Latest Physical Review Letters Stories

2011-06-10 13:31:46

In recent years, UC Santa Barbara scientists showed that they could reproduce a basic superconductor using Einstein's general theory of relativity. Now, using the same theory, they have demonstrated that the Josephson junction could be reproduced. The results are explained in a recent issue of the journal Physical Review Letters. The Josephson junction, a device that was first discovered by Brian David Josephson in the early 1960's, is a main ingredient in applications of superconductivity....

2011-06-08 07:10:00

A dark-matter experiment deep in the Soudan mine of Minnesota now has detected a seasonal signal variation similar to one an Italian experiment has been reporting for more than a decade. The new seasonal variation, recorded by the Coherent Germanium Neutrino Technology (CoGeNT) experiment, is exactly what theoreticians had predicted if dark matter turned out to be what physicists call Weakly Interacting Massive Particles (WIMPs). "We cannot call this a WIMP signal. It's just what you might...

2011-05-18 15:30:00

A biomechanical experiment conducted at the University of Pennsylvania School of Engineering and Applied Science has answered a long-standing theoretical question: Will microorganisms swim faster or slower in elastic fluids? For a prevalent type of swimming, undulation, the answer is "slower." Paulo Arratia, assistant professor of mechanical engineering and applied mechanics, along with student Xiaoning Shen, conducted the experiment. Their findings were published in the journal Physical...

2011-04-21 22:52:53

Scientists outline a test for the theory, which, if proven, would address major problems in particle physics Did the early universe have just one spatial dimension? That's the mind-boggling concept at the heart of a theory that University at Buffalo physicist Dejan Stojkovic and colleagues proposed in 2010. They suggested that the early universe -- which exploded from a single point and was very, very small at first -- was one-dimensional (like a straight line) before expanding to include two...

2011-04-11 14:00:07

When black holes slam into each other, the surrounding space and time surge and undulate like a heaving sea during a storm. This warping of space and time is so complicated that physicists haven't been able to understand the details of what goes on"”until now. "We've found ways to visualize warped space-time like never before," says Kip Thorne, Feynman Professor of Theoretical Physics, Emeritus, at the California Institute of Technology (Caltech). By combining theory with computer...

2011-03-10 18:27:56

New switching device could help build a dream: the ultrafast quantum Internet Northwestern University researchers have developed a new switching device that takes quantum communication to a new level. The device is a practical step toward creating a network that takes advantage of the mysterious and powerful world of quantum mechanics. The researchers can route quantum bits, or entangled particles of light, at very high speeds along a shared network of fiber-optic cable without losing the...

2011-02-26 06:05:00

A new study, published in Physical Review Letters and available online, offers that a controversial theory which challenges the existence of dark matter has been kept afloat by studies of gas-rich galaxies. Instead of calling upon dark matter, the Modified Newtonian Dynamics (MoND) theory says that the effects of gravity change in places where its pull is very low. A new paper suggests that MoND better predicts the relationship between gassy galaxies' rotation speeds and masses. However,...

2011-02-15 13:19:05

An important milestone toward the realization of a large-scale quantum computer, and further demonstration of a new level of the quantum control of light, were accomplished by a team of scientists at UC Santa Barbara and in China and Japan. The study, published in the Feb. 7 issue of the journal Physical Review Letters, involved scientists from Zhejiang University, China, and NEC Corporation, Japan. The experimental effort was pursued in the research groups of UCSB physics professors Andrew...

2011-02-10 07:49:08

Avogadro constant determined with enriched silicon-28 A milestone in the international Avogadro project coordinated by the Physikalisch-Technische Bundesanstalt (PTB) has been reached: With the aid of a single crystal of highly enriched 28Si, the Avogadro constant has now been measured as exactly as never before with a relative overall uncertainty of 3 "¢ 10-8. Within the scope of the redefinition of the kilogram, the value NA = 6.02214078(18) "¢ 1023 mol-1 permits the currently...

2011-02-09 13:12:40

Discovery of mini 'water hammer' effect could lead to materials that water really hates Researchers from Northwestern University and the Massachusetts Institute of Technology (MIT) have studied individual water droplets and discovered a miniature version of the "water hammer," an effect that produces the familiar radiator pipe clanging in older buildings. In piping systems, the water hammer occurs when fluid is forced to stop abruptly, causing huge pressure spikes that can rupture pipe walls....

Word of the Day
  • A Roman unit of weight, 1⁄1728 of a pound.
  • A weight of four grains used in weighing gold and precious stones; a carat.
  • In anatomy, a formation suggesting a husk or pod.
  • The lowest unit in the Roman coinage, the twenty-fourth part of a solidus.
  • A coin of base silver of the Gothic and Lombard kings of Italy.
'Siliqua' comes from a Latin word meaning 'a pod.'