. Scientific Frontline: Physics
Showing posts with label Physics. Show all posts
Showing posts with label Physics. Show all posts

Wednesday, March 13, 2024

Explaining a supernova’s ‘string of pearls’

The simulation shows the shape of the gas cloud on the left and the vortices, or regions of rapidly rotating flow, on the right. Each ring represents a later time in the evolution of the cloud. It shows how a gas cloud that starts as an even ring with no rotation becomes a lumpy ring as the vortices develop. Eventually the gas breaks up into distinct clumps.
Illustration Credit: Michael Wadas, Scientific Computing and Flow Laboratory

Physicists often turn to the Rayleigh-Taylor instability to explain why fluid structures form in plasmas, but that may not be the full story when it comes to the ring of hydrogen clumps around supernova 1987A, research from the University of Michigan suggests.

In a study published in Physical Review Letters, the team argues that the Crow instability does a better job of explaining the “string of pearls” encircling the remnant of the star, shedding light on a longstanding astrophysical mystery.

“The fascinating part about this is that the same mechanism that breaks up airplane wakes could be in play here,” said Michael Wadas, corresponding author of the study and a graduate student in mechanical engineering at the time of the work.

In jet contrails, the Crow instability creates breaks in the smooth line of clouds because of the spiraling airflow coming off the end of each wing, known as wingtip vortices. These vortices flow into one another, creating gaps—something we can see because of the water vapor in the exhaust. And the Crow instability can do something that Rayleigh-Taylor could not: predict the number of clumps seen around the remnant.

“The Rayleigh-Taylor instability could tell you that there might be clumps, but it would be very difficult to pull a number out of it,” said Wadas, who is now a postdoctoral scholar at the California Institute of Technology.

New research on tungsten unlocks potential for improving fusion materials

Through a combination of modeling and state-of-the-art experimental techniques, researchers shed light on the complex behavior of phonons in tungsten. This advancement could lead to the development of more efficient and resilient fusion reactor materials.
Image Credit: Courtesy of SLAC National Accelerator Laboratory

In the pursuit of clean and endless energy, nuclear fusion is a promising frontier. But in fusion reactors, where scientists attempt to make energy by fusing atoms together, mimicking the sun's power generation process, things can get extremely hot. To overcome this, researchers have been diving deep into the science of heat management, focusing on a special metal called tungsten.

New research, led by scientists at the Department of Energy’s SLAC National Accelerator Laboratory, highlights tungsten's potential to significantly improve fusion reactor technology based on new findings about its ability to conduct heat. This advancement could accelerate the development of more efficient and resilient fusion reactor materials. Their results were published today in Science Advances.

"What excites us is the potential of our findings to influence the design of artificial materials for fusion and other energy applications," said collaborator Siegfried Glenzer, director of the High Energy Density Division at SLAC. “Our work demonstrates the capability to probe materials at the atomic scale, providing valuable data for further research and development."

Scientists reveal the first unconventional superconductor that can be found in mineral form in nature

A miassite crystal grown by Paul Canfield.
Photo Credit: Paul Canfield

Scientists from Ames National Laboratory have identified the first unconventional superconductor with a chemical composition also found in nature. Miassite is one of only four minerals found in nature that act as a superconductor when grown in the lab. The team’s investigation of miassite revealed that it is an unconventional superconductor with properties similar to high-temperature superconductors. Their findings further scientists’ understanding of this type of superconductivity, which could lead to more sustainable and economical superconductor-based technology in the future.

Superconductivity is when a material can conduct electricity without energy loss. Superconductors have applications including medical MRI machines, power cables, and quantum computers. Conventional superconductors are well understood but have low critical temperatures. The critical temperature is the highest temperature at which a material acts as a superconductor.

In the 1980s, scientists discovered unconventional superconductors, many of which have much higher critical temperatures. According to Ruslan Prozorov, a scientist at Ames Lab, all these materials are grown in the lab. This fact has led to the general belief that unconventional superconductivity is not a natural phenomenon.

