Content about Physics

  Feature - Grid technology, relativity and the Aurora Borealis Relativity—it’s everywhere. Observers of the Aurora Borealis are witnessing a union between quantum theory and the theory of relativity. Visscher uses this image as a visible example of relativistic effects in atoms. Image courtesy of the University Corporation for Atmospheric Research If you’ve visited Helsinki or Anchorage, you may have seen visible proof of Einstein’s theory of special relativity: the red color in the Aurora Borealis. The atoms forming our atmosphere—mostly oxygen and nitrogen—don’t move fast enough to display relativistic effects, but lightweight particles in these atoms—the electrons—do.     “Electrons can move at about 10% the speed of light,” says Lucas Visscher, theoretical chemist at Vrije University Amsterdam in the Netherlands. “At this speed we begin to see noticeable effects of relativity.” These effects come about because electrons spin as

  Feature - DZero: Doing Double DutySummer 2006: A new layer of silicon detector is ready to fit in the center of the DZero detector.Image courtesy of Dmitri Densiov, FermilabOn the hunt for physics beyond the Standard Model, some DZero physicists search for traces of super-symmetry, lepto-quarks, quark substructure and other curiosities. Others continue to probe the Model, the theoretical backbone of modern high energy physics, by making ever more precise measurements. DZero, located at Fermi National Accelerator Laboratory, Illinois, U.S., is a “general-purpose high energy physics experiment.” As such, the DZero detector slices and dices a broad range of particles and phenomena that only Fermilab’s Tevatron, currently the world’s highest energy particle accelerator, can produce.Last summer the DZero detector was treated to a substantial upgrade, including the addition of new components. After any significant change to a detector, a precise calibration is required to properly quantify subsequent data.&n

Image of the Week - LHC Family Album Schematics of the detectors for the main physics experiments at the Large Hadron Collider.Image courtesy the ALICE, ATLAS, CMS and LHCb experimental collaborations  When the Large Hadron Collider at CERN, Europe’s center for high energy physics, begins colliding particles in 2008 it will provide proton collisions for four large physics experiments that will expand our understanding of the workings of the universe. The ATLAS and CMS collaborations designed multi-purpose detectors; these will hunt for the Higgs boson, traces of supersymmetry and evidence of extra dimensions, among other things. ALICE aims to study the quark-gluon plasma, a new phase of matter expected at extreme energy densities. LHCb will examine beauty quark physics. Photos of the people, equipment and recent activities of the LHC experiments are posted on the CERN Document Server.

Feature - Experiment Dashboard for the LHCA snapshot of the ATLAS distributed data management monitoring from Experiment Dashboard. Click for full image.Image courtest of Experiment Dashboard“This project started from some users saying that the grid does not work,” says Julia Andreeva, who works in CERN’s IT department.Andreeva coordinates a project that aims to show, from the user perspective, exactly what is working in a grid and what is not. The prototype for this project—Experiment Dashboard—began running in October 2005, monitoring jobs for the Compact Muon Solenoid physics experiment at CERN’s Large Hadron Collider. The Experiment Dashboard now provides monitoring service for all four main LHC experiments. With it, researchers can access information about job processing, data management, test transfers and site efficiency. At the beginning of this year the project reached significant milestones: putting a data management monitoring system for the ATLAS experiment into product

Feature - Fermilab Postdoc Gets Word out About the Grid Oliver Gutsche in his office at Fermilab.Image courtesy of Christine Buckley, FermilabOliver Gutsche, a postdoctoral researcher at Fermilab in Batavia, Illinois, U.S., and member of the Compact Muon Solenoid collaboration, participated in the Midwest Grid Workshop at the University of Illinois in Chicago, held March 24–25, where he taught students and scientists how to make the grid best work for them and their science. No stranger to science communication, Gutsche has enjoyed talking about physics since he gave organized tours to neighbors and visitors at DESY, a center for physics research in Germany, during his graduate school days. “In my opinion, the public usually thinks that we physicists just sit in our ivory towers,” he says. “Informing the public helps in changing this.”At the workshop, Gutsche demonstrated the submission of several jobs to the grid; he calls his demo “Discovering the Higgs on OSG.” The grid concept employs i

