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Category: physics – Page 79

New study reveals brain’s fractal-like structure near phase transition, a finding that may be universal across species

While researchers have long studied brain dynamics using imaging (fMRI) and electroencephalograms (EEG), advances in neuroscience have only recently provided massive datasets for the brain’s cellular structure. These data opened possibilities for Kovács and his team to apply statistical physics techniques to measure the physical structure of neurons.

For the new study, Kovács and Ansell analyzed publicly available data of 3D brain reconstructions from humans, fruit flies and mice. By examining the brain at nanoscale resolution, the researchers found the samples showcased hallmarks of physical properties associated with criticality.

One such property is the well-known, fractal-like structure of neurons. This nontrivial fractal-dimension is an example of a set of observables, called “critical exponents,” that emerge when a system is close to a phase transition.

New insights on the role of nucleon exchange in nuclear fusion

A recent study has explored the influence on low-energy fusion processes of isospin composition. This is a key nuclear property that differentiates protons from neutrons. The researchers used and theoretical modeling to investigate the fusion of different nuclei with varying isospin configurations. The results show that the isospin composition of the nuclei in a fusion reaction plays a crucial role in understanding the reaction. The paper is published in the journal Physical Review C.

In this study, researchers at Fisk University and Vanderbilt University used high-performance computational and theoretical modeling techniques to conduct a detailed many-body method study of how the dynamics of isospin influence nuclear fusion at low energies across a series of isotopes. The study also examined how the shape of the nuclei involved affect these dynamics. In systems where the nuclei are not symmetrical, the dynamics of isospin become particularly important, often leading to a lowered fusion barrier, especially in systems rich in neutrons. This phenomenon can be explored using facilities that specialize in the generation of beams composed of exotic, unstable nuclei.

The findings provide critical knowledge regarding the fundamental nuclear processes governing these reactions, which have broad implications for fields such as , astrophysics, and, perhaps someday, fusion-based energy.

Astrophysicists calculate the likelihood that Earth was exposed to cold harsh interstellar clouds 2 million years ago

Around two million years ago, Earth was a very different place, with our early human ancestors living alongside saber-toothed tigers, mastodons, and enormous rodents. And, depending on where they were, they may have been cold: Earth had fallen into a deep freeze, with multiple ice ages coming and going until about 12,000 years ago.

Scientists theorize that ice ages occur for a number of reasons, including the planet’s tilt and rotation, shifting plate tectonics, volcanic eruptions, and carbon dioxide levels in the atmosphere. But what if drastic changes like these are not only a result of Earth’s environment, but also the sun’s location in the galaxy?

In a new paper published in Nature Astronomy, lead author and astrophysicist Merav Opher—an astronomy professor at Boston University and fellow at Harvard Radcliffe Institute— found evidence that some two million years ago, the solar system encountered an so dense that it could have interfered with the sun’s . Opher and her co-authors believe this shows that the sun’s location in space might shape Earth’s history more than previously considered.

Beyond Einstein: Groundbreaking Map of the Universe Redefines Cosmic Models

The DESI collaboration is conducting a groundbreaking experiment to understand the universe’s expansion and acceleration. Their work with the DESI instrument has enabled them to map the cosmos from its early stages to the present, challenging existing models of the universe. Initial findings suggest there may be more to discover about dark energy and cosmic acceleration. The project’s innovative approach, including a fully blinded analysis, ensures that their conclusions are based on unbiased data, paving the way for future discoveries in astrophysics. Credit: SciTechDaily.com.

The DESI collaboration is examining the universe’s accelerating expansion through comprehensive mapping from its early stages to the present. Their findings challenge traditional cosmic models and suggest new insights into dark energy, all while utilizing groundbreaking, unbiased research methods.

A team of researchers, including an astrophysicist from The University of Texas at Dallas, as part of the Dark Energy Spectroscopic Instrument (DESI) collaboration, is leading a groundbreaking experiment aimed at exploring the universe’s expansion and acceleration.

The Physics of Failure: Analyzing Hubble’s Gyroscope Malfunction

The Hubble Space Telescope is currently in safe mode due to gyroscope problems, suspending its science activities. However, NASA remains optimistic about its future contributions to space exploration, working in tandem with other telescopes.

On May 24, NASA’s Hubble Space Telescope entered safe mode due to an ongoing gyroscope (gyro) issue, suspending science operations. Hubble’s instruments remain stable, and the telescope is in good health.

The telescope automatically entered safe mode when one of its three gyroscopes returned faulty telemetry readings. Hubble’s gyros measure the telescope’s slew rates and are part of the system that determines and controls precisely the direction the telescope is pointed.

“Extraordinary” Slow-Spinning Neutron Star Shakes Astrophysics

Most collapsed stars fully rotate in seconds. This one takes almost an hour.

Australian scientists from the University of Sydney and Australia’s national science agency, CSIRO, have detected what is likely a neutron star spinning slower than any other ever measured.

No other radio-emitting neutron star, out of the more than 3,000 discovered so far, has been discovered rotating so slowly. The results are published today (June 5) in Nature Astronomy.