Prozorov explained that it is difficult to find superconductors in nature because most superconducting elements and compounds are metals and tend to react with other elements, like oxygen. He said that miassite (Rh17S15) is an interesting mineral for several reasons, one of which is its complex chemical formula. “Intuitively, you think that this is something which is produced deliberately during a focused search, and it cannot possibly exist in nature,” said Prozorov, “But it turns out it does.”

Satellites for quantum communications

Tobias Vogl investigates single photon sources in 2D materials in an experimental setup
Photo Credit: Jens Meyer / University of Jena

Through steady advances in the development of quantum computers and their ever-improving performance, it will be possible in the future to crack our current encryption processes. To address this challenge, researchers at the Technical University of Munich (TUM) are participating in an international research consortium to develop encryption methods that will apply physical laws to prevent the interception of messages. To safeguard communications over long distances, the QUICK³ space mission will deploy satellites.

How can it be ensured that data transmitted through the internet can be read only by the intended recipient? At present our data are encrypted with mathematical methods that rely on the idea that the factorization of large numbers is a difficult task. With the increasing power of quantum computers, however, these mathematical codes will probably no longer be secure in the future.

Ultra-short light pulses enable high-precision "artificial nose"

Hongtao Hu and Vinzenz Stummer
Photo Credit: Courtesy of Technische Universität Wien

A new spectroscopy method has been developed at TU Wien: Using a series of laser pulses, chemical analyses can be carried out much faster and more precisely than before.

Whether you want to analyze environmental samples in nature or monitor a chemical experiment, you often need highly sensitive sensors that can "sniff out" even tiny traces of a certain gas with extreme accuracy. Variants of Raman spectroscopy are often used for this purpose: Different molecules react in very characteristic ways to light of different wavelengths. If you irradiate a sample with the appropriate light and measure exactly how the light is modified by the sample, you can find out whether the sample contains a certain gas or not.

However, scientists at TU Wien (Vienna) have now taken a significant step forward in this area: a new method has been developed to generate and precisely control suitable light for such experiments. This not only enables much greater accuracy than before; the method also works without moving parts and is therefore much faster than the best technologies to date. The method has now been published in the journal Light: Science and Applications.

Is life based on a seeming violation of Newton’s law in molecular interactions?

Interactions between molecules that are not equal and opposite, a seeming violation of Newton’s third law of motion, can occur naturally according to new research. A kinase enzyme adds a chemical modification to other molecules, resulting in a phosphorylated protein. Phosphatase enzymes remove the modifications, such that the kinases create products that are acted upon by phosphatases and vice versa. Researchers demonstrated that the kinase is attracted to the phosphatase, but the phosphatase is repelled by the kinase, in what is called a non-reciprocal interaction.
Illustration Credit: Niladri Sekhar Mandal / Pennsylvania State University
(CC BY-NC-ND 4.0 DEED)

It turns out that every action may not have an equal and opposite reaction, despite what Newton’s third law of motion says, according to new research conducted by a team from Penn State and the University of Maine. The finding could offer insight into how certain molecular interactions could have evolved in a pre-life world.

The work was published in the journal Chem, and the researchers said this is the first demonstration of the mechanism by which these interactions occur at the molecular level. Last year’s discovery by researchers at Kyoto University that sperm movement does not cause an opposite reaction in its environment as it moves provided an example of a seeming violation of Newton’s third law of motion, but it did not address the mechanism.

“We all have heard the phrase ‘every action has an equal and opposite reaction,’ to describe Newton’s third law of motion, but we see examples that seemingly violate this every day, especially in the behavior of complex living systems small and large where there is constant input of energy,” said Ayusman Sen, Verne M. Willaman Professor of Chemistry in the Eberly College of Science at Penn State and one of the research team leaders. “An example at the larger scale is that a predator is attracted to its prey, but the prey is repelled by the predator. This type of interaction is called non-reciprocal, and we were interested to see if it also occurred in the much simpler interactions among molecules with constant energy input.”