Feature - Captured in Ice Sky map from the AMANDA neutrino telescope showing the 1,112 atmospheric neutrino candidates observed, plotted in coordinates of right ascension and declination. The locally produced atmospheric neutrino background detected to date is quite uniform, without strong sources. Scale on right reflects excess or deficit from mean background events. Image courtesy of Andrea Silvestri, AMANDA, UCI As scientists explore the most violent phenomena in the universe, the tiny, almost massless particles called neutrinos are valuable messengers, traveling unimpeded across the vast distances of space. “By analyzing neutrino data on the TeraGrid we’ve been able to validate a new kind of ‘telescope’ that gives a dramatic new view of the universe through the window of high-energy neutrinos,” says University of California at Irvine astrophysicist Andrea Silvestri. “This can help scientists unravel a number of longstanding mysteries about the origin and apparent surplus of the high

Feature - Gridifying Geant4Simulation of the nuclear reaction of a cosmic-ray proton in one of the inertial sensors of the Laser Interferometer Space Antenna. LISA is a joint ESA-NASA mission for the first space-borne gravitational wave detector. Image courtesy of Geant4 Twice a year a new version of the Geant4 software is released to the research community. Geant4, a software toolkit that simulates the interactions of particles with scientific instruments, is used by high-energy physicists, space scientists, medical physicists and radiation researchers. These simulations can help engineers alter instrument design for optimal performance or teach researchers how to best analyze their data.Before a release, the new version of Geant4 must be carefully tested. Evaluators from the Geant4 development team compare the simulation results of two previous Geant4 versions, looking for significant differences. Since December 2004, these tests have been run at several Worldwide LHC Computing Grid sites using the EGEE infrastructure. Grid comput

Feature - Widening the Gateway to India The “Gateway to India” in Mumbai. By typing in a simple command on Monday 12 February 2007, Gavin McCance initiated the first file transfer between CERN and India on the Worldwide LHC Computing Grid. Connection via the WLCG will give Indian researchers the same level of access to Large Hadron Collider particle physics experiments as researchers in European or North American countries. “It’s a good feeling to be involved in a collaboration like this,” says McCance,  of the WLCG and CERN. The file transfer, containing one gigabyte of test data, reached India in less then seven minutes and represents the first drop of an imminent deluge on the WLCG transfer service. Once the CERN Large Hadron Collider is generating particle physics data, the WLCG, which runs on EGEE and Open Science Grid infrastructures, will be needed to manage and process the files. Since the amount of data generated will be larger than one institution could handle, the task of storing a

Feature: Preparing for the Large Hadron Collider Close to 300 members of the WLCG collaboration attended a recent workshop at CERN. Those in attendence represented 27 countries and 86 sites.Image courtesy of Will Venters.  Processing data for the Large Hadron Collider, the next-generation particle accelerator under construction at CERN, Switzerland, is one of the driving forces for development of grid technology. The task of processing the 15 petabytes of data the LHC is predicted to generate each year falls to the Worldwide LHC Computing Grid Collaboration, which recently met at CERN for a week-long workshop in preparation for the start-up of the LHC later this year.“WLCG doesn’t have its own grid,” explained WLCG’s Jamie Shiers. “It uses grids from several different projects. We use two major grid infrastructures: EGEE in Europe, and OSG in the United States, as well as many individual research centers. Th

Feature: Caltech and TeraGrid See the Big Picture    The Samuel Oschin telescope at the Palomar Observatory in California.Courtesy of Palomar Observatory. The Griffith Observatory in Los Angeles recently unveiled a spectacular new display during its grand re-opening. The “Big Picture,” an image of the Virgo Galaxy Cluster 150 feet wide and 18 feet high, recorded for posterity on porcelain-enameled steel tiles, was created using data from the Palomar-QUEST sky surveys that were processed using TeraGrid resources.“The observatory came up with this idea five or six years ago, that a single image of the sky would cover the main wall of their new exhibit hall,” says Caltech astronomer George Djorgovski. “Palomar-QUEST surveys 1.25% of the entire sky each night, and covers the same areas multiple times. By the end of the survey we’ll cover 15,000 square degrees, or 40% of the entire sky.” Even the Big Picture, huge by

Image of the Week: Understanding Galactic Phenomena Computational simulations of magnetically confined plasma jets. Image courtesy Rachid Ouyed, University of Calgary To date, theoretical models have aided researchers as they strive to understand the basic physics underlying galactic phenomena. Rachid Ouyed from the physics and astronomy department at the University of Calgary uses WestGrid computing resources to create computational simulations of magnetically confined plasma jets, propelling his models into a three-dimensional state. Simulations like these could unlock some of the secrets behind the origin and behavior of plasma jets.