless sea of data related to the limitless Cosmos. The simulation=0A= needed to describe a defined space, so the researchers decided to=0A= focus their attention on a huge cubic chunk of the universe with each=0A= side one billion light years long. Now imagine the task of following=0A= 8.6 billion particles of dark matter as they scatter in a space that=0A= would contain over a million galaxies. No wonder the resulting=0A= visualizations are breathtaking.=0A= =0A= However, pleasing the eye was not the only goal the=A0international team=0A= of scientistslead by Joel R. Primack of University of California at=0A= Santa Cruz and Anatoly Klypin of New Mexico State University wanted to=0A= achieve. Their immediate intention was to model the evolution of dark=0A= matter halos. In the greater scheme of things, their desire was to=0A= harness supercomputing to introduce cosmology into the realm of=0A= experimental science.=0A= =0A= The input data fed to the supercomputer were obtained from earth- and=0A= space-based observations conducted over the course of five years by=0A= the NASA Explorer mission WMAP (the Wilkinson Microwave Anisotropy=0A= Probe). Meticulous measurements of the Big Bang's remnant radiant heat=0A= revealed a great deal about the history and composition of the=0A= universe and proved a wonderful raw material for cosmological=0A= simulations. The theoretical backbone for the simulation was provided=0A= by the=A0Lambda Cold Dark Matter=A0(or =CBCDM) model, which offers the=0A= currently prevailing explanation of the origin of the Cosmos. It=0A= postulates that an overwhelming majority of mass in the universe can=0A= be accounted for by Cold Dark Matter and Dark Energy, and it strives=0A= to explain, among other things, the large scale structure of galaxy=0A= clusters.=0A= =0A= The Bolshoi simulation reveals an intricate web of dark matter that=0A= underlies this structure. It shows how dark matter interacts with the=0A= visible universe through its gravitational effects, and how it=0A= contributes to the formation of galaxies and galaxy clusters.=0A= =0A= This important work opens the=A0list of new scientific papers=A0based on=0A= data retrieved from the simulation. As the Bolshoi-generated data=0A= turns out to be in general agreement with the observable Universe, we=0A= can be sure this list is going to grow very quickly.=0A= =0A= * Bolshoi is the Russian term for "great" or "grand".=0A= =0A= -- =0A= http://www.piclist.com PIC/SX FAQ & list archive=0A= View/change your membership options at=0A= http://mailman.mit.edu/mailman/listinfo/piclist=0A= .