By Steve Koppes Aug 3 2017 UChicago physicists play leading role in confirming theory predicted four decades ago In 1,974 a Fermilab physicist predicted a new way for ghostly particles called neutrinos to interact with…
A transparent layer can retard UV rays and moisture, but some conservators worry about application and suitability for aging oil paint.
Remember the philosophical argument our universe is a simulation? Well, a team of astrophysicists say they’ve created the biggest simulated universe yet. But you won’t find any virtual beings in it—or even planets or stars.
The simulation is 9.6 billion light-years to a side, so its smallest structures are still enormous (the size of small galaxies). The model’s 2.1 trillion particles simulate the dark matter glue holding the universe together.
Continue reading “The Biggest Simulation of the Universe Yet Stretches Back to the Big Bang” »
The goal of tackling global warming by turning carbon dioxide into fuel could be one step closer with researchers using a supercomputer to identify a group of “single-atom” catalysts that could play a key role.
Researchers from QUT’s Centre for Materials Science, led by Associate Professor Liangzhi Kou, were part of an international study that used theoretical modelling to identify six metals (nickel, niobium, palladium, rhenium, rhodium, zirconium) that were found to be effective in a reaction that can convert carbon dioxide into sustainable and clean energy sources.
The study published in Nature Communications involved QUT researchers Professor Aijun Du, Professor Yuantong Gu and Dr. Lin Ju.
Scientists managed to arrange the electrons into a honeycomb-like lattice by sandwiching them in an electric field between two atom-thin layers of tungsten compounds, according to research published in the journal Nature last week. The ability to tame them — which scientists accomplished by exploiting the tiniest differences in the atomic structures of the two tungsten layers — marks an incredible experimental achievement that has, until now, eluded the most accomplished labs in physics.
Other researchers have claimed that they created Wigner crystals in the past, and Nature News notes that they had some convincing evidence. But no one’s actually presented imaged evidence of their crystal before, study coauthor and University of California, Berkeley physicist Feng Wang told Nature News in the physicist’s version of a microphone drop.
“If you say you have an electron crystal, show me the crystal,” he said.
Since the discovery of superconductivity in Sr2RuO4 in 1,994 hundreds of studies have been published on this compound, which have suggested that Sr2RuO4 is a very special system with unique properties. These properties make Sr2RuO4 a material with great potential, for example, for the development of future technologies including superconducting spintronics and quantum electronics by virtue of its ability to carry lossless electrical currents and magnetic information simultaneously. An international research team led by scientists at the University of Konstanz has been now able to answer one of the most interesting open questions on Sr2RuO4: why does the superconducting state of this material exhibit some features that are typically found in materials known as ferromagnets, which are considered being antagonists to superconductors? The team has found that Sr2RuO4 hosts a new form of magnetism, which can coexist with superconductivity and exists independently of superconductivity as well. The results have been published in the current issue of Nature Communications.
After a research study that lasted several years and involved 26 researchers from nine different universities and research institutions, the missing piece of the puzzle seems to have been found. Alongside the University of Konstanz, the universities of Salerno, Cambridge, Seoul, Kyoto and Bar Ilan as well as the Japan Atomic Energy Agency, the Paul Scherrer Institute and the Centro Nazionale delle Ricerche participated in the study.
It’s not often that messing around in the lab has produced a fundamental breakthrough, à la Michael Faraday with his magnets and prisms. Even more uncommon is the discovery of the same thing by two research teams at the same time: Newton and Leibniz come to mind. But every so often, even the rarest of events does happen. The summer of 2021 has been a banner season for condensed-matter physics. Three separate teams of researchers have created a crystal made entirely of electrons — and one of them actually did it by accident.
The researchers were working with single-atom-thick semiconductors, cooled to ultra-low temperatures. One team, led by Hongkun Park along with Eugene Demler, both of Harvard, discovered that when very specific numbers of electrons were present in the layers of these slivers of semiconductor, the electrons stopped in their tracks and stood “mysteriously still.” Eventually colleagues recalled an old idea having to do with Wigner crystals, which were one of those things that exist on paper and in theory but had never been verified in life. Wigner had calculated that because of mutual electrostatic repulsion, electrons in a monolayer would assume a tri-grid pattern.
“While there have been published doubts raised about the accuracy of some of this CMB data, taken at face value it appears we may not have the right understanding, and it changes how big the Hubble constant should be today,” Riess said at the time.
“This surprising finding may be an important clue to understanding those mysterious parts of the universe that make up 95% of everything and don’t emit light, such as dark energy, dark matter and dark radiation.” Given its breadth and scope, astronomers around the world have taken the findings of Riess and his colleagues very seriously. After all, in 2011 Riess had shared the Nobel Prize in Physics for the initial discovery that the universe wasn’t just expanding, but that the rate at which it was doing so was also increasing.
Erik Verlinde of the University of Amsterdam has spent much of his time since 2010 attempting to develop a totally new theory of gravity, one that explains such observations without the need to invoke the likes of dark matter and dark energy. This resulted in his theory of emergent gravity, so-called because gravity is not a fundamental force after all, but an emergent phenomenon, similar to temperature emerging from the movement of particles.
BepiColombo will fly by the planet’s night side, so images during the closest approach wouldn’t be able to show much detail.
The mission team anticipates the images will show large impact craters that are scattered across Mercury’s surface, much like our moon. The researchers can use the images to map Mercury’s surface and learn more about the planet’s composition.
Some of the instruments on both orbiters will be turned on during the flyby so they can get a first whiff of Mercury’s magnetic field, plasma and particles.
Unplanned discovery could lead to future pivotal discoveries in batteries, fuel cells, devices for converting heat to electricity and more.
Scientists normally conduct their research by carefully selecting a research problem, devising an appropriate plan to solve it and executing that plan. But unplanned discoveries can happen along the way.
Mercouri Kanatzidis, professor at Northwestern University with a joint appointment in the U.S. Department of Energy’s (DOE) Argonne National Laboratory, was searching for a new superconductor with unconventional behavior when he made an unexpected discovery. It was a material that is only four atoms thick and allows for studying the motion of charged particles in only two dimensions. Such studies could spur the invention of new materials for a variety of energy conversion devices.