Tuesday, March 12, 2024

You Didn’t See It Coming: the Spontaneous Nature of Turbulence

Photo Credit: Scientific Frontline 

We experience turbulence every day: a gust of wind, water gushing down a river or mid-flight bumps on an airplane.

Although it may be easy to understand what causes some kinds of turbulence — a felled tree in a river or a bear splashing around for salmon — there is now evidence that a very small disturbance at the start can have dramatic effects later. Instead of a tree, think of a twig — or even the swerving motion of a molecule.

University of California San Diego Chancellor’s Distinguished Professor of Physics Nigel Goldenfeld, along with his former student Dmytro Bandak, and Professors Alexei Mailybaev and Gregory Eyink, has shown in theoretical models of turbulence that even molecular motions can create large-scale patterns of randomness over a defined period of time. Their work appears in Physical Review Letters.

The butterfly effect

A butterfly flaps its wings in Brazil which later causes a tornado in Texas. Although we may commonly use the phrase to denote the seeming interconnectedness of our own lives, the term “butterfly effect” is sometimes associated with chaos theory. Goldenfeld said their work represents a more extreme version of the butterfly effect, first described by mathematician and meteorologist Edward Lorenz in 1969.

Saturday, March 9, 2024

Exploring the Surface Properties of NiO with Low-Energy Electron Diffraction


Antiferromagnetic (AF) crystals like NiO are experiencing a renaissance as promising materials for ultrafast spintronics. To re-establish old experimental results of surface property investigations and present new theoretical analysis, researchers from Sophia University carried out low-energy electron diffraction (LEED) analysis of AF crystal NiO. They reported an I-V spectra of ‘half-order beam’ and observed a surface wave resonance effect, providing useful insights into energy-temperature dependence of LEED and coherent spin exchange scattering in NiO.

Spintronics is a field that deals with electronics that exploit the intrinsic spin of electrons and their associated magnetic moment for applications such as quantum computing and memory storage devices. Owing to its spin and magnetism exhibited in its insulator-metal phase transition, the strongly correlated electron systems of nickel oxide (NiO) have been thoroughly explored for over eight decades. Interest in its unique antiferromagnetic (AF) and spin properties has seen a revival lately, since NiO is a potential material for ultrafast spintronics devices.

Despite this rise in popularity, exploration of its surface magnetic properties using low-energy electron diffraction (LEED) technique has not received much attention since the 1970s. To review the understanding of the surface properties, Professor Masamitsu Hoshino and Emeritus Professor Hiroshi Tanaka, both from the Department of Materials and Life Sciences at Sophia University, Japan, revisited the surface LEED crystallography of NiO. The results of their quantitative experimental study investigating the coherent exchange scattering in Ni2+ ions in AF single crystal NiO were reported in The European Physical Journal D.

Monday, March 4, 2024

Umbrella for Atoms: The First Protective Layer for 2d Quantum Materials

Amalgamation of experimental images. At the top, a scanning tunneling microscopy image displays the graphene’s honeycomb lattice (the protective layer). In the center, electron microscopy shows a top view of the material indenene as a triangular lattice. Below it is a side view of the silicon carbide substrate. It can be seen that both the indenene and the graphene consist of a single atomic layer.
Image Credit: © Jonas Erhardt/Christoph Maeder

As silicon-based computer chips approach their physical limitations in the quest for faster and smaller designs, the search for alternative materials that remain functional at atomic scales is one of science's biggest challenges. In a groundbreaking development, researchers at the Würzburg-Dresden Cluster of Excellence ct.qmat have engineered a protective film that shields quantum semiconductor layers just one atom thick from environmental influences without compromising their revolutionary quantum properties. This puts the application of these delicate atomic layers in ultrathin electronic components within realistic reach. The findings have just been published in Nature Communications.

2D Quantum Materials Instead of Silicon

The race to create increasingly faster and more powerful computer chips continues as transistors, their fundamental components, shrink to ever smaller and more compact sizes. In a few years, these transistors will measure just a few atoms across – by which point, the miniaturization of the silicon technology currently used will have reached its physical limits. Consequently, the quest for alternative materials with entirely new properties is crucial for future technological advancements.

