Astronomers have discovered a huge filament of hot gas bridging four galaxy clusters. At 10 times as massive as our galaxy, the thread could contain some of the universe’s ‘missing’ matter, addressing a decades-long mystery.
Category: space – Page 97
By measuring gases around young stars, astronomers unlock major clues to planet formation
An international team of scientists led by astronomers from the University of Wisconsin–Madison has produced the most accurate measurement of the gases swirling around young stars and how their mass changes over time. The discovery joins many pieces of a puzzle that may reveal which kinds of planets form—rocky Earth-types, gas giants like Jupiter, or balls of ice in the Neptune mold—as star systems mature.
Dramatic stretch in quantum materials confirms 100-year-old prediction
Research from the University of St Andrews has set a new benchmark for the precision with which researchers can explore fundamental physics in quantum materials. The work has implications extending from materials science to advanced computing, as well as confirming a nearly 100-year-old prediction.
The researchers explored magnetoelastic coupling, which is the change in the size or shape of a material when exposed to a magnetic field. It is usually a small effect, but one that has technological consequences.
A team from the School of Physics and Astronomy at the University of St Andrews has now discovered that this effect is remarkably large in a case where one wouldn’t have expected it—in a transition metal oxide. Oxides are a chemical compound containing at least one oxygen atom and one other element in its chemical formula. High-temperature superconductors are one of the most prominent examples of a transition metal oxide.
Is our universe the ultimate computer?
Whether we are simply characters in an advanced virtual world is a much-debated theory, challenging previous thinking about the universe and our existence.
The possibility that the entire universe is informational in nature and resembles a computational process is a popular theory among a number of well-known figures, including Elon Musk. The thinking comes from within a branch of science known as information physics, which suggests physical reality is actually made up of structured information.
In an article published in AIP Advances and included in the journal’s “Editor’s Picks,” a physicist from the University of Portsmouth, Dr. Melvin Vopson, presents findings which indicate that gravity or gravitational force is the result of a computational process within the universe.
Crystal melting and the glass transition obey the same physical law
The melting of crystals is the process by which an increase in temperature induces the disruption of the ordered crystalline lattice, leading to the disordered structure and highly fluctuating dynamic behavior of liquids. At the glass transition, where an amorphous solid (a glass) turns into a liquid, there is no obvious change in structure, and only the dynamics of the atoms change, going from strongly localized dynamics in space (in the glass state) to the highly fluctuating (diffusive) dynamics in the liquid.
The search for the atomic-scale mechanism of 3D crystal melting has a long history in physics, and famous physicists such as Max Born, Neville Mott and Frederick Lindemann proposed different ways to look at it. I have always had the impression that we still do not understand the melting of 3D crystals, which is a highly complicated cooperative process involving nonlinearly coupled dynamics of a huge number of atoms. This complexity I always found very fascinating.
Comparatively, the melting of 2D solids, mediated by dislocations-unbinding, is much better understood, and the theory that describes it led to the 2017 Nobel prize in physics for Kosterlitz and Thouless.
Hunga volcano eruption’s unexpected Southern Hemisphere cooling effect challenges geoengineering assumptions
When Hunga Tonga–Hunga Haʻapai, an underwater volcano near Tonga in the South Pacific Ocean, erupted in 2022, scientists expected that it would spew enough water vapor into the stratosphere to push global temperatures past the 1.5 C threshold set by the Paris Accords. A new UCLA-led study shows that not only did the eruption not warm the planet, but it actually reduced temperatures over the Southern Hemisphere by 0.1 C.
The reason: The eruption formed smaller sulfate aerosols that had an efficient cooling effect that unexpectedly outweighed the warming effect of the water vapor. Meanwhile, the water vapor interacted with sulfur dioxide and other atmospheric components, including ozone, in ways that did not amplify warming.
While that’s good news, the study also suggests that efforts to reverse climate change by loading the atmosphere with substances that react with solar radiation to send heat back out into space, an effort known as geoengineering, are potentially even riskier than previously thought and must take new complications into account.