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For over a century, physicists have grappled with one of the most profound questions in science: How do the rules of quantum mechanics, which govern the smallest particles, fit with the laws of general relativity, which describe the universe on the largest scales?

The optical lattice clock, one of the most precise timekeeping devices, is becoming a powerful tool used to tackle this great challenge. Within an optical lattice clock, atoms are trapped in a “lattice” potential formed by laser beams and are manipulated with precise control of quantum coherence and interactions governed by .

Simultaneously, according to Einstein’s laws of general relativity, time moves slower in stronger gravitational fields. This effect, known as gravitational redshift, leads to a tiny shift of atoms’ internal energy levels depending on their position in gravitational fields, causing their “ticking”—the oscillations that define time in optical lattice clocks—to change.

Astronomers have discovered strong evidence for the closest supermassive black hole outside of the Milky Way galaxy. This giant black hole is located in the Large Magellanic Cloud, one of the nearest galactic neighbors to our own.

To make this discovery, researchers traced the paths with ultra-fine precision of 21 stars on the outskirts of the Milky Way. These stars are traveling so fast that they will escape the gravitational clutches of the Milky Way or any nearby galaxy. Astronomers refer to these as “” stars.

Similar to how recreate the origin of a bullet based on its trajectory, researchers determined where these come from. They found that about half are linked to the at the center of the Milky Way. However, the other half originated from somewhere else: a previously-unknown giant black hole in the Large Magellanic Cloud (LMC).

A phone screen you can’t scratch no matter how many times you drop it; glasses that prevent glare; a windshield that doesn’t get dusty. These are all possibilities thanks to a new way to produce sapphire.

Researchers at The University of Texas at Austin have discovered techniques to bestow superpowers upon , a material that most of us think of as just a pretty jewel. But sapphire is seen as a critical material across many different areas, from defense to consumer electronics to next-generation windows, because it’s nearly impossible to scratch.

“Sapphire is such a high-value material because of its hardness and many other favorable properties,” said Chih-Hao Chang, associate professor in the Walker Department of Mechanical Engineering and leader of the new research. “But the same properties that make it attractive also make it difficult to manufacture at small scales.”

Many physicists and engineers have recently been trying to demonstrate the potential of quantum computers for tackling some problems that are particularly demanding and are difficult to solve for classical computers. A task that has been found to be challenging for both quantum and classical computers is finding the ground state (i.e., lowest possible energy state) of systems with multiple interacting quantum particles, called quantum many-body systems.

When one of these systems is placed in a thermal bath (i.e., an environment with a fixed temperature that interacts with the systems), it is known to cool down without always reaching its . In some instances, a can get trapped at a so-called local minimum; a state in which its energy is lower than other neighboring states but not at the lowest possible level.

Researchers at California Institute of Technology and the AWS Center for Quantum Computing recently showed that while finding the local minimum for a system is difficult for classical computers, it could be far easier for quantum computers.

Researchers at the Fritz Haber Institute have developed the Automatic Process Explorer (APE), an approach that enhances our understanding of atomic and molecular processes. By dynamically refining simulations, APE has uncovered unexpected complexities in the oxidation of palladium (Pd) surfaces, offering new insights into catalyst behavior. The study is published in the journal Physical Review Letters.

Kinetic Monte Carlo (kMC) simulations are essential for studying the long-term evolution of atomic and molecular processes. They are widely used in fields like surface catalysis, where reactions on material surfaces are crucial for developing efficient catalysts that accelerate reactions in and pollution control. Traditional kMC simulations rely on predefined inputs, which can limit their ability to capture complex atomic movements. This is where the Automatic Process Explorer (APE) comes in.

Developed by the Theory Department at the Fritz Haber Institute, APE overcomes biases in traditional kMC simulations by dynamically updating the list of processes based on the system’s current state. This approach encourages exploration of new structures, promoting diversity and efficiency in structural exploration. APE separates process exploration from kMC simulations, using fuzzy machine-learning classification to identify distinct atomic environments. This allows for a broader exploration of potential atomic movements.

A collaborative research team has introduced a nitrogen-centric framework that explains the light-absorbing effects of atmospheric organic aerosols. Published in Science, this study reveals that nitrogen-containing compounds play a dominant role in the absorption of sunlight by atmospheric organic aerosols worldwide. This discovery signifies a major step towards improving climate models and developing more targeted strategies to mitigate the climate impact of airborne particles.

Atmospheric organic aerosols influence climate by absorbing and scattering sunlight, particularly within the near-ultraviolet to visible range. Due to their complex composition and continuous chemical transformation in the atmosphere, accurately assessing their climate effects has remained a challenge.

The study was jointly led by Prof. Fu Tzung-May, Professor of the School of Environmental Science and Engineering at Southern University of Science and Technology (SUSTech) and National Center for Applied Mathematics Shenzhen (NCAMS), and Prof. Yu Jianzhen, Chair Professor of the Department of Chemistry and the Division of Environment and Sustainability at Hong Kong University of Science and Technology (HKUST).

Scientists at Yokohama National University, in collaboration with RIKEN and other institutions in Japan and Korea, have made an important discovery about how electrons move and behave in molecules. This discovery could potentially lead to advances in electronics, energy transfer, and chemical reactions.

Published in the Science, their study reveals a new way to control the distribution of electrons in molecules using very fast phase-controlled pulses of light in the .

Atoms and molecules contain negatively charged electrons that usually stay in specific energy levels, like layers, around the positively charged nucleus. The way these electrons are arranged in the molecule is key to how the molecule behaves.

A small international team of nanotechnologists, engineers and physicists has developed a way to force laser light into becoming a supersolid. Their paper is published in the journal Nature. The editors at Nature have published a Research Briefing in the same issue summarizing the work.

Supersolids are entities that exist only in the quantum world, and, up until now, they have all been made using . Prior research has shown that they have zero viscosity and are formed in crystal-like structures similar to the way atoms are arranged in salt crystals.

Because of their nature, supersolids have been created in extremely cold environments where the can be seen. Notably, one of the team members on this new effort was part of the team that demonstrated more than a decade ago that light could become a fluid under the right set of circumstances.

Neutrinos generated through solar fusion reactions travel effortlessly through the sun’s dense core. Each specific fusion process creates neutrinos with distinctive signatures, potentially providing a method to examine the sun’s internal structure. Multiple neutrino detection observatories on Earth are now capturing these solar particles, which can be analyzed alongside reactor-produced neutrinos with the data eventually enabling researchers to construct a detailed map of the interior of the sun.

The sun is a massive sphere of hot plasma at the center of our solar system and provides the light and heat to make life on Earth possible. Composed mostly of hydrogen and helium, it generates energy through , converting hydrogen into helium in its core. This process releases an enormous amount of energy which we perceive as heat and light.

The sun’s surface, or photosphere, is around 5,500°C, while its core reaches over 15 million°C. It influences everything from our climate to space weather, sending out and occasional bursts of radiation known as . As an average middle-aged star, the sun is about 4.6 billion years old and will (hopefully) continue burning for another 5 billion years before evolving into a red giant and eventually becoming a white dwarf.

Traditional microscopy often relies on labeling samples with dyes, but this process is costly and time-consuming. To overcome these limitations, researchers have developed a computational quantitative phase imaging (QPI) method using chromatic aberration and generative AI.

By leveraging the natural variations in focus distances of different wavelengths, the technique constructs through-focus image stacks from a single exposure. With the help of a specially trained diffusion model, this approach enables high-quality imaging of biological specimens, including real-world clinical samples like red blood cells. The breakthrough could revolutionize diagnostics, providing an accessible and efficient alternative to conventional imaging techniques.

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