Wednesday, February 28, 2024

Study unlocks nanoscale secrets for designing next-generation solar cells

A team of MIT researchers and several other institutions has revealed ways to optimize efficiency and better control degradation, by engineering the nanoscale structure of perovskite devices. Team members include Madeleine Laitz, left, and lead author Dane deQuilettes.
Photo Credit: Courtesy of the researchers
(CC BY-NC-ND 4.0 DEED)

Perovskites, a broad class of compounds with a particular kind of crystal structure, have long been seen as a promising alternative or supplement to today’s silicon or cadmium telluride solar panels. They could be far more lightweight and inexpensive, and could be coated onto virtually any substrate, including paper or flexible plastic that could be rolled up for easy transport.

In their efficiency at converting sunlight to electricity, perovskites are becoming comparable to silicon, whose manufacture still requires long, complex, and energy-intensive processes. One big remaining drawback is longevity: They tend to break down in a matter of months to years, while silicon solar panels can last more than two decades. And their efficiency over large module areas still lags behind silicon. Now, a team of researchers at MIT and several other institutions has revealed ways to optimize efficiency and better control degradation, by engineering the nanoscale structure of perovskite devices.

The study reveals new insights on how to make high-efficiency perovskite solar cells, and also provides new directions for engineers working to bring these solar cells to the commercial marketplace. The work is described today in the journal Nature Energy, in a paper by Dane deQuilettes, a recent MIT postdoc who is now co-founder and chief science officer of the MIT spinout Optigon, along with MIT professors Vladimir Bulovic and Moungi Bawendi, and 10 others at MIT and in Washington state, the U.K., and Korea.

“Ten years ago, if you had asked us what would be the ultimate solution to the rapid development of solar technologies, the answer would have been something that works as well as silicon but whose manufacturing is much simpler,” Bulovic says. “And before we knew it, the field of perovskite photovoltaics appeared. They were as efficient as silicon, and they were as easy to paint on as it is to paint on a piece of paper. The result was tremendous excitement in the field.”

Diamonds are a chip's best friend

Highly precise optical absorption spectra of diamond reveal ultra-fine splitting
Illustration Credit: KyotoU/Nobuko Naka

Besides being "a girl's best friend," diamonds have broad industrial applications, such as in solid-state electronics. New technologies aim to produce high-purity synthetic crystals that become excellent semiconductors when doped with impurities as electron donors or acceptors of other elements.

These extra electrons -- or holes -- do not participate in atomic bonding but sometimes bind to excitons -- quasi-particles consisting of an electron and an electron hole -- in semiconductors and other condensed matter. Doping may cause physical changes, but how the exciton complex -- a bound state of two positively-charged holes and one negatively-charged electron -- manifests in diamonds doped with boron has remained unconfirmed. Two conflicting interpretations exist of the exciton's structure.

An international team of researchers led by Kyoto University has now determined the magnitude of the spin-orbit interaction in acceptor-bound excitons in a semiconductor.

"We broke through the energy resolution limit of conventional luminescence measurements by directly observing the fine structure of bound excitons in boron-doped blue diamond, using optical absorption," says team leader Nobuko Naka of KyotoU's Graduate School of Science.

Tuesday, February 27, 2024

Merons realized in synthetic antiferromagnets

Direct observation of antiferromagnetic merons and antimerons
Illustration Credit: Mona Bhukta

Researchers in Germany and Japan have been able for the first time to identify collective topological spin structures called merons in layered synthetic antiferromagnets

The electronic devices we use on a day-to-day basis are powered by electrical currents. This is the case with our living room lights, washing machines, and televisions, to name but a few examples. Data processing in computers also relies on information provided by tiny charge carriers called electrons. The field of spintronics, however, employs a different concept. Instead of the charge of electrons, the spintronic approach is to exploit their magnetic moment, in other words, their spin, to store and process information – aiming to make the computers of the future more compact, fast, and sustainable. One way of processing information based on this approach is to use the magnetic vortices called skyrmions or, alternatively, their still little understood and rarer cousins called 'merons'. Both are collective topological structures formed of numerous individual spins. Merons have to date only been observed in natural antiferromagnets, where they are difficult to both analyze and manipulate.

