Understanding Physics

Physicists have used nuclear magnetic resonance to investigate the destructive effects of the crystallization of salt

Admin — Tue, 12 Jul 2005 22:15:43 -0700

Salt-weathering is one of the main causes of rock disintegration in nature, particularly in deserts, polar regions and along coastlines. However, it is also a very widespread cause of damage to man-made constructions. Bridges, for example, are attacked by de-icing salts, and cities such as Bahrain, Abu Dhabi and Adelaide are affected by rising damp from high ground-water levels. Indeed, many examples of cultural heritage, including the Islamic sites of Bokhara and Petra in Jordan and the Sphinx in Egypt, may ultimately be destroyed due to the effects of salt-weathering.

Now Lourens Rijniers and colleagues at Eindhoven University in the Netherlands have developed a way to observe the solubility of various salts inside porous materials directly (Phys. Rev. Lett. 94 075503).

To read the full version of this article - and the rest of the May issue of Physics World - please subscribe to their print edition.

New Supercomputer Built For Physics Research

Admin — Tue, 28 Jun 2005 22:13:47 -0700

A new computer – the RIKEN BNL Research Center supercomputer – was unveiled today at a dedication ceremony at the U.S. Department of Energy's Brookhaven National Laboratory attended by physicists from around the world.

It is called QCDOC for quantum chromodynamics on a chip, and it was designed and built by Brookhaven Lab, Columbia University, IBM, RIKEN -- The Institute of Physical and Chemical Research in Japan, and the University of Edinburgh.

The computer has 10 teraflops of peak computing power, which makes it capable of performing 10 trillion arithmetic calculations per second, with sustained speeds of five teraflops.

The $5-million computer took three years to build and is funded by RIKEN, with infrastructure support from DOE's Office of Science.

Taking up only 100 square feet of floor space, the supercomputer is installed at Brookhaven Lab in the RIKEN-BNL Research Center, a physics research center formed by RIKEN and Brookhaven Lab in 1997. QCDOC achieves its ultra-fast speed by harnessing the power of 12,288 individual computers, each with its own memory and an extremely fast interprocessor communication network. Each processor is constructed on a single silicon chip, so the supercomputer is essentially 12,288 interconnected chips. This simple design leads to a low power requirement of about 100 kilowatts compared to the many megawatts typical of most commercial supercomputers.

QCDOC will be used for physics research for 90 percent of its operating time. With the help of the computer, physicists hope to determine the properties of a state of matter currently under intense study at Brookhaven's premiere accelerator, the Relativistic Heavy Ion Collider (RHIC). One of the major discoveries emerging from RHIC is the creation of a form of hot, dense (10 to 30 times denser than a nucleon) matter whose properties are consistent with those of a strongly coupled plasma of subatomic quarks and gluons – the so-called quark-gluon plasma that existed a few microseconds after the birth of the universe.

Related to this effort, the supercomputer will be used for calculations in quantum chromodynamics – the physics theory that describes the interactions of subatomic quarks and gluons. In particular, physicists hope to understand the reason for the existence of six types of quarks that have widely varied masses. With this powerful computer, they can disentangle quarks from their interactions with gluons to gain important data about both particles' properties.

During the remaining 10 percent of operating time, researchers will use the supercomputer to pursue scientific projects in a variety of fields, including biology and materials science.

The RIKEN-BNL QCDOC is one of three similar computers that have been built by the same team of collaborators. Funded by the Particle Physics and Astronomy Research Council in the United Kingdom, the second computer, now completed and beginning operation, is located at the University of Edinburgh, Scotland. The third, which is funded by DOE's Office of Science, will be located at Brookhaven Lab and used by a community of U.S. scientists for calculations in quantum chromodynamics. Now undergoing testing, the third QCDOC is due to be ready for operations by summer 2005. Working on related and sometimes different problems using these three supercomputers, researchers hope to make significant contributions in physics and other scientific fields.

Source: Brookhaven National Laboratory

New Robotic Arm could be cost-effective alternative to traditional therapy.

Admin — Sun, 26 Jun 2005 22:20:45 -0700

Arizona State University researchers and Tempe-based Kinetic Muscles, Inc., have developed a robotic arm to help stroke survivors regain the ability to perform basic tasks, such as reaching for objects or feeding themselves. The rehabilitative device aids in task-oriented repetitive therapy, and the hope is that it will provide a cost-effective alternative to traditional therapy. This would enable a wider population to regain maximum motor function.

Read the full story here.

The Biodesign Institute at Arizona State University integrates research in diverse disciplines including biology, engineering, medicine, physics, information technology and cognitive science. This approach is designed to accelerate discoveries that can be rapidly adopted by the private sector. For information, visit www.biodesign.asu.edu or call ( 480 ) 727-8322.

The Ira A. Fulton School of Engineering not only provides educational experience for engineering, computer science and construction students, it engages in use-inspired research in a multidisciplinary setting to benefit individuals, society and the environment. For more information, visit http://www.fulton.asu.edu.

Worldwide relay of lights at Princeton University

Admin — Sun, 24 Apr 2005 04:38:02 -0700

Posted to: Physics News

"PRINCETON, N.J. (AP) _ Physicists and Albert Einstein buffs around the world began flipping switches and dialing phones Monday night to commemorate World Year of Physics and the 50th anniversary of Einstein's death.

A worldwide relay of lights got under way at 8:45 p.m. with the illumination of the football stadium and two towers on the campus of Princeton University.

About 140 groups across the United States planned to illuminate everything from college campuses to private homes, said Claire Gmachl, an associate professor of electrical engineering at Princeton University who was organizing the campus' start of the relay.'

Click here to read the full article.

Updating Policy for the Handbook of Chemistry & Physics

Admin — Wed, 20 Apr 2005 14:51:38 -0700

Posted to: Physics News

"Each annual edition provides an opportunity to add new material, update/expand existing tables, and correct errors. Certainly, all errors that we have found or that have been brought to our attention by users are corrected in each new edition. We typically introduce five or six new topics each year, and five to ten existing tables are updated or expanded. The net result is the at least 5% of the book is substantially changed each year. In some years, when a very long table is updated, the changes can amount to 10-20%." - Read More