Several years after Duke University researchers announced spectacular behavior of a low density ultracold gas cloud, researchers at Brookhaven National Laboratory have observed strikingly similar properties in a very hot and dense plasma "fluid" created to simulate conditions when the universe was about one millionths of a second old.
The plasma was formed at a colossal 2 million degrees Kelvin temperatures within Brookhaven's Relativistic Heavy Ion Collider (RHIC). The gas cloud was cooled to only .1 millionths of a degree Kelvin temperatures using a laser light "trap" and magnetic field at Duke. But both drastically different systems expanded something like exploding cigars. And their constituent matter also showed signs of flowing almost free of any viscosity -- a "nearly perfect" fluid, said Duke physics professor John Thomas.
"There's about 19 orders of magnitude difference in temperature and about 25 orders of magnitude difference in density, but the commonality of both is almost zero viscosity flow," said Thomas.
Thomas will report on his laboratory's experiments with "fermion" gases and their possible relevance to RHIC's "quark-gluon plasma" research as well as to string theory during a Sunday, Feb. 15 symposium organized by Brookhaven during the American Association of Science's 2009 Annual meeting, to be held in Chicago.
In a November, 2002 report in the research journal Science, Thomas and co-researchers described what happened after they confined a cloud of lithium-6 atoms and cooled them to 100 billionths of a degree above absolute zero. When the ultracooled, cigar-shaped cloud was then released from the trap, it expanded "anisotropically," meaning "fastest along the direction that was initially narrow," he recalled.
Lithium atoms are of the fermion class, meaning that that their spin-states normally make them keep more of a distance from each other than their chummier counterpart class of atoms -- the bosons. But under the extreme conditions of his experiments, even fermions find ways to collide to form what are called "strong interactions," he said.
Brookhaven's RHIC is designed to smash gold atoms together near the speed of light. Its goal is to create energies colossal enough to break apart their nuclei into an ultrahot gas of the most fundamental particles, "naked" quarks and gluons. Theoreticians believe such a "quark-gluon plasma" has not existed since a split-second after the Big Bang.
As the results of those experiments began to surface in April, 2005, RHIC experimenters found that "the cigar shaped plasma looked very much like the cigar- shaped cloud in our trap," Thomas said. That cloud also expanded anisotropically in keeping with what theorists in the field had predicted. Researchers also found that this plasma behaved as an almost-perfect fluid. Meanwhile, further work by Thomas's group has documented almost viscosity-free fluid states in its cold fermion gases.
Thomas noted that quarks themselves are also fermions. "So there's quite a broad overlap, and a genuine common interest in these two patterns. We don't have exactly the same system as at RHIC. But in a broad sense there are similarities that could be exploited to get some insight."
Meanwhile, researchers involved in string theory have also approached Thomas about similarities between his fermion findings and the predicted behavior of what those theorists call "strongly interacting quantum fields," he said. "It's not clear, though, that the prediction has any relevance to Fermi atoms colliding in a trap. However, the closeness of the initial cold gas measurements to the predictions is striking."
Elements of string theory aim at bridging the gap between quantum mechanics and general relativity by proposing that the true fundamental particles are actually ultra-tiny strings vibrating in multiple dimensions.
Monte Basgall | EurekAlert!
New manifestation of magnetic monopoles discovered
08.12.2017 | Institute of Science and Technology Austria
NASA's SuperTIGER balloon flies again to study heavy cosmic particles
07.12.2017 | NASA/Goddard Space Flight Center
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."
Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...
08.12.2017 | Event News
07.12.2017 | Event News
05.12.2017 | Event News
08.12.2017 | Life Sciences
08.12.2017 | Information Technology
08.12.2017 | Information Technology