New quantum entangled material could pave way for ultrathin quantum technologies

Artistic illustration depicts heavy-fermion Kondo matter in a monolayer material.
Illustration Credit: Adolfo Fumega/Aalto University

Researchers reveal the microscopic nature of the quantum entangled state of a new monolayer van der Waals material

Two-dimensional quantum materials provide a unique platform for new quantum technologies, because they offer the flexibility of combining different monolayers featuring radically distinct quantum states. Different two-dimensional materials can provide building blocks with features like superconductivity, magnetism, and topological matter. But so far, creating a monolayer of heavy-fermion Kondo matter – a state of matter dominated by quantum entanglement – has eluded scientists. Now, researchers at Aalto University have shown that it’s theoretically possible for heavy-fermion Kondo matter to appear in a monolayer material, and they’ve described the microscopic interactions that produces its unconventional behavior. These findings were published in Nano Letters.

“Heavy-fermion materials are promising candidates to discover unconventional topological superconductivity, a potential building block for quantum computers robust to noise,” says Adolfo Fumega, the first author of the paper and a post-doctoral researcher at Aalto University.

These materials can feature two phases: one analogous to a conventional magnet, and one where the state of the system is dominated by quantum entanglement, known as the heavy-fermion Kondo state. At the transition between the magnetic phase and the heavy-fermion state, macroscopic quantum fluctuations appear, leading to exotic states of matter including unconventional superconducting phases.

Out of the desert, a quantum powerhouse rises

Postdoctoral researcher Caitlin McCowan inspects pieces of silicon at the atomic level. She uses a scanning tunneling microscope to spot imperfections as part of a quantum research project at Sandia National Laboratories.
Photo Credit: Craig Fritz

They knew it was an ambitious goal. But by the time they announced it in 2022, Sandia National Laboratories and The University of New Mexico — two of the state’s largest research institutions — had been working out their strategy for more than a year.

Their goal: transform the state into a global powerhouse in the emerging quantum technology market. Success would mean the arrival of tech companies and startups, jobs and investments — an economic resurgence for the southwestern state.

The plan is picking up steam.

In January, Sandia and UNM created the Quantum New Mexico Institute, a cooperatively run research center headquartered at the university. This marks a major milestone in the comprehensive strategy to advance research, court businesses and train a quantum-ready workforce.

“Our vision is to make New Mexico a destination for quantum companies and scientists across the world,” said Setso Metodi, institute co-director and Sandia manager of quantum computer science.

Monday, February 26, 2024

Laser-focused look at spinning electrons shatters world record for precision

The Compton polarimeter’s laser system, used to measure the parallel spin of electrons, is aligned during the Calcium Radius Experiment at Jefferson Lab.
Photo Credit: Jefferson Lab /Dave Gaskell

Scientists are getting a more detailed look than ever before at the electrons they use in precision experiments.

Nuclear physicists with the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility have shattered a nearly 30-year-old record for the measurement of parallel spin within an electron beam – or electron beam polarimetry, for short. The achievement sets the stage for high-profile experiments at Jefferson Lab that could open the door to new physics discoveries.

In a peer-reviewed paper published in the journal Physical Review C, a collaboration of Jefferson Lab researchers and scientific users reported a measurement more precise than a benchmark achieved during the 1994-95 run of the SLAC Large Detector (SLD) experiment at the SLAC National Accelerator Laboratory in Menlo Park, California.

“No one has measured the polarization of an electron beam to this precision at any lab, anywhere in the world,” said Dave Gaskell, an experimental nuclear physicist at Jefferson Lab and a co-author on the paper. “That’s the headline here. This isn’t just a benchmark for Compton polarimetry, but for any electron polarization measurement technique.”

