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Nov 19, 2024

Simulations reveal black holes inherit magnetic fields from parent stars

Posted by in categories: cosmology, particle physics

Black holes are one of the most enigmatic stellar objects. While best known for swallowing up their surroundings into a gravity pit from which nothing can escape, they can also shoot off powerful jets of charged particles, leading to explosive bursts of gamma rays that can release more energy in mere seconds than our sun will emit in its entire lifetime.

For such a spectacular event to occur, a black hole needs to carry a powerful . Where this magnetism comes from, however, has been a long-standing mystery.

Using calculations of black hole formation, scientists at the Flatiron Institute and their collaborators have finally found the origin of those magnetic fields: the collapsing parent stars of the themselves. The researchers report their results November 18 in The Astrophysical Journal Letters.

Nov 19, 2024

Adjusting accelerators with help from machine learning

Posted by in categories: nuclear energy, particle physics, robotics/AI

Banks of computer screens stacked two and three high line the walls. The screens are covered with numbers and graphs that are unintelligible to an untrained eye. But they tell a story to the operators staffing the particle accelerator control room. The numbers describe how the accelerator is speeding up tiny particles to smash into targets or other particles.

However, even the best operator can’t fully track the miniscule shifts over time that affect the accelerator’s machinery. Scientists are investigating how to use computers to make the tiny adjustments necessary to keep particle accelerators running at their best.

Researchers use accelerators to better understand materials and the particles that make them up. Chemists and biologists use them to study ultra-fast processes like photosynthesis. Nuclear and high energy physicists smash together protons and other particles to learn more about the building blocks of our universe.

Nov 19, 2024

New study reveals possible origins of dark matter in ‘Dark Big Bang’ scenario

Posted by in categories: cosmology, particle physics

Recent research by a student-faculty team at Colgate University unlocks new clues that could radically change the world’s understanding of the origin of dark matter.

Assistant Professor of Physics and Astronomy Cosmin Ilie and Richard Casey have explored an idea put forth by two scientists at the University of Texas at Austin, Katherine Freese and Martin Winkler, suggesting that dark matter may have originated from a separate “Dark Big Bang,” occurring shortly after the birth of the universe.

It is widely accepted that all the matter filling our universe (including dark matter) originated from one major event—the Big Bang. This corresponds to the end of the cosmic inflation period, when the vacuum energy that drove the very brief extreme expansion initial phase of our universe was converted into a hot plasma of radiation and particles.

Nov 19, 2024

Statistical approach improves models of atmosphere on early Earth and exoplanets

Posted by in categories: chemistry, energy, space

As energy from the sun reaches Earth, some solar radiation is absorbed by the atmosphere, leading to chemical reactions like the formation of ozone and the breakup of gas molecules. A new approach for modeling these reactions, developed by a team led by scientists at Penn State, may improve our understanding of the atmosphere on early Earth and help in the search for habitable conditions on planets beyond our solar system.

The researchers have reported in the journal JGR Atmospheres that using a statistical method called correlated-k can improve existing photochemical models used to understand conditions on early Earth.

The approach can help scientists better understand the atmospheric composition of early Earth and will play an important role as new observatories come online in the coming decades that can provide new data on exoplanet atmospheres, the scientists said.

Nov 19, 2024

Team creates world’s first tunable-wavelength blue semiconductor laser

Posted by in categories: innovation, physics

In a new study, researchers at Osaka University have created the world’s first compact, tunable-wavelength blue semiconductor laser, a significant advancement for far-ultraviolet light technology with promising applications in sterilization and disinfection.

This innovative laser employs a specially-designed periodically slotted structure in nitride semiconductors, making possible a blue wavelength laser that is both practical and adaptable for various disinfection technologies. The work is published in the journal Applied Physics Express.

The research team had previously demonstrated second-harmonic generation at wavelengths below 230 nm by using transverse quasi-phase-matching devices crafted from aluminum nitride and vertical microcavity wavelength conversion devices incorporating SrB4O7 nonlinear optical crystals.

Nov 19, 2024

Long-lived Schrödinger’s-cat state achieves Heisenberg-limited sensitivity

Posted by in categories: particle physics, quantum physics

A team led by Prof. Lu Zhengtian and Researcher Xia Tian from the University of Science and Technology of China (USTC) realized a Schrödinger-cat state with minute-scale lifetime using optically trapped cold atoms, significantly enhancing the sensitivity of quantum metrology measurements. The study was published in Nature Photonics.

In quantum metrology, particle spin not only serves as a potent probe for measuring magnetic fields, inertia, and a variety of physical phenomena, but also holds the potential for exploring new physics beyond the Standard Model. The high-spin Schrödinger-cat state, a superposition of two oppositely directed and furthest-apart spin states, offers significant advantages for spin measurements.

On one hand, the high spin quantum number amplifies the precession frequency signal. On the other hand, the cat states are insensitive to some environmental interference, thus suppressing measurement noise. However, one major technical challenge in applying cat states in experiments is how to maintain a sufficiently long coherence time.

Nov 19, 2024

Physicists predict exotic form of matter with potential for quantum computing

Posted by in categories: computing, quantum physics

MIT physicists have shown that it should be possible to create an exotic form of matter that could be manipulated to form the qubit (quantum bit) building blocks of future quantum computers that are even more powerful than the quantum computers in development today.

The work builds on a discovery last year of materials that host electrons that can split into fractions of themselves but, importantly, can do so without the application of a magnetic field. The general phenomenon of electron fractionalization was first discovered in 1982 and resulted in a Nobel Prize.

That work, however, required the application of a magnetic field. The ability to create the fractionalized electrons without a magnetic field opens new possibilities for basic research and makes the materials hosting them more useful for applications.

Nov 19, 2024

Experimental Demonstration of Mode-Coupled and High-Brightness Self-Amplified Spontaneous Emission in an X-Ray Free-Electron Laser

Posted by in category: futurism

The first experimental demonstration of two schemes to enhance the longitudinal coherence of SASE-XFEL pulses shows that the SASE pulse bandwidth can be reduced by up to a factor of three.

Nov 19, 2024

Psychoacoustic and Archeoacoustic nature of ancient Aztec skull whistles

Posted by in category: futurism

A series of psychoacoustic and neuroimaging studies reveal the effect that the sound of Aztec skull whistles has on modern listeners; the sound, which is perceived as a mixture of voice-like, scream-like, and technological, triggers affective processing.

Nov 18, 2024

Fat cells have epigenetics-based memory: Researchers discover mechanism behind weight loss yo-yo effect

Posted by in categories: biotech/medical, chemistry, genetics, health

Can weight loss leave a lasting imprint on our fat cells?

Losing weight is often touted as a cornerstone of better health, particularly for people dealing with obesity and its associated health risks.


Anyone who has ever tried to get rid of a few extra kilos knows the frustration: the weight drops initially, only to be back within a matter of weeks—the yo-yo effect has struck. Researchers at ETH Zurich have now been able to show that this is all down to epigenetics.

Continue reading “Fat cells have epigenetics-based memory: Researchers discover mechanism behind weight loss yo-yo effect” »

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