Compton polarimetry involves detecting photons – particles of light – scattered by charged particles, such as electrons. That scattering, aka the Compton effect, can be achieved by sending laser light and an electron beam on a collision course.

Electrons – and photons – carry a property called spin (which physicists measure as angular momentum). Like mass or electric charge, spin is an intrinsic property of the electron. When particles spin in the same direction at a given time, the quantity is known as polarization. And for physicists probing the heart of matter on the tiniest scales, knowledge of that polarization is crucial.

“Think of the electron beam as a tool that you're using to measure something, like a ruler,” said Mark Macrae Dalton, another Jefferson Lab physicist and co-author on the paper. “Is it in inches or is it in millimeters? You have to understand the ruler in order to understand any measurement. Otherwise, you can’t measure anything.”

Resurrecting niobium for quantum science

The Josephson junction is the information-processing heart of the superconducting qubit. Pictured here is the niobium Josephson junction engineered by David Schuster of Stanford University and his team. Their junction design has resurrected niobium as a viable option as a core qubit material.
Image Credit: Alexander Anferov/the University of Chicago’s Pritzker Nanofabrication Facility.

For years, niobium was considered an underperformer when it came to superconducting qubits. Now scientists supported by Q-NEXT have found a way to engineer a high-performing niobium-based qubit and so take advantage of niobium’s superior qualities.

When it comes to quantum technology, niobium is making a comeback.

For the past 15 years, niobium has been sitting on the bench after experiencing a few mediocre at-bats as a core qubit material.

Qubits are the fundamental components of quantum devices. One qubit type relies on superconductivity to process information.

Touted for its superior qualities as a superconductor, niobium was always a promising candidate for quantum technologies. But scientists found niobium difficult to engineer as a core qubit component, and so it was relegated to the second string on Team Superconducting Qubit.

Now, a group led by Stanford University’s David Schuster has demonstrated a way to create niobium-based qubits that rival the state-of-the-art for their class.

Friday, February 23, 2024

Super Strong Magnetic Fields Leave Imprint on Nuclear Matter

Collisions of heavy ions generate an immensely strong electromagnetic field. Scientists investigate traces of this powerful electromagnetic field in the quark-gluon plasma (QGP), a state where quarks and gluons are liberated from the colliding protons and neutrons.
Illustration Credit: Tiffany Bowman and Jen Abramowitz/Brookhaven National Laboratory

A new analysis by the STAR collaboration at the Relativistic Heavy Ion Collider (RHIC), a particle collider at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, provides the first direct evidence of the imprint left by what may be the universe’s most powerful magnetic fields on “deconfined” nuclear matter. The evidence comes from measuring the way differently charged particles separate when emerging from collisions of atomic nuclei at this DOE Office of Science user facility.

As described in the journal Physical Review X, the data indicate that powerful magnetic fields generated in off-center collisions induce an electric current in the quarks and gluons set free, or deconfined, from protons and neutrons by the particle smashups. The findings give scientists a new way to study the electrical conductivity of this “quark-gluon plasma” (QGP) to learn more about these fundamental building blocks of atomic nuclei.

“This is the first measurement of how the magnetic field interacts with the quark-gluon plasma (QGP),” said Diyu Shen, a STAR physicist from Fudan University in China and a leader of the new analysis. In fact, measuring the impact of that interaction provides direct evidence that these powerful magnetic fields exist.

Wednesday, February 21, 2024

Electrons become fractions of themselves in graphene

The fractional quantum Hall effect has generally been seen under very high magnetic fields, but MIT physicists have now observed it in simple graphene. In a five-layer graphene/hexagonal boron nitride (hBN) moire superlattice, electrons (blue ball) interact with each other strongly and behave as if they are broken into fractional charges.
Image Credit: Sampson Wilcox, RLE
(CC BY-NC-ND 4.0 DEED)

The electron is the basic unit of electricity, as it carries a single negative charge. This is what we’re taught in high school physics, and it is overwhelmingly the case in most materials in nature.

But in very special states of matter, electrons can splinter into fractions of their whole. This phenomenon, known as “fractional charge,” is exceedingly rare, and if it can be corralled and controlled, the exotic electronic state could help to build resilient, fault-tolerant quantum computers.

To date, this effect, known to physicists as the “fractional quantum Hall effect,” has been observed a handful of times, and mostly under very high, carefully maintained magnetic fields. Only recently have scientists seen the effect in a material that did not require such powerful magnetic manipulation.

Now, MIT physicists have observed the elusive fractional charge effect, this time in a simpler material: five layers of graphene — an atom-thin layer of carbon that stems from graphite and common pencil lead. They report their results today in Nature.

They found that when five sheets of graphene are stacked like steps on a staircase, the resulting structure inherently provides just the right conditions for electrons to pass through as fractions of their total charge, with no need for any external magnetic field.

The results are the first evidence of the “fractional quantum anomalous Hall effect” (the term “anomalous” refers to the absence of a magnetic field) in crystalline graphene, a material that physicists did not expect to exhibit this effect.

“This five-layer graphene is a material system where many good surprises happen,” says study author Long Ju, assistant professor of physics at MIT. “Fractional charge is just so exotic, and now we can realize this effect with a much simpler system and without a magnetic field. That in itself is important for fundamental physics. And it could enable the possibility for a type of quantum computing that is more robust against perturbation.”

Cloud model could help with climate research

Clouds have a number of important functions. They act as reflectors whereby water droplets in the cloud reflect radiation back to the Earth, which contributes to the greenhouse effect.
Photo Credit: Rodion Kutsaiev

When clouds meet clear skies, cloud droplets evaporate as they mix with dry air. A new study involving researchers from the University of Gothenburg has succeeded in capturing what happens in a model. Ultimately, this could lead to more accurate climate modeling in the future.

The clouds in the sky have a significant impact on our climate. Not only do they produce precipitation and provide shade from the sun, they also act as large reflectors that prevent the radiation of heat from the Earth – commonly known as the greenhouse effect.

“Although clouds have been studied for a long time, they are one of the biggest sources of uncertainty in climate models,” explains Bernhard Mehlig, Professor of Complex Systems at the University of Gothenburg. “This is because there are so many factors that determine how the clouds affect radiation. And the turbulence in the atmosphere means that everything is in constant motion. This makes things even more complicated.”

Tuesday, February 20, 2024

The Radcliffe Wave is Waving

How the Radcliffe Wave moves through the backyard of our Sun (yellow dot). Blue dots are clusters of baby stars. The white line is a theoretical model by Ralf Konietzka and collaborators that explains the current shape and motion of the Wave. The magenta and green lines at the beginning show how and to what extent the Radcliffe Wave will move in the future. Background is a cartoon model of the Milky Way. 
Illustration Credit: Ralf Konietzka, Alyssa Goodman & WorldWide Telescope

CfA astronomers report oscillation of our giant, gaseous neighbor.

A few years ago, astronomers at the Center for Astrophysics | Harvard & Smithsonian (CfA) uncovered one of the Milky Way's greatest secrets: an enormous, wave-shaped chain of gaseous clouds in our sun’s backyard, giving birth to clusters of stars along the spiral arm of the galaxy we call home.

Naming this astonishing new structure the Radcliffe Wave, in honor of the Harvard Radcliffe Institute where the undulation was originally discovered, astronomers at CfA now report in Nature that the Radcliffe Wave not only looks like a wave, but also moves like one – oscillating through space much like "the wave" moving through a stadium full of fans.

"By using the motion of baby stars born in the gaseous clouds along the Radcliffe Wave," said Ralf Konietzka, the paper's lead author and a Ph.D. student at Harvard’s Kenneth C. Griffin Graduate School of Arts and Sciences and CfA, "we can trace the motion of their natal gas to show that the Radcliffe Wave is actually waving."

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